The Effect Of Senofilcon A Silicone Hydrogel Soft Contact Lens Wear Interruption On Corneal Topography

To evaluate the effect of soft contact lens (SCL) interruption on corneal thickness and shape changes and to compare spherical and toric SCL in this respect.

University of Health Sciences Turkey, Beyoglu Eye Training and Research Hospital, Beyoglu, Istanbul, Turkey

Patients who wore reusable, senofilicone A-containing silicone hydrogel SCLs and had at least two weeks of interruption before refractive surgery were analyzed in 2 groups according to lens design (Spherical SCL: 19 eyes, Toric SCL: 21 eyes). Corneal thickness and topography parameters were evaluated at presentation and after SCL interruption using the Sirius (Costruzione Strumenti Oftalmici, Firenze, Italy), and compared between groups.

Manifested refractive examination indicated no significant change in spherical and spherical equivalent values pre and post-SCL interruption(p>0.05),but significant differences in cylindrical values(p<0.001).Thinnest and central corneal thickness, corneal volume,symmetry index(SIf, SIb),keratoconus vertex(KVf, KVb),and Baiocchi Calossi Versaci(BCVf/ BCVb) showed no significant differences between groups before and after interruption.Corneal keratometry values differed significantly between groups pre and post-interruption(p<0.05).In the spherical SCL group,no significant change in corneal topographic parameters post-interruption was observed.However, the toric SCL group exhibited a significant flattening of flat keratometry values(p=0.028).

Among senofilicone A-containing silicone hydrogel SCLs, spherical lenses do not cause significant topographic changes on the corneal surface, while toric lenses may cause significant changes in the flat keratometry value. It may be valuable to question the SCL material and whether it is spherical or toric when evaluating SCL wearers before refractive surgery.