Pars Plana Vitrectomy Combined With Phacoemulsification Cataract Surgery in Phakic Diabetes Retinopathy Patients

Study Overview
=================
Brief Summary
-----------------
Pars plana vitrectomy (PPV) is one of the most widely used surgical therapies to proliferative diabetic retinopathy in the world. However, as a predictable consequence of PPV surgery, postoperative cataract is observed in 79%-95% of phakic diabetes retinopathy patients after PPV in 6-24 months and a subsequent cataract surgery is usually required. While, the subsequent cataract surgeries not only bring additional economy and workload burden, but also increase the surgical risks. Since the two-step surgical approach has its defects, the combination of PPV and phacoemulsification is an ideal surgical option. This study is a multi-center prospective study, aimed to evaluate the effect of PPV combined with phacoemulsification cataract surgery in phakic diabetes retinopathy patients, and make a comparation between the combined surgery and the two-step surgery in patients without severe lens opacities.

Detailed Description
-----------------
The prevalence of diabetes retinopathy is increasing dramatically recent years. Pars plana vitrectomy (PPV) is one of the most widely used surgical therapies to proliferative diabetic retinopathy in the world. However, as a predictable consequence of PPV surgery, postoperative cataract is observed in 79%-95% of phakic diabetes retinopathy patients after PPV in 6-24 months.Generally, subsequent cataract surgeries are required for the phakic patients within 6-16 months after the PPV surgery to improve visualization. While, the subsequent cataract surgeries not only bring additional economy and workload burden, but also increase the surgical risks because of the deep anterior chamber, zonular dehiscence, and inflammation. Since the two-step surgical approach has its defects, the combination of PPV and phacoemulsification is an ideal surgical option, which is only suggested in patients with severe lens opacities before the PPV surgery so far. For those with mild-moderate lens opacities, the benefits of combined surgery is unknown. This study is a multi-center prospective study, aimed to evaluate the effect of PPV combined with phacoemulsification cataract surgery in phakic diabetes retinopathy patients, and make a comparation between the combined surgery and the two-step surgery in patients without severe lens opacities.

Official Title
-----------------
The Effect of Pars Plana Vitrectomy Combined With Phacoemulsification Cataract Surgery in Phakic Diabetes Retinopathy Patients Over 45 Years Old: a Multicenter Randomized Controlled Clinical Study

Conditions
-----------------
Diabetic Retinopathy, Diabetic Cataract

Intervention / Treatment
-----------------
* Procedure: Pars plana vitrectomy combined with cataract surgery.
* Procedure: Pars plana vitrectomy with subsequent cataract surgery.


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Proliferative diabetes retinopathy ; Age over 45 years old; mild-moderate lens opacities(LOCSⅢ : C3N3P3 or below); recognition of at least one alphabet in ETDRS chart. Exclusion Criteria: Long-standing retinal detachment (more than three months), macular affected Low Vision or blind on the other eye; Macular degeneration, including age-related macular degeneration and Polypoidal choroidal vasculopathy; Ocular trauma; Glaucoma; Hereditary retinopathy; Severe lens opacities before the surgery (LOCSⅢ : C4N4P4 or above).

Ages Eligible for Study
-----------------
Minimum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Combined surgery group<br>In this group, all eligible patients will receive pars plana vitrectomy combined with phacoemulsification cataract surgery. | Procedure: Pars plana vitrectomy combined with cataract surgery.<br>* In the combined surgery group, phakic diabetes retinopathy patients over 45 years old without severe lens opacity will receive pars plana vitrectomy combined with phacoemulsification and intraocular lens (IOL) implantation at the same time.<br>|
| Active Comparator: Subsequent surgery group<br>In this group, all eligible patients will receive pars plana vitrectomy first. And a subsequent phacoemulsification will be systematically performed 6 months after the PPV surgery. | Procedure: Pars plana vitrectomy with subsequent cataract surgery.<br>* In the control group, phakic diabetes retinopathy patients over 45 years old without severe lens opacity will first receive pars plana vitrectomy and a subsequent phacoemulsification with IOL implantation will be performed at least 6 month after the PPV.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best correct visual acuity (BCVA) | BCVA with early treatment diabetic retinopathy study (ETDRS) letters | Change from Baseline at 1 week after the surgery(s) | 
| Best correct visual acuity | BCVA with ETDRS letters | Change from Baseline at 1 month after the surgery(s) | 
| Best correct visual acuity | BCVA with ETDRS letters | Change from Baseline at 3 months after the surgery(s) | 
| Best correct visual acuity | BCVA with ETDRS letters | Change from Baseline at 6 months after the surgery(s) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VFQ-25 score | Visual Function Questionnaire-25, values from 0-100, the higher scores mean a better outcome | Change from Baseline at 6 months after the surgery(s). | 
| Complications | Common complications after the surgery like glaucoma, macular edema, iritis, et. al. | through study completion, an average of 1 year | 
| Treatment costs | The amount of money paid on the surgery(s) by each patient. | through study completion, an average of 1 year | 
| Working delay time | The working delay time due to the surgery(s). | through study completion, an average of 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Diabetic Retinopathy, Diabetic Cataract, Pars plana vitrectomy, Phacoemulsification