Part 1 Flashcards
(83 cards)
1
Q
Outer membrane of eye
A
Anterior most 1/5th cornea
White 4/5th sclera
Covered w bulbar cunjuctiva with sclera beneath
2
Q
What is limbus
A
Junction of cornea and sclera
3
Q
Pupil size? Function
A
2-4mm
Dilate- mydriasis
Contract- miosis
4
Q
Miosis by?
A
Sphincter pupilae muscle constriction
5
Q
Mydriasis by?
A
Dilator pupilae muscle
6
Q
Sphincter pupilae muscle innervated by which nerve?
A
Oculomotor nerve CN3
7
Q
Dilator pupilae innervated bywhich nerve?
A
Sympathetic nerves
8
Q
Heterochromia iridum
A
Different colour of Iris in different eyes
One eye brown one eye blue
9
Q
Heterochromia iridis
A
Different colour in same eye
10
Q
Patient comes with partial ptosis, miosis, enophthalmos of one eye and anhydrosis on one side of face. There’s loss of cilliospinal reflex
What is Dx?
A
Horner’s syndrome
11
Q
Horners syndrome
A
Piece MEAL
P- partial ptosis
M - miosis
E - enophthalmos
A - anhydrosis
L - loss of cilliospinal reflex
Occurs due to compression of cervical sympathetic chain.
Partial ptosis caused by Muller’s muscle palsy which is innervated by sympathetic nerve
Miosis caused due to palsy of dilator pupilae muscle nerve, also sympathetic.
12
Q
Ptosis caused by which nerve palsy?
A
Lavator palpebra superioris
13
Q
Which lung tumour leads to Horner syndrome?
A
Pancoast tumour
Superior sulcus tumour of the lung causing compression of the cervical sympathetic chain
14
Q
Eye components
A
Outer fibrous layer- cornea and sclera
Middle layer is vascular - Iris, ciliary body and choroid
Inner layer is neural- retina
15
Q
Thinnest, anterior most part of retina
A
Orra serrata
16
Q
Ciliary body components
A
Pars plana
Pars plicata- responsible for aqueous humour production.
17
Q
Volume of orbit
A
30ml
18
Q
Volume of eyeball
A
7ml
19
Q
Volume of posterior segment
A
4ml
Posterior segment is filled by vitreous humour
(Portion posterior to the lens)
20
Q
Volume of anterior chamber and posterior chamber
A
0.25ml AC
0.06ml PC
Anterior segment is divided into anterior and posterior chambers.
21
Q
Eye development starts by which week of gestation?
A
3rd week of intrauterine life
(21 days)
22
Q
Neuroectoderm derivatives
A
VOIR
V- secondary virtuous
O- optic nerve
I - iris
R - retina
23
Q
Neural crest sells derivatives
A
** C3OST**
C- cornea
C- ciliary ganglion
C- ciliary muscles
O- optic nerve sheath
S- sclera (partly made from mesoderm)
T- trebacular meshwork (drainage of AH)
24
Q
Normal Axial length?
A
Newborn- 16.5mm
Adult- 24mm
25
Normal Corneal size?
Newborn- 9mm
Adult- 11mm
Takes 2 years to reach adult size
26
Newborn eye is hypermetropic by how much?
+2 to +3 diopters
27
Lens derives it’s nourishment from?
Aqueous humour, more than vitreous humour
28
Refractive power of eye?
+60 diopters
Corneal- +43D
Lens- +17D
29
Refractive Indices
Refractive Index of-
Aqueous = Vitreous = 1.34
Cornea- 1.37
Lens- 1.39
Center of Lens- 1.42 (max)
30
Lens capsule is made up of?
Type 4 collagen
31
Type 4 collagen also present in?
Basement membrane
32
Lens capsule is thinnest at?
Posterior pole
33
Coloboma
Congenital anomaly caused by Inability of hyaloid fissure to close (closes by 7-8 wk of IUL)
Most common type- infronasal
(Pupil dripping down. See picture)
34
Anterior lenticonus
Hereditary condition
Anterior conical protrusion of lens
Seen in **Alport syndrome**
Triad-
Can’t hear (SNHL)
Can’t see (AL)
Can’t pee (nephritic syn)
35
Most common cause of cataract
Old-age
senility
36
Most important drugs that cause cataract
Steroids
37
Most common cause of blindness
First- cataract
Second- refractive error
38
Most dangerous type of cataract
Posterior polar cataract
Characteristic **onion peel appearance** of opacification of lens
39
What type of cataract is seen in diabetes mellitus?
**Snowflake cataract**
More common in **type 1** than type 2.
Due to accumulation of **sorbitol,** made by conversion of glucose by **aldose reductase enzyme**
40
Cataract due to deposition of **copper** in lens?
Sunflower cataract
Seen in **Wilsons disease** and **chalcosis**
41
Copper deposition causing brown ring formation around cornea?
**kayser Fleischer Ring** or kf ring
In copper excess conditions
(Wilson’s disease and chalcosis)
Cu deposition in the **descemets membrane** of cornea.
42
Which type of cataract seen in galactosaemia?
**Oil drop cataract**
due to accumulation of **galactitol/ dulcitol**
Caused by conversion of galactose by aldose reductase enzyme
43
Only reversible cataract?
Oil drop cataract
44
Blunt trauma causes, which type of cataract?
**Rosette cataract**
Rose petal like pattern
45
Most common type of complicated cataract
Posterior subcapsular cataract
46
Stages of cataract
1- Incipient cataract
2- Immature cataract
3- Intumescent cataract
4- Mature cataract
5- Hypermature cataract
o Calcified
o Morgagnian
47
Complication of morgagnian cataract
Phacolytic glaucoma
48
Complication of sclerotic/calcified cataract
Phacotopic glaucoma
49
Features of hypermature/morgagnian cataract
**Bag of milk** appearance, due to cortex liquefication
and **sunken nucleus**
50
Patient with
**Gradual painless loss of vision**
Glare
Coloured halos
Second sight
Dx?
Cataract
Second sight means near vision is getting better, seen mc in **nuclear cataract**
Senile cataract
51
Rx of cataract
1st line- **phacoemulsification**
Incision is 3.2mm
1- keratome used to make incision in SICS( small incision cataract surgery)
2 ant. chamber is maintained by hydroxypolymethylcellulose
3 capsuporrhexis
4 hydrodissection
5 sculpting of nucleus
6 cracking of nucleus
7 emulsification of each quadrants
8 cortical cleanup and insertion of IOL
52
Cataract surgery also done bye other procedure?
FLCS
femtolaser assisted cataract surgery
Is a type of **Nd Glass laser**
Wavelength of 1053nm
53
Complications of cataract surgery
**UGH** syndrome:
Uveitis
Glaucoma
Hyphaema (blood in ant chamber
Early complications of anterior chamber IOL insertion
54
Intraocular lens
Rigid- poly methylmethacrylate
Foldable- best- acrylic.
Ideal site - posterior chamber
(In the bag)
55
Endophthalmitis
Dx
Rx
Inflammation of vascular and retinal layer of eye
Can be early or late
Early: staph epidermididis
Late: propionibacterium acne
**red sclera
Hazy cornea
Hypopyom- pus in ant chamber
Sudden pain full loss of vision**
*early complication of cataract surgery*
Rx- intravitreal inj. of antibiotics
56
Late complication of cataract surgery
Posterior capsular pacification PCO
/Secondary cataract
Can be of 2 types
1- elschnig’s pearls. More common (children) pearly opacities
2- sommering rings
Patient will present after 6 to 8 months of cataract surgery with **Gradual painless loss of vision**
**Rx- Nd yag laser capsulotomy** (opening)
57
Nd Yag laser
neodymium-doped yttrium aluminium garnet
Wavelength: 1064 nm
Common in posterior capsular opacities (capsulotomy)
58
Subluxation
MCC- marfans syndrome- fibrillin 1 gene mutation
MC type- Superotemporal subluxation
Inferonasal subluxation- caused by homocystinuria
59
Congenital cataract
- abnormal white pupillary reflex= leucokoria
-mc type- **blue dot 🔵 cataract** (universal)
- vision is perfectly normal.
- **zonular cataract** (opacification of zonules) / lamellar cataract.
- can lead to blindness
60
Raccoon eyes
Bilateral ecchymosis
Due to **anterior cranial fossa fracture**
61
Vossius’ Ring
Pigmented ring like shape formed by iris coming into contact w cornea due to a **concussion injury** and leaving some pigment behind
62
Orbital Fracture
Most common- floor of orbit fracture
With characteristic **tear drop** sign.
Weakest wall- medial wall of orbit
Palsy-
1- infraorbital nerve
2- inferior rectus muscle
63
D shaped pupil
Iridodialysis
Separation of iris form it’s base
64
Pt. Complains
Redness
Watering
Discharge
Conjunctivitis
65
Most common type of conjunctivitis?
Viral
**adenovirus**
66
Most common bacteria, causing conjunctivitis?
Staphylococcus aureus
67
Angular conjunctivitis MCC
MCC- morexella axenfeld
Temporal side of the conjunctiva/lateral canthus maceration
68
Subconjunctival haemorrhage
PACE
Haemorrhagic conjunctivitis, more commonly seen in viral
P- picorna virus
A- adenovirus
C- coxsakie
E- entero virus/ echo
MCC- Accu haemorrhagic conjunctivitis- Apollo virus.
69
Trachoma
-Chronic inflammation of cornea and conjunctiva
Corneal opacity- pannus
-Also known as- Egyptian ophthalmia
- cause- clamydia trachomatus (a- c serotypes)
- SAFE strategy
Surgery
Antibiotics
Facial cleanliness
Environmental sanitation
- DOC- azithromycin
- prophylactic- 1% tetracycline ointment
70
Trachoma features
-Follicles give sago grain appearance
-Papillae give velvety appearance
-Arlt’s line - conjunctival scarring in the upper lid
-Herber’t pits- depresses scar follicles on the upper limbus (pathognomic feature)
*HAPPy For Trachoma*
71
Opthalmia neonatorum
-Infection in first 28 days of life
-MCC- clamydia trachomatis(D to K)
-Most severe- gonococcal (1-3 days)
Hsv if after a week
72
Vernal keratocunjunctivitis VKC
Also called spring cataract
Type 1 hypersensitivity to exogenous allergens
More common in young boys
**Olopatadine** -DOC
- **HORNER TRANTA SPOTS** eosinophilic accumulation at the upper limbus
- **cobblestone pppilae** over the palpebral conjunctiva.
- **shield ulcer**
-Thick ropey discharge **maxwell Lyon sign**
- **pseudo garantoxon**
Rx-
Preventive - Avoid allergens, Dry hot climate, rubbing eyes,
Lid hygiene, sun glasses, cold compression.
**Antihistmamines (Topical/Oral)
Mast cell stabilisers
NSAIDs - Ketotifen
Topical or Oral Steroids
Acetylcysteine drops
Topical Cyclosporin
Supratarsal injection of steroids**
73
Arcus senilis/ gerontoxon
Arch like deposition of lipids in corneal periphery
74
Phlyctenular conjunctivitis
-Type 4 hypersensitivity reaction
-By endogenous allergens
-Most common- staph aureus + tuberculin protein
Common in tb
75
Pterygium
- Wing shaped flap of conjunctiva seen encroaching the cornea
- cause- UV B Rays causing elasticity degeneration
- more common on nasal side
- surgery indications- cosmesis (don’t look nice)
- stocker’s line (iron deposits)
- Types: progressive, regressive, stationary.
76
Ptregium rx
1. Tear substitute
2. Topical steroids
3. Sunglasses and then simple/conjunctival flap excision
4. Bare sclera/conjunctival autograft/flap surgery for excision
To prevent recurrence after excision all of the following Conjunctival autograft:
6. Amniotic membrane transplantation
7. Mitomycin C with excision to prevent recurrence
8. Radiation
9. Argon Laser
10. Peripheral lamellar keratoplaty.
77
Bitot spots
White frothy toothpaste like spots on sclera
Feature of - **xerophthalmia**
**vit. A deficiency**
First feature- night blindness
First sign- conjunctival dryness
(X1a- conjunctival xerosis
X1b- bitot spots
X2- corneal xerosis
X3a- corneal ulceration
X3b- keratomalacia
XN- night blindness
XF- xerophthalmia fundus)
78
Thickest layer of cornea
Stroma
79
Normal cell count of endothelium layer of cornea
2500 cells/cubic meter
Checked by specular microscope
Fall below 500 leads to corneal opacity
80
Corneal ulcer
MCC- bacterial
Signs-
hazy cornea
Hypopyon- **mobile and sterile**
81
Most common corneal dystrophy
Epithelial
82
Most common stromal corneal dystrophy
Lettice
83
Interstitial keratitis
Involves the stroma of cornea
Feature of congenital syphilis
Hutchinsons triad-
Hutchinson teeth
Interstitial keratitis
Sensorineural hearing loss
