Efficacy of Corneo-Scleral Lenses in Keratoconus Across Severity Grades: A Retrospective Cohort from South India

Abstract Aims: To evaluate the improvement in visual acuity provided by corneo-scleral contact lenses (CSLs) in patients with keratoconus as compared to spectacle correction, and to assess the effectiveness of CSLs across varying severities of keratoconus based on the Amsler-Krumeich classification. Methods: This retrospective study included 19 eyes diagnosed with keratoconus that were fitted with corneo-scleral contact lenses (CSLs). Spectacle-corrected and CSL-corrected visual acuities were recorded and compared after converting to log MAR values. Contact lens fitting was performed using the trial lens method, based on sagittal height and fluorescein staining patterns to ensure optimal fit. The effectiveness of CSLs was further evaluated in relation to the severity of keratoconus, classified according to the Amsler-Krumeich staging system. Results: A total of 19 eyes from patients with keratoconus were included in the study, of which 14 eyes (73.7%) had undergone prior corneal collagen cross-linking (CXL). The cohort consisted of 16 males and 3 females, with a mean age of 19.74 years. The mean spectacle-corrected visual acuity was 0.68 ± 0.40 log MAR, while the mean CSL-corrected visual acuity significantly improved to 0.06 ± 0.09 log MAR (p < 0.001). Conclusion: Corneo-scleral contact lenses (CSLs) demonstrated significant improvement in visual acuity compared to spectacle correction in patients with keratoconus. Given their non-invasive nature, excellent visual outcomes, and suitability even in advanced stages of the disease, CSLs represent an effective alternative to surgical interventions. Their use may reduce the need for corneal transplantation in select patients while maintaining high visual quality and patient comfort.