topic 2: glaucoma part 2 Flashcards
what is OHT?
what are the risk factors of OHT progessing to glaucoma? (who are at risk)
4 - 7% of individuals older than 40 years have IOPs > 21 mmHg without detectable glaucomatous damage
- IOP ≥ 30 mmHg, treat as for POAG
- Greater age
- Thinner central corneal thickness (CCT)
- Larger C/D ratio (OHT has 10% chances of progressing to POAG after 5 years)
what are the 6 characteristics of primary open angle glaucoma?
- AC angle=open
- outflow= slow
- Most common
- Chronic
- Usually bilateral (happens in both eyes)
- Asymmetrical dmg
what are the 8 risk factors of POAG? (who are at risk)
- Race: More prevalent in Blacks than in Whites and Orientals
- Age: 40 - 60 age group, risk increases with increasing age
- High Myopia
- FmHx: 1/10 risk for first degree relative
- Systemic diseases: Diabetes mellitus, Hypertension
- Smoking
- Steroid use
8. Ocular: Consistently high IOP Large CD ratio Higher Myopia Retinal disease: CRVO, RP
what are the signs of POAG?
*High IOP: > 21 mmHg (28-32 mmHg)
POAG can occur with normal IOP while high IOP may not have POAG
Diurnal variation of > 4 - 6 mmHg
*Large C/D ratio: >0.5
C/D ratio asymmetry: > 0.2
*Notching or loss of neural rim
Bayoneting/baring/nasal sweep of BV
Drance hemorrhages
*NFL defect/loss
Peripapillary atrophy
*Glaucomatous VF loss
Open & normal filtration angle
what are the symptoms of POAG?
Usually asymptomatic
History taking important– ask about frequency of eye examination
what is the management for POAG?
IOP reduction: greater the damage, the greater the IOP should be reduced
Urgent referral for medical/surgical Tx
Regular follow up: 6 ~ 12 months
what is normal tension glaucoma commonly associated with? what are its 2 signs and 1 symptoms?
Associated with poor vascular perfusion of the ONH
signs:
IOP ≤ 21 mmHg
Glaucomatous disc damage and VF defect
symptoms
Asymptomatic
what is the management for NTG?
Take detailed history
Do IOP phasing (when IOP is monitored at different time)
May require drug treatment
what are the risk factors for angle closure glaucoma?
- Race: South-East Asians, Chinese, Eskimos
- Age: > 40
- Hyperopia
- Family History
- Shorter axial length
- Larger crystalline lens size
- Dim illumination
- Post pupil dilation
- Emotional disturbance
what are the signs and symptoms of ACG?
- Blur vision
- Haloes, hazy vision
- Severe eye pain, headaches
- Nausea, vomiting
- Conjunctival injection / ‘red eye’
- Oval non-reactive mid-dilated pupil
- Corneal epithelial oedema
- Shallow or closed AC angle
what is the pathogenesis of ACG? (relate to pupillary block)
Iris recedes during pupillary dilation (e.g. in a dim room)
Crystalline lens moves anteriorly
Iris buries itself into the lens when pupil tries to dilate
Relative pupil block
Aqueous cannot flow into the anterior chamber
Aqueous builds up in the posterior chamber
Iris bombe
Iridocorneal contact
Increase in IOP → causing eye pain, corneal oedema (hazy, seeing halos) and conjunctival injection/redness.
what is the mangement for ACG and sub-acute ACG?
Immediate referral to drop IOP
Normally require surgical tx, followed by drugs
Follow up: every 3 months
Peripheral Iridotomy is 1st choice
what is Sub-Acute Angle Closure Glaucoma?
Intermittent episodes of blurred vision and ocular discomfort, with narrow angles
Repeated sub acute attacks may result in Primary Angle Closure Glaucoma
what is congenital glaucoma?
glaucoma caused by mal-development of the AC angle
Usually manifest before 3rd birthday, other manifest before 16th birthday
Usually sporadic; primary happens at irregular intervals
what is commonly associated with congenital glaucoma?
Sturge-Weber syndrome Corneal dysgenesis/mal-development Rubella Aniridia Retinoblastoma
