Bilateral Comparison of Conventional Epithelial Laser In Situ Keratomileusis and Lamellar Epithelial Debridement for Moderate to High Myopia

Photorefractive keratectomy in the correction of astigmatism using Schwind Amaris 750s laser

AIM

To evaluate the results of three photorefractive keratectomy (PRK) procedures in the treatment of astigmatism.

METHODS

In this retrospective comparative case series, 89 eyes of 50 patients who underwent PRK treatment for astigmatism were enrolled. The patients were divided into 3 groups based on the PRK procedure: Group 1: PRK without mitomycin-C (MMC) application, Group 2: PRK with MMC application, and Group 3: Trans-Photorefractive Keratectomy (T-PRK). The efficacy, safety, predictability, and complications of treatment were assessed at 1, 3 and 6 months after the treatment.

RESULTS

At postoperative 6 months, the percentage of postoperative uncorrected visual acuity (UCVA) of 20/20 or better was 55.6% (20 eyes) in group 1, 75% (15 eyes) in group 2, and 75.8% (25 eyes) in group 3 (P=0.144). The percentage of postoperative best corrected visual acuity (BCVA) of unchanged or gained ≥1 lines was 80.6% (29 eyes) in group 1, 70% (14 eyes) in group 2, and 90.9% (30 eyes) in group 3 (P=0.151). The percentage of postoperative BCVA of lost ≥2 lines was 11.1% (4 eyes) in group 1, 20% (4 eyes) in group 2, and 6.1% (2 eyes) in group 3. The mean manifest refractive spherical equivalent (MRSE) and mean cylindrical refraction were not significantly different among the each groups (P>0.05). At postoperative 6 months, the percentage of MRSE of within ±0.50 D was 100% (36 eyes) in Group 1, 100% (20 eyes) in Group 2, and 93.9% (31 eyes) in Group 3. At the each follow-up period, there was no significant difference in number of eyes with haze and mean haze score(P>0.05).

CONCLUSION

The study showed that PRK without MMC, PRK with MMC and T-PRK appears to have similar effectiveness, safety and predictability in the treatment of astigmatism. The incidence of haze was also similar between the three groups.

Flap-off epi-LASIK versus automated epithelial brush in PRK: a prospective comparison study of pain and reepithelialization times

PURPOSE

To compare the effect of flap-off epi-LASIK versus automated brush epithelial removal on pain and wound healing in low myopic photorefractive keratectomy (PRK).

METHODS

In this prospective intraindividual study 60 patients received surface ablation in each eye. Epithelial removal was performed by an automated brush technique in one eye (brush group) and epi-LASIK with flap removal (flap-off group) in the fellow eye. The epithelial defect size was measured daily after surgery until both eyes were reepithelialized. Postoperative pain on a scale from 0 to 6 and topical and oral analgesic medication use was recorded until the bandage contact lens was removed.

RESULTS

The flap-off group had significantly less postoperative pain on days 1 (P=.0003), 2 (P=.0001), 3 (P<.0001), and 4 (P<.0001) compared to the brush group. However, the average difference in pain scores between groups was only 0.33 points out of 6. No difference was noted in the normalized overall percentage rate of healing over the first 4 days in the flap-off group (5.41±1.39%/hour) compared to the brush group (5.42±1.94%/hour) (P=.97).

CONCLUSIONS

The flap-off group showed a statistically but not clinically significant advantage over the brush group in pain scores. However, no difference was noted in the percentage rate of epithelial healing time between the two groups.

Transepithelial photorefractive keratectomy: clinical results

PURPOSE

To assess the effectiveness, safety, and comfort of transepithelial photorefractive keratectomy (PRK) using the Amaris laser platform.

SETTING

Ophthalmic Consultants of Beirut, Jal-El-Dib, Metn, Lebanon.

DESIGN

Comparative case series.

METHODS

Myopic eyes with or without astigmatism were treated by transepithelial PRK (study group) and compared with variable-adjusted eyes treated by conventional PRK (control group) during which the epithelium was removed with alcohol. Postoperative pain, epithelial healing time, uncorrected distance visual acuity (UDVA), manifest refraction, and haze were analyzed.

RESULTS

The mean subjective postoperative pain score (out of 10, indicating worst pain) at 48 hours was 2.0 in the study group (50 eyes) and 4.5 in the control group (50 eyes) (P=.02). The mean time to complete epithelial healing was 2.5 days ± 0.6 (SD) and 3.7 ± 0.8 days, respectively (P=.01). At 1 week, the UDVA was statistically significantly better in the control group; however, at 3 months, there was no statistically significant difference in UDVA, corrected distance visual acuity, or manifest refraction between the groups. Haze was significantly less in the study group (P<.01).

CONCLUSIONS

Transepithelial PRK for mild to moderate myopia with or without astigmatism was safe and easier to perform than conventional PRK, and patients had less pain, less postoperative haze, and a faster healing time. The visual outcomes with the 2 techniques were comparable.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.