Time Serial Analysis on Preemptive Analgesia of Preoperative Topical Diclofenac and Ketorolac in Photorefractive Keratectomy(PRK)

The investigators performed this study to investigate pain prevention of preoperative topical nonsteroidal anti-inflammatory drug (NSAID) in photorefractive keratectomy(PRK) using time serial pain scoring.

Inclusion Criteria:

1. at least 19 years of age
2. simultaneous bilateral PRK schedule
3. more than 400μm(including epithelium) of postoperative corneal thickness
4. less than 150μm of ablation depth.

Exclusion Criteria:

1. a history of ocular surgery or trauma
2. two-diopter more difference in spherical equivalent (SE) between the eyes, 3. keratoconus or other corneal pathology

4. use of systemic or topical NSAID within 1 month before the surgery 5. history of allergic reaction to aspirin or other NSAIDs 6. glaucoma or ocular hypertension (> 20 mmHg) 7. collagen vascular diseases 8. diabetic retinopathy 9. pregnancy or lactation 10. intraoperative complications.