Ocular Hypotony and Refractive Predictability in RRD Surgery

Impact of Preoperative Ocular Hypotony on Refractive Predictability After Phacovitrectomy for Rhegmatogenous Retinal Detachment

This study evaluates how preoperative ocular hypotony (Goldmann IOP ≤ 7 mmHg) affects refractive predictability, axial length measurements, and visual outcomes in patients undergoing combined phacovitrectomy with silicone oil for rhegmatogenous retinal detachment.

This observational cohort study is designed to evaluate the impact of preoperative ocular hypotony (defined as Goldmann IOP ≤ 7 mmHg) on refractive outcomes, biometry parameters, and visual acuity after combined phacovitrectomy for RRD. All included eyes undergo standard 25-gauge pars plana vitrectomy with cataract extraction with IOL implantation, endolaser photocoagulation, and silicone oil tamponade.

The study population consists of eyes with primary RRD and stratified into two cohorts according to preoperative IOP:

Hypotony group - eyes with Goldmann IOP ≤ 7 mmHg; Control group - eyes with normal preoperative IOP .

Inclusion Criteria:

• Diagnosis of primary rhegmatogenous retinal detachment (RRD)
• Single-stage combined phacovitrectomy with clear corneal phacoemulsification with IOL implantation and 25G pars plana vitrectomy with silicone oil tamponade in the study eye
• Preoperative intraocular pressure (IOP) in the study eye measured by Goldmann applanation tonometry: Hypotony group: IOP ≤ 7 mmHg; Normotony group: IOP > 7 mmHg
• Planned silicone oil removal approximately 3 months after the initial combined surgery and ability to attend follow-up for refractive assessment 1 month after silicone oil removal
• Age (e.g., ≥18 years) and ability to provide informed consent

Exclusion Criteria:

• Previous intraocular surgery in the study eye
• Secondary or complex RRD associated with ocular trauma, uveitis or other active intraocular inflammation, proliferative diabetic retinopathy or other advanced vascular retinopathies, significant ocular malformations or congenital anomalies of the globe or posterior segment, pre-existing advanced glaucoma or uncontrolled ocular hypertension, or other optic nerve pathology that could confound visual and refractive outcomes, corneal opacity, significant corneal irregularity, or media opacity precluding reliable biometry or accurate axial length measurement in the study eye, systemic diseases or autoimmune conditions with known ocular involvement that may affect the retina, choroid, or refraction