Forward-scattered and backward-scattered light in moderate keratoconus.
Celia Villanueva1,2, Francesco Viviano1, María García-Montero1
1Optometry and Vision Department, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain.
Summary
Objective scatter index (OSI) and retinal straylight are significantly different in moderate keratoconus (KC) patients compared to healthy individuals. These findings suggest KC alters light scattering in the eye.
Area of Science:
- Ophthalmology
- Optical Physics
Background:
- Keratoconus (KC) is a progressive eye condition affecting corneal shape.
- Assessing light scattering is crucial for understanding visual impairment in KC.
Purpose of the Study:
- To evaluate backscattered light, objective scatter index (OSI), and retinal straylight in moderate KC patients versus healthy controls.
Main Methods:
- Prospective observational study with 33 KC and 34 non-KC subjects.
- Corneal densitometry via Scheimpflug tomography.
- Intraocular straylight measured using a straylight meter and the Optical Quality Analysis System (OQAS).
Main Results:
- Significant differences in corneal densitometry (except 6-10mm zone), OSI, and retinal straylight between KC and non-KC groups.
- Moderate correlation found between OSI and retinal straylight (LOG(s)).
- Weak, non-significant correlations between corneal densitometry and other parameters.
Conclusions:
- Backscattered light, retinal straylight, and OSI clearly differ between healthy and moderate KC eyes.
- KC stages II and III likely alter light scattering within the eye.
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