Resident Complicaitons of Intravitreal Injections at a Large County Hospital

INTRODUCTION: Intravitreal injections (IVIs) have now surpassed cataract surgery as the most frequently performed procedure in ophthalmology. Their incidence has increased from less than 3,000 in 1999 to more than 2.3 million in 2012. The most common pharmacologic agents administered intravitreally inhibit angiogenesis by blocking vascular endothelial growth factor. Diabetic macular edema, exudative age-related macular degeneration, and venous-occlusion associated macular edema are the most common indications. As such, IVI usage will only increase in the future as the population ages, new medications become available, and indications broaden. With IVIs being performed at increasing rates at the Parkland county hospitalﾒs resident ophthalmology clinic, identification of an accurate risk profile must be delineated, including possible complications during cataract surgery. METHODS: A retrospective chart review of patients who received one or more IVIs by an ophthalmology resident at Parkland between 01/2010 and 07/2016 was conducted. Charts were reviewed for a variety of IVI-related complications as well as the incidence of posterior capsule rupture (PCR) during cataract surgery, after one or more IVIs. RESULTS: 1893 eyes (from 1300 subjects) that had undergone at least one IVI were included. Of a total of 8642 IVIs that were reviewed, 76 complications (0.88%) were noted. Their nature ranged from relatively non-vision threatening (corneal abrasion, ptosis, and posterior vitreous detachment) to severely vision threatening (endophthalmitis, intraocular pressure (IOP) elevation, retinal detachment (RD), and other patient movement-related complications). The majority of complications did not occur at a significantly higher or lower rate than those reported in the literature. However, a significantly lower rate of RD (p=0.039) and a significantly higher rate of acute and chronic IOP elevation (p=0.001) was found. Further, of 354 cataract surgeries included and reviewed on eyes with prior IVIs, PCR occurred 12 eyes. Of these 13 eyes, 7 eyes were excluded for a prior history of pars plana vitrectomy, a known independent risk factor for PCR. This resulted in a PCR rate of 1.41% compared to average rates in literature of 1.9-2.1% (p=0.677). DISCUSSION: Resident administered IVIs at Parkland pose an overall low risk of complication, minimally different from IVIs administered at other institutions. The PCR rate in eyes with a history of IVIs at Parkland, excluding previously vitrectomized eyes, is not significantly different than the standard rate in literature. This data will prove useful in analyzing the unique risks of IVIs and subsequent cataract surgeries in individual patients. The etiology of the increased rates of IOP elevations at Parkland requires further investigation.