After the release of a large, randomized, multicentered, prospective trial by the European Society of Cataract and Refractive Surgeons, which showed a fivefold decrease in the rates of postoperative endophthalmitis after prophylactic intracameral cefuroxime injection, there has been a steady increase in the number of ophthalmologists who routinely use prophylactic intracameral antibiotics after cataract surgery. Up until recently, the most common choice in the United States has been vancomycin, selected by 52% of providers of those who use intracameral antibiotics. Its low cost, broad coverage, ease of availability, and previously reported safety profile all contributed to its popularity. However, since 2014, there have been a number of reports describing a rare and devastating retinal condition, termed “hemorrhagic occlusive retinal vasculitis (HORV),” whose only common link was the use of intracameral vancomycin during an otherwise routine cataract surgery. Frustratingly, the presentation of this disease often had a delayed onset. Therefore, in the most devastating cases of HORV, individuals did not develop any symptoms until both eyes had already undergone bilateral sequential cataract surgery, and some of these patients went on to develop bilateral severe visual loss. Because of the severity of this disease, the U.S. FDA now suggests avoiding intracameral vancomycin for endophthalmitis prophylaxis during cataract surgery.
Due in part to the delated presentation, the underlying pathophysiology of HORV is theorized to be immune-mediated, as opposed to a direct toxic effect of vancomycin. The time course of presentation and appearance of the disease is consistent with a type III hypersensitivity reaction, which has a peak onset of 1 to 2 weeks after initial antigen introduction, and primarily affects the postcapillary venules. Type III hypersensitivity responses are driven by antigen–antibody complex deposition within the walls of the blood vessels, leading to activation of macrophages, complement, and other inflammatory mediators. HORV may be similar to a known rare type III hypersensitivity reaction to vancomycin that occurs in the skin: leukocytoclastic vasculitis. However, a recent clinical–pathologic correlation suggested that the inflammatory response in this disease was a T-cell–mediated response which primarily affects the choroid, rather than an antibody-mediated response that affects the retina, and future studies may shed light on the specific pathogenesis of this disease.
88.1.1 Common Symptoms
Symptoms typically begin 1 to 21 days (mean = 8 days) postoperatively with painless peripheral scotomas or blurred vision; patients with less severe findings may be asymptomatic.
88.1.2 Examination Findings
Typical findings include mild to moderate anterior chamber reaction without a hypopyon, and mild to moderate vitreous inflammation, with a relatively clear view to the posterior pole (which may help distinguish this disease from postoperative endophthalmitis). Most notably, patients often have large, sectoral areas of retinal vascular occlusion, with intraretinal hemorrhages localized to areas of retinal vascular occlusion. Hemorrhages are usually large or confluent, but occasionally appear as smaller dot hemorrhages (▶ Fig. 88.1, ▶ Fig. 88.2). Rarely, peripheral retinal vascular occlusion without retinal hemorrhage has been seen. Venules may be sheathed and surrounded by particularly dense clusters of hemorrhages. The peripheral retina appears to be nearly always involved, but severe cases may also demonstrate macular ischemia and whitening.
Fig. 88.1 Hemorrhagic occlusive retinal vasculitis (HORV) secondary to drug exposure. (a) Color mosaic photograph of the right eye of a patient with HORV. The disease developed 1 week after otherwise uncomplicated cataract surgery, which was performed using intracameral vancomycin 1 mg/0.1 mL. The right eye surgery was performed first, followed by the left eye surgery 1 week later. The photo demonstrates extensive confluent retinal hemorrhages in regions of retinal nonperfusion, as well as macular whitening. (b) Optical coherence tomography of the macula demonstrates inner retinal thickening and hyperreflectivity (consistent with macular ischemia), as well as a small pocket of subfoveal fluid. (c) Widefield fluorescein angiography demonstrates extensive peripheral retinal nonperfusion which co-localize with areas of retinal hemorrhage.