Phenotypic characterization of X-linked retinoschisis: Clinical, electroretinography, and optical coherence tomography variables.
OBJECTIVE
To study the phenotypic characteristics of X-linked retinoschisis (XLRS) and report the clinical, electroretinogram (ERG), and optical coherence tomography (OCT) variables in Indian eyes.


METHODS
A retrospective study.


METHODS
Medical records of 21 patients with retinoschisis who were genetically confirmed to have RS1 mutation were reviewed. The phenotype characterization included the age of onset, best-corrected visual acuity, refractive error, fundus findings, OCT, and ERG.


METHODS
Data from both the eyes were used for analysis. A P < 0.05 was set as statistical significance. Data were not normally distributed (P < 0.05, Shapiro wilk); hence, nonparametric tests were used for statistical analysis.


RESULTS
All were males whose mean age of presentation was 9 years. Visual acuity was moderately impaired (median 0.6 logMAR, interquartile range: 0.47, 1) in these eyes with a hyperopic refractive error of median +1.75 Ds (interquartile range: +0.50 Ds, +4.25 Ds). About 54.7% of the eyes had both foveal and peripheral schisis, isolated foveal schisis was seen in 28.5% of the eyes, and schisis with retinal detachment was seen in 16.6% of the eyes. The inner nuclear layer was found to be commonly involved in the schisis, followed by outer nuclear and plexiform layers as evident on OCT. On ERG, a- and b-wave amplitudes were significantly reduced in eyes with foveal and peripheral schisis when compared to the eyes with only foveal schisis (P < 0.05).


CONCLUSIONS
XLRS has phenotypic heterogeneity as evident on OCT, ERG, and clinical findings.
Department of Optometry, Elite School of Optometry, Chennai and Birla Institute of Technology and Science, Pilani, Rajasthan, India.
Srividya
S
Neriyanuri
Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
Sudha
S
Dhandayuthapani
Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
Jayamuruga Pandian
JP
Arunachalam
Department of Vitreo-retina, Shri Bhagwan Mahaveer Vitreoretinal Services, Sankara Nethralaya, Chennai, Tamil Nadu, India.
Rajiv
R
Raman
D000293:Adolescent; D002648:Child; D004252:DNA Mutational Analysis; D004596:Electroretinography / Q000379:methods*; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D012160:Retina / Q000473:pathology*; D041441:Retinoschisis / Q000175:diagnosis / Q000235:genetics*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D055815:Young Adult
D005136:Eye Proteins