Refractive Changes Following Vitrectomy

Study Overview
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Brief Summary
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We aimed o compare the refractive changes associated with pars plana vitrectomy with or without intraocular gas tamponade in pseudophakic eyes. This retrospective study included pseudophakic patients with Nd:YAG laser posterior capsulotomy who underwent 23G PPV between February 2015 and March 2019. Group 1 consisted of patients with regmatogenous RD who underwent PPV and 12% perflouropropane (C3F8) gas tamponade whereas Group 2 consisted of patients who underwent PPV for epiretinal membrane or vitreous hemorrhage (VH). No tamponade was used in Group 2. Minimum follow-up was 12 months.

Detailed Description
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This research was reviewed by an independent ethical review board and conforms with the principles and applicable guidelines for the protection of human subjects in biomedical research. This was a retrospective, comparative case series including pseudophakic patients who underwent PPV. Group 1 consisted of patients with pseudophakic RRD who underwent PPV and 12% perflouropropane (C3F8) gas tamponade whereas Group 2 consisted of patients with ERM or VH who underwent PPV without any tamponade between February 2015 and March 2019 at Bursa Retina Eye Hospital. Informed consent was obtained from all the participants. The study was in line with the ethical standarts of the Helsinki Declaration Patient eligibility Patients who underwent uncomplicated cataract surgery with phacoemulsification and in-the-bag IOL implantation and subsequent neodymium:yttrium-aluminum-garnet (Nd:YAG) laser due to capsular opacification were included. Preoperative refractive data obtained after Nd:YAG laser and six months prior to vitrectomy surgery. Postoperative refractive data was obtained at 12 months after vitrectomy. Eyes with a preoperative spherical refractive error > ±6 D or cylindrical refractive error > ±3 D were excluded. Also eyes with corneal disorders were excluded. Ocular parameters All patients underwent complete ophtalmic examination including best corrected visual acuity (BCVA) in the logMAR scale, slit-lamp examination, intraocular pressure (IOP) assessment, fundus examination and autokeratorefractometry (auto kerato-refractometer KR-8800 from Topcon, Tokyo, Japan) at preoperative and postoperative month-12. Induced astigmatism values were calculated through vector analysis. Surgical procedures All surgeries were performed by the same surgeon (S.Y.). Retrobulbar block anesthesia (a mixture of 2 ml of lidocaine hydrochloride 2% and 2 ml of bupivacaine hydrochloride 0.5%) was used. Three port 23-gauge (G) transconjunctival PPV was performed using the vitrectomy system DORC (Dutch Ophthalmic Research Center, Zuidland, Netherlands) and Zeiss microscope with EIBOS 2 (Haag Streit, Mason, OH, USA) attachment for non-contact fundus viewing. In group 1, all patients underwent a near-complete vitrectomy including base shaving, laser endo-photocoagulation and C3F8 gas tamponade. In group 2, patients with ERM received a limited vitrectomy including; core vitrectomy, induction of a posterior vitreous detachment if not present and peeling of the ERM and inner limiting membrane (ILM). Peripheral retina was examined with indentation to identify any retinal breaks. Neither laser endo-photocoagulation, nor gas tamponade and vitreous base shaving was performed. For patients with VH patients, a near-complete vitrectomy, including base shaving, laser endo-photocoagulation was performed except for gas tamponade. In both groups, the sclera is sutured with 8-0 polyglactin suture (Vicryl) in case of wound leakage.

Official Title
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Refractive Changes in Pseudophakic Eyes Following Vitrectomy With or Without Gas Tamponade

Conditions
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Retinal Detachment, Refractive Errors, Vitreous Hemorrhage, Epiretinal Membrane

Intervention / Treatment
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* Other: pars plana vitrectomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Patients aged ≥ 18 years Pseudophakic patients who underwent pars plana vitrectomy Exclusion Criteria Patients aged 18 years > Patients with a spherical refractive error > ±6 D Patients with a cylindrical refractive error > ±3 D

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group<br>27 patients, Group 1 consisted of patients with pseudophakic rhegmatogoneous retinal detachment who underwent pars plana vitrectomy and 12% perflouropropane (C3F8) gas tamponade and 20 patients Group 2 consisted of patients with epiretinal membrane or vitreous hemorrhage who underwent PPV without any tamponade | Other: pars plana vitrectomy<br>* 23 gauge pars plana vitrectomy was performed for retinal detachment, vitreous hemorrhage or epiretinal membrane<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The rate of spherical and cylindrical refractive changes | Changes in spherical and cylindrical refractive error 12 months after pars plana vitrectomy | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Myopic shift, Gas tamponade, Pars plana vitrectomy