An interventional study of Combined Phacovitrectomy with Intraocular Lens Implantation and Silicone Oil Tamponade and Silicone Oil Removal in Rhegmatogenous Retinal Detachment and Hypotony Ocular, sponsored by Kazakh Eye Research Institute. Active, not recruiting at 1 site in Kazakhstan. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-18.
Sponsored by Kazakh Eye Research Institute · Not applicable, Interventional, and Treatment
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 .
Exclusion Criteria:
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 · Procedure: Silicone Oil Removal
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 · Procedure: Silicone Oil Removal
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 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.
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.
Time frame: 1 month after silicone oil removal
Axial Length Measurement
Difference between preoperative and postoperative axial length measurements, and its correlation with preoperative IOP status.
Time frame: 1 month after silicone oil removal
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
Time frame: 3 months after combined surgery, 1 month after silicone oil removal
Plan to share: Undecided
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This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Ocular Hypotension
Kazakh Eye Research Institute