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NCT Number: NCT07283614

Ocular Hypotony and Refractive Predictability in RRD Surgery

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.

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Key information

Conditions

Rhegmatogenous Retinal Detachment Eye Diseases Hypotony Ocular Ocular Hypotension

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Kazakh Eye Research Institute

Almaty, 050012, Kazakhstan

About this study

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 .

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Combined Phacovitrectomy with Intraocular Lens Implantation and Silicone Oil Tamponade

Procedure

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.

Silicone Oil Removal

Procedure

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.

Primary outcomes

  1. Mean Absolute Error (MAE) of Postoperative Refraction

    Time frame: 1 month after silicone oil removal

    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.

Secondary outcomes

  1. Axial Length Measurement

    Time frame: 1 month after silicone oil removal

    Difference between preoperative and postoperative axial length measurements, and its correlation with preoperative IOP status.

  2. Best-Corrected Visual Acuity

    Time frame: 3 months after combined surgery, 1 month after silicone oil removal

    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

Sponsors and collaborators

Lead sponsor

Kazakh Eye Research Institute

Network

Registry information

Official study title

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

Acronym: HYP-RRD

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Dec 16, 2025
Registry last updated
Mar 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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