Energy Optimization For Visumax 800 In Refractive Surgery: A Comparative Analysis Of Wide Vs Small Spot Spacing In Small Incision Lenticule Extraction (Smile)

The Visumax 800 femtosecond laser system has revolutionized refractive surgery, providing precise control over energy settings for lenticule extraction. This study aims to evaluate the impact of energy optimization on surgical outcomes by comparing two distinct spot spacing and energy settings, specifically focusing on wide spacing vs small spot spacing in small incision lenticule extraction.

Single surgeon, single centre retropspective study

A total of 231 eyes were included in this retrospective study, with patients divided into two groups based on the energy and spot settings used during lenticule extraction. Comprehensive data were collected and analysed, including postoperative UCVA at day 1 (D1PO) and UCVA and BCVA at month 1; the time to extraction of the lenticule; the incidence of failed cuts in both groups; and the development of any interface haze month 1.

There were 115 eyes in the wider spot spacing group and 116 in the narrower group. At D1PO, median logMAR UCVA was better in the narrower-spot group (0.00, IQR 0.18) vs the wider-spot group (0.07, IQR 0.10). UCVA of 0.1 or better was achieved in 85% vs 80% of eyes, respectively. However, by 1 month, median UCVA and BCVA were identical in both groups [UCVA -0.1 (IQR 0.1–0.15), BCVA -0.1 (IQR 0)]. Lenticule extraction times were similar: 46.79 sec (IQR 16.74) in the narrower-spot group vs 45.05 sec (IQR 13.10) in the wider-spot group. Failed cuts occurred in two cases per group, linked to below-average energy index settings. Corneal densitometry at D1 and 1 month showed no significant difference in interface haze between groups.

This study contributes to the ongoing optimization of energy and spot settings for the Visumax 800 femtosecond laser system in lenticule extraction surgery. The comparative analysis of wide spacing vs small spot spacing in small incision lenticule extraction provides valuable data on the time efficiency of the procedure, early visual outcomes, reliability of the cutting process, and the occurrence of interface haze. The results aim to inform surgeons about the potential benefits and considerations associated with different energy settings, ultimately enhancing the precision and safety of lenticule extraction performed with the Visumax 800 system