LASIK retreatment based on manifest refraction in hyperopic eyes with a difference of no more than 1.00 D between cycloplegic and manifest refraction was safe, effective and predictable, according to a study.
LASIK retreatment for hyperopia is challenging, and it has not been established whether preoperative cycloplegic or manifest refraction, or a combination of the two, should be used in the laser nomogram, according to researchers. In this retrospective, multicenter study, good results were obtained in 113 eyes of 113 patients by focusing the treatment on manifest refraction.
The procedure was performed under a mechanically separated flap, using the Allegretto excimer laser platform (Wavelight). The ablation was centered on the visual axis, “which is recommended in hyperopic eyes with relatively large angle k’s,” the authors noted.
Postoperative uncorrected distance visual acuity was equivalent to preoperative corrected distance visual acuity in 85 eyes (75%). Five eyes still lost two lines after retreatment as compared with 26 eyes that lost three lines after the first treatment.
Results were within + 0.50 D of attempted correction in 81% of the eyes, but 79.3% were undercorrected by 1.0 D or more. This was statistically more common with higher preoperative spherical equivalent, of 2.50 D or more.
A significant reduction in coma, trefoil and total higher-order aberrations was obtained. Results were stable, and no eye had flap complications or vision-threatening complications.
“We recommend cautioning the patient about lower predictability and suggest basing the arithmetic mean calculated from the preoperative manifest and cycloplegic spherical equivalent if the preoperative difference between cycloplegic and manifest refraction (manifest-cycloplegic difference) is 1.00 D or more,” the authors wrote.
According to the authors, “hyperopic LASIK must be held to the same standards as myopic LASIK,” and further studies are needed to better understand the role of cycloplegic refraction in the LASIK treatment for hyperopia, thus improving the refractive outcomes. – by Michela Cimberle
Disclosure: The authors reported no relevant financial disclosures.
The predictability of hyperopic LASIK and its retreatments has been a subject of controversy for a long time, and this study specifically addresses the outcomes of those cases in which the discrepancy between cycloplegic and manifest refraction is less than 1.0 D.
The authors confirm that refractive regression exists in these patients, which leads to a decrease in predictability. This increases along the magnitude spherical equivalent to treat. The authors identify that the patients with cycloplegic and manifest refraction up to 1.0 D are the best group for this type of LASIK surgery.
Within the limits of hyperopic correction defined in this paper, hyperopic LASIK is safe and predictable, and these outcomes improve with reoperation.
It may be important to note that hyperopic LASIK was performed in this study with the Allegretto Wavelight 250 Hz laser platform (Alcon) and mechanical flap separation with the SBK microkeratome with 90µ head (Moria).
Original Date: Jan 2 2018