Session Title: Vitreoretinal Surgery II
Session Date/Time: Friday 18/09/2015 | 08:00-10:00
Paper Time: 09:04
First Author: : N.Borah INDIA
Co Author(s): : H. Amin
PURPOSE:an observational study of 4 eyes of 4 patients who had unusual complications during intravitreal ozurdex implant. Immediate and delayed effect of the complications were studied till 6 months post-operatively.
4 eyes of 4 patients had received intra-vitreal Ozurdex (0.7mg) single injection for macular edema due to various diseases. These eyes.experienced intraoperative complications during the procedure. Post-operative adverse effects (if any) of the ozurdex pallets/fragments within the eye and its effect on retina, optic disc and macular edema was studied.
4 eyes in 4 patients ( male= 2, female=2), age (M= 45, 51years) and (F= 65, 59years) were studied. Duration of study- January, 2014 to December, 2014. Pre-operative indications were - 1. recurrent macular edema following CRVO- 2 eyes,2. diabetic macular edema-2 eyes. All these eyes had received either intravitreal avastin or intravitreal lucentis prior to intravitreal ozurdex. None of these eyes underwent prior vitrectomy. 1 eye was pseudophakic and 3 were phakic. Post-operative follow up- 1st week then monthly for six months. Pre-operative and post operative visual acuity assessment, slit- lamp examination, IOP, fundus examination, OCT and FFA were done in all eyes. The Ozurdex (dexamethasone 0.7 mg) injections were given with all aseptic precautions in the operation theatre under the operating microscope. Topical betadine solution(10%) was instilled into the conjunctival sac prior to and after the injection. Peribulbar anaesthesia (2% xylocaine) was administered. Pre (4 times daily X 1 day) and post operative(6 times daily X 7 days) moxifloxacin eye drop was also used . Procedure: safety pin was removed and bevel of the applicator was introduced into the eye (inferior temporal quadrant) and ozurdex implant was injected .
immediately after pushing the press button following sequence of events took place 1.In all 4 eyes there was a sudden give away feel , thus the pallets passed through the vitreous gel, hit the posterior fundus and bounced back into mid vitreous cavity. In 2 eyes the pallets broke into 2 unequal pieces. Immediate indirect opthalmoscopic examination did not reveal any retinal (break , haemorrhage) , optic nerve head injury. Post injection all 4 patients complained of large floaters affecting vision. These floaters gradually decreased in size and disappeared at mean 5 months. Pre-and post- injection mean visual acuity(log mar) was 0.875 ± 0.189 and 0.425 ±0.095 respectively. In 2 eyes the ozurdex implants broke into two pieces and migrated anteriorly behind the posterior capsule (at 1 month follow up ). Implants could be observed in the vitreous cavity till mean 4.9 months (4-6 mo). No eyes developed retinal break or detachment. Post injection all eyes showed IOP rise from 1st month onwards. IOP rise was controlled by topical medications (timolol maleate, 0.5%). Mean IOP- post-operative (23.75 ,±1.71 mm Hg), pre-operative(17.75,±1.71 mm Hg),p-value= 0.001. OCT (4 eyes) showed resolution of macular edema (mean pre-operative 413.5µ (SD±97.24), post-operative 255µ(SD±26.39).p value= 0.03.
Due to sudden and forceful release of the dexamethasone implant, injury to the posterior fundus (retina, optic disc) is a possibility. Post-vitrectomized eyes could be more at a risk. Breaking of these pallets on impact may cause increased vitreous floaters and affect the pharmacodynamics of the dexamethasone implant, which ideally should be effective in the vitreous cavity for a longer period. A more smoother release mechanism would be ideal for the delivery of the pallet.