Automated in situ keratomileusis for myopia

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• In situ keratomileusis is an evolving surgical procedure for myopia correction.
• This study examines an intermediate stage of the technique using a microkeratome for refractive cuts.
• The procedure involved sutured corneal discs and an early automated microkeratome without reoperations.

Purpose of the Study:

• To evaluate the refractive and visual acuity outcomes of early in situ keratomileusis.
• To assess the efficacy and stability of this intermediate surgical technique.

Main Methods:

• Retrospective chart review of 107 eyes (73 patients) undergoing in situ keratomileusis with an automated microkeratome (Ruiz corneal shaper).
• Follow-up of 63 eyes for a mean of 1 year, with manifest refraction as the primary outcome measure.
• Surgery followed the Ruiz nomogram, creating a corneal disc and a plano refractive cut.

Main Results:

• Mean baseline refraction was -11.97 D; at 1 year, mean refraction was -1.86 D.
• Only 21% achieved refraction within +/- 0.50 D, and 35% within +/- 1.00 D.
• Significant undercorrection (> -1.00 D) occurred in 57% of eyes; uncorrected visual acuity of 20/40 or better was achieved in only 21% of eyes.

Conclusions:

• In situ keratomileusis at this developmental stage yielded unsatisfactory refractive and visual acuity results.
• The technique using an automated corneal shaper and sutured discs demonstrated limitations.
• Refractive outcomes showed a trend towards increasing myopia over time, indicating instability.