Short-term Anterior Segment Changes After Pars Plana Vitrectomy (PPV) and Silicone Oil (SO) Tamponade, Anterior Segment OCT (AS-OCT) Study.
Short-term Anterior Segment Changes After Pars Plana Vitrectomy (PPV) and Silicone Oil (SO) Tamponade, Anterior Segment OCT (AS-OCT) Study.
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.
Type of the study: A prospective comparative study.
Study Setting: Assiut university hospital.
Study subjects:
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
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.
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:
Primary (main):
Mean change in central anterior chamber depth after PPV with SO tamponade.
Secondary (subsidiary):
Mean change in peripheral anterior chamber depth, mean change in anterior chamber angle and mean change anterior chamber angle entry area.
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
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.