Phase IV Study to Evaluate the Efficacy of Lagricel® Ofteno PF Compared to Thealoz® Duo After Photorefractive Keratectomy (PRK)

Inclusion Criteria:

• • Age ≥ 18 and ≤ 45 years old
• Being on PRK postoperative day 1 (right eye will be evaluated for efficacy)
• Presenting a PRK surgical corneal ablation surface of 5.5 to 6.0 mm
• PRK corneal output ≤ 60 µm
• Preoperative refraction of -1.0 to -4.5 D of myopia or myopic astigmatism (in thiscase, the sum of both values with a spherical equivalent no greater than -4.5 D)
• Being capable of voluntarily grant a signed informed consent.
• Being willing and able to meet the requirements of the study such as attendingprogrammed visits, treatment plan and other study procedures.
• Being willing and able to modify the required lifestyle activities.
• Women in child-bearing age must assure the continuation (start ≥ 30 days prior toinformed consent signing) of a hormonal contraceptive method or intrauterine device (IUD) during the study.

Exclusion Criteria:

• Having suffered any complications during and after PRK surgical procedure previous toinclusion in the study.
• Use of mitomycin during PRK
• Being subjected to PRK retreatment of previous history of any other kind of refractivesurgery.
• Pregnancy, breastfeeding or planning to become pregnant during the time of the study
• Having participated in clinical trials within 30 days prior to signing this study'sinformed consent form.
• Having participated previously in this study.
• Diagnosis of any of the following:
• Allergic, viral or bacterial conjunctivitis
• Dry eye
• Anterior blepharitis
• Parasite infestation of ocular structures (Demodex, for example)
• Previous history of ocular herpes
• Previous history of ocular inflammation (such as uveitis)
• Corneal or conjunctival ulcers
• Glaucoma
• Previous history of drug addiction within the last 2 years previous to signing thisstudy's informed consent form.
• Having a previous history of any ophthalmological surgical procedure, within the last 3 months prior to the informed consent signing date.
• Previous history of any medical affliction, acute or chronic (such as DiabetesMellitus type I/II, autoimmune diseases or HIV), that according to the investigatormay increase either the risk to the patient for participating in this study or therisk of interference of the accurate interpretation of results.
• Use of medications (such as retinoic acid) that according to the investigator'scriteria may increase either the risk to the patient for participating in this studyor the risk of interference of the accurate interpretation of results.
• Known hypersensitivity to any of the components of the products used in this study.