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June 2012

 
Journal Highlights
New Findings from Ophthalmology, AJO, and Archives
 
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Ophthalmology:

American Journal of Ophthalmology:

Archives of Ophthalmology:

Roundup of Other Journals:

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Ophthalmology

Epimacular Brachytherapy in Challenging Cases of Active AMD
Ophthalmology
Published online April 1, 2012

Epimacular brachytherapy (EMB) involves delivering local, targeted radiation to the neovascular tissue that causes wet age-related macular degeneration (AMD). Following pars plana vitrectomy, the sealed radiation source is temporarily placed over the fovea in the vitreous cavity via an intraocular cannula. Dugel et al. found that EMB is generally a safe and effective approach to stabilizing visual acuity in patients with chronic, active AMD. They believe that these findings may help reduce the need for frequent anti-VEGF injections. 

The authors present 12-month safety and efficacy data from the three-year prospective MERITAGE (Macular Epiretinal Brachytherapy in Treated Age-Related Macular Degeneration) trial. The trial involved 53 eyes of 53 patients with AMD who needed frequent VEGF re-treatment. Prior to enrollment, participants underwent an average of 12.5 anti-VEGF injections annually. After EMB treatment, 81 percent maintained stable vision. The patients underwent a mean of 3.49 anti-VEGF re-treatments in 12 months. Adverse side effects possibly or probably related to EMB or vitrectomy included conjunctival hemorrhage, cataract, resolving vitreous hemorrhage, and eye pain.

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SD-OCT and Reversal of Optic Disc Cupping After Glaucoma Surgery
Ophthalmology

Published online March 30, 2012

In an effort to better understand the reversal of optic disc cupping after glaucoma surgery, Lee et al. used spectral-domain optical coherence tomography (SD-OCT) to evaluate the structural changes in the deep optic nerve head after IOP lowering via trabeculectomy. At six months after surgery, they found both a significant reduction in the posterior displacement of the lamina cribrosa (LC) and a significant increase in the thickness of the LC and prelaminar tissue. The authors believe that the anterior movement of the LC is likely the cause of the cupping reversal.

This observational case series involved 35 eyes of 35 patients with primary open-angle glaucoma who underwent trabeculectomy. SD-OCT was conducted before surgery and up to six months following surgery. Factors associated with reduced anterior LC movement included age, amount of baseline LC displacement, and magnitude of IOP decrease.

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Clinical Features of Herpetic Scleritis
Ophthalmology
Published online March 29, 2012

Given that herpesviruses are the most common cause of infectious scleritis, Gonzalez-Gonzalez et al. set out to describe the clinical features most often seen in these patients. A retrospective case series revealed that the following function as a diagnostic indicator of herpetic scleritis: unilateral presentation, moderate to severe pain, associated uveitis or keratitis, and acute onset. 

The investigators reviewed the electronic health records of 500 patients with scleritis. Of the 47 patients who had an underlying infectious cause for their scleritis, 35 were diagnosed with a herpesvirus infection, five had tuberculosis, and the remaining seven presented with other infectious diseases. The authors noted that while herpetic scleritis accounts for 7 percent of all scleritis cases in this series, diagnosis may be difficult when there is not a pathognomonic clinical picture.

The authors recommend scleral biopsy to diagnose this condition. When this option is not available, oral acyclovir may be considered. They also encourage timely diagnosis and early therapy to prevent vision loss, which is greater among these patients than individuals with idiopathic scleritis.

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Ocular Trauma Score Reliable in Predicting Visual Outcome in Traumatic Cataract
Ophthalmology

Published online March 28, 2012

Shah et al. have found that the Ocular Trauma Score (OTS) is a reliable predictor of visual outcome six weeks after surgery in patients with traumatic cataract. They also found that, in the management of traumatic cataracts, patients with open-globe injuries achieved satisfactory vision more often than those with closed-globe injuries.

The researchers enrolled a total of 787 eyes of 787 subjects with traumatic cataracts and examined the eyes to review comorbidities caused by trauma. Surgery was performed for traumatic cataracts, IOLs were implanted, and patients were treated for amblyopia, as applicable. The patients were reexamined six weeks postoperatively. Using the Birmingham Eye Trauma Terminology System, the researchers divided patients into two traumatic cataract groups: open-globe injury and closed-globe injury. They analyzed the relationship of visual acuity with demographic and clinical variables, predicted visual outcomes using the OTS, and compared predictions with the actual outcomes using statistical tests.

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American Journal of Ophthalmology

Preservative-Free Tafluprost vs. Timolol in Patients With OAG
June’s AJO

In a randomized, double-masked, multicenter clinical trial, Chabi et al. examined the efficacy and safety of tafluprost and timolol in patients with open-angle glaucoma or ocular hypertension. They found that tafluprost is an efficacious and generally well-tolerated ocular hypotensive agent with an IOP-lowering effect that is noninferior to that of timolol.

A total of 643 patients were randomized; 618 completed the study. After discontinuation and washout of pretrial ocular hypotensive treatment, patients were randomized to 12 weeks of treatment with either tafluprost or timolol. The researchers measured IOP three times during the day at baseline and at two, six, and 12 weeks. They hypothesized that tafluprost would be noninferior to timolol over 12 weeks with regard to change from baseline IOP. The trial was powered for a noninferiority margin of 1.5 mmHg at each of the nine time points assessed.

IOPs during the baseline visit ranged from 23.8 to 26.1 mmHg in the tafluprost group and 23.5 to 26 mmHg in the timolol group. IOPs at the three time points during the 12-week visit ranged from 17.4 to 18.6 mmHg for tafluprost and 17.9 to 18.5 mmHg for timolol. Comparing the difference between the IOP-lowering powers of the two treatments, the authors found that at all nine time points, the upper limits of the 95 percent confidence intervals were less than the prespecified noninferiority margin. Similar percentages of tafluprost and timolol patients reported ocular pain, stinging, irritation, and pruritus. The percentages of tafluprost and timolol patients reporting conjunctival hyperemia were 4.4 and 1.2 percent, respectively.

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Treatment Patterns for AMD in Medicare Beneficiaries
June’s AJO

In a retrospective, cohort study of Medicare beneficiaries, Curtis et al. found that treatment of newly diagnosed AMD changed significantly between 2006 and 2008, most notably in the increasing use of anti-VEGF therapies. However, few patients treated with anti-VEGF medications received monthly injections, and discontinuation rates were high.

The article reviews trends among 284,380 Medicare beneficiaries who had a new AMD diagnosis between 2006 and 2008. The authors used the cumulative incidence function to estimate rates of the procedure’s use and the mean frequency function to estimate the cumulative mean number of intravitreal injections. They utilized Cox log-binomial regression to estimate predictors of the use of VEGF antagonists within one year after diagnosis. Discontinuation of anti-VEGF therapy was defined by absence of treatment for 12 months.

The proportion of patients receiving anti-VEGF therapy increased from 60.3 to 72.7 percent, photodynamic therapy decreased from 12.8 to 5.3 percent, and thermal laser treatment decreased from 5.5 to 3.2 percent. African-American patients and patients with dementia were less likely than Caucasian patients to receive anti-VEGF therapy. Among patients who received anti-VEGF therapy, the mean number of injections within one year of the first injection was 4.3 per treated eye. Anti-VEGF therapy was discontinued in 53.6 percent of eyes within one year, and in 61.7 percent of eyes within 18 months.

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Posterior Chamber Phakic IOL vs. LASIK for Low to Moderate Myopia
June’s AJO

Kamiya et al. compared postoperative visual function after implantable collamer lens (ICL) placement and wavefront-guided LASIK in eyes with low to moderate myopia. They found that ICLs induced significantly fewer ocular higher-order aberrations than LASIK. Moreover, contrast sensitivity was significantly improved after ICL implantation but unchanged after LASIK.

This observational case study included 30 eyes of 20 patients undergoing ICL implantation and 64 eyes of 38 patients undergoing LASIK for the correction of low to moderate myopia. The researchers measured both ocular higher-order aberrations and contrast sensitivity function with Hartmann-Shack aberrometry and a contrast sensitivity unit before and three months after surgery.

For 4- and 6-mm pupils, the changes in ocular third-order aberrations, fourth-order aberrations, and total higher-order aberrations after ICL implantation were significantly less than those after LASIK. The postoperative area under the log contrast sensitivity function was significantly increased after ICL implantation, whereas it was not significantly changed after LASIK.

The authors concluded that, even in the correction of low to moderate myopia, ICLs appear to be superior to wavefront-guided LASIK in visual function, suggesting that it may be a viable treatment option.

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Archives of Ophthalmology

Vitamin D and Retinopathy in Adults With Diabetes Mellitus
May’s Archives

Patrick et al. explored a hypothesized association between vitamin D inadequacy and diabetic retinopathy. Among the 1,790 adults with diabetes included in the study, the percentage of individuals with vitamin D deficiency increased with severity of retinopathy, but there was no statistically significant correlation between absolute serum concentration and retinopathy severity.   

This cross-sectional study analyzed data from adults aged 40 years and older with diabetes who participated in the Third National Health and Nutrition Examination Survey. The researchers evaluated the relationship between vitamin D deficiency and severity of diabetic retinopathy as well as the relationship between absolute serum concentration and severity of retinopathy in the presence of covariates such as age, race, obesity, and persistent hyperglycemia.

The authors concluded that these findings—combined with previous research indicating possible anti-inflammatory and antiangiogenic properties of vitamin D—suggest the need for further investigation of a possible connection between vitamin D and diabetic retinopathy.

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Resolution of Nasolacrimal Duct Obstruction With Nonsurgical Management
May’s Archives

Petersen et al. found that more than half of nasolacrimal duct obstruction (NLDO) cases involving infants between 6 and 10 months old resolved within six months of nonsurgical management.

The researchers prescribed nasolacrimal duct massage and topical antibiotics (as needed) to 107 infants (116 eyes) between the ages of 6 and 10 months with NLDO and no history of prior nasolacrimal duct surgery.

Resolution of the obstruction was assessed six months after study entry and was defined as the absence of all clinical signs of NLDO (epiphora, increased tear lake, or mucous discharge) and without undergoing NLDO surgery. Exploratory analyses assessed whether baseline characteristics such as age, gender, laterality, and prior treatment were associated with the probability of NLDO resolution without surgery.

At the six-month examination, the NLDO had resolved without surgery in 77 eyes (66 percent). None of the baseline characteristics evaluated were found to be associated with resolution.

The authors concluded that knowledge of the rate of NLDO resolution without surgery will help clinicians and parents effectively discuss treatment options.

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Ophthalmology summaries are written by Lori Baker Schena, EdD, and edited by John Kerrison, MD. American Journal of Ophthalmology summaries are edited by Thomas J. Liesegang, MD. Archives of Ophthalmology summaries are written by the lead authors.

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Roundup of Other Journals

23-Gauge vs. 20-Gauge Transconjunctival Sutureless Vitrectomy
Eye

Published online March 2, 2012

Ahn et al. found that, in the early postoperative period, 23-gauge transconjunctival sutureless vitrectomy (TSV) resulted in a more stable and lower IOP than did 20-gauge vitrectomy. These findings indicate that 23-gauge TSV may be a more beneficial approach for patients with optic nerves that are vulnerable to higher or fluctuating IOP.

In this retrospective, interventional case series, the researchers performed 338 cases of 23-gauge TSV and 476 cases of 20-gauge vitrectomy using the same Accurus vitrectomy system. They compared IOP readings one day, one week, and one month following surgery. At one day after surgery, the mean IOP of the 20-gauge vitrectomy patients was significantly higher (20.6 ± 8.02 mmHg) than in the 23-gauge TSV patients (12.8 ± 4.48 mmHg). However, the authors found that these differences were not significant at one week and one month. In addition, the IOP pattern was more stable with the 23-gauge TSV.

The 23-gauge TSV group showed significantly higher incidences of hypotony at one day after surgery than the 20-gauge vitrectomy group. On the other hand, the incidence of hypertony was significantly greater in the 20-gauge vitrectomy group at one day. The incidences of hypotony and hypertony at one week and one month were not significantly different between the 20- and 23-gauge vitrectomy groups.

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Gauge Size and Cataract Progression Following Vitrectomy
Retina

2012;32(3):499-505

Almony et al. found that the gauge size of vitrectomy instrumentation does not have an impact on the progression of nuclear sclerotic cataract.

This observational, interventional study included 42 eyes: 11 eyes had 20-gauge surgery, 22 had 23-gauge surgery, and nine had 25-gauge surgery. Before vitrectomy surgery, each patient underwent digital Scheimpflug lens photography to quantify the density of nuclear light scattering in pixel intensity units. Digital Scheimpflug lens photography was repeated six months and 12 months after vitrectomy surgery.

The authors demonstrated that the surgeries led to significant progression of nuclear sclerotic cataract in all of the study eyes compared with the fellow unoperated eye.

The investigators concluded that their results reflect the latest ophthalmic knowledge of what causes nuclear sclerotic cataract. One of the roles of vitreous gel is to protect the lens from exposure to molecular oxygen within the eye. Vitrectomy surgery removes this protective gel, leading to more rapid oxidative damage of the crystalline lens, which in turn results in significant progression of the nuclear sclerotic cataract. This occurs regardless of the size of the vitrectomy instruments.

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New Agent to Treat Leber Hereditary Optic Neuropathy
Archives of Neurology

2012;69(3):331-338

In a small, open-label clinical trial of a new therapeutic agent, EPI-743, Sadun et al. found that four of five patients with Leber hereditary optic neuropathy (LHON) experienced disease arrest and reversal of vision loss. According to the authors, this agent may represent the first effective treatment for LHON—a mitochondrial disease caused by single-point mutations occurring in mitochondrial DNA. The condition usually affects young male patients and, in most instances, leads to persistent bilateral blindness.

In this study, five patients with genetically confirmed LHON received EPI-743 three times daily by mouth (100 to 400 mg per dose) in the active converting phase of their clinical course. Four patients exhibited arrest of disease progression with visual loss reversal, and two of those patients demonstrated a total recovery of visual acuity. No adverse events were reported.

The authors observed that the restoration of vision experienced by 80 percent of these patients suggests that retinal ganglion cells thought to have undergone cell death may have a reversible component.

They are launching a multicenter, controlled study to confirm these observations. Any positive results could possibly provide proof of concept for a new class of drugs to treat LHON and other mitochondrial pathophysiologic conditions.

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Roundup of Other Journals is written by Lori Baker Schena, EdD, and edited by Deepak P. Edward, MD.

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