A population-based genetic association study of 3,541 patients recruited from the Los Angeles Latino Eye Study has shown that African ancestry and its interaction with hypertension is associated with higher intraocular pressure in Latinos.

Study participants were genotyped, and simple and multiple linear regression, as well as quantile regression, analyses were performed to investigate the relationship between genetic ancestry and IOP.

African ancestry was significantly associated with higher IOP in Latinos in a simple linear regression analysis (p=0.002). After adjusting for age, gender, body mass index, systolic blood pressure, central corneal thickness and type 2 diabetes, the association remained significant (p=0.0005). The main association was modified by a significant interaction between African ancestry and hypertension (p=0.037), with hypertensive individuals experiencing a greater increase in IOP with increasing African ancestry.

Ophthalmology 2016;123:102-108.
Nannini D, Torres M, Chen Y, Taylor K, et al.

Some Clinical Judgment Leeway in ROP Treatment
Researchers at a host of U.S. centers report a study they say has important clinical implications in the management of retinopathy of prematurity.

The group generated a database of 1,444 eyes prospectively from all babies screened for ROP at six major ROP centers whose parents provided informed consent. The retrospective study reviewed all patients treated for ROP milder than type 1, with the main outcome being indications for treatment.

A total of 137 eyes of 70 infants were treated for ROP. Of the 137, 13 (9.5 percent) were treated despite a clinical diagnosis milder than type 1 ROP. Indications for treatment included active ROP with the fellow eye being treated for type 1 ROP (two eyes, 15.4 percent); concerning structural changes (nine eyes, 69.2 percent), including tangential traction with temporal vessel straightening concerning for macular dragging (eight eyes, 61.5 percent) and thick stage 3 membranes with anteroposterior traction concerning for progression to stage 4 ROP (three eyes, 23.1 percent); persistent ROP at an advanced postmenstrual age (four eyes, 30.8 percent); and/or vitreous hemorrhage (three eyes, 23.1 percent).

Experts in this study occasionally recommended treatment in eyes with disease less than type 1 ROP. The study highlights the role of individual clinical judgment in situations not covered by evidence-based treatment guidelines, the authors concluded.

Am J Ophthalmol 2016;163:1-10.
Gupta M, Chan R, Anzures R, Ostmo S, et al.

Glaucoma Rx Coverage Before And After Medicare Part D
A new study indicates that Medicare Part D enrolled most beneficiaries with glaucoma who previously lacked prescription drug coverage, but suggests that coverage gains lag among the near-poor. While the data evaluated changes in coverage among cohorts of beneficiaries and not from longitudinal follow-up of patients, targeted efforts to improve prescription drug coverage among vulnerable beneficiaries would likely improve access to prescribed ocular hypotensive medications.

To determine changes in prescription drug coverage and out-of-pocket spending after the implementation of Medicare Part D across income strata, and to identify characteristics of beneficiaries associated with prescription status, researchers designed a longitudinal observational study using the Medicare Current Beneficiary Survey (pooled 2004, 2005, 2007 and 2008 data). Participants were non-institutionalized Medicare beneficiaries who filled at least one glaucoma prescription during the survey years.

Survey respondents included more than 11,000 participants in each of the survey years. The sample included 19,045 glaucoma prescriptions, and 2,519 Medicare beneficiaries who filled at least one glaucoma prescription during the study years. Overall, 574 (22.8 percent) beneficiaries reported living below the poverty level, and 795 (31.6 percent) had incomes consistent with near-poor status. The implementation of Medicare Part D resulted in increased rates of prescription drug coverage across all economic strata, with reductions in beneficiaries without coverage from 22.8 percent to 4 percent among poor beneficiaries, 29.1 percent to 7.3 percent among near-poor beneficiaries and 19.9 percent to 3.7 percent among higher-income beneficiaries.
Despite these gains, near-poor status remained a risk factor for lack of prescription drug coverage after Medicare Part D implementation (p=0.04). No differences were identified in adjusted out-of-pocket drug costs between the near-poor and those with higher income, although out-of-pocket costs were 37 percent (p<0.001) lower among the poor relative to those with higher income.

JAMA Ophthalmol 2016;134:2:212-220.
Blumberg D, Prager A, Leibmann J.

T-CAT Safe and Effective
Topography-guided custom ablation treatment (T-CAT) can achieve predictable refractive outcomes and reduce visual symptoms with stable results through 12 months, say U.S. researchers. (The researchers and the T-CAT study group were supported by or consultants to Alcon.)

The prospective, observational, nonrandomized, unmasked study enrolled 212 patients (249 eyes) at nine clinical sites. Patients were 18 to 65 years old with myopia or myopic astigmatism with a manifest refraction spherical equivalent (MRSE) up to -9 D and astigmatism of 6 D or less. Patients with previous refractive surgery or abnormal topography were excluded. Corneal topographies were obtained using the Allegro Topolyzer, and laser treatment was delivered with the Allegretto Wave Eye-Q excimer laser system. Visual outcomes were evaluated postoperatively at seven time points over 12 months.

The T-CAT procedure significantly reduced the MRSE and cylinder, with stability of outcomes evident from three to 12 months after surgery. Compared with the preoperative corrected distance visual acuity, the postoperative uncorrected distance VA improved by one line or more in 30 percent of eyes and the postoperative UDVA was at least as good as the preoperative CDVA in 90 percent of eyes. Most visual symptoms improved after T-CAT. No significant treatment-related adverse events or loss of vision occurred.

J Cataract Refract Surg 2016,42:11-18.

Stulting RD, Fant BS, T-CAT Study Group.

LCT and AMT Compared
Citing a dearth of studies comparing different surgical procedures for the treatment of corneal thinning, Brazilian researchers assessed lamellar corneal transplantation (considered efficient, but subject to allograft rejection, opacification or high astigmatism) versus amniotic membrane transplantation (considered a good alternative, but not as resistant as LCT and the tissue can be reabsorbed after surgery). The prospective, randomized, interventional and comparative study included consecutive patients with corneal thinning over six months. Subjects were examined before transplant surgery and then at six intervals over six months after surgery; ultrasound biomicroscopy was performed before and at 30, 90 and 180 days after surgery to assess corneal thinning.

Herpes simplex infection was the main cause of corneal thinning (nine eyes); followed by surgery (cataract, glaucoma, five cases); and a single case each of rheumatoid arthritis, chemical burn, perforating trauma, previous band keratopathy treatment, and Stevens-Johnson syndrome. Although all patients showed significant increase in final thickness in the area of thinning, it was higher in those subjected to LCT at 180 days postoperatively. Regardless of the surgical technique, all patients showed epithelialization. Patients undergoing AMT showed an 89 percent decrease in neovascularization. Final corrected distance visual acuity was better in patients subjected to AMT.

LCT proved to be the best option for treating corneal thinning, the authors say. AMT represents an alternative that allows good visual recovery but does not restore corneal thickness as efficiently as LCT.

Cornea 2016;35:438-44.

de Farias C, Allemann N, Gomes JÁ.