American Academy of Ophthalmology Web Site: www.aao.org
New Findings from Ophthalmology, AJO and Archives
June’s American Journal of Ophthalmology:
May’s Archives of Ophthalmology:
Roundup of Other Journals:
Sultan et al. found that intravitreal pegaptanib sodium 0.3 mg is well tolerated and demonstrates superior efficacy to sham in patients with diabetic macular edema. The authors point out that this off-label use of intravitreal pegaptanib is an effective treatment alternative for patients with DME, and that this and prior study data show the treatment provides a positive safety profile.
In this two-year, comparative study, patients received injections of either pegaptanib or sham every six weeks for a total of nine injections, and could receive focal/grid photocoagulation beginning at week 18. During the second year, injections were administered on an as-needed basis and could be given as often as every six weeks. Results showed that 36.8 percent of the pegaptanib group experienced an improvement in visual acuity of more than 10 letters at week 54 compared with 19.7 percent of the sham patients. By week 102, pegaptanib-treated patients gained on average 6.1 letters compared with 1.3 letters for sham. In addition, significantly fewer pegaptanib than sham patients received focal/grid laser treatment during the study.
In a retrospective, interventional case series, Dhaybi et al. report that propranolol appears to be effective in treating periocular infantile hemangiomas.
The treatment protocol for the 18 patients called for administering propranolol 0.5 mg/kg/day initially, with an incremental increase of 0.5 mg/kg/day every four days—up to a maximum of 2 or 3 mg/kg/day. In 17 of the 18 patients, the infantile hemangiomas decreased in size—with a greater reduction occurring when the propranolol was given during the proliferative growth phase of the hemangioma. At the end of the mean follow-up of 10.4 months, none of the patients had amblyopia. In addition, anisometropic astigmatism decreased to a nonamblyogenic level following treatment in five of seven patients.
The authors caution that their treatment protocol required the correct use of an electrical sphygmomanometer for every patient—a cost/availability factor that may limit the drug’s applicability. They conclude that while propanolol may be effective as a first-line treatment approach for periocular infantile hemangiomas, prospective studies with longer follow-up are essential.
In a meta-analysis of randomized controlled trials, Pan et al. demonstrated the superiority of fibrin glue, a blood-derived product that consists of fibrinogen and thrombin, over suture for conjunctival autografting in pterygium surgery. Glue was associated with significantly decreased operating time and was more effective in reducing recurrence rate—without increasing the risk of complications.
For this study, the researchers identified seven studies involving 342 patients (366 eyes). The fibrin-glue procedure was approximately 17 minutes shorter than the suture operation. Recurrence rates varied among the studies, but, on average, the fibrin-glue group showed a significantly reduced recurrence rate—a result the authors attribute to different follow-up periods among the studies.
The authors encourage ophthalmologists to consider using fibrin glue in pterygium surgery, while calling for an analysis of its cost-effectiveness.
American Journal of Ophthalmology
Ivermectin is a broad-spectrum antiparasitic drug primarily used to treat strongyloidiasis and onchocerciasis; however, evidence supports its off-label use against some arthropods. Holzchuh et al. found that ivermectin successfully reduced the number of Demodex folliculorum found in the lashes of patients with refractory blepharitis.
In a noncomparative, interventional case series, the researchers examined 24 eyes of 12 patients with refractory posterior blepharitis with the presence of D. folliculorum in lash samples. Patients were instructed to take one dose of oral ivermectin (200 µg/kg) and to repeat the treatment after seven days. The researchers obtained tear meniscus height, Schirmer test results, noninvasive tear film break-up time, corneal fluorescein and rose bengal staining scores, and quantification of the absolute number of D. folliculorum found in the lashes from all patients one day before and 28 days after the two-dose treatment.
A significant reduction was observed in the absolute number of D. folliculorum found in the lashes after the treatment with oral ivermectin. Average values of Schirmer test results and tear film break-up time improved significantly after the treatment of oral ivermectin. The authors observed no significant improvement in average lacrimal meniscus height or value of corneal fluorescein and rose bengal staining after treatment with oral ivermectin.
For the genetic analysis of patients with congenital ocular malformations, Balikova et al. evaluated the clinical usefulness of the array comparative genomic hybridization technique. Causal deletions were identified in five of 37 patients, affecting OTX2, FOXC1 and VPS13B (COH1), the downstream regulatory region of PAX6, and a de novo deletion on chromosome 16.
The researchers collected samples from 37 patients with negative results for the routine diagnostic workup, including normal karyotype and mutation analysis of appropriate genes. Samples from both parents also were tested. High-resolution, genomewide oligoarray was applied. Confirmation of the results was obtained with independent techniques.
Five patients carried causal submicroscopic imbalance; this high frequency of chromosomal aberrations warrants consideration of the implementation of array comparative genomic hybridization in the diagnostic workup of these patients. Moreover, this screening technique broadens the phenotypic and mutational spectrum associated with genes known to be involved in the cause of congenital ocular malformation.
In an observational, case control study, Oh et al. found that the prevalence of antiplatelet agent use has increased since the mid-1990s in patients undergoing vitreoretinal surgery (VRS). However, the use of these drugs probably does not increase the risk of postoperative intraocular bleeding. They also found that anticoagulant use was associated with a higher risk of postop bleeding, but without serious consequences.
A total of 822 patients who had VRS during intervals in 1994, 2004 and 2008 underwent chart review. The researchers evaluated the proportion of patients using antiplatelets or anticoagulants; the incidence of early postoperative intraocular bleeding; and clinical consequence of the hemorrhage.
Thirty-one of 213 patients (14.6 percent) who underwent VRS in 1994, 103 of 361 patients (28.5 percent) in 2004 and 80 of 248 patients (32.3 percent) in 2008 had taken antiplatelet therapy. The rates of anticoagulant therapy did not vary. The incidence of bleeding was higher (20.0 percent) in the patients who did not suspend antiplatelets before surgery than in those who did, but this difference lost statistical significance in a multivariate analysis.
Anticoagulant use was associated with intraocular hemorrhage at postoperative first day after vitrectomy. No reoperation or failure of the surgery was attributable to the hemorrhage in anticoagulant or antiplatelet patients.
Archives of Ophthalmology
Quek et al. examined the persistence rates of Singaporean patients who started taking topical IOP-lowering monotherapy. The authors found that patients taking prostaglandin analogues had better persistence rates at one year than patients taking timolol maleate and all other medications. Those who were nonpersistent at one year were younger, more likely not to be Singaporean, more likely not to be receiving government subsidies and more likely to be receiving unilateral therapy.
The researchers traced the pharmacy dispensing records of 2,781 patients who started taking a single IOP-lowering medication between Oct. 1, 2005, and Sept. 30, 2006. The study duration included the three-year period from the date of first prescription. A patient was defined as persistent if he or she had a prescription filled for the same medication before, or within 90 days after, the previous prescription had lapsed during this period. The researchers assessed persistence after one and three years. After one year, only 22.5 percent of patients persistently received the same therapy, and this decreased to 11.5 percent after three years.
De Moraes et al. investigated the risk factors associated with rapid visual field progression in treated glaucoma patients. The most significant factors identified were: older age, presence of exfoliation syndrome, decreased central corneal thickness, higher peak IOP, disc hemorrhage and beta-zone peripapillary atrophy. Of note, peak pressure had a stronger association with visual field progression than mean follow-up pressure or fluctuation in follow-up pressure.
The study included a cohort of 587 patients (587 eyes) with glaucomatous optic neuropathy and visual field loss. They were followed for an average of six years.
Visual field progression outcomes were determined using trend analysis—which provides rates of sensitivity change over time—as opposed to event analysis, which defines progression (yes or no) based on comparison to baseline visual field data. By using a large population from a clinical practice, the authors were able to test whether the risk factors described by the major clinical trials can also be applied in a real-world scenario.
Frick et al. assessed the cost-effectiveness of two common approaches for managing nasolacrimal duct obstruction in infants between 6 and 10 months of age: immediate office-based probing surgery (IOPS) and facility-based probing surgery deferred for six months (DFPS).
The authors found that as the spontaneous resolution (SR) rate after presentation increases, the cost of the DFPS approach decreases because fewer higher-cost in-facility probings are needed.
The authors combined the published literature, the Medicare 2009 fee schedule and consensus assumptions to form a model of outcomes for the IOPS and DFPS approaches. They assessed overall cost of treatment, chance of success, and months of symptoms avoided by using IOPS. Sensitivity analyses were also conducted to evaluate the impact of several factors, including the SR rate.
Assuming an SR rate of 75 percent, the IOPS approach costs about 20 percent more than the DFPS approach and was about 4 percent less effective, although it had fewer months of symptoms than IOPS. The cost of IOPS was $44 per additional month of symptoms avoided. (At an SR rate of 50 percent, DFPS costs $342 more than IOPS and $16,709 per additional success. At an SR rate of 90 percent, DFPS costs $413 less than IOPS, with IOPS costing $169 per additional month of symptoms avoided.)
The authors conclude that a more precise estimate of the SR rate is needed to improve the model because it is a key factor in cost-effectiveness.
Roundup of Other Journals
Seider et al. have found a high prevalence of narrow anterior chamber angles in 122 self-declared Filipino-American patients presenting at a comprehensive ophthalmology clinic.
At least one eye in 24 percent of these patients had a narrow anterior chamber angle—a sharp contrast to findings from a group of Caucasian patients in the same clinic of whom none had narrow angles. The researchers also found the Filipino-American angle grade decreased significantly with increasingly hyperopic refraction and larger cup-to-disc ratio. Finally, Filipino-American women had significantly decreased angle grades compared with men.
Eckstein et al. found that 3-D orbital analysis may prove a valuable tool when planning aesthetic and reconstructive orbitofacial surgery. For this study, the authors generated 3-D orbital reconstructions from 15 Western and 12 Asian orbits. In addition to creating a novel measurement method, they found quantitative and qualitative differences between the Western and Asian orbital rim and globe configurations. These differences might indicate that variations in the bony architecture could be a contributing factor to surface-anatomy racial differences in the periorbital area.
Traditionally, characterization of the periocular region has involved examining the observable soft-tissue anatomy of the patient. However, the researchers sought to take this analysis one step further, using recent advances in computing power and the availability of 3-D reconstructions to understand and describe the relationship of the globe and its bony support across the 360-degree area of the orbital rim.
Their work has resulted in a technique to analyze globe position relative to any point on the orbital rim.