A One - Month Outcome Of The Corneal Lenticular Extraction For Advance Refractive Correction (Clear) Procedure Using A Low Energy Femtosecond Laser.

The Corneal Lenticular Extraction for Advance Refractive Correction (CLEAR) procedure was first introduced worldwide in 2017. It is the preferred treatment due to the lower pulse energy laser, fast repetition rates, small size and overlapping spots that ensure smooth surface of ablation thus minimizing the effects of Opaque Bubble Layer (OBL) formation. The flapless technique induces minimum dry eye, allowing faster healing duration and good visual and refractive outcome for the patients.

Since VISTA is the first and only center to perform this technique in Malaysia, this study aimed to report a 1-month postoperative visual outcome of CLEAR performed at Vista Eye Specialist, Malaysia.

The refractive surgery was performed by two  ophthalmologists at Vista Eye Specialist, Selangor, Malaysia with the same surgical method and technology.

All patients underwent comprehensive eye examination prior to the refractive surgery. Only patients with stable refraction, sphere power range between -3.00D to -6.00D, with cylindrical power of less or equivalent to -2.00D, not having deep set eyes and a residual calculated post-operative corneal thickness of 330 nm or more were enrolled for this CLEAR refractive treatment. Post-operative refraction was performed at day 1, 7 and 30 to determine any improvement in visual acuity. Visual acuity was converted to logmar notation for statistical analysis. Additionally, central corneal thickness (CCT) was also measured before and at day 30 postoperative.

A total of 29 eyes from 15 patients were included, (11 females and 4 males). The age of the patients at the time of treatment was between 21 to 40 years old (M=32.73; SD=5.75). The mean preoperative spherical equivalent (SE) refraction, total cylindrical power and CCT were -4.79±0.84D, -0.75±0.52DC and 555.52±29.03µm. The unaided distance visual acuity and SE were significantly improved at day 1 postoperative with marked improvement seen at day 7 and continued to be stable at day 30. The total cylindrical power did not significantly change at day 1 postoperative, but markedly reduced at day 7 with further small reduction seen at day 30. The average reduction in CCT across participants measured at day 30 postoperative was 89.24micron.  

The CLEAR procedure has demonstrated positive visual outcomes, with the best visual acuity potentially achieved as early as day 7 postoperatively.  Additionally, the CLEAR procedure did not significantly ablate corneal tissue due to its flapless benefit, therefore can be considered for patients with a larger degree of refractive error.