Abstract
Purpose :
The purpose of this study was to compare the size and position of the halo with different soft contact lenses for myopia control.
Methods :
A study was performed with 18 participants (15 females and 3 males) with a mean age of 23.72±2.14 years. Participants had myopia between -0.50D to -6.00D, with astigmatism no more than -0.75D. A total of 8 myopia control soft contact lenses were evaluated, which were classified into 3 different designs: One lens has a dual focus (DF) design, two of them extended depth of focus (EDOF) design and the remaining five lenses, a multifocal (MF) design with different additions. Under scotopic conditions and monocularly, the participant was placed 2 metres away from the instrument (Light Disturbance Analyzer, Binarytarget Lda. Braga, Portugal). The instrument used a central LED light of 5mm diameter and 240 LED lights of 1mm diameter peripherally, distributed in 24 meridians. In this study, only 12 meridians were evaluated. During the test, the central light was always turned on. The test consisted of to identify a peripheral stimulus around the central stimulus. SPSS (version 28.0.1.1; SPSS Inc., Chicago, IL, USA) was used for statistical analysis. A p-value<0.05 was considered statistically significant.
Results :
Two main parameters of the halo were analyzed: halo size (BFCr) and halo direction (BFCx and BFCy). For this study, both eyes were analysed, but no statistically significant differences were found between the two eyes (p>0.05), so only the right eyes were selected.
All study lenses showed statistically significant differences (p<0.05) in halo size compared to their habitual correction. The lens design with the largest halo size was a high addition MF design with BFCr of 16.04±8.52 mm. However, the lens with the smallest halo size was also a low addition MF design, with a BFCr of 3.42±1.41 mm. As for the halo position results, the lens that showed the largest deviation was a high addition MF design lens, with a BFCx of 2.80±1.75 mm, while the lens that showed the best halo centration was an EDOF design lens, with a BFCx of 0.02±0.32 mm.
Conclusions :
All myopia control designs evaluated in this study have created a larger halo size than the participants usual correction. The halo size is related to the addition of the lens, not just the design. Further studies are required to assess the relationship between these parameters.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.