EVALUATION OF THE RELATIONSHIP BETWEEN EARLY HEALING RESPONSES IN ANGLE, ASSESSED BY ANTERIOR SEGMENT OCT FOLLOWING GATT SURGERY, AND CHANGES IN INTRAOCULAR PRESSURE REDUCTION AND MEDICATION COUNT ASSOCIATED WITH THE PROCEDURE

Evaluation of the relationship between early healing responses (HR) in angle, assessed by anterior segment OCT following uncomplicated GATT surgery, and changes in intraocular pressure (IOP) reduction and the number of antiglaucoma medications (AGM) used.

A retrospective study conducted at a tertiary referral center.

The study included 24 eyes of 21 patients who underwent uncomplicated GATT surgery performed by the same surgeon (RDG) at our hospital. Eyes with ocular surgery or laser treatment within the last 6 months prior to surgery, eyes with active uveitis, patients with a history of ocular trauma, or eyes with a refractive error exceeding 3D spherical and 2D astigmatic values were excluded. Detailed ophthalmological evaluations were conducted for patients before GATT and at 1 month after GATT. The HR in the nasal and temporal angles at 1 month post-GATT was assessed using swept-source OCT anterior segment imaging. The HR was classified into two groups: those with significant scarring and those without. The relationship between the HR and surgery-related changes in IOP and AGM count was evaluated.

Seventeen of the patients were male, with an average age of 61±7 years. 14 eyes had a diagnosis of primary open-angle glaucoma, 7 eyes had pseudoexfoliation glaucoma, 2 eyes had uveitic glaucoma, and 1 eye had steroid-induced glaucoma. 9 were phakic, and 15 were pseudophakic. A 270 degrees GATT procedure was performed in 5 eyes, and a 360 degrees GATT procedure in 19 eyes. Postoperatively, hyphema developed in 16 eyes (66.7%); however, none required anterior chamber lavage. Significant scarring was observed in the nasal quadrant in eight eyes (33.3%) and in the temporal quadrant in eleven eyes (45.8%). At the first postoperative month, a significant reduction in IOP and antiglaucoma medication (AGM) usage was observed compared to preoperative levels (14±3 vs. 25±7 mmHg and 1±1 vs. 4±1, p<0.001), while no significant change was noted in best-corrected visual acuity (p>0.05). No significant relationship was found between healing response (HR) and changes in IOP, AGM count, or age (p>0.05). Additionally, there was no significant association between the presence of significant scarring in the nasal or temporal quadrant and the development of hyphema (p>0.05). One patient with a diagnosis of uveitic glaucoma required trabeculectomy surgery later on.

Although significant scarring was detected by anterior segment OCT in the early period following GATT surgery, a significant reduction in IOP and the number of AGM used can still be achieved. The development of postoperative hyphema was not found to be associated with significant scarring. Further studies with a larger patient population, additional cross-sectional anterior segment OCT images from more quadrants, and long-term follow-up will shed more light on this issue.