Pneumovitreolysis for Vitreomacular Traction

Study Overview
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Brief Summary
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In this prospective, non-randomized, single-arm pilot study, conducted at the Eye Clinic of the University Hospital Split, the investigators are going to evaluate the utility of a single intravitreal injection of sulfur hexafluoride in the treatment of patients with symptomatic vitreomacular traction. Following the injection patients are going to be instructed to bend forward several times a day, resembling a drinking bird, hence the name of this maneuver. The investigators plan to include approximately ten eyes, which will be followed up for a three month period. Outcome measures will be common parameters, like adhesion resolution, also to increase comparability with previously conducted studies. The collected data will be used to get an impression of the efficacy and safety of this intervention. Furthermore it will aid in the performance of a power analysis to determine an appropriate sample size for later larger studies.

Detailed Description
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The Ethical Committee of the Split Clinical Hospital Center previously already gave consent for the conduction of this research. Any personal data obtained in this research was and will be kept and handled strictly confidential and according to the Medical Code of Ethics. All reports generated on the basis of this study will utilize the data of a sample of patients with the diagnosis of vitreomacular traction fulfilling the eligibility criteria prior to intervention. The purpose of the examinations, procedures, possible advantages, disadvantages and possible side effects of the intervention will be explained to all participants, possible questions are going to be answered and a signed informed consent obtained. Patients are going to be selected by the study chair from his pool of patients according to the criteria of inclusion and exclusion, as stated below. After obtaining informed consent all patients will be assigned into the intervention group and receive treatment according to our predefined procedural protocol. Neither participants nor researchers will be blinded during the whole course of the study. One of the investigators carries out regular control examinations at one week after the procedure, and then every 2 to 4 weeks thereafter. During each control examination visual acuity and intraocular pressure will be measured, moreover biomicroscopy, indirect ophthalmoscopy, and macular OCT (Cirrus OCT 5000 HD, Zeiss) of the treated eye are going to be performed. The following data are also going to be recorded by the same investigator: patient demographics (age, gender, right eye in relation to left eye), period of intravitreal injection of gas to the separation of the posterior vitreous body (PVD) and monitoring time. Any adverse events that have occurred after gas injection, including eye complications (eg. retinal tear or ablation, infections, increase in intraocular pressure, uveitis, bleeding and damage to the optic nerve), and systemic complications, are going to be recorded. Statistical Analysis will be performed using IBM SPSS©. Descriptive Statistics will include patient demographic data and baseline characteristics. The mean, standard deviations, median, minimum, and maximum will be reported for continuous variables, whereas frequencies and proportions are going to be described for categorical variables. The investigators will furthermore utilize the collected data to perform a power analysis and determine an appropriate sample size for future studies evaluating the utility of a single intravitreal injection of SF6 in the management of symptomatic vitreomacular traction.

Official Title
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Pneumatic Vitreolysis Using the Drinking Bird Technique for Management of Vitreomacular Traction. A Prospective, Non-randomized, Interventional Study.

Conditions
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Vitreomacular Traction Syndrome

Intervention / Treatment
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* Procedure: Pneumatic Vitreolysis in combination with Drinking-Bird-Technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older able to give written informed consent to the procedure diagnosis of symptomatic VMT based on clinical and OCT-findings Exclusion Criteria: any form of retinal tear, macular degeneration, vascular occlusion of the retina, aphakia, high myopia (> -8 diopters), uncontrolled glaucoma, vitreous opacities, retinal ablation, previous vitrectomy surgery.

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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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Interventional Model Description: Prospective, non-randomized, non-blinded, interventional single-arm pilot study.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pneumatic Vitreolysis<br>All included eyes will receive one intravitreal injection of filtered sulfur hexafluoride gas (SF6). | Procedure: Pneumatic Vitreolysis in combination with Drinking-Bird-Technique<br>* Appropriate anesthesia and antiseptic preparation of the surgical field Prophylactic paracentesis of the anterior chamber One intravitreal injection of 0.2 to 0.3 ml of filtered sulfur hexafluoride gas (SF6) into the test eye Remark: Intraocular pressure of the examined eye is to be controlled before the intervention and kept at an appropriate level after paracentesis by manual application of pressure. Patients are instructed to avoid supine position and to lie on one side or the abdomen during sleep until complete resorption of intraocular gas occured. In this period they should bend over several times during the day up to an angle of 90º or as much as possible, resembling the movement of a bird drinking water. (Hence the name drinking-bird-technique.)<br>* Other names: Pneumovitreolysis;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resolution of VMT | Primary outcome measure is going to be resolution of vitreomacular traction as determined by OCT. | Three months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best corrected visual acuity improvement | Visual acuity is going to be measured preoperatively, as well as on each control visit one week, two weeks, one month and three months post-intervention using standard testing by Snellen-chart. | One week, two weeks, one month, three months | 
| Foveal outline | Foveal outline is going to be described preoperatively, as well as on each control visit one week, two weeks, one month and three months post-intervention using OCT. | One week, two weeks, one month, three months | 
| Central foveal thickness | Central foveal thickness is going to be measured preoperatively, as well as on each control visit one week, two weeks, one month and three months post-intervention using OCT. | One week, two weeks, one month, three months | 
| Maximum central foveal thickness | Maximum central foveal thickness during the three-month follow-up period is going to be determined using regular OCT measurements. | Three months | 
| Time needed for resolution | Individual and average time needed for resolution of VMT after intervention will be described. | Three months | 
| Side-effects | All side-effects will be noted during the three-month follow-up period. Patients will be informed before intervention about possible side-effects and asked on every control-visit about occurrence. | Three months | 
| Occurrence of retinal tear or ablatio | Any occurrence of retinal tear or ablatio will be checked for utilizing OCT, included in our report and treated appropriately. | Three months | 
| Number of patients recommended to undergo further therapy by vitrectomy | In the case vitrectomy surgery seems to be necessary for further management, patients will be informed and recommended to continue further operative treatment. The number of patients referred to surgery will be reported. | Three months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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VMT, VMA, Vitreomacular Adhesion, Pneumatic Vitreolysis