Outcomes of Scleral Lens in Different Stages and Cone Locations of Keratoconus

Background : To evaluate the visual performance of scleral contact lenses (SCLs) in patients with keratoconus based on disease stage and cone localization, and to provide data to inform clinical practice. Methods: This retrospective study included 95 eyes from 61 keratoconus patients (34 females and 27 males) who underwent corneal cross-linking and were regularly followed at a single center between December 2019 and December 2023. Patients were categorized according to keratoconus stage (mild, moderate, or advanced) and cone localization (central, paracentral, or inferior) based on corneal topography. Visual acuity was recorded before and after mini SCL fitting, as were corneal topography and anterior segment parameters. Statistical analyses included the Wilcoxon signed-rank test, Mann-Whitney U test, and Kruskal-Wallis test for group comparisons, with Spearman correlation analysis used to assess associations between parameters. Results: The mean patient age was 23.64 ± 7.52 years. Among the eyes evaluated, 44% had mild, 36% moderate, and 20% advanced keratoconus; cone localization was inferior in 56%, central in 34%, and paracentral in 10%. Mean logMAR visual acuity improved significantly from 0.95 ± 0.54 before SCL fitting to 0.14 ± 0.13 after application (p < 0.001), corresponding to a mean Snellen line gain of 0.59 ± 0.20. Visual improvement was significantly greater in eyes with moderate-stage keratoconus and paracentral cone localization compared with other groups (p < 0.05). In advanced keratoconus, the gain in corrected distance visual acuity (CDVA) was negatively correlated with keratometry values and anterior chamber depth. Conclusion: SCLs significantly enhance visual acuity in keratoconus patients, with the most substantial benefit observed in those with moderate-stage disease and paracentral cone localization. These findings highlight the importance of considering both disease stage and cone location when planning SCL fitting, and suggest that paracentral cones may be predictive of superior visual outcomes with mini SCLs.