A prospective, case-controlled study of keratoconus patients with age-, sex-, race- and body mass index-matched controls was conducted at the Ross Eye Institute in Buffalo, with 15 patients enrolled in each group. Extensive eyelid laxity measurements were performed on both groups. Complete medical/ophthalmic histories and Epworth Sleepiness Scales were completed on 50 keratoconus patients and compared to the normal population.
Increased eyelid measurements of the vertical lid pull (p=0.001), lower lid pull (p=0.005), medial canthal tendon distraction (p=0.04) and palpebral width (p=0.01) were found in the keratoconus group compared with the matched control group. A more rubbery tarsus (p=0.03), increased corneal diameter (p=0.02) and increased exophthalmometry measurements (p=0.01) were also found. The prevalence of OSA (24 percent, n=24) and of obesity (52 percent, n=26) were higher in the keratoconus patients than the normal population.
Pihlblad M, Schaefer D.
Outcomes That Influence CXL in Keratoconus and Ectasia
New Jersey doctors looked at the characteristics influencing outcomes of corneal cross-linking for keratoconus and ectasia, finding that patients with worse preoperative corrected distance visual acuity and higher topography-derived maximum keratometry values, particularly with a CDVA of 20/40 or a maximum K of 55 D or more, were most likely to have improvement after corneal cross-linking. No preoperative characteristics were predictive of CXL failure.
Corneal cross-linking was performed at a cornea and refractive surgery practice in eyes with keratoconus (n=66) or corneal ectasia (n=38). Multiple regression and odds ratio analyses were performed to determine independent predictors of changes in maximum K and CDVA one year postop. Preoperative characteristics included sex, age, uncorrected distance visual acuity, CDVA, maximum keratometry, corneal thickness, corneal haze, disease group and cone location. Postoperative improvement in maximum K was defined as flattening of 2 D or more and worsening as steepening of 1 D or more. Improvement in CDVA was defined as a gain of two lines or more, and worsening as a loss of one line or more.
Eyes with a preoperative CDVA of 20/40 or worse were 5.9 times (95 percent CI, 2.2 to 6.4) more likely to improve two or more Snellen lines. Eyes with a maximum K of 55 D or more were 5.4 times (95 percent CI, 2.1 to 14) more likely to have topographic flattening of 2 D or more. No preoperative characteristics significantly predicted worsening of visual acuity or corneal topography.
J Cataract Refract Surg 2013;39:1133-1140.
Greenstein S, Hersh P.
Besifloxacin Associated with Delayed Epithelial Closure
Researchers from Massachusetts report an observation that photorefractive keratectomy patients treated with besifloxacin 0.6% on the stromal bed exhibited significant problems with corneal epithelial healing and delayed visual recovery.
These conclusions were drawn from a retrospective chart review of four patients (seven eyes) in an office-based private practice. The healing parameters examined included epithelial healing time, haze formation, discomfort and visual recovery. These patients were treated with besifloxacin 0.6% under bandage contact lenses placed after PRK was performed.
All the eyes had delayed epithelial closure (mean 8.8 days, r: five to 13 days), and all patients experienced a delayed visual recovery and significant pain after surgery. Two of the four patients experienced recurrent corneal erosions for weeks to months after undergoing PRK. All but one eye developed corneal haze persisting for a year or more after the surgery. Only one eye among the seven treated with besifloxacin 0.6% under BCL had 20/20 or better uncorrected visual acuity three months postop.
Talamo J, Hatch K, Woodcock E.
Bevacizumab vs. Ranibizumab For the Management of DME
A prospective, randomized trial to compare visual acuity and spectral-domain optical coherence tomography outcomes associated with intravitreal bevacizumab vs. intravitreal ranibizumab for the management of diabetic macular edema has determined that both drugs are associated with similar effects on central subfield thickness through one year of follow-up.
Forty-eight patients (63 eyes) with center-involved DME were randomly assigned to receive 1.5 mg (0.06 cc) intravitreal bevacizumab or 0.5 mg (0.05 cc) intravitreal ranibizumab at baseline and monthly if central subfield thickness was greater than 275 µm. Of these, 45 patients (60 eyes) completed 48 weeks of follow-up. At baseline, mean ± standard error BCVA (logMAR) was 0.60 (20/80) ±0.05 in the intravitreal bevacizumab group and 0.63 (20/80) ±0.05 in the intravitreal ranibizumab group. A significant improvement in mean BCVA was observed in both groups at all study visits (p<0.05); this improvement was significantly greater in the intravitreal ranibizumab group compared with the intravitreal bevacizumab group at weeks eight (p=0.032) and 32 (p=0.042). A significant reduction in mean central subfield thickness was observed in both groups at all study visits compared with baseline (p<0.05), with no significant difference in the magnitude of macular thickness reduction between groups. The mean number of injections was significantly higher (p=0.005) in the intravitreal bevacizumab group (9.84) than in the intravitreal ranibizumab group (7.67).
Am J Ophthalmol 2013;156:502-510.
Nepomuceno A, Takaki E, Paes de Almeida F, Peroni R.
Socioeconomic Disparity and U.S. Adult Use of Eye-Care Services
Data from the United States National Health Interview Survey (2002 and 2008) shows that use of eye-care services in adults with self-reported age-related eye disease (AMD, cataracts, diabetic retinopathy or glaucoma) is significantly impacted by both poverty-income ratio and education levels.
National Institute on Minority Health and Health Disparities researchers used a cross-sectional, nationally representative sample of adults, including participants in the 2002 (n=3,586) and the 2008 (n=3,104) National Health Interview Survey who were at least 40 years of age and reported any age-related eye disease. A multiple logistic regression estimated predictive margins and the slope of index inequality measured the relationship between socioeconomic position (SEP) and use of eye-care services across the entire distributions of poverty-income ratio (PIR) and educational attainment.
In 2002, persons with ARED and a PIR of less than 1.5 were significantly less likely than those with a PIR of at least 5.0 to report visiting an eye-care provider (62.7 percent vs. 80.1 percent, p<0.001) or undergoing a dilated eye examination in the past 12 months (64.3 percent vs. 80.4 percent; p<0.001), after adjustment for other factors. Similarly, persons with less than a high school education were less likely than those with at least a college education to report a visit to an eye-care provider (62.9 percent vs. 80.8 percent, p<0.001) or dilated eye examination (64.8 percent vs. 81.4 percent, p<0.001). In 2002, the slope index of inequality showed statistically significant differences for eye-care provider visits across the levels of education (24.4 percent, p=0.006) and in 2008, it showed a significant difference for eye-care provider visits across levels of educational attainment (25.2 percent, p=0.049) and PIR (21.8 percent, p=0.01).
JAMA Ophthalmol 2013;131:1198-1206.
Zhang X, Beckles G, Chou C, Saaddine J, et al.
MMC Unnecessary to Prevent Haze in Higher Myopia Post-PRK
In a double-masked, randomized, prospective trial, United States Naval Medical Center researchers in San Diego evaluated the safety and efficacy of mitomycin-C 0.01% (0.1 mg/mL) in preventing haze formation after wavefront-guided PRK for higher myopia at three exposures, concluding that MMC may not be needed to prevent haze after modern PRK with a four-month steroid taper.
Sixty-, 30- and 15-second exposures (n=10, 9 and 9, respectively) of MMC 0.01% were compared in wavefront-guided PRK for higher myopia. One eye received MMC (surgical sponge) and the other a placebo. All eyes received a four-month tapering postoperative topical steroid regimen. Endothelial cell densities, haze scores, high- and low-contrast acuities and manifest refraction were measured preoperatively and one, three, six and 12 months postoperatively. Outcomes were analyzed as repeated measures over time.
The mean preoperative manifest refraction spherical equivalent was -5.98 D (r: 4.4 to 8.0 D). No eye developed more than trace haze. There was a significant difference in haze scores between MMC-treated eyes and untreated eyes at one and three months (p=0.034) but no difference at six and 12 months. Endothelial cell densities decreased in the treated eyes and untreated eyes at all three exposures at one month but returned to baseline by six months There was no difference in acuities or refractions with or without MMC, and there was no clinically significant difference in haze formation between MMC eyes and control eyes at the concentration and exposure used.
J Cataract Refract Surg 2013;39:1358-1365.
Hofmeister E, Bishop F, Kaupp S, Schallhorn S.
Comparing Oral FA to SD-OCT In Detecting Macular Edema
An international team of researchers evaluated the safety and efficacy of oral fluorescein angiography compared to spectral-domain optical coherence tomography in detecting macular edema, concluding that oral FA is both safe and adequate. They found that oral FA is more sensitive than SD-OCT in detecting ME in cases of retinovascular diseases, but can fail to detect ME in cases of macular holes. To obtain a comprehensive evaluation of the presence of ME from different pathologies, a noninvasive examination with simultaneous oral FA and SD-OCT should be considered, the investigators advise.
The researchers reviewed the results of imaging studies for 1,928 eyes of 1,019 patients who had simultaneously undergone both oral FA and SD-OCT by a confocal laser ophthalmoscope. They determined the sensitivity in detecting ME, the discrepancy rate and kappa agreement for both techniques and with the eyes stratified by disease and diagnosis.
No allergic reactions occurred after oral FA. Mild gastric discomfort was noted in less than 1 percent of patients, while 1,840 eyes (95.4 percent) showed concordance between the two techniques; the kappa agreement was 90.3 percent. For ME, oral FA showed an overall sensitivity of 0.97 and SD-OCT an overall sensitivity of 0.91. Equivalent sensitivity was found in cases of wet age-related macular degeneration (0.99). Detection of ME by SD-OCT was significantly higher in cases of intense leakage on oral FA (p<0.001).
Barteselli G, Chihablani J, Lee S, Wang H, et al.
Prediction of AMD in the General Population
Using data from population-based studies, the Three Continent AMD Consortium (3CC) has developed a prediction model for late AMD. The 3CC state that its model is robust and distinguishes well between those who will develop late AMD and those who will not.
Three population-based studies (the Rotterdam Study, the Beaver Dam Eye Study and the Blue Mountains Eye Study) followed participants (n=10,106) with gradable fundus photographs, genotype data and follow-up data who did not have late AMD at baseline measurements. The features of AMD were graded on fundus photographs using the 3CC AMD severity sale. Associations with known genetic and environmental risk factors were tested using Cox proportional hazard analysis. In the Rotterdam study, the prediction of AMD was estimated for multivariate models by area under receiver operating characteristic curves. The best model was validated in the Beaver Dam Eye Study and the Blue Mountains Eye Study; associations of variables were re-estimated in the pooled data set. Beta coefficients were used to construct a risk score, and risk of incident of late AMD was calculated using Cox proportional hazard analysis. Cumulative risks were estimated used Kaplan-Meier product-limit analysis, and incident late AMD was determined per visit during a median follow-up period of 11.1 years with a total of four to five visits.
Overall, 363 participants developed late AMD; 3,378 participants developed early AMD; and 6,365 participants remained free of any AMD. The highest AUC was achieved with a model including age; sex; 26 nucleotide polymorphisms in AMD risk genes; smoking; body mass index; and baseline AMD phenotype. The AUC of this model was 0.88 in the Rotterdam Study; 0.85 in the Beaver Dam Eye Study and Blue Mountains Eye Study at validation; and 0.87 in the pooled analysis. Individuals with low-risk scores had a hazard ratio of 0.02 (95 percent CI, 0.01 to 0.04) to develop late AMD and individuals with high-risk scores had an HR of 22 (95 percent CI, 15.2 to 31.8). Cumulative risk of late AMD ranged from virtually none to more than 65 percent, for those with the highest risk scores.
Am J Ophthalmol 2013
Buitendijk G, Rochtchina E, Myers C, van Duijn C, et al.