Glaucoma

Question 1

Ciliary body parts

Answer 1

Pars plicata - anterior. makes aqueous humour, finger like
Pars plana - posterior

Question 2

Aqueous humour outflow

Answer 2

1. Trabecular meshwork and Schlemm’s canal
2. Uveoscleral outflow - choroidal and vortex veins

Question 2

Control of aqueous humour secretion

Answer 2

Symphathetic

beta 2 stimulation - increases secretion
alpha 2 stimulation - decreases secretion

Question 3

Trabecular meshwork parts

Answer 3

1. uveal, inner most, large holes
2. Corneoscleral - smaller holes
3. Juxtacanalicular meshwork - connect trabecular meshwork with Schlemm canals

Question 4

Schlemm’s canal

Answer 4

Endothelial lined oval canal - contains holes for channels joining episcleral veins

Question 5

Iridocorneal angle structures

Answer 5

Question 6

Glaucoma triad

Answer 6

1. raised IOP (not necessary)
2. Optic disc changes
3. Visual field changes

Question 7

IOP

Answer 7

Goldmann tonometry
11-21mmHg
high at morning and supine

affected by: CCT, astigmatism and axial length

Question 8

Neuroretinal rim thickness

Answer 8

ISNT rule
Inferior (thickest)
Superior
Nasal
Temporal (tinnest)

Question 9

Glaucoma optic disc changes

Answer 9

Neuroretinal rim becomes thin
Optic disc cupping - cup/disc ratio increases >0.3

Question 10

Visual field testing

Answer 10

Perimetry (Humphry is automated)

Question 11

Gonioscopy anterior chamber structures

Answer 11

1. Posterior corneal surface (Descemet membrane)
2. Schwalbe line
3. Non pigmented TM
4. Pigmented TM
5. Scleral spur
6. Ciliary body
7. Iris

Question 12

Trabeculotomy

Answer 12

Fistula between anterior chamber and sub-Tenon capsule

Antimetabolites (5FU, mitomycin c) used to prevent bleb failure

Question 13

Selectiev laser trabeculoplasty

Answer 13

In open angle glaucoma - laser to trabecular meshwork

Frequency doubled Nd:YAG

Question 14

Peripheral iridotomy

Answer 14

Definitive in closed angle glaucoma

Nd:YAG (1064 nm)

Question 15

Peripheral iridoplasty

Answer 15

temporary in closed angle glaucoma, burning the iris and pulling it away from TM

Argon (455-529nm)

Question 16

Causes of post vitreo-retinal surgery glaucoma

Answer 16

1. Scleral bukling
2. Intraocular gasses
3. silicon oil
4. Viterectomy

Question 17

Post cataract surgery glaucoma

Answer 17

inflammation due to leaked visco-elastic material

Question 18

Ocular HTN

Answer 18

IOP > 21mmHg but no glaucomatous changes

monitor. treat if consistently > 30mmHg

Question 19

Risk factors for primary open angle glaucoma

Answer 19

1. MYOC and OPTN mutations
2. Myopia
3. Afro-Caribbean
4. Age
5. smoking and steroids

Question 20

Primary angle closure glaucoma risk factors

Answer 20

Age
East asian
Hypermetropia (short axial length)
FHx

Question 21

Pathophysiology of PACG

Answer 21

1. Relative pupillary blocl
2. Plateau iris (chinese)

Question 22

PACG mx

Answer 22

Supine, IV acetazolamide, topical timolol
Iridotomy (Nd:YAG)

Question 23

Past resolved APAC

Answer 23

Descemet folds
Glaukomflecken

Question 24

Congenital glaucoma

Answer 24

Bilateral, AR
Raised IOP (>12mmHg)

mx
cornea clear - goniotomy
cornea cloudy - trabeculotomy

Question 25

Features of pigment dispersion syndrome

Answer 25

raised IOP, can lead to glaucomatous changes

1. Pigmented TM
2. Raised IOP
3. mid peripheral spoke like defects on transillumination
4. Spindle like pigments on corneal endothelium (Krukenberg spindles)