Incidence and causes of negative dysphotopsia after uncomplicated cataract surgery – A randomized clinical trial

PURPOSE: The purpose of this study is to find incidence of negative dysphotopsia (ND) in eyes undergoing clear corneal phacoemulsification and identify its causes including corneal wound hydration and type of intraocular lens (IOL). METHODS: In this randomized clinical trial, consenting adult patients undergoing phacoemulsification were randomized to receive a hydrophobic (Alcon Acrysof(®) SN60WF) or a hydrophilic acrylic IOL (CT Asphina(®) 603P, Carl Zeiss Meditec) in a 1:1 ratio. At time of surgery, eyes were again randomized in 1:1 fashion to receive stromal wound hydration or not (n = 80 each in four groups). Primary outcome measure was the incidence of ND between eyes receiving stromal hydration versus no hydration. Those with ND were observed for 5 years after surgery. RESULTS: Of the 320 eyes, 29 (9.06%) reported ND of which 24 (83%) were transient. Eyes with wound hydration had significantly higher proportion of ND (n = 21/160, 13%) compared to no hydration (n = 8/160, 5%) (P = 0.01). Additionally, eyes with wound hydration were three times more likely to experience ND (odds ratio = 3.29, 95% CI = 1.3–8.2, P = 0.01). Majority of eyes (20/21, 95%) with ND after hydration had it transiently while half (4/8, 50%) of those with ND without wound hydration had it persistently at 6 weeks (P < 0.001) and continued to experience ND for 5 years but did not request intervention. CONCLUSION: ND occurred in 9% cases with majority being transient. Corneal wound hydration led to significant higher likelihood of experiencing transient ND. Those with persistent ND for more than 6 weeks (1.5%) continue to experience ND for at least 5 years.