Straylight before and after LASEK in Myopia: Changes in Retinal Straylight

Abstract

PURPOSE.To quantify the changes in retinal straylight that occur after laser-assisted subepithelial keratectomy (LASEK). METHODS. This prospective study included 86 eyes of 49 patients who were scheduled for LASEK surgery. Patients were divided into groups based on their preoperative contact lens wear habits: rigid lenses (RCL), soft lenses (SCL), spectacles after a period of contact lenses (SaC), and spectacles only (Specs). Retinal straylight was tested before surgery and 6 months after surgery with the compensation comparison method. Straylight was also compared to a normal reference database. The difference with the average straylight increase with age, called base-and age-corrected (BAC) straylight, was also studied. RESULTS. Before surgery, BAC straylight was found to be strongly elevated, with a value of 0.15 Ϯ 0.14 log units. After LASEK, this decreased to 0.00 Ϯ 0.14 log units. The reduction was significant (paired t-test, P Ͻ Ͻ 0.01) and correlated with preoperative BAC straylight levels (r 2 ϭ 0.332; P Ͻ Ͻ 0.01). There was no correlation between the straylight change and the spherical equivalent of the laser refractive correction (r 2 ϭ 0.042; P ϭ 0.059). Preoperative wear of soft contact lenses increased the BAC straylight by approximately 0.06 log units, with respect to the spectacles groups (P Ͻ 0.05, unpaired t-test), but after surgery, this difference was no longer found (P Ͼ 0.05). CONCLUSIONS. Higher than normal preoperative BAC straylight was found to normalize after LASEK refractive surgery. Wearing soft contact lenses causes an additional increase in preoperative BAC straylight that is eliminated after LASEK. (Invest Ophthalmol Vis Sci.

Backscattered light from the cornea before and after laser-assisted subepithelial keratectomy for myopia

“…13 In forward light scatter, approximately 25% to 30% of the scatter is caused by the cornea 14,15 ; most of the rest originates in the crystalline lens. This corneal straylight can be influenced by contact lens wear 16,17 and conditions such as corneal edema 18 and Fuchs corneal dystrophy. Contrary to what one would expect, we found in a previous study 16 that straylight decreases significantly after photorefractive surgery; this was confirmed independently by Lapid-Gortzak et al 19 The cause of the decrease in straylight is not known at present.…”

“…This corneal straylight can be influenced by contact lens wear 16,17 and conditions such as corneal edema 18 and Fuchs corneal dystrophy. Contrary to what one would expect, we found in a previous study 16 that straylight decreases significantly after photorefractive surgery; this was confirmed independently by Lapid-Gortzak et al 19 The cause of the decrease in straylight is not known at present. This paper describes how a commercial Scheimpflug camera can be used to determine an average backscatter profile of the cornea that is comparable to the profile recently published by Patel et al 7 The study assessed the changes in the backscatter profile after laser-assisted subepithelial keratectomy (LASEK).…”

“…The straylight and ocular biometry data in a subset of these patients were included in an earlier study. 16 The study adhered to the tenets of the Declaration of Helsinki and received ethical committee approval (reference 7/6/24).…”

Measurement of straylight for glare assessment and driving.

“…It found that 33 out of 373 subjects who had had laser refractive surgery scored above this limit. Studies in refractive surgery centres showed somewhat better results (Beerthuizen, Franssen, L., & van den Berg, 2007;Lapid-Gortzak, van der Linden, van der Meulen, Nieuwendaal, & van den Berg, 2010;Rozema et al, 2010;Vignal, Tanzer, Brunstetter, & Schallhorn, 2008). Advancing techniques will, in time, yield more reliable results.…”

Retinal Straylight before and after Implantation of the Bag in the Lens IOL

“…Straylight is often more pronounced in individuals with a light iris color or low skin pigmentation. 2,4 It is known to increase in myopic eyes 5 and to decrease after refractive correction by either laser surgery [6][7][8] or using phakic intraocular lenses. 9 The origin of this effect is not yet understood.…”