Unilateral keratoconus. Incidence and quantitative topographic analysis

Area of Science:

• Ophthalmology
• Corneal topography
• Keratoconus research

Background:

• Keratoconus is a progressive corneal ectasia.
• Unilateral presentation of keratoconus is uncommon.
• Understanding disease progression is crucial for patient management.

Purpose of the Study:

• To determine the incidence of unilateral keratoconus.
• To compare corneal topography metrics between unilateral and bilateral keratoconus.
• To inform clinical decision-making regarding refractive surgery.

Main Methods:

• Retrospective analysis of 164 patients with moderate-to-advanced keratoconus.
• Corneal topography evaluated in both eyes.
• Comparison of Keratoconus Prediction Index (KPI), Surface Asymmetry Index (SAI), and Surface Regularity Index (SRI).

Main Results:

• Only 1.83% of patients presented with unilateral keratoconus.
• No significant differences in KPI, SAI, or SRI between unilateral and bilateral cases.
• One patient initially diagnosed with unilateral keratoconus developed contralateral signs over 4 years.

Conclusions:

• The incidence of clinically diagnosed unilateral keratoconus is very low.
• Quantitative topographic descriptors are similar in unilateral and bilateral keratoconus.
• Contralateral eyes of unilateral keratoconus patients may develop the condition over time, cautioning against refractive surgery.