Cataract and glaucoma surgery in microphthalmic, nanophthalmic, and high hyperopic eyes: a systematic review and...

This systematic review and meta-analysis evaluates refractive error (RE), visual acuity (VA), intraocular pressure (IOP), and anterior chamber depth (ACD) outcomes following surgical procedures in adults (≥ 18 years) with nanophthalmos, microphthalmos, and high hyperopia.

Nanophthalmos, microphthalmos, and high hyperopia are a spectrum of anatomic variants characterized by short axial length and crowded anterior segment. These features create significant risks for angle-closure glaucoma and complex cataract surgery. As existing literature is fragmented and limited to small case series, this study provides a comprehensive evaluation of surgical safety and efficacy in these high-risk populations.

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a search was conducted across five databases (Cochrane, PubMed, Scopus, Ovid MEDLINE, and Embase via Ovid) for studies published between January 2010 and December 2024. Eligible studies reported original clinical data on surgical interventions for adult (≥ 18 years) patients with nanophthalmos, microphthalmos, or high hyperopia with concomitant cataract or glaucoma. Meta-analysis, subgroup analysis, and meta-regression were performed to assess changes in RE, VA, IOP, and ACD.

Meta-analysis of 21 articles involving 957 patients (1,110 eyes) suggests that surgical intervention is associated with improvement in clinical parameters across a spectrum of short eyes. Standalone phacoemulsification significantly reduced RE in nanophthalmic eyes (mean difference (MD) = -13.20 diopters (D); 95% confidence interval (CI): -15.19, -11.22; Q = 3.51, p = 0.48, I² = 0.0%) at medium-term follow-up and in high hyperopic eyes (MD = -9.23 D; 95% CI: -15.02, -3.45; Q = 322.19, p < 0.001, I² = 97.8%) at medium-term follow-up with high heterogeneity in the effects. Standalone phacoemulsification significantly improved VA in nanophthalmic eyes at both short-term (MD = -0.66 logarithm of the minimum angle of resolution (logMAR); 95% CI: -1.30, -0.02; Q = 98.45, p < 0.001, I² = 97.0%) and medium-term (MD = -0.70 logMAR; 95% CI: -1.30, -0.09; Q = 97.14, p < 0.001, I² = 93.8%) follow-up with high heterogeneity in the effects. In contrast, phacoemulsification + filtering surgery resulted in a significant worsening in VA at short-term follow-up for nanophthalmic eyes (MD = 0.28 logMAR; 95% CI: 0.21, 0.35; Q = 1.24, p = 0.27, I² = 19.4%). Significant IOP reduction was achieved primarily through combined procedures in both nanophthalmic and microphthalmic eyes. Presence of concomitant glaucoma was associated with a greater reduction in IOP across all axial lengths. Significant ACD deepening was achieved across all axial lengths (MD = 1.30 millimeters (mm), 95% CI: 0.86, 1.74; Q = 244.55, p < 0.001, I² = 99.3%) with high heterogeneity in the effects. Meta-regression identified a significant study-level association between mean age and post-operative RE (multiple adjusted coefficient: 10.72, p = 0.001). No effect of race was detectable in this study-level meta-regression, although power was limited.

Surgical interventions in adults with nanophthalmos, microphthalmos, and high hyperopia were associated with meaningful improvements in RE, VA, IOP, and ACD, although outcomes varied by underlying diagnosis and procedure type. Standalone phacoemulsification consistently improved refractive and anatomical outcomes, particularly in nanophthalmos and high hyperopia, while combined procedures incorporating vitrectomy or filtering surgery achieved greater IOP reduction in eyes with concomitant glaucoma. Subgroup analyses suggested that shorter axial length and the presence of glaucoma influenced treatment response. However, substantial heterogeneity across studies and frequent post-operative complications highlight the need for standardized surgical protocols and higher-quality prospective studies to better define optimal management strategies for these anatomically complex eyes.

https://www.crd.york.ac.uk/PROSPERO/view/CRD420251033701, identifier CRD420251033701.