In vitro disease modeling of oculocutaneous albinism type 1 and 2 using human induced pluripotent stem cell-derived retinal pigment epithelium.

Oculocutaneous albinism (OCA) encompasses a set of autosomal recessive genetic conditions that affect pigmentation in the eye, skin, and hair. OCA patients display reduced best-corrected visual acuity, reduced to absent ocular pigmentation, abnormalities in fovea development, and/or abnormal decussation of optic nerve fibers. It has been hypothesized that improving eye pigmentation could prevent or rescue some of the vision defects. The goal of the present study was to develop an in vitro model for studying pigmentation defects in human retinal pigment epithelium (RPE). We developed a "disease in a dish" model for OCA1A and OCA2 types using induced pluripotent stem cells to generate RPE. The RPE is a monolayer of cells that are pigmented, polarized, and polygonal in shape, located between the neural retina and choroid, with an important role in vision. Here we show that RPE tissue derived in vitro from OCA patients recapitulates the pigmentation defects seen in albinism, while retaining the apical-basal polarity and normal polygonal morphology of the constituent RPE cells.

Phenotypic and Genetic Spectrum of Autosomal Recessive Bestrophinopathy and Best Vitelliform Macular Dystrophy.

Purpose: Autosomal recessive bestrophinopathy (ARB) and vitelliform macular dystrophy (VMD) are distinct phenotypes, typically inherited through recessive and dominant patterns, respectively. Recessively inherited VMD (arVMD) has been reported, suggesting that dominant and recessive BEST1-related retinopathies represent a single disease spectrum. This study compares adVMD, arVMD, and ARB to determine whether a continuum exists and to define clinical and genetic features to aid diagnosis and management. Methods: One arVMD patient and nine ARB patients underwent standard ophthalmic examination, imaging, electrophysiology, and genetic assessments. A meta-analysis of reported BEST1 variants was compiled, and clinical parameters were analyzed with regard to inheritance and phenotype. Results: Among 10 patients with biallelic BEST1 variants, three novel ARB variants (p.Asp118Ala, p.Leu224Gln, p.Val273del) were discovered. A patient with homozygous p.Glu35Lys was clinically unique, presenting with VMD, including hyperautofluorescence extending beyond the macula, peripheral punctate lesions, and shortened axial-length. A tritan-axis color vision deficit was seen in three of six (50%) of ARB patients. Attempts to distinguish recessively-inherited ARB and dominantly-inherited VMD genotypically, by variant frequency and residue location, did not yield significant differences. Literature meta-analysis with principle component analysis of clinical features demonstrated a spectrum of disease with arVMD falling between adVMD and ARB. Conclusions: This study suggests that arVMD is part of a continuum of autosomal recessive and dominant BEST1-related retinopathies. Detailed clinical and molecular assessments of this cohort and the literature are corroborated by unsupervised analysis, highlighting the overlapping heterogeneity among BEST1-associated clinical diagnoses. Tritan-axis color vision deficit is a previously unreported finding associated with ARB.

Wood-Related Open-Globe Injuries.

Purpose: This work evaluates the clinical characteristics, visual outcomes, and complications of patients treated for open-globe injuries (OGIs) caused by wooden objects. Methods: A retrospective review of medical records was conducted on patients presenting to a tertiary trauma center with an OGI between January 2005 and December 2017. Medical records were isolated for wounds caused by wooden objects. Patient demographics were recorded, with presenting visual acuity (VA), physical examination findings, and wound characteristics. After primary globe repair, secondary complications, need for additional surgery, and visual outcomes were noted until final examination. Main outcome measures were final VA and secondary complications. The Ocular Trauma Score (OTS) was computed and assessed for clinical relevance related to visual outcomes. Results: Thirty-two patients met the inclusion criteria, with 15 (47%) being injured by plant material. Thirty of the patients were men (94%). A large portion of patients presented with hand motion or worse vision (48%), and there were high rates of hyphema (59%), vitreous hemorrhage (31%), retinal detachment (28%), and endophthalmitis (9%). Two patients eventually required enucleation. At last follow-up, 19 patients achieved 20/100 VA or better (59.4%), which correlated with their OTS (P < .001). Conclusions: Despite the high clinical severity of wood OGIs, the potential for visual recovery remains high. The OTS appropriately assesses the severity of injuries and the likely prognosis in this cohort of patients.