RESUMO
Purpose: Glare is a known side effect of intraocular lens (IOL) implantation, affected principally by IOL material and optics, although it is reported subjectively to decrease in impact with time. However, little objective data have been published on changes over time, how these relate to subjective reports, and whether those who will report greater glare symptoms can be predicted prior to IOL implantation. Methods: A total of 32 patients (aged 72.4 ± 8.0 years) with healthy eyes were implanted bilaterally with hydrophilic 600s (Rayner, Worthing, UK) or hydrophobic Acrysof (Alcon, Texas, USA) acrylic IOLs (n = 16 each, randomly assigned). Each patient reported their dysphotopsia symptoms subjectively using the validated forced choice photographic questionnaire for photic phenomena, and halo size resulting from a bright light in a dark environment was quantified objectively in eight orientations using the Aston Halometer. Assessment was performed binocularly pre-operatively and at 1, 2, 3, and 4 weeks after IOL implantation. Setting: The study was carried out at the National Health Service Ophthalmology Department, Queen Elizabeth Hospital, Birmingham, UK. Results: Visual acuity (average 0.37 ± 0.26 logMAR) did not correlate with subjective glare (r = 0.184, p = 0.494) or objective glare (r = 0.294, p = 0.270) pre-surgery. Objective halo size (F = 112.781, p < 0.001) decreased with cataract removal and IOL implantation and continued to decreased over the month after surgery. Subjective dysphotopsia complaints (p < 0.001) were also greater pre-surgery, but did not change thereafter (p = 0.228). In neither case was there a difference with IOL material (p > 0.05). It was not possible to predict post-surgery dysphotopsia from symptoms or a ratio of symptoms to halo size pre-surgery (p > 0.05). Conclusions: Subjective dysphotopsia and objective halos caused by cataracts are greatly reduced by implantation of IOL after cataract removal causing few perceivable symptoms. However, objective measures are able to quantify a further reduction in light scatter over the first month post-IOL implantation, suggesting that any subjective effects over this period are due to the healing process and not due to neuroadaptation.
RESUMO
PURPOSE: To determine the rotational stability of the Rayner 600S intraocular lens (IOL) (Rayner, Worthing, United Kingdom) using objective image analysis techniques. METHODS: A total of 66 patients (mean age: 69.92 ± 8.45 years) with healthy eyes presenting for routine cataract surgery were implanted monocularly with the 600S IOL and followed up over 90 to 180 days postoperatively. Images of the IOL were captured through a maximally dilated pupil (tropicamide 1.0%, phenylephrine 2.5%) immediately after surgery and after 1 to 3 days, 30 days, and 90 to 180 days using a digital slit-lamp biomicro-scope. The orientation of the IOL markings were image analyzed compared to conjunctival blood vessel landmarks visible across all time points to correct for head and rotation. Centration was assessed by drawing ovals to circumscribe the IOL, pupil, and limbus to compare the centers (0.01 mm per-pixel resolution). RESULTS: Absolute values for rotation postoperatively were 1.60° ± 1.13° at 1 to 3 days, 1.58° ± 1.36° at 30 days, and 1.83° ± 1.44° at 90 to 180 days. No lens rotated more than 5°. The average centration relative to the limbus was -0.04 ± 0.25 mm horizontally and 0.04 ± 0.26 mm vertically at 1 to 3 days, 0.00 ± 0.38 mm vertically and 0.01 ± 0.28 mm horizontally at 30 days, and 0.08 ± 0.37 mm vertically and 0.07 ± 0.47 mm horizontally at 90 to 180 days. CONCLUSIONS: The Rayner 600S IOL showed exceptional rotational stability and centration after implantation, meeting the U.S. Food and Drug Administration prescribed American National Standards Institute standards for toric IOLs. [J Refract Surg. 2019;35(1):48-53.].
