Evaluating the Predictive Accuracy of the Kane and SRK/T Formulas in Keratoconus Patients Undergoing Cataract Surgery

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Akbaş Y. B., Davarcı H., KEPEZ YILDIZ B., Ceylan A., Aydın F. O., Yıldırım Y.

Turkish Journal of Ophthalmology, cilt.55, sa.5, ss.245-248, 2025 (Scopus, TRDizin)

Özet

Objectives: To compare the predictive performance of the SRK/T and Kane formulas in eyes with keratoconus undergoing cataract surgery. Materials and Methods: A consecutive series of keratoconic eyes that underwent cataract surgery were retrospectively analyzed. Intraocular lens power was calculated using the SRK/T and Kane Keratoconus formulas. Subjective refraction was evaluated 1 month postoperatively. The mean prediction error (MPE) and percentage of eyes with a prediction error within ±0.50 diopters (D) and ±1.00 D were calculated. Patients were divided into two categories: early-stage (stage 1) and advanced-stage (stage 2-3) keratoconus. Results: Thirty eyes of 25 patients were included in the study. A comparison of MPE between the two formulas in the stage 1 keratoconus group revealed no statistical difference. However, the MPE for the SRK/T formula was found to be significantly higher (p=0.005) in the stage 2-3 group. In the stage 1 group, 84.6% of eyes were within the PE range of ±1.00 D based on the Kane formula, while 76.9% of eyes fell within the ±1.00 D range according to the SRK/T formula. In stage 2-3 group, 41.2% of eyes were within the PE range of ±1.00 D based on the Kane formula, while 29.4% of eyes fell within the ±1.00 D range according to the SRK/T formula. Conclusion: A comparison of the two formulas showed no statistically significant differences in early-stage keratoconus. However, in advanced keratoconus cases, the Kane formula exhibited superior accuracy.