A NEW APPROACH FOR DETECTING PATIENTS COMPLAINING OF DYSPHOTOPSIA AFTER MULTIFOCAL INTRAOCULAR LENS IMPLANTATION DUE TO NON-OPTICAL REASONS

Positive Dysphotopsia (PD) can be defined as any bothering bright artifact [photic phenomena (PP)] perceived by patients along or around direct bright lights or reflected over objects located in the visual field. The aim of this study was to explore possible methods for detection of poor candidates for Multifocal Intraocular Lens (MIOL) implantation who were complaining about PD in the preoperative period without any optical reason that justified their answer.

 

Qvision, Ophthalmology Department, VITHAS Almería Hospital

Eighty-two subjects, aged from 45 to 80 years old, were evaluated during the preoperative screening for presbyopia or cataract surgery, including the following methods of PP measurement: Light Distortion Index (LDI, Light Distortion Analyzer) and a PP gradation simulator (DysphotopsiApp) provided at the same time as the patient experienced the PP by looking at two LED lights. This simulator included a question about the bothersome level of the PP measured on a Likert scale with 5 possible answers from "Not at all" to "Extremely" bothersome. A logistic regression was carried out to determine the cut-off point for the LDI that best predicted the change from a "Slightly" to a "Moderately" bothersome answer. Correlations of LDI with three objective lens sclerosis grading indices were also evaluated: the Ocular Scatter Index (OSI, HD Analyzer), the Ocular Scatter Index (OSI, HD Analyzer), the Lens Dysfunction Index (DLI, iTrace) and the Pentacam Nucleus Status (PNS, Pentacam Wave).

The percentage of patients bothered by the PP were: "Not at all" (22%), "Slightly" (50%), "Moderately" (18.2%) and "Very" (9.8%) bothered. The LDI was significantly correlated with the bothersome question (rho=0.34, p=0.002) and also with OSI (rho=0.67, p<0.0005), DLI (rho=-0.29, 0.007) and PNS (rho=0.48, p<0.0005). The median LDI increased for subjects classified at each of the levels of bothersome, from 7.82% ("Not at all") to 29.13% ("Moderately") bothered. However, the median LDI at the "Very" level decreased to 17.17%. Although the simulator also showed correlations with the bothersome question, no correlations were found with the objective grading methods. The cut-off point that predicted moving from "Slightly" to "Moderately" bothersome was >15.20% for the LDI (ROC AUC=0.64; p=0.05), which could be estimated with the following values of the grading methods: < 2.8 for the OSI, > 7.6 for the DLI and < 2 for the PNS.

 

The fact that 9.8% of patients "Very" bothered by PP showed a median LDI of 17.17% means that PD could not be explained by the optical components of the eye. Including a question about PD in the preoperative screening together with an objective grading method or direct LDI measurement could help to detect such patients with increased PP discomfort prior to surgery whose discomfort might be increased after MIOL implantation.