Ophthalmology

Question 1

Ocular pain

Answer 1

Blepharospasm
Lacrimation
Photophobia
High blink rate

Question 2

Assess vision

Answer 2

Menace
Dazzle
Palpebral
Vestibulo-ocular reflex
PLR
Visual tracking
Maze test

Question 3

Dazzle reflex

Answer 3

Bright light
Subcortical reflex - GA poss
CN2 and7
Present in centrally blind
Absent in subcortical disease

Question 4

Menace

Answer 4

Learned by 3m
Avoid air current (false positive)
Coritcal processing

Question 5

PLR

Answer 5

Sym (dilation)
Asym (constriction
Not reflective of subcortical reflex
Symmetry
Affected by fear

Question 6

Lens selection (+/-D)

Answer 6

<-0 if problems right at back (pos)
-2D to +2D examine fundus
+2D to +10D examine vitreous
+10D to +20D examine lens/AC
+20D to +30D examine cornea/adnexa

Question 7

Further tests

Answer 7

Dilation - tropicamide (shorter acting and duration, atropine (not for dry eye)
IOP (tonometry) - 10-25mm/Hg
Schimmer tear test - >15 mm/min
FLuoroscein

Question 7

Filters scope

Answer 7

Green - blood black, pigment grey
Blue - fluoroscein
White - examination

Question 8

Sclera

Answer 8

Posterior fibrous layer
Layer - episclera, scleral stroma, lamina fusca

Question 9

Corneal anatomy

Answer 9

Avascular
Layers - epithelium, stroma, Descemet’s membrane, endo
Precise collagen arrangement and low cell density

Question 10

Epithelium

Answer 10

Stratified squamous
Not keratinised
Microvili-mucin PTF
Stem cells in limbus
Good regeneration

Question 11

Stroma

Answer 11

Collagen
Keratocytes
ECM, H2O
Rigidity
Avasc healing-
neutrophils, fibroblasts
Vascular -
Vascular invasion, fibrovascular invasion

Question 12

Descemets membrane

Answer 12

Basement membrane of endothelium
Secreted by Endo (thicker if old)
Break - Haab’s striae
Deep ulcer - descemetocoele

Question 13

Endothelium

Answer 13

1 cell thick
Ion pump and dehydrator (stroma)
Limited healing
Hyperplasia/ sliding
Decompensation -> oedema

Question 14

Opacification

Answer 14

Ulcer
Vascularisation
Pigmentation
Oedema
Keratinisation
Fibrosis
Mineral/ lipid deposit

Question 15

Pathology

Answer 15

Corneal oedema
Vascularisation
Keratinomalacia
Stromal infiltrate
Fibrosis
Melanosis

Question 16

Reflex uveitis

Answer 16

Caused by ulcers
Mediated by axonal CN V reflex
Cycloegia and sys NSAID

Question 17

Ulcer

Answer 17

Hole in epi
CS not Dx
Facet -
Dent, Fl -ve, not painful
Perforation -
Siedal test, reduced IOP

Question 18

Siedal test

Answer 18

Test for corneal perforation and aqueous leakage
Apply stain
Cobalt blue
Aqueous running through dye

Question 19

SCCED

Answer 19

Spontaneous Chronic Corneal Epithelial Defect
Boxers, mid aged
Painful persistent
Slow healing
Topical Ana, debride, Ab, lateral partial tarsorrhaphy
GRID keratotomoy
- only for SCCED
Corneal-conjunctival transposition/ pedicle graft (tectonic support)
Cross linking

Question 20

Dermoids

Answer 20

Congenital choristoma of the orbit
Long hairs cause irritation, wick tears
Sx resection, ectomy

Question 21

Corneal lacerations

Answer 21

Risk of perforation
AC collapse
Iris prolapse
Endophthalmitis
2nd glaucoma
Phacoclastic uveitis (refer)

Question 22

Acquired cornea dz

Answer 22

Corneal sequestrum
Corneal lipidosis
- arcus, keratopathy, stromal dystrophy
Ca degeneration
Endothelial dystrophy
pigment keratopathy
Trauma

Question 23

Ca degeneration

Answer 23

Older patients, often 2ndary
High sera Ca
Ca infiltrate and vascularisation
Chalky
Epithelial defects
Keratectomy

Question 24

Corneal lipidosis

Answer 24

Crystaline stromal dystrophy Young adults Slow progression Superficial lipid deposition (ctrl) No Tx Lipid keratopathy - 2°, inflammation, vascularised Corneal arcus- Sys Hyperlipoproteinaemia Lipid infiltration perilimbal (arc shape) Treat sys dz

Question 25

Endothelial degeneration

Answer 25

Boston terriers Slow progressive decompensation of temporal endothelium -> oedema Keratectomy

Question 26

Pigmentary keratopathy

Answer 26

Response to chronic corneal surface irritation →Progressive corneal surface pigmentation Brachycephalics Genetic component Treatment: Remove irritation Topical ciclosporine