AUTHOR=Kiraly Peter , Seitz Immanuel P. , Abdalla Elsayed Maram E. A. , Downes Susan M. , Patel Chetan K. , Charbel Issa Peter , Birtel Johannes , Mautone Luca , Dulz Simon , Atiskova Yevgeniya , Herrmann Philipp , Vrabič Nika , Jarc-Vidmar Martina , Hawlina Marko , Fischer M. Dominik 

TITLE=Morphological and functional parameters in X-linked retinoschisis patients–A multicentre retrospective cohort study

JOURNAL=Frontiers in Medicine

VOLUME=10

YEAR=2024

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1331889

DOI=10.3389/fmed.2023.1331889

ISSN=2296-858X

ABSTRACT=<sec><title>Introduction</title><p>X-linked retinoschisis (XLRS) is a potential target for gene supplementation approaches. To establish potential structural and functional endpoints for clinical trials, a comprehensive understanding of the inter-eye symmetry, relationship between structural and functional parameters, and disease progression is vital.</p></sec><sec><title>Methods</title><p>In this retrospective multicentre study, 118 eyes of 59 XLRS patients with <italic>RS1</italic> mutations were assessed. Information from center databases included: <italic>RS1</italic> variant; age at presentation; best-corrected visual acuity (BCVA), central retinal thickness (CRT), macular volume (MV) at presentation and at the last follow up; full-field electroretinogram (ERG) findings; presence of peripheral retinoschisis and complications (vitreous hemorrhage, retinal detachment); treatment with systemic or topical carbonic anhydrase inhibitors (CAI).</p></sec><sec><title>Results</title><p>Inter-eye symmetry revealed strong correlation in CRT (<italic>r</italic> = 0.77; <italic>p</italic> &lt; 0.0001) and moderate correlations in MV (<italic>r</italic> = 0.51, <italic>p</italic> &lt; 0.0001) and BCVA (<italic>r</italic> = 0.49; <italic>p</italic> &lt; 0.0001). Weak or no correlations were observed between BCVA and structural parameters (CRT, MV). Peripheral retinoschisis was observed in 40 (68%), retinal detachment in 9 (15%), and vitreous hemorrhage in 5 (8%) patients, respectively. Longitudinal examinations (mean, 4.3 years) showed no BCVA changes; however, a reduction of the CRT (<italic>p</italic> = 0.02), and MV (<italic>p</italic> = 0.01) was observed. Oral and/or topical CAI treatment did not significantly alter the CRT (<italic>p</italic> = 0.34).</p></sec><sec><title>Discussion</title><p>The XLRS phenotype demonstrates a strong CRT symmetry between the eyes within individual patients and stable BCVA over several years. BCVA exhibits a weak correlation with the morphological parameters of retinal thickness (CRT MV). In our cohort, longitudinal functional changes were not significant, likely attributed to the short average follow-up period. Furthermore, CAI treatment didn’t influence both morphological and functional outcomes.</p></sec>