Ocular Surface Changes and Glaucoma: A Prospective Contralateral Study of IOP-Reducing Eyedrops versus iStent Inject Surgery

Kjell Gunnar Gundersen,1 Morten Gundersen,1,2 Christian Nilsen,1,2 Per Graae Jensen1,2 1IFocus Øyeklinikk AS, Haugesund, Rogaland, Norway; 2Department of Life Sciences and Health, Oslo Metropolitan University, Oslo, NorwayCorrespondence: Kjell Gunnar Gundersen, IFocus Øyeklinikk AS, Sørhauggata, 111, Haugesund, 5527, Norway, Tel +47 91 64 87 07, Email kg@ifocus.noPurpose: To compare ocular surface outcomes between interventional glaucoma treatment with trabecular micro-bypass stent implantation and continued topical intraocular pressure-lowering therapy.Patients and Methods: A prospective, single-center, contralateral-eye study of patients with bilateral, mild-to-moderate open-angle glaucoma undergoing implantation of the iStent inject in the study eye, while the fellow eye (control eye) continued topical medications. Just over half the eyes in both groups underwent phacoemulsification. Ocular surface parameters were evaluated using objective tests and validated symptom questionnaires at baseline and at 1, 3, and 6 months.Results: Fifty-six eyes were included, 28 in each group. At 6 months, medication use reduced significantly in study eyes (from 1.9± 1.0 preoperatively to 0.4± 0.6; p< 0.001), but not in control eyes (from 1.5± 0.9 to 1.4± 0.8; p=0.168). Study eyes demonstrated significant improvements in keratograph bulbar redness score (2.4± 0.6 to 2.0± 0.4; p=0.003), and Oxford ocular surface staining (OSS) score (1.6± 1.2 to 0.7± 1.0; p< 0.001) while control eyes did not; improvements in bulbar redness and OSS scores were significantly greater in study eyes (p=0.005 and p=0.045, respectively). Patient-reported symptoms improved significantly: OSDI (Ocular Surface Disease Index) scores decreased from 18.4 ± 16.4 to 9.3 ± 8.9 (p=0.007) and SPEED (Standard Patient Evaluation of Eye Dryness) II scores decreased from 8.0 ± 7.8 to 4.5 ± 4.1 (p=0.005).Conclusion: Interventional glaucoma treatment with trabecular micro-bypass stent implantation significantly reduced medication burden, which was associated with improved signs and symptoms of ocular surface disease at 6 months. Compared to fellow eyes on topical therapy, stent-treated eyes showed better outcomes in selected ocular surface parameters, supporting the benefits of an interventional approach.Keywords: ocular surface disease, glaucoma medications, iStent inject, dry eye disease, MIGS