Eyeworld

18 | EYEWORLD | JUNE/JULY 2020 ASCRS NEWS Contact Flowers: Charles.Flowers@med.usc.edu Wong: Brandon.Wong@med.usc.edu Small pupils, temporally decentered pupils, and positive angle kappa are anatomical factors that increase the risk of NDs. Screening patients preoperatively for these factors can better help us manage patient expectations and potential- ly elucidate definitive postoperative remedies. Horizontal and inferotemporal haptic orien- tation, reverse optic capture, capsular fibrosis over the IOL edge, IOL material, and IOL edge design are all considerations that have been pre- viously explored with varying success. 2–5 Newer work suggests a possible central nervous system etiology as symptoms were reduced on visual field perimetry with contralateral eye occlusion and a lack of reported symptoms in monocu- lar patients. 8 When in doubt, allowing time for spontaneous resolution can always buy some time before attempting other medical or surgical corrections. decreased SEs in nasal eccentricities correlate to the symptoms of NDs including temporal shad- ows or dark spots. As seen in peripheral ocular aberrometry and ray-tracing simulations, there is a large myopic shift in nasal eccentricities. It may be that in eccentric gaze even beyond 30 degrees, the increasing myopic blur is perceived as a relative scotoma as light is split and bent away from this retinal field angle. Finally, the method of determining iris tilt using an individ- ually coded program in Python has not yet been validated to the authors' knowledge. While this method of analysis may provide accurate data, it has not yet been shown to effectively model the eye in the manner it was used in this study. The resulting data from this methodology, however, is quite promising and recapitulates some of the previous work on NDs. In summary, this paper provides exciting clinical and anatomical support to previously posited theories on the etiology of negative dys- photopsias after uncomplicated cataract surgery. continued from page 17 n n n n n Distinct differences in anterior chamber configuration and peripheral aberrations in negative dysphotopsia Luc van Vught, BSc, Gregorius Luyten, MD, Jan-Willem Beenakker, MSc J Cataract Refract Surg. 2020;46(7). Article in press. these clinical measurements and current hypotheses on the etiology of ND. n Results: Patients with ND have a smaller (p=0.03/p=<0.01) and more decentered (p<0.01) pupil than pseudophakic controls. Additionally, an increased temporal tilted iris (p<0.01) and an asymmetric peripheral aberration profile were observed in patients with ND, of which the latter was also apparent in a number of ray tracing models. The combination of these in vivo results and ray tracing simulations indicates that patients with ND have a temporal rotated eye, which confirms the hypothesized relation between ND and an increased angle kappa. n Conclusions: Patients with negative dysphotopsia have a smaller pupil and an increased angle kappa, which make them more susceptible to experience a shadow in the temporal visual field. n Purpose: Provide insight in the anatomical characteristics associated with negative dysphotopsia using quantitative clinical data. n Setting: Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands. n Design: Case-control study. n Methods: Anterior chamber tomography and peripheral aberrometry were measured in twenty-seven pseudophakic patients with negative dysphotopsia (ND) and thirty pseudophakic controls. Based on these measurements, the total corneal power, anterior chamber depth, pupil location and diameter, iris tilt and peripheral ocular wavefront up to 30 degrees eccentricity were compared between both groups. Additionally, ray tracing simulations using pseudophakic eye models were performed to establish a connection between References 1. Osher RH. Negative dyspho- topsia: Long-term study and possible explanation for transient symptoms. J Cataract Refract Surg. 2008;34:10:1699–1707. 2. Holladay JT, Simpson MJ. Negative dysphotopsia: Causes and rationale for prevention and treatment. J Cataract Refract Surg. 2017;43:2:263–275. 3. Masket S, Fram NR. Pseu- dophakic negative dysphotopsia: Surgical management and new theory of etiology. J Cataract Re- fract Surg. 2011;37:1199–1207. 4. Masket S, et al. Surgical management of negative dyspho- topsia. J Cataract Refract Surg. 2018;44:6–16. 5. Henderson BA, et al. New pre- ventative approach for negative dysphotopsia. J Cataract Refract Surg. 2016;42:1449–1455. 6. Davison JA. Positive and negative dysphotopsia in patients with acrylic intraocular lenses. J Cataract Refract Surg. 2000;26:1346–1355. 7. Holladay JT, et al. Negative dysphotopsia: The enigmatic penumbra. J Cataract Refract Surg. 2012;38:1251–1265. 8. Masket S, et al. Neuroadaptive changes in negative dysphotopsia during contralateral eye occlu- sion. J Cataract Refract Surg. 2019;45:242–243.

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