4. Genetic/malignant/systemic/rheumatoid Ophthalmology Flashcards
Outline retinitis pigmentosa
Ae = RPGR gene mutation (300)
- autosomal dominant, recessive or X-linked
Path = progressive loss of rod photoreceptor cells, followed by loss of cone photoreceptor cells
S+S = reduced visual fields + acuity, tunnel vision, loss of night vision
Ix = examination of the retina (bilateral: arteriolar attenuation, bone–spicule peripheral retinal pigmentation, waxy optic disc pallor)
- supportive testing: electroretinogram (subnormal), visual field testing, genetic testing
Mx = low vision aids, portable lighting, orientation and mobility training, vitamin A palmitate supplements (slow worsening), visual prosthesis
Briefly outline retinoblastoma
Ae = mutation of RB gene located at 13q14
- autosomal dominant
- most common primary intraocular tumour in children
Path = developing retinal cell undergoes mutation, RB results
S+S = strabismus (cross-eyed), leukocoria (white pupil), absent red reflex
Ix = US, CT, MRI, bone scan, genetic testing
Mx = chemo, enucleation, external beam RT, ophthalmic plaque brachytherapy, cryotherapy and transpupillary therapy
What is optic neuritis and how should it be managed?
ON = demyelinating inflammation of the optic N
- infection: measles, mumps, chicken pox, TB, syphilis
- autoimmune: sarcoidosis, SLE, MS, DM
- idiopathic
S+S = unilateral temporary vision loss, blurred vision, red desaturation, painful eye movements
Ix = MRI to rule out MS lesions, vasculitis screen, ds-DNA, HIV, syphilis, OCT
Mx = No Tx routinely given, high-dose methylprednisolone, then pred will speed up recovery time
What is amaurosis fugax?
Painless temporary loss of vision in one/both eyes - “black curtain coming down vertically into the field of vision”
Ae = idiopathic, atheromatous disease of the internal carotid or ophthalmic artery, vasospasm, optic neuropathies, giant cell arteritis, angle-closure glaucoma, RICP, orbital compressive disease, blood hyperviscosity or hypercoagulability
Describe monocular vision loss and the location of the lesion
Complete loss of vision in one eye
1) Optic N = both temporal and nasal fibres effected
Describe homonymous hemianopia and the location of the lesion
Loss of the same side of vision L/R in each eye
1) Optic tract = both temporal or both nasal fibres
2) Optic radiations = superior + inferior fibres from both temporal or both nasal fibres
Describe bitemporal hemianopia and the location of the lesion
Loss of outer vision on each side = tunnel vision
1) Optic chiasm = nasal fibres from each eye cross
Describe a quadrantinopia and the location of the lesion
Loss of a quarter of vision
1) superior radiation = UL/R lost
2) inferior radiation = LL/R lost
Describe how giant cell arthritis can effect vision
Most common arteritic anterior ischaemic optic neuropathy
- medium/large vessel systemic vasculitis
S+S = new-onset headache, malaise, jaw claudication, tender scalp and temporal arteries (thickened + absent pulses), neck pain, vision loss (typically monocular)
Start pred 60mg PO promptly, higher IV dose if vision failure
Describe granulomatous disease can effect vision
Granulomatous disease = TB, sarcoid leprosy, brucellosis, toxoplasmosis
- can result in uveitis
S+S = blurred vision or vision loss, photophobia, floaters (black spots or lines in vision), dry or itchy eyes, red eyes, burning sensation in the eyes, pain in the eyes
Sarcoid may cause CN palsies and lacrimal gland swelling
Discuss thyroid eye disease
Path = activation of orbital fibroblasts by autoantibodies directed against thyroid receptors, muscles affected but tendons spared
- most commonly effects inferior rectus = swollen, tight, pain on looking superior
S+S = ocular misalignment/diplopia (swelling/stiff EOM), photophobia, periorbital adipose swelling/prolapse, erythematous lids/eyes, blurred vision, exophthalmos, dry eye, pain
Ix = thyroid stim Ab, TFTs, MRI
Mx = prisms, patch one eye, smoking cessation, aim for euthyroid status, orbital decompression
