Adjusting Laser Parameters for Myopic Laser Blended Vision According to Laser Treatment Zone: A Retrospective Study

The nomograms for the laser procedure "Laser Blended Vision" (Presbyond^®) for myopia were developed based on a 6 mm zone. The aim of these studies is to demonstrate that customized nomograms are necessary when changing the optical zone. The three-month results after the Presbyond^® correction using a 6.4 mm to 6.5 mm optical zone were analyzed in myopic patients. All patients were treated at the University Hospital Gießen and Marburg and for analyses purposes they were divided into two groups. Group 1 was treated from 2017-2019 without a nomogram for this larger optical zone, and group 2 from 2019-2022 with a customized nomogram.

In the retrospective monocentric study, 86 eyes from 43 patients in group 1 and 120 eyes from 60 patients in group 2 were analyzed. All eyes were treated with the 500 kHz VisuMax^® Laser and the Mel90^® Excimer Laser using a 6.4 mm to 6.5 mm optical zone. The results are collected using Datagraph^® software.

The three-month results show overcorrection in both groups concerning the targeted refractive goal. In group 2, the analysis of distance and near vision shows that eyes treated for near vision deviate more than predicted. This is also confirmed in the refractive outcome. However, patient satisfaction is comparable in both groups, and retreatment rate is lower than published, although higher in group 1 than in group 2.

Since PRESBYOND^® targets both, good distance vision does not fully reflect the goal of this procedure. The importance of personalized nomograms for distance and near vision is supported by our results, also the retreatment rate improved, and patient satisfaction influences the decision for retreatment. A separate nomogram for the distance and reading eye to further improve correction predictability is necessary, as predictability in both eyes is differing.