Ocular surface changes after excimer laser phototherapeutic keratectomy

Area of Science:

• Ophthalmology
• Corneal Disease
• Ocular Surface Disease

Background:

• Patients with Avellino dystrophy, granular dystrophy, lattice dystrophy, band keratopathy, and corneal leukoma often present with ocular surface disorders.
• These conditions can lead to significant discomfort and visual impairment.

Purpose of the Study:

• To evaluate the impact of excimer laser phototherapeutic keratectomy (PTK) on ocular surface parameters in patients with specific corneal opacities.
• To compare pre- and post-operative ocular surface conditions in these patients.

Main Methods:

• A prospective case-controlled study involving 33 patients (45 eyes) with superficial corneal opacities and 20 healthy controls (40 eyes).
• Ophthalmic examinations included corneal sensitivity, tear film break-up time (BUT), Schirmer test, tear film lipid layer interferometry, and conjunctival impression cytology.
• Pre- and post-PTK parameters were assessed and compared between groups.

Main Results:

• Pre-PTK, patients exhibited lower corneal sensitivity and BUT, and higher tear film lipid layer and conjunctival squamous metaplasia grades compared to controls.
• Following PTK, these parameters showed significant improvement.
• Goblet cell density was lower pre-PTK in patients but did not significantly change post-PTK; Schirmer test results also remained unchanged.

Conclusions:

• Phototherapeutic keratectomy (PTK) favorably impacts the ocular surface in patients with corneal opacities.
• PTK improves tear film stability and ocular surface health by regularizing the corneal surface.
• The procedure may also enhance mucin production from a healthier corneal epithelium.