Topography-Guided Customized PRK Versus Q-value Adjusted PRK in Correction of Myopia With or Without Astigmatism

Kasr El Aini Hospital104 enrolled

Overview

This study will include patients who will undergo PRK in both eyes, for each patient each eye will be randomly allocated to one of 2 procedures: topography-guided ablation in one eye (group I) and Q-factor customized ablation in the other eye (group II). Alcon/Wavelight Light Laser Technolo¬gie (GmbH, Erlangen, Germany) will be used for photoablation. The wavelight Topolyzer (Wavelight AG, Erlan¬gen, Germany)and CSO Sirius scheimpflug camera combined with Placido corneal topography (CSO, Florence,Italy) will be used before and 1, 3 and 6 months after PRK. Refrac¬tive visual outcomes and corneal aberration changes will be compared between the two treatment modalities.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

104

Conditions

Myopia

Interventions

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age more than 18 years * Myopia with up to -6.5 D with or without astigmatism up to -4.75 D Exclusion Criteria: * anterior segment abnormalities (ie, cataracts, corneal scarring) * basement membrane disease * history of recurrent corneal erosions * Schirmer's test less than 5 mm * established or forme fruste keratoconus * macular or retinal disease * current use of immunosuppressive therapy * autoimmune disease * pregnancy, and lactation

Outcomes

Primary Outcomes

change in Postoperative spherical equivalent depending on manifest refraction after autorefractometer

Time frame: 1 , 3 and 6 months postoperative

change in visual acuity using snellen chart

Time frame: 1 , 3 and 6 months postoperative

change in corneal wavefront aberrations

assessed by topolyzer

Time frame: 1 , 3 and 6 months postoperative

change in Q value anterior at 6mm RMS, RMS of astigmatism, RMS of coma and RMS of spherical aberrations. Strehl ratio : Qvalue,RMS,strehl ratio by CSO Sirius scheimpflug

by CSO Sirius scheimpflug

Time frame: 1,3 and 6months

change in total RMS

by CSO Sirius scheimpflug

Time frame: 1,3 and 6months

change in strehl ratio

by CSO scheimpflug

Time frame: 1,3 and 6 months

change in Q value

assessed by topolyzer

Time frame: 1,3 and 6 months

Secondary Outcomes

efficacy:ratio of postoperative decimal UDVA to preoperative decimal CDVA

ratio of postoperative decimal UDVA to preoperative decimal CDVA

Time frame: 6 months

contrast sensitivity

cambridge low contrast sensitivity

Time frame: 6 months

predictability

eyes within 1.0 D of emmetropia

Time frame: 6 months

safety:ratio of mean preoperative decimal CDVA to mean postoperative decimal CDVA

ratio of mean preoperative decimal CDVA to mean postoperative decimal CDVA

Time frame: 6 months

stability

change of more than 0.5D over

Time frame: 6 months

Topography-Guided Customized PRK Versus Q-value Adjusted PRK in Correction of Myopia With or Without Astigmatism

Overview

Conditions

Interventions

Eligibility

Locations (2)

Outcomes

Primary Outcomes

Secondary Outcomes