Keratoconus and Corneal Ectasia with Relatively Low Keratometry

Area of Science:

• Ophthalmology
• Corneal Science
• Biomechanical Analysis

Background:

• Keratoconus (KC) is a progressive thinning of the cornea.
• Understanding KC prevalence in patients with low keratometry is crucial for diagnosis and management.
• This study investigates clinical corneal ectasia and keratoconus in patients with relatively low keratometry (low-K KC).

Purpose of the Study:

• To demonstrate and estimate the prevalence of clinical corneal ectasia and keratoconus (KC) in patients with low keratometry.
• To analyze the characteristics of low-K KC compared to high-K KC.

Main Methods:

• Retrospective, analytical study of 1054 patients.
• Patients stratified into normal, low-K KC (Kmax < 47.6 D), and high-K KC (Kmax > 47.6 D) groups.
• Comprehensive ophthalmological evaluation with Pentacam and Corvis ST (Oculus, Wetzlar, Germany) examinations.

Main Results:

• 28.30% (90/318) of KC patients presented with low-keratometric values (low-Kmax).
• Mean age in low-Kmax KC group was 37.49 years.
• Corneal tomographic and biomechanical parameters (BAD-D, PRFI, CBI, TBI, SP-A1) were evaluated for the low-Kmax KC group.

Conclusions:

• Low keratometry (Kmax < 47.6 D) occurs in up to 28.30% of clinical keratoconus cases.
• These low-K KC cases exhibit a less severe disease presentation.
• Further large-scale, prospective studies are needed to confirm prevalence and define prognostic factors.