Cataract surgery outcome in eyes with keratoconus

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Diseases

Background:

• Cataract surgery in eyes with keratoconus presents unique challenges for refractive outcome prediction.
• Keratoconus, a progressive corneal ectasia, alters refractive properties, complicating standard surgical planning.

Purpose of the Study:

• To evaluate the refractive results of cataract surgery in patients diagnosed with keratoconus.
• To determine the optimal keratometry (K) measurement strategy for intraocular lens (IOL) power calculation in keratoconic eyes.

Main Methods:

• Retrospective review of 64 patients (92 eyes) undergoing cataract surgery with spherical IOL implantation.
• Analysis of refractive outcomes based on keratoconus severity (mild, moderate, severe) and K value usage (actual vs. standard).

Main Results:

• Mild/moderate keratoconus (K<55 D) using actual K values achieved mean biometry prediction errors (BPE) close to zero (-0.0 D to +0.3 D).
• Severe keratoconus (K>55 D) using actual K values resulted in a significant hyperopic shift (mean BPE +6.8 D).
• Severe keratoconus eyes using a standard K value (43.25 D) showed a smaller mean BPE (+0.6 D).

Conclusions:

• Actual K values are suitable for IOL selection in mild to moderate keratoconus (mean K ≤55 D) targeting low myopia.
• For severe keratoconus, using actual K values can lead to substantial hyperopic refractive errors; considering standard K values is advised.