ocular manifestations of systemic diseases Flashcards
RFs for diabetic retinopathy
- duration of DM
- level of metabolic control
- HTN, HLD, smoking, renal disease, obesity, pregnancy, anemia
findings in nonproliferative diabetic retinopathy
mild: microaneurysms
moderate:
1. dot and blot haemorrhages
2. flame-shaped haemorrhages
3. cotton wool spots
4. hard exudates
5. retinal edema
severe: (4-2-1 rule)
1. dark blot haemorrhages in 4 quadrants
2. venous beading/looping/segmentation inn >/= 2 quadrants
3. intraretinal microvascular abnormalities in >/= 1 quadrant
findings in diabetic maculopathy
- hard exudates
- edema in macula (cannot see macula or fovea)
findings in proliferative diabetic retinopathy
neovascularisation (NVD and NVE)
causes of visual loss
- diabetic maculopathy
- vitreous haemorrhage
- tractional retinal detachment
clinically significant macular edema (CSME)
at least 1 of:
1. Retinal thickening within 500 μm of macular centre
2. Hard exudates within 500 μm of macular centre with adjacent retinal thickening
3. ≥1 disc diameters of retinal thickening, part of which is within 1 disc diameter of macular centre
non surgical treatment for diabetic retinopathy
- Tight glycemic control (HbA1c≤ 7%,)
- control comorbidities / cardiovascular risk factors (HTN, HLD, renal disease) - regular exercise etc
- annual diabetic retinal photography (DRP)
medical treatment for diabetic retinopathy
- Laser photocoagulation:
- Pan-retinal photocoagulation (PRP) for PDR or severe NPDR Complications: ↑ risk of macular edema
- Focal or grid laser photocoagulation (clinically significant macular edema)
- Intra-vitreal injections of corticosteroids or anti-VEGF agents (CSME)
- bevacizumab [Avastin]
- ranibizumab [Lucentis]
- aflibercept [Eyelea]
surgical treatment for diabetic retinopathy
Surgery (vitrectomy): tractional RD or non-clearing vitreous haemorrhage in PDR
classification of hypertensive retinopathy
grade 1: mild vein depression at AV crossing
grade 2: copper wiring, AV nipping
grade 3: haemorrhage, exudates, silver wiring
grade 4: same as grade 3 + disc swelling
management of hypertensive retinopathy
- Treatment of underlying HTN
- If patient previously undiagnosed, refer for assessment:
Grade 1 and 2: non-urgent referral
Grade 3: more urgent referral to eye
Grade 4 hypertensive retinopathy: medical emergency, immediate referral to ED for urgent BP control
what conditions is hypertensive retinopathy associated with?
- Retinal artery occlusions: BRAO, CRAO
- Retinal vein occlusions: BRVO, CRVO stasis, thrombosis, occlusion
- Non-arteritic anterior ischemic optic neuropathy
signs in thyroid eye disease (commonly Graves)
soft tissue inflammation
- periorbital and lid swelling
- conjunctival hyperaemia and chemosis (conjunctival chemosis)
signs in thyroid eye disease (commonly Graves)
can see both inferior and superior sclera
proptosis
what do restricted extraocular movements cause?
binocular diplopia
order of extraocular muscles affected in thyroid eye disease
inferior rectus > medial rectus > superior rectus > lateral rectus
sight threatening complications of thyroid eye disease
- Compressive optic neuropathy
- Glaucoma
- Exposure keratitis with corneal dryness, ulceration and infection
how does thyroid eye disease cause optic neuropathy
oversized recti and orbital fat causing compartment syndrome at apex of orbit causing↓ vision, ↓ colour vision, RAPD, red desaturation
how does thyroid eye disease cause glaucoma
Glaucoma: contraction of extraocular muscles against intraorbital adhesions or orbital congestion due to ↑ tissue volume causing increased IOP
inx for thyroid eye disease
- Bloods: free T4, TSH, anti-TSH receptor Ab
- Radiological (CT, MRI): determine amount of soft tissue involvement, planning for surgical decompression
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6 thyroid eye signs
- chemosis (red eyes)
- proptosis (see from side/top)
- exopthalmos (see bottom of sclera)
- lid retraction (see top of sclera)
- ophthalmoplegia (H - see double)
- lid lag
classical finding on CT orbit (axial, coronal)
enlargement of extraocular muscles that spare tendinous insertions as it’s infiltrative
treatment for thyroid eye disease
conservative
- lubricating eyedrops and tape eyelids shut at night for exposure keratopathy (mild cases)
- systemic immunosuppression with oral or IV steroids (more significant eye disease)