Partial monovision achieved by unilateral implantation of a multifocal add-on lens with bilateral pseudophakia: evaluation and results

PURPOSE: To assess the results of partial monovision (PMV) in comparison to a bilateral monofocal implantation (MMV). METHODS: The PMV group was treated bilaterally with a monofocal intraocular lens (IOL) implantation, followed 3 months later by the implantation of a multifocal AddOn® lens (+ 3.00 D) into the non-dominant eye. The MMV group received a bilateral monofocal IOL implantation intending to achieve a slight anisometropia (0.0 D/ − 0.50 D). The near visual acuity (UNVA), intermediate visual acuity (UIVA), distance visual acuity (UDVA), defocus curve, and Lang-Stereotest II were conducted uncorrected, binocular, and minimum 3 months after the last operation. For the contrast sensitivity test, the patients were refractively corrected. The Quality of Vision Questionnaire (QoV), Visual Function Questionnaire (VF-14), spectacle independence, and general satisfaction were also assessed. RESULTS: A total of 27 PMV patients and 28 MMV patients without ocular diseases relevant to visual acuity were examined. The PMV group was significantly better at UNVA (0.11 ± 0.08 logMAR vs 0.56 ± 0.16 logMAR) and between − 2.00 and − 4.00 D in the defocus curve (p < 0.001). At the UIVA, the PMV group was slightly better (0.11 ± 0.10 logMAR vs 0.20 ± 0.18 logMAR) but not significant (p = 0.054). The UDVA (− 0.13 ± 0.09 logMAR vs − 0.09 ± 0.14 logMAR) (p = 0.315) and contrast sensitivity (p = 0.667) revealed no differences between the groups. The stereo vision was in favor of PMV (p = 0.008). Spectacle independence was statistically better for PMV at distance, intermediate, and near (distance p = 0.012; intermediate p < 0.001; near p < 0.001). In the VF-14 Questionnaire, the PMV was statistically superior (p < 0.001). The QoV Questionnaire showed no differences regarding frequency and severity of visual disturbances. Both groups were highly satisfied (p = 0.509). CONCLUSION: Patients with PMV are more independent of glasses and are able to read without disadvantages in distance vision, due to halos and glare. The concept of PMV is well suited for the desire of eyeglass independence, without optical side effects. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00417-022-05584-y.