External Eye and Cornea Flashcards
(261 cards)
1
Q
What does Alcian blue stain for and what coneal dystrophy is it used to demonstrate in corneal specimens?
A
It stains for mucopolysaccharides and is used to stain specimens with macular dystrophy
2
Q
What does the material found in corneals with lattice dystrophy consist of?
A
Amyloid
3
Q
Bilateral conrneal edema in a newborn with normal intraocular pressues and normal corneal diameters suggest what diagnosis?
A
Congenital heredity endothelial dystrophy. Two forms are recognized: one with an autosomal dominant pattern of inheritance, the other with a recessive pttern of inheritance. Deafness is sometimes an associated finding. Normal intraocular pressure and normal corneal diamter help distinguish this entity from congenital glaucoma.
4
Q
What Chlamydial serotypes cause inclusion conjunctivitis?
A
Serotypes D to K
5
Q
What is the recommendned treatment for gonorrhal infection in an otherwise healthy adult.
A
Cefrtriaxone 1 gm IM for 5 consecutive days.
6
Q
What are the main antibodies found in tears?
A
IgA and secretary IgA
7
Q
If taken in high doses for long periods of time, what type of deposit can chlorpromazne produce in the cornea?
A
It can produce a brownish, poweder-like deposit in the deep storma of the cornea.
8
Q
What is Mooren’s ulcer?
A
It is a peripehral ulcerative keratitis caused by ischemic necrosis from vasulitis of limbal vessels.
9
Q
Describe the two varities of Mooren’s ulcer
A
The limited or torpid is usually unilateral (75%) and seen in an older patient population with equal sex distribution. The second type is usually bilateral (75%), rapidly progressive and typially found in young Nigerian males, which may be an antigen-antibody reaction to helminithic toxins.
10
Q
Which member of the herpes virus family does not produce a keratitis?
A
CMV
11
Q
What is Artl’s line?
A
It consists of subconjunctival scarring along the upper tarsal plate and is seen in trachoma.
12
Q
What are Cogan’s patches?
A
Dellen anterior to horizontal rectus insertions in the elderly.
13
Q
What is an easy way to distinguish episcleritis from scleritis from scleritis?
A
Topical phenylephrine will blanch the inflamed episcleral vessels, but not the scleral ones.
14
Q
What is the most common cause of the 29% of deaths that occur within five years of the onset of necrotizing scleritis?
A
Complicatiosn of systemic vasculitis
15
Q
Patients with long-standing rheumatoid arthritis can develop a necrotizing scleritis without signs of inflammation known as what?
A
Scleromalacia perforans
16
Q
What is the definition of giant papillae?
A
Papillae ≥ 1 mmPapillae ≥ 1 mm
17
Q
What are Haab’s stiae?
A
They are horizontal curvilinear lines representing healed breaks in Descemet’s membrane and occur in eyes with congeital glaucoma.
18
Q
What are Vogt’s striae?
A
They are vertical stress lines in the corneal stroma which disappear with external pressue and are an early sign of keratoconus.
19
Q
What is Munsons’s sign
A
It is a late sign of keratoconus and characterized by indentation of the lower eyelid by the cornea in downgaze.
20
Q
What are Tranta’s dots
A
Tranat’s dots are white spots composed of eosinophils at he limbus of patients with limbal form of vernal conjunctivities and may also occur in atopic keratocnjunctivities and soft contact lens wear.
21
Q
What is a Bitot’s spot?
A
It is a foamy white lesion found at the limbus found in association with vitamin A deficinecy
22
Q
What are Herbert’s pits?
A
They are regressed limbal follicles leaving behind depressed scars and are found in trachoma.
23
Q
What is the inheritance pattern of Reiss-Bucklers’ dystrophy?
A
Autosomal dominant.
24
Q
What are the causes of interstitial keratitis?
A
- Viral: herpes simples, herpes zoster, mumps 2. Bacterial: syphilis, tuerculosis, leprosy, Lyme disease, brucellosis. 3. Parasitic: acnathoamoeba, trypanosomiasis, onchocerciasis, leishmaniasis, filariasis. 4. Cogan’s syndrome.
25
What is Cogan's syndrome?
It is a bilateral interstitial keratitis associated with bilateral deafness, tinnitus and vertigo. Early diagnosis and treatment with systemic steriods may prevent permanent deafness.
26
What systemic disease may be associated with Cogan's syndrome?
Polyarteritis nodosa
27
What other disease besdies Cogan's syndrome can cause interstitial keratitis associated with deafness?
4% of patients with syphilitic interstitial keratitis eventually become deaf months or years after the acute episode.
28
What are some causes of enlarged corneal nerves?
1. Keratoconus 2. Multiple endocrine adenomatosis (MEA) 3. Congenital ichothyosis 4. Idiopathic 5.Refsum's disease 6.Neurofibromatosis 7.Leprosy 8.Posterior polymorphous dystrophy 9.Fuch's endothelial dystrohpy 10. Reiss-Buckler's dystrophy
29
Beading of corneal nerves or a string of pearls appearing to the corneal nerves suggests what ystemic problem?
Leprosy. Lid skin may be thickened and lashes can be absent. In addition, the iris may show characteristic creamy white "pearl" lesions.
30
What is Ferry's line
It is an iron deposit in the cornea near a filtering bleb.
31
A 39-year-old nurse presents with a history of non-healing corneal abrasion that is associated with pain, redness and dense ring infiltrate. She was treated previously with two weeks of intense fortified antibiotics. Cultures performed prior to starting her topical antibiotics were negative for bacteria and fungus. What is the most likely diagnosis?
Anestheic abuse; more common in health care personnel that have access to proparacaine and tetracaine. Suspect the diagnosis in non-healing corneal lucers or abrasions which are culure negative. Dense white ring infiltrates, corneal edema, and even a hypopyon are possible findings.
32
What malignancies are associated with multiple endocrine adenomatosis type Iib (Sipple-Gorlin syndrome)?
Medullary thyroid carcinoma, pheochromocytoma and mucosal neuromas.
33
A 30-year-old male presents for a routine eye exam and refraction. Slit lamp exam reveals are shaped superior corneal thinning with blood vessels extending from the limbus across the area of thinning. Lipid deposition is present at the central edge of the thinned cornea. The epithelium over the area of thinning is intact. The opposite eye appears normal on slit lamp exam. What is the diagnosis?
Terrien's marginal degeneration. Note that this is often bilateral but can be present unilaterally.
34
What would the refraction of the case above most likely show?
High "against the rule" astigmaism in the opposite axis of the thinning.
35
What are the ocular features of Ehlers-Danlos syndrome?
1. Anterior segment: keartoconus, keratoglobus, blue sclera, lens subluxation 2. Posterior segment: high myopia and retinal detachment
36
What is Ehlers-Danlos syndrome?
It is a dominantly inherited collagen disorder caused by a deficiency in hydroxylysine. Its main systemic features are: 1. Hyperelastic skin that bruises easily and heals slowly. 2. Joint hypermobility. 3. Cardiovascular disease. 4.Daphragmatic hernia. 5. Diverticuli of the respiratory and GI tracts.
37
What are the ocular features of osteogenesis imperfecta?
1. Blue sclera. 2. Keratoconus. 3. Megalocornea.
38
What mucopolysaccharidoses are associated with corneal clouding?
Hurler's, Scheie's, Morquio's and Maroteaux-Lamy[s but not in Hunter's and Sanfilippo's
39
What is the primary anitbiotic of choice for an identified Gram-positive keratitis?
Fortified cephalosporins, eg. Cefazolin
40
Is an intraocular tap and systemic antibiotics indicated in patients with bacterial keratitis and reactive hypopyon?
Unless there has been ocular perforation, the presence of hypopyon is almost always a reactive phenomenon and does not signify endophthalmitis.
41
What are the systemic causes of scleritis?
No. An intraocular tap may be hazardous in patients with this condition, since it runs the risk of introducing the organisms into the eye.
42
What viruses usually cause acute hemorrhagic conjunctivitis?
1. Rheumatoid arthritis. 2. Collagen vascular disorders: Wegener's granulomatsis, polyarteritis nodosa, systemic lupus erythematosus. 3. Relapsing polychondritis. 4. Herpes zoster. Porphyria
43
What are some causes of corneal verticillata?
Enterovirus 70 and coxsackie A24, although adenovirus type 11 and 37 have also been implicated.
44
What is Fabry's disease?
1. Drugs: amiodarone, anti-malarials, indomethacin, tamoxifen, chlorpromazine, meperidine, amodiaquine. 2. Fabry's disease.
45
What other anterior segment findings are found in Fabry's disease?
It is a disorder caused by a deficiency in the enzyme alpha-galactosidase. Patients develop angiokeratomas, cardiovascular and renal lesions and episodes of severe pain in the fingers and toes.
46
What does the material in granular dystrophy consist of, and what is the best stain for it?
Spoke-like lens opacities
47
What is Salzmann's nodular degeneration?
The granular material is composed of hyaline and stains brigh red with Masson's trichrome stain.
48
What is the appearance of Salzmann's nodules histopathologically?
Localized replacement of Bowman's layer by hyaline and fibrillar material
49
A middle-aged man presents with a peripheral ulcerative keratitis and a positive hepatitis B surface antigen (HbsAg) lab result. What systemic disease may this patient possibly have?
Polyarteritis nodosa
50
What are the ocular features of polyarteritis nodosa?
1. Aterior segment: peripheral ulcerative keratitis, necrotizing scleritis, secondary Sjogren's syndrome. 2 Posterior segement: retinal artery occulsion, cotton wool spots, choroidal vasculitis, anterior ischemic optic neuropathy.
51
What is Stocker's line
It is an iron deposi on the cornea in front of a pterygium
52
What are some systemic associations of peripheral ulcerative keratitis?
1. Rheumatoid arthritis. 2. Wegener's granulomatosis. 3.Polyarteritis nodosa. 4. Relapsing polychondritis. 5. Systemic lupus erythematosus.
53
What is a Tzanck prep?
This is a Giemsa stain of corneal scrapings of HSV epithelial infection, revealing multinucleated giant cells.
54
Do patients with central cloudy corneas of Francois complain of decreased vision?
No. Central cloudy cornea of Francois is bilateral, hereditary, deep, central shagreen that has no effect on vision.
55
What is the name for the noninflammatory, slowly progressive thinning of the peripheral corneal that begins superiorly and has an associated vascular pannus?
Terrien's marginal degeneration
56
What type of astigmatism may develop from Terrien's marginal degeneration?
"Against-the-rule" astigmatism.
57
Thinning in the lucid area posterior to corneal arcus is known as what?
Furrow degeneration
58
What percent of patients with map-dot-fingerprint will have corneal erosions?
10%
59
What percent of patients with corneal erosions will have map-do-fingerprint?
50%
60
A 3 day old infant is noted to have progressive corneal edema with vertical posterior striae. What is the most likely cuase of this ocular condition?
Birth trauma (forceps delivery) with rupture of Descemet's membrane and endothelium.
61
What are some systemic disorders associated with keratoconus?
1. Atopic dermatitis. 2.Down's syndrome. 3.Marfan's syndrome. 4.Ehler-Danlos syndrome. 5.Osteogenesis imperfecta 6. Mitral valve prolapse.
62
What type of hypersensitivity reaction may be invoked in ocular rosacea?
Type IV hypersensitivity.
63
What stains can be used to identify fungi?
1. Gomori Metamine silver stain. 2.Periodic acid-Schiff 3.Giemsa stain
64
What is blood agar used to culture for?
It is used primarily for isolation of aerobic bacteria and will allow the growth of saprophytic fungi at room temperature.
65
Which anti-Epstein-Barr virus antibody does not peak during the first 6 to 8 weeks of infection with EBV?
EBNA (Epstein-Barr nuclear antigen).
66
Which anti-EBV antibodies remain detectable for life after infection with EBV?
EBNA and VCA-IgG
67
What are other ocular disorders associated with keratoconus?
1. Vernal and atopic keratoconjunctivitis. 2.Leber's congenital amaurosis. 3.Retinitis pigmentosa 4.Aniridia. 5.Ectopia lentis
68
What do the deposits in spheroidal degeneration represent, and what are they caused by?
Spheroidal degeneration is characterized by golden brown spherules in the superficial corneal stroma. They are proteinaceous material resulting from the combined effects of genetic predisposition, aging, actinic exposure, and environmental trauma.
69
What are the causes of corneal cloudingin infants?
1. Coneal edema (birth trauma, glaucoma). 2. Infectious keratitis (rubella, intersitial, gonococcal). 3. Metabolid abnormalities (mucopolysaccharidoses, mucolipidoses). 4. Dystrophies (endothelial and stromal). 5.Sclerocornea.
70
What is the appropriate management of malignant melanoma of the conjunctiva?
Excision using a no-touch techinque with care to include 3-4 mm of normal adjacent conjunctiva and double freeze-thaw applications to the surrounding conjunctiva.
71
What is a Kayser-Fleischer ring?
It consists of copper deposits in Descement's membrane and is found in Wilson's disease
72
What species is responsible for lice infection of the lids (ocular pediculosis)
Phthirus pubis (crab louse).
73
What is the Ziehl-Neelsen stain used to stain for?
Mycobacteria and Nocardia
74
What culture medium is used to grow mycobacteria?
Lowenstein-Jensen
75
What are the causes of band keratopathy?
1. Juvenile rheumatoid arthritis. 2.Hereditary band keratopathy. 3. Chronic iridocyclitis in adults 4. Hypercalcemia and hyperphosphatemia 5. Chronic mercurial exposure 6. Congenital ichthyosis 7. Silicone oil in atnerior chamber 8. Phthisis bulbi 9. Idopathic in elderly
76
How do you remove band keratopathy?
Apply 0.5 mol/L to 0.25 mol/L disodium EDTA solution topically to soften the calcium, then scrape the deposit off. The eye is then patched or a bandage contact lens is applied to allow the epithelium to heal.
77
What are the anterior segment features of Marfan's syndrome?
1. Bilateral upward lens subluxation. 2. Microspherophakia 3.Blue sclerae 4.Keratoconus 5.Angle anomalies. 6.Hypoplastic dilator pupillae
78
How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?How does Onchocerca volvulus cause blindness?
Black fly
79
What are Henderson-Patterson bodies?
They are intracytoplasmic inclusion bodies in the hyperplastic epithelium in umbilicated, nodular lesions caused by molluscum contagiosum. The bodies are small and eosinophilic deep inside the lesion but basophilic and larger near the surface.
80
What type of polymorphonuclear leukocytes are usually present in the conjunctival epithelium: of patients with vernal conjunctivitis?
Eosinophils
81
What is the most appropriate surgical management of squamous cell carcinoma of the conjunctiva?
Wide no-touch surgical excision with supplementary cryoablation.
82
A patient with decompensated Fuch's dystrophy presents with a well-circumscribed, chalky white infiltrate with overlying ulceration associated with pain, photophobia and tearing for the past 4 days. What is the most likely organism in this case?
Staphylococcus aureus.
83
What stains can be used to identify the presene of amyloid deposits in the cornea, and what type of reaction do they exhibit?
1. Dichroism with Congo Red stain. 2. Metachromasia with crystal violet stain. 3. Fluorescence with thioflavin T.
84
An alcoholic elderly patient who lives in the streets presents with a nonperforated corneal ulcer for the past week and a half and maceration of the skin at the lateral canthus. What will the gram stain of the corneal scraping likely show?
Large gram negative diplobacilli of Moraxella lacunata.Large gram negative diplobacilli of Moraxella lacunata.Large gram negative diplobacilli of Moraxella lacunata.Large gram negative diplobacilli of Moraxella lacunata.Large gram negative diplobacilli of Moraxella lacunata.Large gram negative diplobacilli of Moraxella lacunata.Large gram negative diplobacilli of Moraxella lacunata.
85
If Acanthamoeba keratitis is suspected, what type of culture media should be used?
Nonnutrient agar with heat-killed E. coli overlay.
86
What culture media should be used for the growth of fungi?
Sabouraud's agar
87
What condition associated with HLA-DR3 is characterized by recurrent episodes of tearing, foreign body sensation, photophobia, decreased vision, and multiple small corneal epithelial lesions?
Thygeson's superficial punctate keratitis.
88
What infectious diseases can cause interstitial keratitis (IK)?
1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.1. Syphilis. 2. Tuberculosis. 3. Leprosy. 4. B. burgodorferi 5. Rubeola 6. EBV 7. C. trachomatis. 8. Onchocerca volvulus.
89
A 44 year-old woman presents with intense eye irritation associated with hypertopic conjunctiva at the supeior limbus with adjacent filamentary keratitis. What is your diagnosis?
Superior limbic keratocnjunctivitis
90
What systemic disease may be associated with superior limbic keratocnjunctivitis (SLK)?
Thyroid disease in 50% of patients with SLK
91
What is the treatment for SLK?
In mild cases artifical tears and ointment may be sufficient. In more severe cases, 0.5 to 1 % silber nitrate (in was ampoules, not cautery sticks) applied to the superior bulbar and tarsal conjunctiva for 10-20 seconds. Thermal cautery, pressure patching, or bandage contact lenses may be employed. Conjunctival resection may be necessary.
92
This is usually a seasonal recurring, bilateral inflammation of the conjunctiva, which occurs most commonly in male children and young adults.
Vernal keratoconjunctivitis
93
What type of ulcer is associated with vernal?
Shield ulcer
94
What is used as prophylaxis against seasonal recurrences of vernal?
4% Cromolyn sodium qid started at least one month prior to usual onset of symptoms.
95
What type of keratoconjunctivitis may be associated with sheild-shaped anterior subcapsular or posterior subcapsular lens opacities?
Atopic keratocnojunctivitis
96
Whatis a congenital syndrome associated with aqueous tear deficiency (ATD)?
Riley-Day (familial dysautonomia) or Shy-Drager (idiopathic autonomic dysfunction)
97
What is the most common cause of dacryocystitis in adults? In children?
Pneumococcus and Haemophilus influenza respectivelyPneumococcus and Haemophilus influenza respectivelyPneumococcus and Haemophilus influenza respectivelyPneumococcus and Haemophilus influenza respectivelyPneumococcus and Haemophilus influenza respectivelyPneumococcus and Haemophilus influenza respectively
98
What is the diagnostic value of Wright's stain in regards to conjunctivitis?
It is a cytologic stain that highlights eosionphils and their granules - found in hay fever conjunctivitis.
99
What is a classic slit lamp finding of staphylococcal blepharitis?
Collatrettes
100
What should always be on the differential of ocular surface inflammation in patients that have been using topical medication?
Medicomentosa - toxic reaction that can occur after long-term use of topical medications
101
How do the dermoids of epidermal nevus syndrome differ from those of Goldenhar's syndrome?
They tend to be bilateral and more extensive.
102
What is the treatment for gonococcal conjunctivitis?
Ceftriaxone 1 gm IM once (or IV). Copious irrigation with normal saline should be instituted. Since concurrent chlamydial infection ahs been reported in a third of patients, supplemental oral antibiotics should be given to treat chlamydia (tetracycline, oxycycline, minocycline, erythromycin, or azithromycin).
103
What organisms are most commonly associated with phylctenulosis?
Chronic infection with Staphylococcus aureus is the most common cause of phylctenulosis. Tuberculi antigen was most commonly linked to phylctenulosis in the past.Chronic infection with Staphylococcus aureus is the most common cause of phylctenulosis. Tuberculi antigen was most commonly linked to phylctenulosis in the past.Chronic infection with Staphylococcus aureus is the most common cause of phylctenulosis. Tuberculi antigen was most commonly linked to phylctenulosis in the past.Chronic infection with Staphylococcus aureus is the most common cause of phylctenulosis. Tuberculi antigen was most commonly linked to phylctenulosis in the past.Chronic infection with Staphylococcus aureus is the most common cause of phylctenulosis. Tuberculi antigen was most commonly linked to phylctenulosis in the past.Chronic infection with Staphylococcus aureus is the most common cause of phylctenulosis. Tuberculi antigen was most commonly linked to phylctenulosis in the past.
104
What is the classic slit lamp finding of Demodex infection?What is the classic slit lamp finding of Demodex infection?What is the classic slit lamp finding of Demodex infection?What is the classic slit lamp finding of Demodex infection?What is the classic slit lamp finding of Demodex infection?What is the classic slit lamp finding of Demodex infection?
Sleeving of eyelash bases
105
How is Trichinella spiralis contracted?How is Trichinella spiralis contracted?How is Trichinella spiralis contracted?How is Trichinella spiralis contracted?How is Trichinella spiralis contracted?How is Trichinella spiralis contracted?
Ingestion of raw or half-cooked pork
106
What is the treatment for Trichinella infections?What is the treatment for Trichinella infections?What is the treatment for Trichinella infections?What is the treatment for Trichinella infections?What is the treatment for Trichinella infections?What is the treatment for Trichinella infections?
Thiabendazole
107
What are Schaumann bodies?
They are nonspecific intro-giant cell deposits commonly seen in sarcoid
108
What does scurf on eyelashed indicated?
Seborrhea.
109
What can be seen histopathologically at Descement's membrane in corneas with deep stromal involvement by herpes simplex?
There is a granulomatous reaction to Descemet's membrane.
110
What type of staining pattern will likely be seen in a patient wearing rigid gas-permeable lenses who complains of a scratchy sensation after 6 to 8 hours of wearing time?
3 and 9 o'clock staining, which occurs in up to 80% of RGP-wearing patients.
111
What is Sattler's veil?
This is central epithelial edema resulting from hypoxic stress, which may occur with either rigid or soft contact lenses, and is best seen with sclerotic scatter or retroillumination. This is usually associated with a tight lens fit. Patients will complain of hazy vision or blur after removing their contact lenses that usually dissipates after about an hour.
112
What organisms commonly causes infectious crystalline keratophathy and in what clincal setting is it usually seen?
Streptococcus viridans usually causes infectious crystalline keratophathy. It most often occurs in the setting of a compromised host, such as a post-corneal graft patient on long-standing cortiocsteriod treatment.Streptococcus viridans usually causes infectious crystalline keratophathy. It most often occurs in the setting of a compromised host, such as a post-corneal graft patient on long-standing cortiocsteriod treatment.Streptococcus viridans usually causes infectious crystalline keratophathy. It most often occurs in the setting of a compromised host, such as a post-corneal graft patient on long-standing cortiocsteriod treatment.Streptococcus viridans usually causes infectious crystalline keratophathy. It most often occurs in the setting of a compromised host, such as a post-corneal graft patient on long-standing cortiocsteriod treatment.Streptococcus viridans usually causes infectious crystalline keratophathy. It most often occurs in the setting of a compromised host, such as a post-corneal graft patient on long-standing cortiocsteriod treatment.Streptococcus viridans usually causes infectious crystalline keratophathy. It most often occurs in the setting of a compromised host, such as a post-corneal graft patient on long-standing cortiocsteriod treatment.
113
What anitibiotic would be appropriate for a streptococcal infection of the cornea?
Fortified cephalosporin or vancomycin
114
What is the recurrence rate of herpes simplex in the corneal graft following penetrating keratoplasty for herpetic corneal ulcers?
Approximately 20%.
115
What is a Fleischer ring?
It is iron deposition at the basal epithelium and is diagnostic of keratoconus.
116
Which disease produces greater corneal anesthesia in keratitis of comparable severity, herpes simples or herpes zoster?
Herpes zoster, which can markedly diminish corneal sensation even in the mildest cases of keratitis, produces greater corneal anesthesia than herpes simplex.
117
How does pellucid marginal degeneration differ from keratoconus?
In pellucid marginal degeneration, the thinnest area is not at the apex of the ocne but in a crescentic distribution near the inferior limbus.
118
What is the appropriate management for acute corneal hydrops in a patient with keratoconus?
Cycloplegics are used to manage the mild iritis that may be present, and topical hypertonic saline drops and ointment may help to reduce the swelling of the corneal stroma and epithelium.
119
What stain is used to identify the trophozoites and cysts of Acanthomoeba in corneal sections?What stain is used to identify the trophozoites and cysts of Acanthomoeba in corneal sections?What stain is used to identify the trophozoites and cysts of Acanthomoeba in corneal sections?What stain is used to identify the trophozoites and cysts of Acanthomoeba in corneal sections?What stain is used to identify the trophozoites and cysts of Acanthomoeba in corneal sections?
Calofluor white stain.
120
What does immunofluorescent staining of ocnjunctival specimens from patients with ocular cicatricial pemphigoid (OCP) demonstrate?
Systemic corticosteroids, diaminodiphenylsulfone (Dapsone), cyclophosphamide (Cytoxan), and azathioprine (Imuran) are all currently being tried. Epilation/cryotherapy for trichiasis, mucosal grafting for fornix reconstruction, and topical corticosteriods for acute exacerbations are adjuncive measures.
121
What is the difference between pemphigus vulgaris and ocular cicatricial pemphigoid with regards to the conjunctival changes produced?
Pemphigus vulgaris forms intraepithelial bullae, a mild, self-limiting conjunctivitis, and no scar formation nor involvement of the substantia propria or dermis. OCP produces subepithelial fibrosis, subconjnctival scarring, and fornix foreshortening and symblepharon formation.
122
A 75- year-old female with history of open angel glaucoma presents with a pgimented lesion in the inferior fornix of the left eye. A biopsy is performed to rule out melanoma but comes back negative for melanin. What might this represent?
Adrenochrome deposit from the use of phinephrine compounds for her glaucoma.
123
What is a pyogenic granuloma?
They are composed of granulation tissue and proliferating vascular endothelial cells in reaction to an inciting event such as strabisumus surgery, inflammation (chalazion), chemical burns, limbal surgery, or foreign bodies. They are rapidly developing lesions onsets is typically days to weeks.
124
What is thioglycolate broth used to culture for?
Anaerobic bacteria.
125
How thick is the central cornea?
0.5 mm.
126
What are Krukenberg's spindles?
They are melanin depositsi oriented vertically on the endothelium and are found in pigment dispersion syndrome or pigmentary glaucoma.
127
In what age group does ligneous conjunctivitis usually affect?
Ligneous conjunctivitis is an idiopathic chronic conjunctivitis that usually affects children.
128
What part of the conjunctiva is usually affected by ligneous conjunctivitis?
A fibrinous exudate first develops usually in the upper palpebral conjunctiva, which is then infiltrated by granulation tissue, although the bulbar conjunctiva can also be involved.
129
In what other extraocular locations can ligneous conjunctivitis manifest?
Nasopharynx, buccal mucosa, middle ear, tympanic membrane, vagina, and cervix
130
What is the most dangerous complication of herpes zoster keratitis?
Neuropharlytic epithelial breakdown and diffuse stromal edema and infiltration, which can result in chronic trophic ulceration, corneal melting and perforation.
131
How would you treat herpes zoster neuroparalytic keratitis that has reulted in a trophic ulcer?
This may respond to soft contact lens wear or to cyanoacylate gluing in advanced cases. Neovascularization is a sign of healing and should be allowed to take place. These eyes are poor surgical risks for keratoplasty.
132
A patient with herpes zoster keratitis is fitted with a therapeutic bandage contact lens. Two days later, he presents with hypopyon. There is no corneal infiltrate seen. How would you manage this case?
An infection is probably unlikely if the hypopyon follows the application of a bandage lens by only 2 or 3 days and if a stromal infiltrate is absent or of long duration. Sterile uveitis and hypopyon has been associated with lens fit too steeply and ma be related to anterior segment ischemia. This complication can be managed by cycloplegia and lens removal.
133
What are the main indications for use of a Gunderson conjunctival flap?
1. Chronic sterile ulcerations, eg. Herpes simplex, herpes zoster, chemical and thermal burns, sicca, neurotrophic ulcers. 2. Bullous keratopathy. 3. Closed but unstable corneal wounds. 4. Eyes being prepared for a prosthetic shell.
134
What topcial medications can produce a cicatrizing conjunctivitis?
Timolol, pilocarpine, echothiophate iodide and idoxuridine.
135
What is the importance of Hutchinson's sign?
In patients with HZO, vesicles and ithcing at the tip of the nose indicates involvement of the nasociliary branch of the trigeminal nerve, which also supplies the cornea and other intraocular structures.
136
Where does most of the glucose for corneal epithelium comes from?
Aqueous humor
137
What type of collagen do Descemet's membrane and Bowman's membrane consist of?
Descement's membrane consists of type IV collagen while Bowman's membrane is made of type I collagen.
138
How far do myelinated nerve fibers extend into the normal cornea?
Myelination ends within 2 mm of the limbus
139
What percentage of patinets with Terrien's marginal degneration are male?
75%
140
What type of astigmatism is usually associated with Terrien's marginal degeneration?
"Against-the-rule" astigmatism.
141
A 58-year-old patient presnets with bilateral intersitial keratitis and hearing problems. Serologic tests for syphilis are negative. What is the probably diagnosis and how could deafness be prevented?
Cogan's syndrome, which is a bilateral non-luetic intersitial keratitis associated with bilateral deafness. Early systemi steroid administration will prevent deafness.
142
What percentage of patients with syphilitic interstitial keratitis will become deaf?
4% of patients with syphilitc interstial keratis will become deaf, whih may occur monhs or years after the acute episode.
143
What are leber cells?
Leber cells are macrophages that have phagocytosed debris and are found in the conjunctival stroma in patients with trachoma.
144
What is the definition of microcornea?
Corneal diameter ≤ mm.Corneal diameter ≤ mm.Corneal diameter ≤ mm.Corneal diameter ≤ mm.
145
What type of astigmatism is produced by keratoconus?
Irregular astigmatism
146
What sign is seen on retinosocpy of an eye with keratoconus?
Scissoring reflex
147
What is Rizzuti's sign?
It is a conical reflection on the nasal cornea when a light is shown from the temporal side in an eye with keratoconus.
148
What are causes of decreased corneal reflexes?
1. Keratitis (herpes simplex, herpes zoster, leprosy). 2. Corneal dystrophies (lattice, Reiss-Buckler's, Schnyder's). 3.Diabetes, especially juvenile onset. 4. Cerebello-pontine anglge umors, eg. Acoustic neuroma. 5. Cavernous sinus and superior orbital lesions. 6. Intracranial aneurysms. 7. Iatrongenic (cataract and corneal surgery, prolonged contact lens wear, surgical section of the trigeminal nerve). 8. Riley-Day syndrome.
149
What systemic diseases are associated with lattice dystrophy types 1 and 2?
Lattic dystrohpy type 1 is not associated with any systemic disease, but type 2 is assoiated with systemic amyloidosis (Meretoja syndrome)
150
What is the relative risk of ulcerative keratitis among users of extended-wear contact lneses and daily wear soft contact lenses who wore them overnight as compared to users of such lenses who did not?
Users of extended wear contact lenses who wore them overnight had a 10 to 15 times greater risk of microbial keratitis as users of daily wear lenses who did not. Users of daily wear soft contact lenses who sometimes wore them overnight had 9 times the risk of the users of such lenses who did not.
151
What are corneal filaments composed of?
Mucus and desquamated epithelial cells.
152
What is the definition of megalocornea in a child age 1 year?
>12 mm horizontally
153
What medications appear to be useful in treating Acanthamoeba keratitis?What medications appear to be useful in treating Acanthamoeba keratitis?What medications appear to be useful in treating Acanthamoeba keratitis?
1. Neomycin-polymyxin B-gramicidin. 2. Neomycin. 3. Natamycin 5% topical suspension. 4. Miconazole 1% topical solution 5. Propamidine isethionate 0.1% drops (Brolene). 6. Dibromopropamidine 0.15% ointment.
154
What are the eosinophilic intranuclear inclusion bodies of HSV epithelial infection called?
Lipshutz bodies
155
Which anit-viral agent may produce preauricular lymphadenopathy as a hypersensitivity reaction?
Idoxuridine.
156
Which anit-viral medications inhibit DNA synthesis by acting as thymidine analogs?
Trifluridine and idoxuridine
157
How does acyclovir inhibit HSV DNA synthesis?
Acyclovir, activated only by herpes virus-induced thymidine kinase, irreversibly binds to viral DNA polymerase and acts as a viral DNA chain terminator.
158
What abrnoamlity of the eye is normally the cuase of iron deposition?
Abnormailities of tear pooling
159
Deep stromal depositon of gold is seen in what condition?
Chrysiasis
160
This syndrome is characterized by hyperkeratotic lesions of th palms, soles, and elbows, and nonstaining corneal pseudodendrites.
ICE syndrome (iridocorneal endothelial syndrome)
161
What is the distinctive corneal change seen in sphingolipidoses?
Corneal verticillata.
162
What is the most common corneal lipid deposition condition?
Arcus senilis.
163
Asymmetric arcus should lead to what kind of work-up?
Carotid artery work-up is indicated.
164
A photophobic very short person with polychromatic conjunctival and corneal crystals and photophobia probably has what disease?
Cystinosis
165
What topical medication could be used to reduce the density of crystals in the previously mentioned short person?
Cysteamine drops.
166
Which bacterial conjunctivitis can produce preauricular lymphadenopathy?
Gonococcal conjunctivitis.
167
What type of blepharoconjunctivitis does Moraxella lacunata produce?What type of blepharoconjunctivitis does Moraxella lacunata produce?
Anugular blepharoconjunctivitis.
168
How do you treat C. diphtheriae conjunctivitis?How do you treat C. diphtheriae conjunctivitis?
Use systemic antibiotics to treat the conjunctivitis and diphtheria antitoxin to prevent systemic effects of the exotoxin.
169
What topical eye medications are recommended by the Centers for Disease Control (CDC) for the prevention of ophthalmia neonatroum?
Erythromycin 0.5% ophthalmic ointment, tetracycline 1% ophthalmic ointment or silver nitrate 1% aqueous solutions are used within 1 hour of delivery on neonates.
170
What is an important difference between neonatal and adult inclusion conjunctivitis in terms of conjunctival response?
A follicular response is rarely seen in neonatal inclusion conjunctivitis.
171
What is the most common anterior segment infection in HIV patients?
Herpes zoster ophthalmicus is probably the most common infection in the anterior segment. The keratitis and uveitis may be unusually severe and have a protracted course.
172
What is a Khodadoust line?
It is a line of keratic precipitates on the endothelial surface of a corneal graft at the margin of the graft and the host occurring during corneal endothelial graft rejection.
173
What is the cause of corneal graft failure in the immediate postoperative period?
In the immediate postoperative period, graft failure is often due to a defect in the donor material itself and is never due to immunologic rejection.
174
When does corneal graft rejection occur after a corneal transplant?
The term corneal graft rejection is used to define an immunologically mediated process in which the graft, having been clear for several weeks to months, suddenly develops graft rejection with inflammatory signs.
175
How long can topical steroids be used to reduce posttraumatic iritis and inflammation following an alkali burn?
1% prednisolone or 0.1% dexamehasone applied topically several times a day for the first 10 days is safe and effective in reducing posttraumatic iritis and inflammation. However, if after 10 days corneal reepithelialization has not occurred, the steroid dosage must be tapered rapidly and discontinued within 1 to 2 days to avoid accelerating stromal ulceration.
176
What HLA type is found more frequently in ocular pemphigoid?
HLA-B12
177
A young male presents with extensive molluseum contagiosum in upper and lower eyelids bilaterally. What other serological test would you obtain?
An HIV test is necessary in this case.
178
Name 3 indication for amniotic membrane transplantation.
Steven-Johnson syndrome, chemical burn, persistent cornea epithelial defects.
179
What is the most common indication for limbal transplantation?
Chemical injury may result in the complete loss of corneal epithelium and stem cells
180
What kind of allergic eye diseases is 4% Cromolyn sodium approved for?
Vernal conjunctivitis and atopic keratoconjunctivits but not seasonal or hay-fever allergic conjunctivitis.
181
What is Maxwell Lyon sign?
In vernal conjunctivitis, the mucus production becomes thicker and tenacious. The copy strands have mucous discharge and an elastic quality described as the Maswell Lyon sign.
182
What is the major difference between allergic conjunctivitis versus toxic conjunctivitis?
Papillary reactions are both seen in allergic and toxic conjunctivitis, but a folliucular component may be present in toxic conjunctivitis. In addition, the hyperemia and chemosis may occur less diffusely and relatively spare the superior aspect of bulbar conjunctiva.
183
What are some of the infectious causes of Parinaud's oculoglandular syndrome?
1. Cat-scratch disease (Bartonella henselae). 2. Tularemia (Francisella tularensis). 3. Sporotrichosis (Sporotrichum schenckii). 4. Lymphogranuloma venereum (serotypes L1, L2, L3) 5. Syphilis 6. Tuberculosis.
184
What is Paton's sign?
Multiple, short, comma-shaped conjunctival capillary segments found near the limbus in SS disease and SC disease of sicle cell anemia.
185
What enzyme screening test is required prior to treating cicatricial pemphigoid with dapsone?
Make sure the patient is not glucose-6-phosephate dehydrogenase-deficient.
186
What viruses are more likely to cause pedunculated papilloma?
Human papilloma virus (HPV) type 6 and 11
187
What is the most common ocular finding in Graft-Versus-Host disease (GVHD)?
The most common ocular manifestation is keratoconjunctivitis sicca (KCS).
188
What is the maximim size of corneal perforation that can be sealed with tissue glue?
2 mm.
189
What are the ocular manifestations reprted in dermatitis herpetiformis?
Chronic or recurrent cicatrizing conjunctivitis producing subepithelial fibrosis and symblepharon
190
How early after birth can you detect a clinical follicular response in conjunctiva?
A follicular response is not seen prior to 6-8 weeks of life.
191
Where is the most common place to find conjunctival intraepithelial neoplasia?
95% of lesions occur at limbal regoin, within the interpalpebral fissure.
192
What are the hisotlogical findings that can differentiate mucoepidermoid carcinomoa from squamous cell carcinoma?
Histologically, both conjunctival mucoepidermoid carcinoma and squamous cell carcinoma consist of squamous cells. However, squamous cell carcinoma does not have goblet cells while mucoepidermoid carcinoma does.
193
What is the differential diagnosis when you see a patient with a smooth "fish-flesh" mass in the inferior conjunctiva?
Amyloidosis, lymphoma and benighn reactive lympoid hyperplasia.
194
Where do ocular dermoids and dermolipomas commonly occur?
Dermoids most commonly involve the inferotemporal imbal corneal and epibulbar region. Dermolipomas arise near the insertin of lateral rectus muscle and may extend upward to the superior fornix.
195
What is the treatment for molluseum contagiousm?
Treatment includes excision, curetting, or cryotherapy of the lesions.
196
What is floppy eyelid syndrome?
Often associated with obesity, floppy eyelid syndrome results from extreme laxity of the upper lid. It is proposed that eversion of the lid occurs during sleep which allows contact of the ocnjunctiva with the pillow or bedding. The patient develops chronic papillary conjunctivitis as a result of repated trauma.
197
What is the treatment for floppy eyelid syndrome?
Treatment consists of taping the lid closed and wearing a shield. Horizontal lid shortening procedures may also be performed.
198
What is the most common causative agent in hyperacute conjunctiits?
Neiseria gonorrhea (or, less often, N. meningitidis)
199
What are the histological finings of pingueculas?
Normal, atrophic, or hyperkeratotic conjunctival epithelium. The substantia propria shows basophilic degeneration.
200
When does keratoconus usually progress, and when does it usually stabilize?
Progression during adolescence and stabilization when patient is fully-grown.
201
What is a very early retionscopic sign of keratoconus?
Scissoring of the red reflex.
202
What is the mainstay of treatment used in keratoconus that is not at the stage for penetrating keratoplasty?
Glasses and RGP contact lenses.
203
What will a rupture of Descemet's membrane cause in a keratoconus patient?
Acute corneal hydrops.
204
Does this usually heal or is surgery immediately indicated?
This usaully heals in 6-12 weeks, and surgery is not immediatel indicated.
205
Which abnormal layer of the cornea is responsible for the initiation of keratoconus?
Bowman's layer becomes fibrillated and fragmented.
206
What disease may be associated with a pinguecula that is brownish in hue?
Gaucher's disease
207
What metabolites acumulate in the mucopolysaccharidosis syndromes?
Heparin, dermatin and keratin sulfates
208
A 50-year-old male born in Halifax county, North Carolina present with elevated translucent-white limbal lesions which have dilated vessels. On quetioning his father and grandfather have similar lesions. The patient also has leukoplakie oral lesions. What is your diagnosis?
Benign hereditary intraepithelial dyskeratosis.
209
What factors are associated with the development of conjunctival intraepithelial neoplasia (CIN)?
1. Actinic exposure. 2. Heav cigarette smoking. 3. Exposure to petroleum products. 4.Light hair and ocular pigmentation. 5.Xerderma pigmentosa 6. HIV infection. 7.Soft contact lens wear
210
In what percentage of patients does primary acquired melanosis (PAM) of the conjunctiva progress to malignant melanoma?
30%
211
What does the "rule of thirds" when speaking of conjunctival melanoma state?
1/3 arise from nevi (mortality 20%), 1/3 arise from PAM (mortality 40%) and 1/3 arise de novo (mortality 40%)
212
What is the most important prognostic indicator in conjunctival melanoma?
Thickness. A positive relationship btween thickness and mortality has been found.
213
Where do conjunctival melanomas most commonly metastasize to?
Conjunctival melanomas share with cutaneous melanomas the ability to invade lymphatics and metastasize, most commonly the prequricular and intraparotid nodes.
214
What are the causes of membranous conjunctivitis?
1. Alkaline chemicals. 2.Corynebacterium diphtheriae. 3. Pneumococcus. 4.Gonococcus. 5. Adenovirus. 6. Stevens-Johnson 7. OCP (ocular cicatricial pemphigoid). 8. Herpes simplex virus. 9. Ligneous conjunctivitis 10. Neonatal inclusion conjunctivitis 11. Vernal and atopic conjunctivitis 12. Staphylococcus. 13. Beta-hemolytic streptocci1. Alkaline chemicals. 2.Corynebacterium diphtheriae. 3. Pneumococcus. 4.Gonococcus. 5. Adenovirus. 6. Stevens-Johnson 7. OCP (ocular cicatricial pemphigoid). 8. Herpes simplex virus. 9. Ligneous conjunctivitis 10. Neonatal inclusion conjunctivitis 11. Vernal and atopic conjunctivitis 12. Staphylococcus. 13. Beta-hemolytic streptocci1. Alkaline chemicals. 2.Corynebacterium diphtheriae. 3. Pneumococcus. 4.Gonococcus. 5. Adenovirus. 6. Stevens-Johnson 7. OCP (ocular cicatricial pemphigoid). 8. Herpes simplex virus. 9. Ligneous conjunctivitis 10. Neonatal inclusion conjunctivitis 11. Vernal and atopic conjunctivitis 12. Staphylococcus. 13. Beta-hemolytic streptocci1. Alkaline chemicals. 2.Corynebacterium diphtheriae. 3. Pneumococcus. 4.Gonococcus. 5. Adenovirus. 6. Stevens-Johnson 7. OCP (ocular cicatricial pemphigoid). 8. Herpes simplex virus. 9. Ligneous conjunctivitis 10. Neonatal inclusion conjunctivitis 11. Vernal and atopic conjunctivitis 12. Staphylococcus. 13. Beta-hemolytic streptocci
215
Angular blepharitis is most commonly cuased by which organisms?
Moraxella lacunata and staphylococcus.Moraxella lacunata and staphylococcus.Moraxella lacunata and staphylococcus.Moraxella lacunata and staphylococcus.
216
A 25-year old male is referred from a family practitioner with chronic conjunctivitis which initially responded to sulfacetamide drops. Symptoms return when the patient was taken off drops after two weeks. Slit lamp exam reveals a fine micropannus, punctate keratopathy, and follicular conjunctivitis in the right eye with minimal signs in the left. What is the diagnosis?
Chlamydia inclusion conjunctivitis; initially suppressed but not eradicated by sulfacetamide drops.
217
How does neonatal inclusion conjunctivitis differ from the adult version?
Caused by the same serotypes of C. trachomatis (D-K), the neonala form is more likely to be associated with conjunctival membranes. Intracytoplasmic inclusions are seen in greater numbers on Giemsa staining. There tends to be no follicular response, there is a greater discharge, and the infection is more liekly to respond to topical medications (erythromycin or sulfacetamide).
218
What are the three most common bacteria isolated from the normal eyelid?
Staphylococcus aureus, Propionibacterium acnes, and Corynebacterium species.Staphylococcus aureus, Propionibacterium acnes, and Corynebacterium species.Staphylococcus aureus, Propionibacterium acnes, and Corynebacterium species.Staphylococcus aureus, Propionibacterium acnes, and Corynebacterium species.
219
What are causes of acute follicular conunctivitis?
1. Adenoviral infections. 2. Hepes simplex. 3. Inclusion (chlamydial). 4. Newcastle disase (poultry handlers or veterinarians). 5. Enterovirus. 6. Cat-scatch fever.
220
A patient with a diagnosis of dry eye presentswith a worsening of symptoms over the last several weeks. Examination does not reveal any signs of infection of allergy. Her Schirmer's test is dramatically decreased from previous baseline studies. What is the most likely cause?
The patient may have been placed on a new medication such as antidepressant, diruetic or antihistamine.
221
A patient with a diagnosis of dry eye presents with worsening symptoms over the last several weeks. She has not started on any new systemic medications and recently increased the dosing frequency of her current eye drops, an over the counter artificial tear preparation, from four times a day to every hour. What is the most likely cause and what would be seen on slit lamp exam?
This patient most likely has medicamentosa from using drops containing presevatives such as benzlyalkonium chloride. Slip lamp exam would reveal diffuse punctate epithelial keratopathy and inflamed conjunctiva. Treatment would consist of discontinuing her current drops and starting on preservative free teardrops. Punctal occlusion could also be considered.
222
A 30-year-old female patient presents with unilateral follicular conjunctivitis, diffuse punctate epithelial keratopathy, and a palpale small preauricular lymph node. What is the differential diagnosis?
The differential diagnosis would include cat-scratch fever (Parinaud oculoglandular syndrome) and herpes zoster. Some topical medications such as carbachol and timolol can cause a toxic follicular response.
223
Would topical steroid drops be helpful in this patient?
Although topical steroid drops would make the patient more comfortable and less photophobic in the case of adenoviral keratoconjunctivitsi, the differential diagnosis includes herpes simplex, which would be made worse by the use of this therapy. Especially since the infeciton is unilateral, this possiblity must be kept in mind.
224
What corneal dystrophies usually do not recur following corneal transplantation?
Only Fuch's and posterior polymorphous dystrophy does not usually recur.
225
Epithelial vesicles that appear as tiny bubble-like blebs on retroillumination in the intrapalpebral area of the corneal surface are found in this anterior corneal dystrophy
Meesman's dystrophy
226
Which stromal dystrophy is caused by an abnormal synthesis of keratin sulfate?
Macular dystrophy
227
Which stromal dystrohpy is associated with hyperlipoproteinemia or elevated serum cholesterol in up to 50% of cases?
Central crystalline dystrophy of Schnyder.
228
What are the different causes of symblepharon?
1. Ocular cicatricial pemphigoid. 2. Steven-Johnson syndrome. 3. Old chemical or radiation injury. 4. Atopic keratoconjunctivitis. 5. Ocular rosacea is a less common cause. 6. Topical drops associated with conjunctival scarring include idoxuridine (IDU), pilocarpine, timolol, epinephrine, and echothiophate iodide.
229
What three corneal dystrophies map to chromosome 5q?
Avellino, Lattice type 1, and granular corneal dystrophies are autosomal dominant stromal dystrophies that have been mapped to chromosome 5.
230
A 45-year-old female patient notes pain, photophobia, and slightly decreased vision in one eye on awakening. This is the third episode in many months. Describe the corneal lesions that might be associated with this problm.
This patient has recurrent corneal erosions. She may have a localized area of microcysts in any area of repeated breakdown. This is most likely to occur if the patient has a history of corneal abrasions. Map line, dots and fingerprint lesions are all characteristic of epithelial basement membrane dystrophy and may be present in one or both eyes. Synthesis of a thickened, reduplicated, abnormal basement membrane is responsible for the appearance and the poor adhesion of the overling epithelium.
231
What type of treatments might be appropriate for recurrent corneal erosions?
Treatment would consist of a trial of hypertonic saline drops and ointment at bedtime. A bandage contact lens could also be tried. Unresponsive cases might requiresuperficial keratectomy or anterior corneal stromal puncture.
232
Which of the following alkalies penetrate the eye quickest: ammonia, lye, caustic potash (KOH), magnesium hydroxide, or lime (calcium hydroxide)?
Penetration of alkali is cation dependent and is most rapid with ammonia. Magnesium hydroxide is important because it is found in many fireworks. Eye injuries occurring with fire works can be a combination of mechanical, chemical and thermal trauma. The other agents noted are listed in order of most rapid to least rapid penetration.
233
What is the total power of the cornea in air?
The cornea has a power in air of approximately - 45 D. This is because the posterior surface is more curved than the anterior surface. The refractive effect of the posterior surface is neutralized by aqeous. A favorite board question.
234
What ocular finding could help distinguish the peripheral corneal ulceration assocated with Mooren's ulcer and a similar corneal problem in a patient with Wegner's granuiomatis?
Associated scleritis would most likely be seen in the patient with Wegner's granulomatosis and not in a patient with Mooren's ulcer.
235
What percentage of patients with recurrent HSV eye disease will have stromal involvement?
<15%
236
What complication of HSV disease can lead to nonhealing trophic epithelial defects?
Corneal anesthesia
237
What percentage of adults will experience zoster infection?
20%
238
What percentage of patients with HZO will have ocular involvement?
70%
239
What is the leading rish factor for the development of fungal keratitis?
Trauma caused by plant or vegetable material
240
The most important symptom differentiating episcleritis from scleritis is what?
Pain. The ocular pain occurring in scleritis is often described as a deep, boring, and pain wheras patients with episcleritis generally have only mild discomfort or irritaiton.
241
What is the recommended treatment for trachoma?
Topcial and oral tetracycline or erythromycin.
242
What is the proposed cause of subepithelial infiltrates associated with EKC (adenoviral)?
Immune response to viral antigens depostited in the supeficial corneal stroma.
243
Where does herpesvirus reside while in a latent nonpathologic state prior to reactivation in the eye?
Trigeminal ganglion.
244
What is the difference between a dendrite and a pseudodendrite?
Dendrites have terminal bulbs, while pseudodendrites do not.
245
What is the most commonly associated ocular finding in patients with sclerocorneal?
Corneal plana.
246
What is nonprogressive corneal enlargement that is not the result of congenital glaucoma?
Megalocornea
247
How is megalocornea inherited, and is it unilateral or bilateral?
X-linked recessive and bilateral
248
What is an eye that is small but otherwise normal and an eye that is small and malformed?
Nanophthalmos and microphthalmos, respectively.
249
What is the name for a cornea that is less than 43 diopters?
Cornea plana.
250
What is thought to be the main cause of pingueculae?
Ultraviolet light exposure (actinic damage)
251
What layer of the cornea is invaded and destroyed by pterygia?
"Against-the-rule"
252
What is th recurrence rates after simple resection of a pterygium and if a conjunctival autograft is used?
Simple resection - 40%. Resection with conjunctival autograft - 5%.
253
Histopathologically, what are common conjunctival concretions?
Epithelial inclusion cysts filled with epithelial debris and keratin.
254
In what layer of the cornea do you find the lipid that cuases arcus senilis?
Corneal stroma
255
Arcus in patients under 40 is an indicator of what and a prognosticator of what?
Indicates hyperlipoproteinemia and prognosticates coronary artery disease.
256
Which stromal dystrohpy has mild stromal haze composed of polygonal gray areas that clears peripherally?
Central cloudy dystrophy of Francois - aka posterior crocodile shagreen.
257
This is a rare, dominanat, stationary dystrophy that presents at birth with central corneal clouding that is often confused with congenital glaucoma.
Congenital hereditary stromal dystrophy (CHSD).
258
Why I it importatn to note corneal gutatta in pre-operative patients?
Progression to corneal decompensation and edema may be accelerated after intraocular surgery. As many as 1/3 of corneal endothelial cells may be lost during uncomplicated cataract extraction.
259
In what group of patients is Fuch's endothelial dystrophy most common?
Postmenopausal women.
260
At what time of day are the symptoms of Fuch's dystrophy the worst and why?
Morning - decreased corneal surface evaporation while asleep.
261
Which corneal dystrophy can show endothelial bands with scalloped edges composed of large endothelial cells that stain positive for keratin?
Posterior polymorphous dystrophy (PPMD)
