Optical Coherence Tomography in Knobloch Syndrome.

BACKGROUND AND OBJECTIVE: Knobloch syndrome is a genetic disorder defined by occipital defect, high myopia, and vitreoretinal degeneration. The authors studied retinal changes in patients with Knobloch syndrome using optical coherence tomography (OCT). PATIENTS AND METHODS: The authors report patients with Knobloch syndrome who received OCT testing during their care from 2011 to 2016. Diagnosis was based on high myopia, characteristic fundus, and occipital scalp or skull abnormalities with/without featureless irides and/or ectopia lentis. When available, diagnosis was confirmed by the detection of COL18A1 mutations. RESULTS: The authors studied eight eyes from five patients. Two eyes were excluded due to chronic retinal detachment. OCT findings included epiretinal membrane, peripapillary vitreoretinal traction with retinoschisis, absent or rudimentary foveal pits, mean macular thickness of 113.4 µm, poor lamination, retinal pigment epithelium (RPE) atrophy, photoreceptor depletion, and mean choroidal thickness of 168.5 µm with enlarged choroidal vessels. CONCLUSION: OCT findings in Knobloch syndrome include abnormal vitreoretinal traction, poor foveal differentiation, poor retinal lamination, retinal thinning, RPE attenuation, myopic choroidal thinning, and pachychoroid. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e203-e210.].

Ophthalmic manifestations of Heimler syndrome due to PEX6 mutations.

BACKGROUND/AIMS: Pigmentary retinal dystrophy and macular dystrophy have been previously reported in Heimler syndrome due to mutations in PEX1. Here we reported the ocular manifestations in Heimler syndrome due to mutations in PEX6. MATERIALS AND METHODS: Medical records were reviewed to identify patient demographics, ophthalmic and systemic findings, and results of diagnostic testing including whole genome sequencing. RESULTS: Patient 1 is 12-year-old boy with a novel mutation c.275T>G (p.Val92Gly) and known mutation c.1802G>A (p.Arg601Gln) in PEX6. Patient 2 is a 7-year-old girl with the same known c.1802G>A (p.Arg601Gln) mutation and another novel missense mutation c.296G>T (p.Arg99Leu). Both patients exhibited a pigmentary retinopathy. Visual acuity in patient 1 was 20/80 and 20/25 following treatment of intraretinal cystoid spaces with carbonic anhydrase inhibitors, while patient 2 had visual acuity of 20/20 in both eyes without intraretinal cysts. Fundus autofluorescence showed a multitude of hyperfluorescent deposits in the paramacular area of both eyes. OCTs revealed significant depletion of photoreceptors in both patients and macular intraretinal cystoid spaces in one patient. Full field electroretinograms showed normal or abnormal photopic but normal scotopic responses. Multifocal electroretinograms were abnormal. CONCLUSIONS: Heimler syndrome due to biallelic PEX6 mutations demonstrates a macular dystrophy with characteristic fundus autofluorescence and may be complicated by intraretinal cystoid spaces.