A novel multifunctional, intravitreal injection assistant: evaluation and comparison with conventional technique

Aim The aim of this work is to evaluate the use of a newly developed multifunctional intravitreal injection (IVI) assistant (IIA) to assist the delivery of intravitreal drugs that are the mainstay of current retinal medical therapy, and to compare the assistant with the conventional IVI technique used by most surgeons as regards ease of use, safety, simplicity of the technique, stabilization of the eye during injection, and complications regarding the use of this device.Design This is an interventional study.Patients and methods A total of 90 eyes of 90 patients attending and referred to the retina clinics of Research Institute of Ophthalmology complaining of diminution of visual acuity and/or metamorphopsia, with varying vitreoretinal and macular pathologies and in need of IVIs of either antivascular endothelial growth factor and/or triamcinolone acetonide as a means to treat their eye problem were recruited into the study. The patients were randomly divided into two groups of 45 patients in each group, irrespective of their age, sex, diagnosis of the retinal condition, or the material required for injection. Group A patients had their IVI with the conventional freehand technique, whereas in group B patients IVI was proceeded using the novel multifunctional IVI assistant. Evaluation of the technique used for both groups and all allied problems and comments as regards patient satisfaction, surgeon’s impression, ease of insertion and use of the device, stabilization of the eye, and complications during and postinjection were recorded and analyzed. Treatment and re-treatment protocols were the same for both groups. All the patients were followed up after the injection the first day, first week, weekly for 1 month, and then monthly thereafter. Re-injections for each patient were planned as ‘re-treat as needed’ protocol.Results In all, 68.9% of the patients had diabetic macular edema, 13.3% had neovascular age-related macular degeneration (wet type AMD), 10% had macular edema following retinal vein occlusion, and 7.8% had leaking choroidal neovascularization associated with high myopia. In group A, 62.2% were male and 37.8% were female. The mean age of these patients was 48±4 years. In group B, 53.3% were male and 46.7% were female, and the mean age was 54±6 years. Complications met with during IVI procedure were categorized into two separate entities: procedure-related complications and complications specific to the agent used. The injection procedure was successful for both groups of patients. There was no difficulty met with in group B patients using the IIA, and there was no need to use caliper, fixation forceps, or cotton wool bud. Injections were performed posterior to the limbus at 3.5 mm for aphakic and pseudophakic and at 4 mm for phakic patients. Pressure applied by the assistant was gentle enough and patients had no annoying pain, and even most of them did not notice the needle used for injection. There were no complications related to the injection technique. Subconjunctival hemorrhage was noted in six patients in group A and in two patients in group B. In all, 11.1% of patients from group A and 15.5% of patients from group B complained of postinjection vitreal floaters. One diabetic patient in group A had corneal abrasion. No traumatic lens injury, retinal hemorrhage, tear, or detachment were recorded in any of the patients in both groups. Not a single case of postinjection toxic inflammatory reaction or endophthalmitis was observed. Drug reflux from the injection site was noticed in 8.9% in group A, and no reflux was noted in group B patients. None of the patients had postinjection increase of increased intraocular pressure.Conclusion The newly developed IVI assistant facilitated IVI and provided safe, accurate, consistent, and rapid injections into the intravitreal compartment of the eye.It guided the needle at a fixed angle to penetrate the eye either at a distance of 3.5 or 4 mm from the limbus, allowed a stepped injection, ability to simultaneously inject two types of medication, as well as provided a guided controlled paracentesis. It is a multifunctional device, believed to be a worthy addition to the ophthalmological surgical armamentarium