Cornea Flashcards
(99 cards)
1
Q
Power of cornea
A
43-45 D
2
Q
Refractive index of cornea
A
1.37
3
Q
Diameter of cornea
A
11-11.75
4
Q
Megalocornea
A
> 13 mm
5
Q
Microcornea
A
<10 mm
6
Q
How is cornea dehydrated
A
Barrier function of endothelial cells
Na+/K+ ATPase pump
7
Q
Number of Endothelial cells in adults
A
2500-3000 cells/ sq.mm
8
Q
Number of endothelial cells in children
A
3500-3000 cells/sq.mm
9
Q
Number of cells in endothelium which causes hydration of cornea
A
<500 cells/sq.mm
10
Q
Features of corneal decompensation (hydration of cornea)
A
Stromal oedema
Bullous keratopathy
Bullae
11
Q
Organisms which penetrate intact epithelium
A
N – Neisseria gonorrhoea N– Neisseria meningitis L – listeria D – diphtheria H – haemophilia S – shigella
12
Q
Name some investigations related to cornea
A
Keratometry – curvature of cornea Corneal topography– Plácido’s disc– qualitative assessment Pachymetry- thickness of cornea Specular microscopy-To examine endothelial cells Corneal sensation Microbiological investigation
13
Q
corneal sensation tests
A
Qualitative –With a wisp of cotton
Quantitative – aesthesiometre> The length of filament when patient starts feeling sensation
Shorter the length the more pressure is needed and lesser the corneal sensation
14
Q
Microbiological investigations of cornea
A
Staining and culture
15
Q
The main clinical features of keratitis
A
Pain Redness (ciliary congestion) Photophobia Blepharospasm Discharge
16
Q
What are the type of redness and what is their pathology
A
Conjunctival congestion – only conjunctival pathology
Circumciliary congestion – deeper blood vessel
17
Q
What type of hypopyon present in bacterial keratitis
A
Sterile hypopyon
18
Q
Three types of bacterial keratitis
A
Localised
Perforating
Sloughing
19
Q
Ulcus Serpens
A
Hypopion corneal ulcer caused by pneumococcus
20
Q
2 things NOT to do for infective corneal ulcer
A
No steroids
No pad/bandage
21
Q
Management of non-healing ulcer
A
Debridement
Chemical cauterisation
Conjunctival flapping
22
Q
What are the local antiseptics used for chemical cauterisation in the management of non-healing ulcer
A
Trichloroacetic acid
Carbolic acid
23
Q
Management of impending perforation
A
Anti-glaucoma drugs
Cyano acrylate blue
BCL – bandage contact lens
24
Q
Types of contact lens
A
Soft
Semi soft also known as rigid gas permeable
25
Most common cause of bacterial keratitis
Staphylococcus aureus
| Staphylococcus epidermidis
26
If there is corneal perforation in 48 hours which organism is it
Pseudomonas
27
Treatment of bacterial keratitis
Please check your notes
28
What is the aetiology of fungal keratitis
Drama by vegetative/organic matter
29
Fungal keratitis also known as
Keratomycosis
30
Most common fungus infecting cornea
Aspergillus fumigatus
| Fusarium
31
Most common fungus infecting lids
Candida
32
Most common fungus infecting endophthalmitis
Candida
33
Most common fungus infecting orbit
Mucormycosis
34
Compare to bacterial keratitis which is more prominent signs or symptoms in fungal keratitis
Bacterial keratitis – symptoms are more than science
| Fungal keratitis – signs are more than symptoms
35
Examination findings in fungal keratitis
Satellite nodules
hyphae
Unsterile hypopyon
Immune ring
36
Investigations in fungal keratitis
Staining – KOH Smear, gomori’s methamine, silver stain
| Culture – SDA, brain heart infusion broth
37
Treatment of fungal keratitis
DOC – Natamycin
Nystatin eye ointment
Flucanazole (Candida)
38
Causes of viral keratitis
HSV (More common)
| HZO
39
Pathognomic feature of viral keratitis
Decreased corneal sensation
40
Other causes of decreased corneal sensation
Diabetes
| Leprosy
41
Examination findings in herpes simplex keratitis
Endothelium
Corneal oedema, disciform keratitis (endothelitis in disc shape)
Stroma
keratitis
Epithelium
Superficial punctate keratitis, dendritic ulcers with knobbed ends
Geographical ulcer
42
Treatment of herpes Simplex keratitis
Acyclovir eye ointment (3%)
| Five times a day
43
What are the three main components of herpes zoster ophthalmicus
Skin lesion
Eye involvement
Trigeminal neuralgia
44
Hutchison’s rule. And why?
If the tip of the nose is involved the eye will be involved
| It indicates involvement of nasociliary nerve (ophthalmic division of fifth nerve)
45
Examination findings in herpes zoster ophthalmicus
Endothelium
Disciform keratitis
Trauma
Nummula keratitis
Epithelium
SPK
Pseudo dendritis/micro dendritis
46
Herpes zoster ophthalmicus is associated with
Uveitis
Cranial nerve palsy three, four, six
Most commonly third nerve
47
Treatment of herpes zoster opthalmicus
```
3% Acyclovir five times a day
Oral antiviral (acyclovir/vancyclovir)
```
48
Meta herpetic keratitis
Keratitis due to toxicity of anti-viral drugs
| Ulcer not healing
49
Most common nerve involved in zoster
Frontal nerve
50
Aetiology of acanthamoeba keratitis
Soft contact lens users
Washing lenses with tap water
Or
Swimming without goggles and soft contact lens
51
What is the most common infection after contact lens use
Pseudomonas
52
Metabolically most active layer of cornea
Endothelium
53
Examination findings of acanthamoeba keratitis
Ring lesion
| Can I present with pseudodendrites or reticular patter
54
Investigations in acanthamoeba keratitis
Staining
Calcoflour white
Acridine Orange
Lactophenol blue
Culture
Non-nutrient agar with E. coli
55
Treatment of acanthamoeba
PHMB (find full form)
Propamidine isothionate
Neomycin
56
Interstitial keratitis
Stromal keratitis with no involvement of epithelium and endothelium
57
Aetiology of interstitial keratitis
```
Syphilis
Leprosy
TB
Sarcoidosis
Cogan syndrome (interstitial keratitis plus deafness)
```
58
Salmon patch seen in which condition
Interstitial keratitis
59
Keratoconus
Elastic dystrophy of cornea characterised by its conical protrusion
60
Dystrophy meaning
Idiopathic spontaneous change with no inflammatory component
61
What is keratoGlobus
Uniform protrusion of the cornea
62
What is the vision defect of keratoconus
Myopia plus irregular astigmatism
63
What is Flescher’s ring
Iron in epithelium
Seen in keratoconus
Generally recall all the examination findings of keratoconus
64
What is Munson’s sign
V shaped deformity of lower lid on down gaze
| Seen in keratoconus
65
What do you see in retinoscopy of keratoconus
Scissors reflex
66
Causes of thickening of corneal nerves
Leprosy
| NF1
67
What is votes striae Vogt striae
Break in descemets membrane
68
In which condition is oil globules reflex scene
In patients of anterior lenticonus (slitlamp examination)
69
What is the treatment of keratoconus
```
Contact lens (RGP)
C3R treatment Corneal collagen cross-linking plus riboflavin
```
70
Best prognosis of penetrating keratoplasty is in?
Keratoconus
| Chances of graft rejection is minimum
71
Main principle of keratoplasty
Replacement of diseased cornea by donor cornea
72
Within how many hours of death should the cornea be taken from the cadaver
Within Six hours of death
| It may be extended to 12 hours
73
Types of storage media of cornea and number of hours can be stored
Short-term storage – 48 hours: moist chamber
Intermediate term – four days: MK medium, McCary kaufman
Long-term –
30 days: organ culture
In definite: cryopreservation
74
Types of keratoplasty
Penetrating full thickness replacement
| Lamellar partial thickness replacement-Anterior lamellar, posterior lamellar
75
DALK
DLEK
DSEK/DSAEK
DMEK
Full forms of all lol
Also know what is being removed in the Donor and what is being put in the host
Deep anterior lamellar keratoplasty
Deep lamellar endothelia keratoplasty
Descemet’s stripping endothelial (automated) keratoplasty
Descemet’s membrane endothelial keratoplasty
76
Clinical signs of graft rejection
```
Corneal oedema (most)
Keratic precipitates
Corneal vascularisation
Stromal infiltrates
Khodadoust line
Krachmer spots(Least)
```
77
What is khodadoust line
Corneal graft endothelial rejection line composed of inflammatory cells
78
What is krachmer spots
Sub-epithelial infiltrates
79
Most common infection after keratoplasty
Staphylococcus epidermidis
80
Indications of keratoplasty
keratoconus
Corneal dystrophy
Bullous keratopathy (Aphakia,pseudophakia)
Central corneal opacity
81
What is keratoprosthesis
Surgical procedure where diseased cornea is replaced by artificial cornea
82
Names of keratoprosthesis
Boston KP
| OOKP (osteo – odonto – KP)
83
What is Arcus senilis
Lipid deposition in stroma
84
Band shaped keratopathy
| Aetiology
Calcium deposition in the form of a band
Mostly idiopathic, or chronic uveitis in children of JRA
Pthysis bulbi
Hypercalcaemia (sarcoidosis)
85
Treatment of band shaped keratopathy
Debride epithelium
Chelation with EDTA
Bandage
86
Climatic droplet keratopathy
| Aetiology
Also known as actinic keratopathy
| Exposure to UV rays
87
Pathogenesis of Actinic keratopathy
UV rays act on serum protein causing golden proteinaceous deposit on cornea
88
Degrees of corneal opacity is
Nebular
Macular
Lucomatous
Adherent leucoma
89
Which type of corneal opacity has maximum diminishing of vision
Nebula
| Because it diffract light and interferes with the function of normal/clear cornea as well
90
Types of corneal dystrophy
Epithelial
Stromal
Endothelial
91
Types of epithelial dystrophy cornea
Micro cystic or map – dot or fingerprint
Meesmans
Reis buckler
92
Types of stromal corneal dystrophy
Granular
Macular
Lattice
93
Types of endothelial corneal dystrophy
Fuch’s endothelial dystrophy
| Posterior polymorphous dystrophy
94
Most common corneal dystrophy
Micro cystic
95
Most common stromal Corneal dystrophy
Lattice
96
Least common corneal dystrophy
Macular
97
Which corneal dystrophy is autosomal recessive
Macular
98
Which corneal dystrophy is associated with mucopolysaccharide
Macular
99
Which part of the cornea does Reis Buckler affect
Bowmans membrane
