الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 45 |  |  |
| | | from | 45 | | |
Abstract
Refractive surgery to treat ametropia is increasing, to become among the most commonly performed procedures in medicine. PRK was the first type of surface ablation procedure (refractive eye surgery) in which laser is used to remove corneal tissue rather than a blade.
Several methods were used to remove the epithelium during PRK, including: conventional (mechanical, chemical) or trans-epithelial PRK. Single-step trans-PRK using Amaris excimer laser is atreatment in which the epithelial removal is using a population-based epithelial profile; this type combines the epithelial and the stromal laser ablation in one step.
This prospective study aimed to compare visual and refractive outcomes between the Conventional PRK and Tans-PRK in the treatment of mild to moderate myopia with or without mild astigmatism.
The study was carried out on 40 eyes of 20 patients aged 18 years old or older of either sex with myopia up to -4D and Astigmatism up to -1.50 who were divided into (2) groups. group (A) included the eyes treated by conventional PRK using manual scrapping of the epithelium, while group (B) included the eyes treated by trans epithelial PRK.
Every patient had full ocular examination and for each eye we assessed UCDVA and BCDVA preoperative and within 2- 3 months postoperative for both groups.
The visual outcomes of the surgery were evaluated by its effect on UCDVA, BCDVA, refraction and occurrence of corneal haze.
According to postoperative UCDVA there was a statistically significant difference between the two groups.
There was no statistically significant difference between the two groups regarding the postoperative mean BCDVA.
There was no statistically significant difference between the two groups regarding the occurrence of postoperative corneal haze.
There was a statistically significant improvement of UCDVA after the surgery by both techniques, but transepithelial PRK group had higher UCDVA which can be attributed to the higher incidence of residual postoperative refractive error and the higher percentage of postoperative corneal haze in the conventional PRK group.
Our study demonstrated that both techniques are safer, but the efficacy index and predictability were higher in the transepithelial group in comparison to the conventional PRK group.