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December Patient Literature Roundup

Friday, December 28, 2012

Hemang K. Pandya, MD
Michael M. Altaweel, MD, Section Co-Editor
Asheesh Tewari, MD 

Maintenance of Anticoagulant and Antiplatelet Agents for Patients Undergoing

Peribulbar Anesthesia and Vitreoretinal Surgery

Passemard M, Koehrer P, Juniot A, Bron AM, Creuzot-Garcher C. Retina. 2012;32(9):1868-873. doi:10.1097/IAE.0b013e31825097ae.

Vitreoretinal surgeons are frequently faced with the dilemma of operating on patients who require continued use of anticoagulant or antiplatelet therapy through the perioperative period. Examples include patients with prior thromboembolism or valvular heart disease, and those with drug-eluting stents.

This retrospective study evaluated the prevalence of anticoagulation and antiplatelet agent therapy in patients undergoing retinal surgery and compared the outcome of surgery with peribulbar anesthesia between groups.

The study included 206 eyes of 206 patients: 144 eyes (69.9%) without any anticoagulant or antiplatelet therapy; 12 eyes (5.8%) with anticoagulants; and 44 eyes (21.4%) with antiplatelet agents. Six eyes (2.9%) received both anticoagulant and antiplatelet agents.

Although the incidence of mild postoperative hemorrhagic complications was similar between groups (P = .127), the risk of potential sight-threatening hemorrhagic complication (vitreous hemorrhage, retinal hemorrhage, and retinal hematoma) was higher in patients receiving antiplatelet agents (20.5%, P < .003).

Application to Practice: Vitreoretinal surgeons must work in concert with the patient’s primary physician to determine whether anticoagulant or antiplatelet therapy can be temporarily discontinued to decrease the risk of hemorrhagic complications. In this series using peribulbar anesthesia, the risk was elevated only in those continuing antiplatelet therapy. Prior studies have reported an increased risk with anticoagulant treatment. Peribulbar anesthesia reduces the chance of a retrobulbar hemorrhage in this setting. General anesthesia can also be utilized if the international normalized ratio (INR) is high.

Relevance to Patients: These results should provide a stimulus for increased interaction between vitreoretinal surgeons and their primary care counterparts. Patients can be expected to feel reassured that a multidisciplinary team of physicians is involved in managing their medications during surgery. 

Safety of Pars Plana Vitrectomy in Eyes With Plaque-Irradiated Posterior Uveal Melanoma

Bansal AS, Bianciotto CG, Maguire JI, Regillo CD, Shields JA, Shields CL. Arch Ophthalmol. 2012;130(10):1285-1290. doi:10.1001/archophthalmol.2012.2391.

Eyes treated with radioactive plaque for the management of choroidal melanoma may subsequently develop vitreous hemorrhage as a consequence of radiation retinopathy, tumor necrosis, posterior vitreous detachment, or vascular occlusion. This retrospective study examined whether vitrectomy performed in such eyes led to an increased risk of melanoma-related complications such as extrascleral extension, local melanoma recurrence, and systemic melanoma metastasis.

Forty-seven eyes of 47 patients with a history of iodine 125-labeled plaque radiotherapy for choroidal melanoma had vitrectomy for vitreous hemorrhage. The hemorrhage was initially observed in most patients, and the mean interval between the onset of vitreous hemorrhage and pars plana vitrectomy (PPV) was 13 months. The mean duration of follow-up after vitrectomy was 5 years.

There were no cases of extrascleral extension of melanoma or dissemination within the eye. One eye developed local recurrence 2 years after PPV and was treated with transpupillary thermotherapy. Systemic melanoma metastasis occurred in 4 patients (9%) during a mean follow-up of 5 years after plaque radiotherapy. This compared with a metastasis rate of 15% over the same period in a large published cohort from the same institution. Vitrectomy was successful in resolving the vitreous hemorrhage, but visual outcome was limited in some cases by radiation maculopathy or papillopathy.

Application to Practice: This series included eyes with a history of regressed melanoma post-plaque radiotherapy. Secondary vitreous hemorrhage can be safely managed with vitrectomy and does not increase the risk of intraocular tumor dissemination, extrascleral extension, or systemic metastasis.

Relevance to Patients: Patients and their families may have concerns regarding the risk of melanoma returning after further surgery for bleeding within the eye (vitreous hemorrhage). This study shows that when the melanoma was resolved with plaque radiotherapy, patients who needed a vitrectomy did not have re-activation of their melanoma. 

Retinal Artery Occlusion and the 3-Year Risk of Stroke in Taiwan: A Nationwide Population-Based Study

[published online ahead of print July 17, 2012]
Chang YS, Jan RL, Weng SF, et al. Am J Ophthalmol. 2012;154(4):645-652.e1. doi:10.1016/j.ajo.2012.03.046.

Retinal artery occulsion (RAO) is an ophthalmic emergency considered analogous to a stroke in the eye and carries a poor visual prognosis. RAO and stroke share systemic risk factors such as hypertension, diabetes mellitus, and hyperlipidemia. Hence, RAO is suspected to be an early warning sign for subsequent stroke. This retrospective study investigated whether RAO increases the risk of developing stroke. 

Four hundred and sixty-four eyes (464 patients) were diagnosed with RAO and compared with 2748 randomly selected control patients. Within a 3-year follow-up period, 91 RAO patients (19.61%) and 280 control patients (10.05%) were diagnosed with stroke (P < .0001). In particular, the risk of stroke was higher in the first 6 months following RAO onset (P < .0001). Interestingly, they found that central retinal artery occlusion (CRAO) patients had a higher incidence of stroke than following branch retinal artery occlusion (BRAO).    

Application to Practice: This study provided data that retinal artery occlusion is associated with an increased risk of subsequent stroke. This should prompt retinal physicians to refer patients to neurologists or internists for early evaluation and secondary prevention of stroke.

Ranibizumab for Edema of the Macula in Diabetes Study: 3-Year Outcomes and the Need for Prolonged Frequent Treatment

[published online ahead of print October 8, 2012].
Do DV, Nguyen QD, Khwaja AA, et al; for the READ-2 Study Group. Arch Ophthalmol. doi:10.1001/2013.jamaophthalmol.91.

The Ranibizumab for Edema of the Macula in Diabetes 2 (READ-2) Study was a multicenter trial in which diabetic macular edema (DME) patients were randomized to receive intravitreal ranibizumab, focal/grid laser, or a combination of ranibizumab/laser. At the 6-month end point, patients treated with ranibizumab showed significantly greater improvement in mean best-corrected visual acuity (BCVA) compared with the other groups. 

The visual benefits of ranibizumab treatment were maintained during the subsequent 18 months. At 24 months, BCVA had improved by 7.2 letters in the ranibizumab group, 5.1 letters in laser group, and 6.8 letters in ranibizumab plus laser group. Despite the improved BCVA at 24 months, many patients had persistent macular edema with a mean foveal thickness (FTH) of 340μm (ranibizumab), 286μm (laser), and 258μm (ranibizumab/laser). This prospective study was an extension of the initial trial and assessed the benefit of increased follow-up and treatment with ranibizumab in DME patients between 24 and 36 months. 

After 24 months, all READ-2 patients were followed monthly and received 0.5mg ranibizumab if FTH was 250μm or greater. In the ranibizumab group, the mean improvement from baseline BCVA was 7.2 letters at 24 months and 10.3 letters at 36 months (P = .009). Also, FTH improved from 352μm at 24 months to 282μm at 36 months (P = .006). Changes in BCVA and FTH were not statistically significant in the other groups. Patients in the laser or ranibizumab/laser group had less edema during this period and required fewer ranibizumab injections between 24 and 36 months.