Clinical characteristics of patients with nanophthalmos in Gloucestershire

Introduction: A nanophthalmic eye is defined an eye with a short axial length (AL), in this study we defined this as less than or equal to 20 mm. Traditionally these eyes are thought to have a high rate of ocular comorbidity and associated low visual acuity. However, due to nanophthalmos being a rare condition, with an estimated prevalence of around 0.27% in the UK population, there is a relative paucity of literature describing its clinical characteristics. Therefore, we carried out a retrospective review of all patients with nanophthalmos who had undergone cataract surgery at Gloucestershire Hospitals NHS Foundation Trust (GHNHSFT) aiming to describe the demographic, visual and clinical features of these patients. Method(s): Cases were found using the medisoft audit tool for cataract surgery outcomes for all cataract surgeries performed at GHNHSFT between 1 Jan 2006 and 31 Dec 2023. Data was collected from electronic patient record (MedisoftR) and paper notes. Patients under 17 years of age and those with inaccurate biometry were excluded. Collected data included age, gender, ethnicity, age at cataract surgery, ocular biometry, refraction, intraocular pressure, number of intraocular pressure lowering medications, details of procedures undertaken to lower intraocular pressure, ocular comorbidities and family history of ocular comorbidities. Result(s): Between 1 Jan 2006 and 31 Dec 2023, 62364 cataract operations on 41366 patients above the age of 17 were performed at GHNHSFT. 86 nanophthalmic eyes underwent cataract surgery over this 18 year catchment period. On average, every year our unit completed 5 cases of cataract surgery on nanophthalmic eyes. There was one case of nanophthalmic eye in every 725 cases of cataract surgery. Of the 59 patients included in the study, 14 were male and 45 were female. Around 90% of the patients (53 out of 59) were ethnically white British. The mean age at the time of cataract operation in this cohort was 66.5 years (range: 17 to 86 years). The mean AL was 19.24 mm (range: 14.9 to 20.0 mm); 71 eyes had an AL between 19.00 and 20.00 mm, and 15 eyes had an AL less than 19.00 mm. The mean anterior chamber depth was 2.4 mm (range: 1.87 to 4.05 mm). Preoperatively, the best-corrected visual acuity (BCVA) was 0.50; 16 eyes had vision worse than 1.0 logMAR and 5 eyes had vision worse than counting fingers. The mean spherical equivalent was 7.75 (range: -1D to 17.25D). The mean intraocular pressure (IOP) was 15.2 mmHg, and 17 eyes required IOP lowering medication. 9 eyes were diagnosed with angle closure glaucoma. Amblyopia was present in 7% of eyes (n =6). Family history of glaucoma was reported in one patient, while another had a family history of nanophthalmos. Approximately 25% of eyes (n =22) required laser iridotomy. None of the eyes in this cohort required trabeculectomy for IOP control, although three eyes underwent cyclodiode treatment for pressure management. Conclusion(s): At Gloucestershire Hospitals NHS Foundation Trust, for every 725 cataract surgeries, there was one case of nanophthalmos. In our study 25% of nanophthalmic eyes required laser iridotomy, 20% of required IOP medication, 10% had angle closure glaucoma and 7% had amblyopia. Traditionally it is taught that nanophthalmic eyes have high rates of ocular comorbidities and lower visual acuity, our study is consistent with this.

Citation

Common et al (2025). Clinical characteristics of patients with nanophthalmos in Gloucestershire. Eye 39 (Suppl 2), 191–318 (2025). https://doi.org/10.1038/s41433-025-03831-0

DOI

10.1038/s41433-025-03831-0

URI

https://hdl.handle.net/20.500.14709/1292