American Academy of Ophthalmology Web Site: www.aao.org
New Findings from Ophthalmology, AJO and Archives
May’s American Journal of Ophthalmology:
April’s Archives of Ophthalmology:
Roundup of Other Journals:
Gillies et al. have found that intravitreal triamcinolone acetonide (IVTA) plus laser more frequently results in vision improvement of more than 10 letters compared with laser alone. However, IVTA eyes are more likely to experience cataract and elevated IOP.
The researchers randomly assigned 84 eyes of 54 participants to receive IVTA plus laser (42 eyes) or laser treatment alone (42 eyes). At 24 months, improvement of more than 10 logMAR letters occurred in 36 percent of eyes treated with ITVA plus laser, compared with 17 percent of eyes treated with laser alone.
Cataracts were removed from 61 percent of phakic eyes treated with IVTA plus laser compared with none of the laser-only eyes. Treatment for elevated IOP was required in 64 percent of eyes treated with IVTA plus laser compared with 24 percent of laser-only eyes.
The authors conclude that IVTA may be a useful adjunct to laser treatment in certain patients with diabetic macular edema.
Given the challenges associated with monthly injections of ranibizumab to treat subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration, would a quarterly treatment regimen be just as effective? According to Schmidt-Erfurth et al., the answer is no.
This study is the first prospective trial designed to directly compare monthly and quarterly ranibizumab dosing regimens. The researchers randomized 353 patients with primary or recurrent subfoveal CNV secondary to AMD 1:1:1 to 0.3-mg quarterly, 0.5-mg quarterly or 0.3-mg monthly doses of ranibizumab. Treatment involved a loading phase of three consecutive monthly injections followed by a nine-month maintenance phase of either monthly or quarterly injections. The gain in BCVA in the monthly regimen was higher than that of the quarterly regimens at 12 months.
The results are consistent with clinical guidelines recommending rigorous monthly monitoring with timely re-treatment to achieve the best outcomes.
Rahi et al. reported results from an epidemiological investigation of myopia that included 2,487 randomly selected 44-year-old members from the 1958 British birth cohort.
At age 44, patients underwent autorefraction along with an epidemiological questionnaire looking at four “life-stage” models—preconceptional; prenatal, perinatal and postnatal; childhood; and adult—to examine the influence of early life biology, social status, growth patterns and eye-specific factors as they relate to myopia. Results suggested that at least one in three working adults in the United Kingdom has clinically significant myopia.
Myopia was associated with low birth weight for gestational age as well as for gender, greater maternal age, higher paternal occupational social class and maternal smoking in early pregnancy. In adults, myopia was associated with higher educational attainment and socioeconomic status, and greater height.
The authors conclude that there is a need for a paradigm shift in myopia research and suggest an integrated approach that includes application of genetic, epidemiological and statistical data studied across a lifetime in large, unselected populations.
American Journal of Ophthalmology
Dry eye disease is a commonly encountered condition in clinical practice and affects up to 20 percent of the population in North America. Lemp et al. performed a prospective, observational case series to determine the clinical usefulness of tear osmolarity and commonly used objective tests to diagnose dry eye disease.
This multicenter, 10-site study consisted of 314 consecutive subjects between 18 and 82 years of age. The researchers performed six tests: bilateral tear osmolarity, tear film break-up time, corneal staining, conjunctival staining, Schirmer test and meibomian gland grading. They then measured diagnostic performance against a composite index of objective measurements that classified subjects as having normal, mild or moderate, or severe dry eye. The main outcome measures were sensitivity, specificity, area under the receiver operating characteristic curve and intereye variability.
Of the six tests, the researchers found tear osmolarity to have superior diagnostic performance. The most sensitive threshold between normal and mild or moderate subjects was 308 mOsms/l, whereas the most specific was found at 315 mOsms/l. At a cutoff of 312 mOsms/l, tear hyperosmolarity exhibited 73 percent sensitivity and 92 percent specificity. By contrast, the other common tests exhibited either poor sensitivity (corneal staining, 54 percent; conjunctival staining, 60 percent; meibomian gland grading, 61 percent) or poor specificity (tear film break-up time, 45 percent; Schirmer test, 51 percent). Tear osmolarity also had the highest area under the receiver operating characteristic curve. Intereye differences in osmolarity were found to correlate with increasing disease severity.
The authors conclude that tear osmolarity is the best single metric both to diagnose and classify dry eye disease. They also note that intereye variability is a characteristic of dry eye not seen in normal subjects.
Brechner et al. reviewed all Medicare fee-for-service Part B claims for age-related macular degeneration during 2008 and described the usage patterns of pharmacological treatments for AMD in Medicare fee-for-service beneficiaries.
In this study, the researchers first identified Medicare beneficiaries having undergone treatment. The data collected from each visit for a given beneficiary included age, race, gender, Medicare region, state/zip code of residence, date of visit, whether or not the beneficiary had a treatment, the type and amount of drug, and dollars paid by Medicare. The main outcome measures were the number and rate of treatments, the types of drugs used for treatment and the payments for these drugs.
Of the 222,886 unique beneficiaries, 146,276 (65.6 percent) received bevacizumab and 80,929 (36.3 percent) received ranibizumab. A total of 824,525 injections were performed with 480,025 injections of bevacizumab (58 percent) and 336,898 injections of ranibizumab (41 percent). National rates of injections per 100,000 fee-for-service Part B Medicare beneficiaries for bevacizumab and ranibizumab were 1,506 and 1,057, respectively. Total payments by Medicare were $20,290,952 for bevacizumab and $536,642,693 for ranibizumab. In 39 out of 50 states, the rate of injection was higher for bevacizumab than ranibizumab.
Results from the study showed that, in 2008, bevacizumab was used at a higher rate than ranibizumab for the treatment of AMD. Even though bevacizumab accounted for 58 percent of all injections, Medicare paid $516 million more for ranibizumab than bevacizumab.
This study suggests that despite its off-label designation, intravitreal bevacizumab is currently the standard-of-care treatment for AMD.
Archives of Ophthalmology
Fintelmann et al. investigated whether recent use of topical fluoroquinolones is a risk factor for in vitro fluoroquinolone resistance in Staphylococcus aureus ocular isolates.
The authors performed disc diffusion susceptibility testing of ciprofloxacin, moxifloxacin and gatifloxacin for all ocular isolates of S. aureus. They also reviewed medical records to determine any topical or systemic fluoroquinolone use within the three months prior to culture.
Of 200 S. aureus cultures, 41 were resistant to ciprofloxacin, moxifloxacin and gatifloxacin. Fluoroquinolone-resistant S. aureus isolates were from older patients (mean, 65.5 years) compared with fluoroquinolone-susceptible isolates (mean, 52.1 years). Use of fluoroquinolones in the preceding three months was more frequent in resistant isolates than in susceptible isolates, as was recent hospitalization.
The authors conclude that recent topical fluoroquinolone use is significantly associated with fluoroquinolone resistance in S. aureus isolates from ocular cultures. Other risk factors associated with fluoroquinolone resistance included older age, systemic immunosuppression and recent hospital or nursing home admission. Given the retrospective nature of this study, it is not possible to determine whether fluoroquinolone resistance was present in the isolates prior to the use of antibiotics or whether it was induced by fluoroquinolone use.
There is concern that poor vitamin-D status is common and may increase the risk for chronic diseases. Only one previous study has examined the relationship of vitamin-D status to age-related macular degeneration; it found evidence for a protective association.
In this study, Millen et al. sought to determine whether a protective effect could be confirmed in a study sample in which vitamin-D status was assessed prior to assessment of AMD. Researchers examined the relationship between vitamin-D status—measured by serum 25-hydroxyvitamin D (25(OH)D) concentrations—and the prevalence of early AMD among participants of the Carotenoids in Age-Related Eye Disease Study.
The researchers took stereoscopic fundus photographs of 1,287 female participants aged 56 to 84 years without advanced AMD to assess status of AMD. Serum samples collected an average of six years earlier were assayed for 25(OH)D concentrations. Two hundred and forty-one women had early AMD. The odds of having early AMD among women with high vs. low 25(OH)D concentrations were compared using logistic regression and adjusted for age, smoking, iris pigmentation, family history of AMD, cardiovascular disease, diabetes and hormone therapy use.
High concentrations of serum 25(OH)D were associated with decreased odds of early AMD in women younger than 75 years of age and increased odds in women 75 years or older. Further adjustment for body mass index and recreational physical activity attenuated the observed association in women younger than 75 years.
Roundup of Other Journals
In a letter to the editor, Bruce et al. report results from the FOTO-ED (Fundus Photography vs. Ophthalmoscopy Trial Outcomes in the Emergency Department) study, which looked at the usefulness of nonmydriatic fundus photography in detecting ocular fundus abnormalities related to emergency department care.
The study was prompted by the perceived underuse of direct ophthalmoscopy in the emergency department setting due to limited training, increased demands on the physician’s time and the need for pharmacologic pupillary dilation.
The researchers enrolled 350 adult patients who presented in the emergency department with headache, acute focal neurologic deficit or acute visual change, or whose diastolic blood pressure was 120 mmHg or higher. Trained nurse practitioners took ocular fundus photographs with a nonmydriatic fundus camera, and these photographs were then reviewed by a neuro-ophthalmologist within 24 hours. This approach resulted in relevant ocular findings in 44 patients: 13 cases of optic-nerve edema, 13 intraocular hemorrhages, 10 instances of hypertensive retinopathy, four cases of arterial vascular occlusion and four instances of optic-nerve pallor.
The authors conclude that nonmydriatic fundus photography can be performed by nonphysician staff and provides the ability to detect relevant ocular findings that may otherwise be missed.
In this cohort study, Knorz et al. evaluated the safety and effectiveness of an angle-supported phakic IOL for correction of moderate to high myopia. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), predictability, stability of the manifest refraction spherical equivalent (MRSE), adverse events and endothelial cell density (ECD).
The researchers presented pooled interim data from 360 patients assessed for up to three years, postoperatively. Of the 104 patients who reached the three-year visit, the UDVA was 20/40 or better in 101 (97.1 percent) and 20/20 or better in 48 (46.2 percent). The CDVA was 20/32 or better in 103 (99 percent) of the 104 patients and 20/20 or better in 84 (80.8 percent). The mean MRSE was –0.24 D ± 0.55. The residual refractive error was within ±0.50 D of target in 82 patients (78.8 percent) and within ±1 D in 95 patients (91.3 percent). The annualized percentage loss in central ECD and peripheral ECD from six months to three years was 0.41 percent and 1.11 percent, respectively. No pupil ovalization, pupillary block or retinal detachment was observed.