{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,26]],"date-time":"2026-06-26T23:33:15Z","timestamp":1782516795719,"version":"3.54.5"},"reference-count":49,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,6,26]],"date-time":"2025-06-26T00:00:00Z","timestamp":1750896000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>Background\/Objectives: Inherited retinal diseases (IRDs) are a heterogeneous group of rare eye disorders characterized by progressive photoreceptor degeneration, leading to severe visual impairment or even blindness. This study aims to investigate the prevalence, types, and clinical significance of ophthalmic comorbidities in Portuguese patients with IRDs. Methods: This nationwide Portuguese population-based retrospective study was based on the IRD-PT registry (retina.com.pt). Statistical analysis was conducted using Microsoft\u00ae Excel\u00ae for Microsoft 365 and IBM SPSS Statistics version 29.0.2.0. Informed consent was obtained from all participants. Results: A total of 1531 patients (1254 families) from six centers were enrolled. The cohort consisted of 51% males, with a mean age of 45.8 \u00b1 19.3 years and a mean age at diagnosis of 39.4 \u00b1 19.5 years. Overall, ocular comorbidities were reported in 644 patients (42.1%). In 176 individuals (11.5%), multiple concurrent comorbidities were found. Cataract was the most common comorbidity (21.3%), followed by amblyopia (6.3%) and high myopia (5.9%). Statistically significant associations with ocular comorbidities were observed in isolated progressive IRDs. Specifically, AR RP was associated with cataract (p &lt; 0.001), and gene analysis revealed several significant associations. CRB1 was statistically linked to epiretinal membrane (ERM) (p = 0.003), EYS with cataract (p = 0.001), PROM1 with choroidal neovascularization (CNV) (p = 0.0026), and USH2A with macular hole (p = 0.01). Patients with the RPE65 mutation in Leber congenital amaurosis were associated with ERM (p = 0.019). There was also a significant association between X-linked RP and high myopia (p &lt; 0.001) and CNV in Best disease (p &lt; 0.001); in syndromic IRDs, cataract, cystoid macular edema, and ERM were observed in Usher syndrome, p = 0.002, p = 0.002, and p = 0.005, respectively, and the MYO7A gene was linked to cataract (p = 0.041) and strabismus (p = 0.013); pseudoxanthoma elasticum was significantly associated with CNV (p = 0.002); and foveal hypoplasia was associated with anterior segment dysgenesis (p &lt; 0.001). Conclusions: This study enhances the current understanding of ocular comorbidities in IRDs in Portuguese patients. Common findings were cataract, refractive error, and CME. Stationary IRDs and pattern dystrophies showed fewer concomitant comorbidities, supporting their classification as non-progressive or benign conditions. The significance of registries like IRD-PT cannot be overstated, particularly in the context of rare diseases. These databases serve multiple crucial functions in enabling detailed documentation of disease characteristics and long-term monitoring of disease progression.<\/jats:p>","DOI":"10.3390\/genes16070743","type":"journal-article","created":{"date-parts":[[2025,6,27]],"date-time":"2025-06-27T05:29:58Z","timestamp":1751002198000},"page":"743","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Exploring Concomitant Ophthalmic Comorbidities in Portuguese Patients with Inherited Retinal Diseases: A Comprehensive Clinical Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-1454-2219","authenticated-orcid":false,"given":"Rita","family":"Mesquita","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3495-4649","authenticated-orcid":false,"given":"Ana","family":"Marta","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Unidade Local de Sa\u00fade de Santo Ant\u00f3nio, EPE (ULSSA), 4099-001 Porto, Portugal"},{"name":"Instituto Ci\u00eancias Biom\u00e9dicas Abel Salazar (ICBAS), 4050-313 Porto, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-6964-646X","authenticated-orcid":false,"given":"Pedro","family":"Marques-Couto","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Unidade Local de Sa\u00fade de S\u00e3o Jo\u00e3o, EPE (ULSSJ), 4200-319 Porto, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9","family":"Costa","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Unidade Local de Sa\u00fade de Braga (ULSB), 4710-243 Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7415-813X","authenticated-orcid":false,"given":"S\u00e9rgio","family":"Estrela-Silva","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Unidade Local de Sa\u00fade de S\u00e3o Jo\u00e3o, EPE (ULSSJ), 4200-319 Porto, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diogo","family":"Cabral","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Unidade Local de Sa\u00fade de Almada-Seixal, EPE (ULSAS), 2850-267 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1014-0483","authenticated-orcid":false,"given":"Jo\u00e3o Pedro","family":"Marques","sequence":"additional","affiliation":[{"name":"Clinical Academic Centre of Coimbra (CACC), 3000-370 Coimbra, Portugal"},{"name":"Department of Ophthalmology, Hospitais da Universidade de Coimbra, Unidade Local de Sa\u00fade de Coimbra, EPE (ULSC), 3004-561 Coimbra, Portugal"},{"name":"University Clinic of Ophthalmology, Faculty of Medicine, University of Coimbra (FMUC), 3000-370 Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6125-5486","authenticated-orcid":false,"given":"Sara","family":"Vaz-Pereira","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal"},{"name":"Department of Ophthalmology, Unidade Local de Sa\u00fade de Santa Maria (ULSSM), 1649-028 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,26]]},"reference":[{"key":"ref_1","unstructured":"Bowling, B. 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