Corneal Astigmatism Outcomes After Simultaneous Pterygium Excision Using The Bare Sclera Technique and Manual Small Incision Cataract Surgery: Protocol for a Prospective Single-Arm Pre-Post Interventional Cohort Study.

BACKGROUND: Pterygium and cataract frequently coexist in populations with high UV light exposure, particularly in rural India. Both conditions impair visual acuity and reduce quality of life. Simultaneous small incision cataract surgery (SICS) combined with pterygium excision offers the advantages of a single surgical session, faster rehabilitation, and lower cost compared with sequential procedures. However, SICS uses a superior scleral tunnel incision of 6.5 to 7 mm, which itself induces against-the-rule surgically induced astigmatism. The net astigmatic outcome of simultaneous SICS and pterygium excision-specifically, whether the reduction of pterygium-induced with-the-rule astigmatism offsets SICS-induced against-the-rule astigmatism-has not been prospectively characterized in a resource-limited setting. The bare sclera technique, while not designed to minimize recurrence, was selected to isolate the corneal astigmatic effects of fibrovascular tissue removal without confounding variables associated with conjunctival grafting. OBJECTIVE: This protocol describes a prospective single-arm pre-post interventional cohort study designed to quantify the change in the magnitude and axis of corneal astigmatism from baseline to day 30 following manual SICS with posterior chamber intraocular lens (IOL) implantation, followed by primary nasal pterygium excision using the bare sclera technique, in a single operative sitting. METHODS: This prospective single-arm pre-post interventional cohort study will be conducted at the Department of Ophthalmology, Acharya Vinoba Bhave Rural Hospital, Datta Meghe Institute of Higher Education and Research (DMIHER), Wardha, India. A total of 100 participants aged ≥35 years with visually significant cataract and grade 1 to 2 primary nasal pterygium will undergo standardized simultaneous surgery consisting of manual SICS with posterior chamber IOL implantation, followed by bare sclera pterygium excision in a single operative sitting. The study evaluates short-term postoperative outcomes over 30 days; long-term corneal stabilization and recurrence assessment are beyond its scope. As this is a single-arm exploratory study without a comparator group, causal inferences will not be made. The sample size (N=100) was calculated using paired continuous outcomes based on the expected change in keratometric astigmatism. The primary outcome is change in keratometric corneal astigmatism (magnitude and axis) from baseline to day 30. Secondary outcomes include Alpins vector analysis, the association between pterygium size and preoperative astigmatism, changes in visual acuity, refractive surprise, early fibrovascular regrowth, patient satisfaction, and complications. Follow-up assessments will occur on day 1, day 15, and day 30. RESULTS: Ethics approval was obtained on June 30, 2025. Participant recruitment began on November 1, 2025. As of September 2026, 40 participants have been enrolled. Data analysis is expected to be conducted following completion of follow-up. CONCLUSIONS: This protocol will generate prospective data on corneal astigmatism following simultaneous manual SICS and bare sclera pterygium excision to inform surgical planning, IOL selection, and patient counseling in SICS-predominant resource-limited settings. TRIAL REGISTRATION: Clinical Trials Registry-India CTRI/2025/10/095785; https://tinyurl.com/mry8se6y. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/96749.