Ocular Hypotony and Refractive Predictability in RRD Surgery (HYP-RRD)

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Rhegmatogenous Retinal Detachment; Hypotony Ocular
• Intervention / Treatment: Procedure: Combined Phacovitrectomy with Intraocular Lens Implantation and Silicone Oil Tamponade; Procedure: Silicone Oil Removal

Detailed Description

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 .

• Study Type: Interventional
• Enrollment (Estimated): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Kazakhstan
  • Almaty, Kazakhstan, 050012
    • Kazakh Eye Research Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: RRD Patients with Ocular Hypotony; Patients with primary rhegmatogenous retinal detachment (RRD) and preoperative ocular hypotony, defined as Goldmann intraocular pressure (IOP) ≤ 7 mmHg, undergoing combined phacoemulsification and IOL implantation, pars plana vitrectomy with silicone oil tamponade. Silicone oil is planned to be removed approximately 3 months after the initial combined surgery and detailed refractive assessment is performed 1 month after silicone oil removal. This cohort is used to evaluate the impact of preoperative hypotony on axial length measurements, refractive predictability (MAE, % within ±0.50 D), and visual outcomes.	Procedure: Combined Phacovitrectomy with Intraocular Lens Implantation and Silicone Oil Tamponade; Standardized single-stage clear corneal phacoemulsification with IOL implantation is combined with three-port 25-gauge pars plana vitrectomy, fluid-air exchange, endolaser photocoagulation, and silicone oil tamponade for rhegmatogenous retinal detachment. After cataract extraction and IOL placement, pars plana vitrectomy is performed with fluid-air exchange to reattach the retina, endolaser photocoagulation around retinal breaks, and tamponade with silicone oil.; Procedure: Silicone Oil Removal; Silicone oil removal is performed approximately 3 months after the initial combined phacovitrectomy. Three-port 25-gauge pars plana access and pressure-controlled fluid-silicone exchange with balanced salt solution to completely remove silicone oil from the vitreous cavity. At the end of surgery, sclerotomies are sutured.
Active Comparator: RRD patients with normal IOP; Patients with primary rhegmatogenous retinal detachment (RRD) and normal preoperative IOP (> 7 mmHg) undergoing the same combined phacovitrectomy with IOL implantation and silicone oil tamponade. Silicone oil is planned to be removed approximately 3 months after the initial combined surgery and detailed refractive assessment is performed 1 month after silicone oil removal. This cohort serves as the comparison group for the hypotony arm to determine whether normal preoperative IOP is associated with more accurate axial length measurements, better refractive predictability, and comparable or superior visual outcomes.	Procedure: Combined Phacovitrectomy with Intraocular Lens Implantation and Silicone Oil Tamponade; Standardized single-stage clear corneal phacoemulsification with IOL implantation is combined with three-port 25-gauge pars plana vitrectomy, fluid-air exchange, endolaser photocoagulation, and silicone oil tamponade for rhegmatogenous retinal detachment. After cataract extraction and IOL placement, pars plana vitrectomy is performed with fluid-air exchange to reattach the retina, endolaser photocoagulation around retinal breaks, and tamponade with silicone oil.; Procedure: Silicone Oil Removal; Silicone oil removal is performed approximately 3 months after the initial combined phacovitrectomy. Three-port 25-gauge pars plana access and pressure-controlled fluid-silicone exchange with balanced salt solution to completely remove silicone oil from the vitreous cavity. At the end of surgery, sclerotomies are sutured.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Absolute Error (MAE) of Postoperative Refraction	Mean Absolute Error between the target refraction predicted by preoperative IOL power calculation and the achieved postoperative spherical equivalent refraction, calculated in diopters for each eye. Percentage of eyes in each group with an Mean Absolute Error ≤ ±0.50 diopters between the target refraction and the achieved postoperative spherical equivalent refraction.	1 month after silicone oil removal

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Best-Corrected Visual Acuity	Best-Corrected Visual Acuity measured in Logarithm of the Minimum Angle of Resolution (LogMAR) units using standard visual acuity charts and compared between hypotony and normotony groups after surgery and silicone oil removal	3 months after combined surgery, 1 month after silicone oil removal
Axial Length Measurement	Difference between preoperative and postoperative axial length measurements, and its correlation with preoperative IOP status.	1 month after silicone oil removal

Collaborators and Investigators

• Sponsor: Kazakh Eye Research Institute

Study record dates

Study Major Dates

• Study Start (Actual): December 8, 2025
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): October 17, 2026

Study Registration Dates

• First Submitted: December 4, 2025
• First Submitted That Met QC Criteria: December 4, 2025
• First Posted (Actual): December 16, 2025

Study Record Updates

• Last Update Posted (Actual): March 18, 2026
• Last Update Submitted That Met QC Criteria: March 16, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: cataract surgery; vitreoretinal surgery; Rhegmatogenous Retinal Detachment; Hypotony Ocular; intraocular lens calculation; refractive assessment
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypotension; Surgical Procedures, Operative; Ophthalmologic Surgical Procedures; Refractive Surgical Procedures; Lens Implantation, Intraocular
• Other Study ID Numbers: IRB-194-2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No