Methods for assessing forward and backward light scatter in patients with cataract
Alja Crnej1, Nino Hirnschall1, Con Petsoglou1
1From Moorfields Eye Hospital (Crnej, Hirnschall, Petsoglou, Findl), London, United Kingdom; Massachusetts Eye and Ear Infirmary (Crnej), Harvard University, Boston, Massachusetts, USA; Vienna Institute of Research in Ocular Surgery (Hirnschall, Findl), Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria; Sydney Eye Hospital (Petsoglou), Sydney, Australia.
Journal of Cataract and Refractive Surgery
|September 18, 2017
Summary
Objective light scatter measurements for cataract assessment are not interchangeable. Forward light scatter, measured with a straylight meter, may aid preoperative decisions by providing vision quality data independent of acuity.
Area of Science:
- Ophthalmology
- Optical Engineering
- Vision Science
Background:
- Cataract surgery is a common procedure to restore vision.
- Assessing the impact of different cataract types on vision quality is crucial.
- Objective scatter measurements offer potential alternatives to traditional visual acuity tests.
Purpose of the Study:
- To compare objective methods for assessing backward and forward light scatter.
- To correlate light scatter measurements with psychophysical tests in cataract patients.
- To evaluate the utility of these methods in preoperative decision-making.
Main Methods:
- Prospective case series involving 56 patients undergoing cataract surgery.
- Backward light scatter measured with Scheimpflug imaging (Pentacam HR).
- Forward light scatter measured with a straylight meter (C-Quant) and double-pass method (PSF meter).
- Correlations with visual acuity and contrast sensitivity (photopic and mesopic).
Main Results:
- Low correlations were found between different light scatter measurement devices.
- The highest correlation was between straylight meter and Scheimpflug measurements (r=0.32).
- The point-spread function (PSF) meter showed the best correlation with corrected distance visual acuity (r=0.45).
Conclusions:
- Forward and backward light scatter measurements are not interchangeable.
- Scatter, as a measure of vision quality, is independent of visual acuity.
- Forward light scatter measurement using a straylight meter can be a valuable tool for preoperative assessment.
