Evaluation Of Epithelial And Corneal Aberrations Following Smile For Varying Degrees Of Myopia.

To evaluate the epithelial and corneal aberrations in patients following SMILE(small incision lenticule excision) for varying degrees of myopia.

Nethradhama superspeciality eye hospital, Bangalore, India.

This retrospective study included age matched subjects undergoing SMILE procedure for varying degrees of myopia. According to the preoperative spherical equivalent(SE), eyes were divided into three groups: high (> -6.1 D) , moderate (-3.1 D to -6 D ) and low ( < -3 D)myopia. Follow-up visits were conducted at 1 day, 2 weeks, 3months and 6 months. SE, corneal and epithelial aberrations were measured using an OCT based tomographer MS-39,(CSO ITALY ) and compared between the three groups.

A total of 150 eyes from 150 patients (n=50 eyes in each group) were analysed. Pre-op SE in low, moderate and high myopia was-2.25± 0.25 D, -3.91± 0.83D and -5.914± 5.914D which reduced to 0.0D, -0.014± 0.05 D and – 0.01± 0.05 D at 6 months, respectively. At 6 months, a significant increase in epithelial aberrations ,corneal HOA( higher order aberrations) and total corneal aberrations(LOA+HOA) was noted, irrespective of the degree of myopia (p <0.01).Across the groups, a significant increase in corneal spherical aberrations was noted for high myopia group when compared to the moderate and low myopia groups(p<0.01). No significant  differences were observed with regard to the epithelial aberrations between the different myopia groups.

While correcting different grades of myopia with SMILE, the most  significant change was observed in corneal spherical aberrations, that increased in proportion to the degree of myopia corrected.Epithelial aberration profile did not seem to differ significantly between the groups.