Arch Ophthalmol. 2009 Oct;127(10):1290-5.
van der Meulen IJ, Engelbrecht LA, Van Riet TC, Lapid-Gortzak R, Nieuwendaal CP, Mourits MP, van den Berg TJ.
Department of Ophthalmology, Academic Medical Center, A2 Room 123.1, Meibergdreef 9, 1100 DD Amsterdam, the Netherlands. This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract
OBJECTIVES: To quantify the effect of the capsulorrhexis on straylight and to determine optimal capsulorrhexis size.
METHODS: Fifty-six pseudophakic eyes with intact capsulorrhexis were included in the study. Straylight was measured with a straylight meter before and after pupil dilation. Capsulorrhexis and pupil diameter were measured and opacity of the anterior capsule was graded (on a scale of 0-5) with the slitlamp. Capsulorrhexis size and opacity were compared with the difference in straylight values between natural and dilated pupils.
RESULTS: The mean capsulorrhexis diameter was 4.5 mm (range, 2.9-6.2 mm). Most anterior capsular rims were opaque in the area of contact with the intraocular lens (62.5% higher than grade 1). Mean straylight before pupil dilation was log(s)=1.25 (range, 0.68-2.13), which increased to 1.46 (range, 0.88-2.22) after pupil dilation, which corresponds to a 62% increase (P <.001). The effect of capsulorrhexis size and opacity on the increase in straylight in scotopic conditions can be quantified by the following formula: Deltas = 19 x (grading of anterior capsular rim) x (fraction of pupil area covered by rhexis).
CONCLUSIONS: The influence of size and opacity of the capsulorrhexis via straylight is described in a quantitative model. Capsulorrhexis size must be greater than 4 mm to prevent functional problems at night.
PMID: 19822845 [PubMed - indexed for MEDLINE]