Short-term Anterior Segment Changes After Pars Plana Vitrectomy (PPV) and Silicone Oil (SO) Tamponade, Anterior Segment OCT (AS-OCT) Study.

Overview

The purpose of our study is to utilize AS-OCT to analyze the anterior segment morphological changes in the early postoperative period of patients who will undergo PPV with silicone oil injection.

1. Type of the study: A prospective comparative study. 2. Study Setting: Assiut university hospital. 3. Study subjects: 1. Inclusion criteria: Patients suffering from different vitreo-retinal disorders (rhegmatogenous retinal detachment, diabetic vitreous hemorrhage, diabetic tractional retinal detachment) with either preserved crystalline lens or previous cataract surgery (at least 3 months prior to PPV) will be recruited 2. Exclusion criteria: Patient with previous history of ocular trauma, co-existing glaucoma, co-existing anterior uveitis, complicated cataract surgery, IOL-related complications, previous vitreo-retinal surgery, visually significant cataract (necessitating combined phacoemulsification with PPV and SO) and significant corneal opacity will be excluded. If any significant post-PPV complication develops, patient will be excluded from the study. 3. Sample Size Calculation: Thirty eyes (30 patients) will undergo PPV with SO tamponade and AS-OCT analysis prior to surgery and 1 week post-operatively to achieve study power of 80% with 0.05 significance. 4 -Study tools (in detail, e.g., lab methods, instruments, steps, chemicals, …): All participants underwent best-corrected visual acuity (BCVA) by Snellen's chart, Slit lamp assessment of the anterior segment, dilated fundus examination, intra-ocular pressure (IOP) measurement by calibrated Goldmann Applanation Tonometer (GAT). Baseline Ophthalmic ultrasound and Axial length measurement will be obtained. Anterior segment OCT (AS-OCT) protocol All eyes will be examined by AS-OCT (Nidek RS-3000 Advance, Tokyo, Japan) 1-2 days prior to vitreo-retinal surgery and one week after surgery by single experienced physician. Poor fixation or poor image signal (less than 3/10) will exclude the patient from the study. Anterior segment OCT (AS-OCT) parameters The following anterior segment parameters will be evaluated; central and peripheral anterior chamber depth (cACD, pACD), anterior chamber angle (ACA) and central corneal thickness (CCT). 5 -Research outcome measures: <!-- --> 1. Primary (main): Mean change in central anterior chamber depth after PPV with SO tamponade. 2. Secondary (subsidiary): Mean change in peripheral anterior chamber depth, mean change in anterior chamber angle and mean change anterior chamber angle entry area.

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Eligibility

Outcomes