Changes in Power and Cylinder Axis of Toric Soft Contact Lenses (LKL)

Astigmatism is a common refractive error resulting from a toric-surfaced cornea which using a toric soft contact lens could be one of the therapy options. Due to the numerous possible combinations between sphere powers, cylinder powers, and cylinder axes, manufacturers of disposable soft toric contact lenses limit their toric lens range, while still aiming to cater to the majority of astigmatic patients. Due to that reason, the possibility of astigmatism patients getting a different combination of power and axis with toric soft contact lenses sold on the market will be high due to SKU limitations. This research aims to ascertain the impact of altering cylinder power and axis on visual quality and convenience in astigmatism participants using toric soft contact lens. The study was conducted at Kirana Ciptomangunkusumo Hospital, Jakarta, starting in April 2020. The study is a prospective, randomized, participant-masked, crossover clinical trial where the participants were tested for the following conditions on different days using full spherocylinder correction and under-correction by 0.25, 0.50, and 0.75 DC while maintaining spherical equivalence. Axis was also misaligned between -30° and +30°, in 10° steps. For each visit, the patient was examined visual acuity, contrast visual acuity using the Pelli-Robson, and assessed patient comfort using the VAS method.