الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
This prospective study was conducted upon 30 eyes of 30 patients aiming to compare between the post LASIK and PRK inflammatory dry eye disease through measuring the MMP-9 using the inflammadry test.
The patients in rolled in this study were between 20 to 39 years old, that had LASIK or PRK surgery within the last 48 hours before.
Medical history, surgical history and drug history were taken from all patients, and a comprehensive ophthalmic examination was performed before and after the surgeries.
Testing patients were performed by Snellen chart to evaluate the BCVA to evaluate any visual faults after the surgery, full slit lamp examination was performed to exclude any dry eye disease signs before the surgery.
Dry eye is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear instability.
LASIK (laser in situ keratomileusis) is a surgical procedure designed to correct refractive errors through creating a corneal flap using a microkeratome, reshaping the cornea using excimer laser to remove tissue from the underlying stromal bed and then replacing the flap.
Photorefractive keratectomy (PRK) is another surgical procedure designed to correct refractive errors using excimer laser but the entire corneal epithelium is removed, then the right amount of corneal stromal tissue is ablated similar to that in LASIK.
Post-LASIK or PRK dry eye is the most common postoperative dry eye after ophthalmic surgeries.
On the corneal surface, the hyperosmolarity of the tear fluid seen in DE has been shown to trigger the stress-activated protein kinase (SAPK) signalling cascade. SAPK signalling leads to the release of MMP-9 from corneal epithelial cells themselves, thus initiating a cycle of progressive inflammation.
MMP-9 is a 23 zinc and calcium ion-dependent enzyme important for tissue remodelling in normal physiological processes like wound healing and bone development MMP-9 is also understood to play a pathogenic role in inflammatory disease, arthritis, cardiovascular diseases, pulmonary diseases, and cancer.
After the surgery inflammadry test was performed within 48 hours to measure the MMP-9 in the eyes then the test was repeated after one week from the surgery.
The patient was informed not to put any eye drops for at least an hour before the test so as not to give false results.
Tear samples were collected from the palpebral conjunctiva with the sample collector fleece until it glistens, indicating that the sampling fleece is saturated.
The sampling fleece is then placed within the test cassette with the addition of buffer solution. Within 10 minutes, if there is an MMP-9 antibody-antigen interaction on the immunoassay test strip, the result window will read positive with two lines (one blue and the other one red).
The test was performed for the 30 eyes which 15 of them had LASIK surgery and the other 15 had PRK and results were positive for all cases.
So LASIK and PRK both cause inflammatory dry eye and not responding well to the corticosteroid treatment.