Retina/Vitreous/Other Uveitis Flashcards
• Most common causes of vitreous hemorrhage
1) PDR; 2) retinal break without detachment; 3) PVD; 4) rhegmatogenous RD; 5) NV after RVO.
• Causes of crystalline retinopathy
tamoxifen toxicity, methyoyfluorane toxicity, nitrofurantoin toxicity, canthaxanthine toxicity, talc, antifreeze ingestion, primary hereditary hyperoxyuria, bietti crystalline dystrophy
• Gyrate atrophy:
mutation in OAT gene, gyrate chorioretinal lesions, PSC, high myopia with astigmatism, hyper ornithemia. Autosomal recessive inheritance. Tx is dietary argenine restriction and B6 supplementation.
• Best dystrophy gene
BEST1 gene. Adult onset foveomacular vitelliform dystrophy (AFVD) is similar. Implied genes for that are PRPH2, IMPG1 and IMPG2
• Stargardt’s gene
ABCA4
• Gyrate atrophy gene
OAT
• RD prognosis
best for small holes or retinal dialysis and those associated with demarcation lines. Worse for aphakic / pseudophakic eyes, worse for PVR, giant retinal tears, choroidal detachment, inflammation, or traumatic posterior breaks
• DRS study
PRP vs no laser for severe NPDR or PDR—end point was severe vision loss (PRP helps).
• EDTRS
focal laser reduces moderate vision loss and increased chance of 2 line gain in people with CSME. Early scatter PRP results in a small reduction in the risk of severe vision loss.
• DRVS
(diabetic retinopathy vitrectomy study): early vitrectomy for nonclearing vitreous hemorrhage increased chances of 20/40 vision in type 1 diabetics
• DCCT
(diabetes control complications trial): intensive control of blood glucose reduced risk of developing retinopathy by 76% and slowed progression by 54% in type 1 diabetics.
• COMS study (large):
enucleation alone vs. XRT followed by enucleation—no difference in outcome.
• COMS study (medium):
brachytherapy vs enucleation had similar mortality. Mets were found in approx. 10% of enucleated patients
• COMS study (small):
mortality 1% at 5 years with observation only.
• Choroideremia:
CHM gene, x-linked recessive. Starts mottled pigment then scalloped. Typically no change in vasculature or optic atrophy. Gene product is within the RPE not the choroid. Most have good vision until 30s-40s.
• FEVR
genetic, autosomal dominant with variable expressivity. Looks like ROP but not preterm babies.
• IP (incontinentia pigmenti):
otherwise known as bloch Sulzberger syndrome; x-linked dominant lethal in hemizygous form (lethal in males). Involves eyes, skin and brain. Skin findings include bullae on the extremities, hyperpigmented macules on the trunk. Brain abnormalities include microcephaly, seizures, intellectual disability. Eye findings are like ROP.
• Chance of progression to PDR:
with severe NPDR it is 15% chance in 1 year, for very severe NPDR it is 45% chance to progress
• Consideration for prophylactic barrier in people with lattice dystrophy:
usually lattice confers 1% risk of RD. It is found in 6-10% of eyes but in 20-30% of eyes with RDs. Consider laser if high myopia, history of RD in the fellow eye, presence of flap tears within the lattice, or aphakia (not pseudophakia).
• Gyrate atrophy
OAT gene. Restrict argenine, supplement with B6. Autosomal recessive. Associated with PSC cataracts, high myopia with high astigmatism, hyperornithemia (if normal ornithine levels reconsider diagnosis). VA usually normal until approx. 10 years old, but night blindness usually starts within the first decade of life.
• PHPV:
distinguish from RB by long ciliary processes. Also usually in microphthalmic eyes whereas RB is usually in normally sized eyes.
• Von Hippel Landau
chromosome 3. Retinal hemangioblastomas with CNS / systemic disease. Vision loss can occur from exudate our serous RD. primary cause of death is cerebellar hemangioblastomas and renal cell carcinoma. A thorough systemic workup is needed. You can also get other findings like pheochromocytomas, meningiomas, liver cysts, spinal cord tumors, etc.
