Modified Tel-Aviv Protocol For Post-Dalk Irrigular Astigmatism: A Case Series

Deep anterior lamellar keratoplasty (DALK) is increasingly preferred over Penetrating keratoplasty (PKP)for treating corneal ectasia and other corneal stroma disorders. Previous research has shown that after DALK, spherical refractive errors range from −13.0 to +7.0 D, and astigmatism varies from 0.0 to 10.0 D, and many times, the astigmatism is irregular. Some patients experience difficulty tolerating contact lenses, creating a need for alternative ways to improve their visual acuity.

Care-Vision Laser Center, Tel Aviv, Israel

This study includes five eyes from five patients who previously underwent DALK. Post-DALK, they experienced significant astigmatism irregularly affecting their visual acuity and had difficulty tolerating contact lenses. They were treated using a modified Tel Aviv Protocol, which involved ePRK without adjunct corneal cross-linking. The procedure included epithelial PRK using the EX500 excimer laser, delivered on the visual axis with cyclotorsion correction, treating up to 80% of refractive astigmatism. MMC was applied for 1 minute. Pre- and post-treatment visual acuity and refraction were recorded for each patient.

The mean age of the patients was 44.25 ± 8.06 years. All patients demonstrated significant improvement in uncorrected visual acuity (UCVA) following treatment, from 0.24 ± 0.35 to 0.48 ± 0.25 (decimal). Additionally, refraction showed improvement: the sphere decreased from 2.9 ± 0.80 to 0.31 ± 0.38, and the cylinder decreased from 4.7 ± 1.92 to 1.44 ± 0.83. No significant complications, such as haze or ectasia, were observed during the follow-up period.

This case series highlights the potential of the modified Tel Aviv Protocol ( epithelial PRK), as an effective option for post-DALK patients who do not tolerate contact lenses, achieving substantial visual improvement.