Safety of the bag-in-the-lens implantation regarding the development of clinically significant pseudophakic cystoid macular edema: A retrospective case series study

PURPOSE: To determine the incidence of clinically significant pseudophakic cystoid macular edema (CSPME) after phacoemulsification using the ‘bag-in-the-lens’ lens (BIL) implantation technique and to examine the influence of associated risk factors for clinically significant pseudophakic macular edema (CSPME), both ocular and systemic. METHODS: This retrospective study included 2419 first-operated eyes of 2419 adults who underwent phacoemulsification cataract surgery using the BIL implantation technique between January 2013 and December 2018 in the Antwerp University Hospital, Belgium. The significance of several risk factors (age, gender, previous history, intra- and postoperative complications) was examined by extraction of electronic medical files. RESULTS: The 3-month incidence of CSPME in the subgroup without risk factors was 0.00% (95% CI: 0.00 –NA). The 3-month incidence of CSPME in the subgroup with risk factors was 0.57% (95% CI 0.22–1.29%). The 3-month incidence of CSPME in the total population of 2419 patients was 0.29% (95% CI: 0.11–0.65%). The risk factors most significantly associated with CSPME included renal insufficiency (hazard ration [HR]: 5.42; 95% CI: 1.69–17.44; P = .014), exudative age-related macular degeneration (HR: 74.50, 95% CI: 25.75–215.6; P < .001) and retinal vein occlusion (HR: 22.48, 95% CI: 4.55–111.02; P = .005). CONCLUSIONS: In the absence of risk factors, the incidence of CSPME was zero. We can conclude that Primary Posterior Continuous Curvilinear Capsulorhexis (PPCCC) does not increase the risk for CSPME. Non-inferiority of the BIL implantation regarding the development of CSPME, relative to the traditional ‘lens-in-the-bag’ (LIB) implantation, confirms that BIL is a safe surgical technique. This study also illustrates a previously undescribed risk factor for developing CSPME, namely renal insufficiency.