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.
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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
12
1. Appropriate anesthesia and antiseptic preparation of the surgical field 2. Prophylactic paracentesis of the anterior chamber 3. 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. 4. 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".)
University Hospital of Split, Department of Ophthalmology
Split, Croatia
Resolution of VMT
Primary outcome measure is going to be resolution of vitreomacular traction as determined by OCT.
Time frame: Three months
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Three months
Time needed for resolution
Individual and average time needed for resolution of VMT after intervention will be described.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Three months
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