This Issue At A Glance
Ophthalmology Volume 119, Number 4, April 2012
Meta-Analysis Compares Topical to Regional Anesthesia in Cataract Patients According to findings from a meta-analysis conducted by Zhao et al (p. 659), intraoperative and postoperative pain perception is significantly higher in cataract patients treated with topical anesthesia (TA) compared with those who treated with retrobulbar/peribulbar anesthesia (RBA/ PBA). However, the 2 approaches achieve similar surgical outcomes. The comprehensive literature search encompassing 15 trials compared 1084 eyes who underwent phacoemulsification with TA to 1121 eyes who had RBA/PBA. In addition to the higher pain levels, the TA group demonstrated more frequent inadvertent ocular movement and a greater intraoperative need for supplementary anesthesia. Yet the patients significantly preferred TA. The RBA/PBA group reported more frequent anesthesia-related complications including chemosis, periorbital hematoma, and subconjunctival hemorrhage. The researchers conclude that while TA does not provide the same level of pain relief as RBA/PBA, it is nevertheless tolerated reasonably well. Given the numerous anesthetic approaches available today, surgeons can tailor their anesthetic choice based on each patient’s unique clinical profile, i.e., the presence of higher blood pressure, and pain tolerance.
Long-Term Corticosteroids Help Prevent Rejection in Penetrating Keratoplasty In a prospective, randomized clinical trial, Shimazaki et al (p. 668) have found that prolonged use of 0.1% fluorometholone helps to prevent rejection following penetrating keratoplasty (PKP). Of the initial 42 patients in this 12-month trial randomly assigned to either the steroid group (treated with 0.1% fluorometholone 3 times a day) or the no-steroid group (discontinuation of steroid eye drops), 4 in the steroid group and 6 in the no-steroid group did not complete the trial. Of the remaining patients, 1 patient in the steroid group and 6 in the non-steroid group developed endothelial rejection at an average of 5.2⫾4.5 (mean ⫾ standard deviation) months after they entered the study–a significant differ ence. In contrast, the researchers did not detect a significant difference betweenthegroupsinvisualacuity,intraocularpressure,epithelialdamage, tear-film break-up time, cataract progression, infection, or incidence of systemic side effects. The authors conclude lose-dose corticosteroids should be considered in PKP patients, even in those at low risk of rejection.
Correlating Clinical Features, MRI, and Histopathologic Findings in Retinoblastoma Chawla et al (p. 850) present findings from what they maintain is the first prospective study on the relationship among clinical features, magnetic resonance imaging (MRI) and histopathologic findings in eyes primarily enucleated for retinoblastoma. The study involved 75 patients with Group E retinoblastoma. The investigators found neovascularization of the iris, raised intraocular pressure, shallow anterior chamber, and tumor volume correlated well with high-risk histopathology. They note the accuracy of
MRI in detecting choroidal invasion was 68%–a figure found in earlier, similar reports. This shows that microscopic invasion of the choroid may be missed on MRI. Detection of ciliary body invasion was more accurate (93.3%) compared with previous studies, and MRI correctly detected scleral invasion in all affected eyes, with no false-positive findings. Given the limitations of MRI in reliably predicting microscopic infiltration of the choroid and optic nerve, the authors conclude any decision to treat with neoadjuvant chemotherapy based on suspected post-laminar invasion on MRI is not justified without histopathologic evidence of disease.
Two Phase III Studies Show Benefits of Ranibizumab in Diabetic Macular Edema Nguyen et al (p. 789) provide evidence from 2 large, randomized, multicenter, phase III sham-controlled studies of ranibizumab demonstrating that visual loss from diabetic macular edema (DME) can be reversed, and clinically significant, sustained visual improvements can be achieved with low rates of side effects. The RISE trial involved 377 patients randomized to sham, 0.5-mg monthly intravitreal ranibizumab injections or 0.3-mg injections; the RIDE trial involved 382 patients. Monthly ranibizumab injections proved superior to sham across all measures of vision improvement. In addition to a gain of ⱖ15 letters or 3 eye chart lines, a nearly 2-line benefit over sham was observed for average vision change. More ranibizumab-related patients had Snellen equivalent best corrected visual acuity of ⱖ20/40 at 24 months. Optical coherence tomography (OCT) showed significant improvements in macular edema in ranibizumabtreated patients. Also, the ranibizumab group underwent significantly fewer macular laser procedures. The researchers assert these findings provide ophthalmologists with a considerable body of evidence supporting ranibizumab as a viable approach to manage DME.
Twenty-Year Study: Trabeculectomy a LongTerm Treatment Alternative Results from a 20-year retrospective cohort study indicate trabeculectomy surgery represents a long-term solution to control intraocular pressure (IOP) in many patients. Landers et al (p. 694) found that in a group of 234 predominantly Caucasian patients (330 procedures), almost 60% of trabeculectomies survived up to 20 years without the need for topical medication. This figure rose to 90% when including those being treated with additional tropical medication. Younger patients or those with uveitic glaucoma were at greater risk of trabeculectomy failure, and patients with pseudoexfoliation or aphakia were more likely to progress to blindness. In addition, individuals using 2 or more topical medications or with advanced visual field loss at the time of surgery were more at risk of both trabeculectomy failure and blindness. While these data support trabeculectomy surgery for long-term IOP control, the authors recommend that clinicians look at such risk factors as patient age, preoperative topical medication use, and the type and severity of glaucoma when considering trabeculectomy surgery to manage their glaucoma patients.
Lori Baker Schena, EdD, and John Kerrison, MD