Ron Rajecki

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	Researchers using the Age-Related Eye Disease Study (AREDS) lens grading scale have found that long-term clinically relevant outcomes can be predicted by 2-year changes in severity of lens opacities.

, researchers from the National Eye Institute, National Institutes of Health (US) and contract research organization EMMES Corp. conducted a prospective cohort study within a randomized clinical trial of oral supplements. The study enrolled AREDS participants who were free of late age-related macular

	degeneration throughout the study, and whose eyes were phakic at baseline.

	The researchers examined 3,466 baseline and annual lens photographs of AREDS participants and graded them for cataract severity. They then collected data on cataract surgery and visual acuity through semiannual clinical examinations. Adjusted Cox proportional hazard models were used to analyse the association of the change in lens opacities at 2 years with the incidence of cataract surgery and visual acuity loss of 2 lines or more at 5 years.

	They found that the adjusted hazard ratios (HRs) for association of progression to cataract surgery at 5 years were:

			2.77 HR for nuclear cataract increase of 1.0 unit or more at 2 years compared with less than 1.0 unit change

			1.91 HR for cortical cataract increase of 5% or more in lens opacity in the central 5 mm of the lens at 2 years compared with less than 5% increase

			8.25 HR for posterior subcapsular cataract increase of 5% or more versus less than 5% in the central 5 mm of the lens.

	For vision loss of 2 lines or more at 5 years, the HRs were as follows:

			1.83 HR for nuclear cataract increase of 1.0 unit or more at 2 years compared with less than 1.0 unit change

			1.13 HR for cortical cataract increase of 5% or more in lens opacity in the central 5 mm of the lens at 2 years compared with less than 5% increase

			3.05 HR for posterior subcapsular cataract increase of 5% or more versus less than 5% in the central 5 mm of the lens.

Articles

Researchers using the AREDS lens grading scale have found that long-term clinically relevant outcomes can be predicted by 2-year changes in severity of lens opacities.

Lens opacity AREDS score predicts progression

Cataract surgery: corneal asphericity affects refractive outcome

	When using third-generation IOL power formulas, be sure to take anterior surface corneal asphericity into consideration because it can influence the refractive outcome, according to researchers from Italy and the United States.

Metrics help explain balance issues in glaucoma patients

Journal of Cataract and Refractive Surgery

, the researchers conducted a retrospective comparative case series of 115 eyes in 115 consecutive patients, all of which were implanted with the same type of intraocular lens (Acrysof SA60AT, Alcon).

	The researchers calculated intraocular lens power using the Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. Asphericity (Q-value) was measured by three different methods: a Placido-disk corneal topographer, a rotating Scheimpflug camera, and a rotating Scheimpflug camera combined with Placido-disk corneal topography All measurements were conducted at 8.0 mm.

	By linear regression, the relationship between the error in refraction prediction (as measured 1 month post-surgery) and the Q-value was assessed.

	The researchers found that with all of the formulas and devices, there was a statistically significant relationship between the error in refraction prediction and the Q-value with all formulas: A more negative Q-value (prolate cornea) was associated with a myopic outcome in all cases, whereas a more positive Q-value (oblate cornea) was associated with a hyperopic outcome.

	To read the abstract of the study, click 

Next: OCT angiography useful in patients with diabetic retinopathy

OCT angiography useful in patients with diabetic retinopathy

	Ophthalmologists may find optical coherence tomography (OCT) angiography clinically useful to evaluate the microvascular status and therapeutic effect of treatments for diabetic retinopathy (DR), according to a prospective study out of Japan published in the 

	The researchers noted that microaneurysms and retinal non-perfused areas can be clearly visualized, and the technology also allows each layer of the retinal capillaries to be observed closely. Also, quantitative information on new vessels can be obtained.

	Using a high-speed, 840-nm wavelength spectral-domain OCT device (RTVue XR Avanti, Optovue), the investigators scanned 47 eyes of 25 patients who had DR. They detected blood flow using the split-spectrum amplitude-decorrelation angiography algorithm. They also obtained fluorescein angiography (FA) images in all eyes. The scientists compared their ability to visualize microaneurysms, retinal non-perfused areas and neovascularization with that of the en-face OCT angiograms.

	The researchers found that, in 42 eyes, FA-detected microaneurysms near the macula showed up as focally dilated saccular or fusiform capillaries on OCT angiograms of the superficial and/or deep capillary plexus. FA-visualized retinal non-perfused areas looked like lesions with no or sparse capillaries on OCT angiograms. In 7 eyes, area measurement of retinal non-perfusion near the macula showed a difference between the extent of non-perfused areas in superficial and deep plexuses. In 4 eyes, researchers could clearly visualize the vascular structures of neovascularization at the optic disc using OCT angiography. They quantified decreases and re-increases of flow in new vessels in an eye treated with anti-vascular endothelial growth factor.

Next: Metrics help explain balance issues in glaucoma patients

	New metrics developed by a research team with members from the United States, Brazil, and The Netherlands may help ophthalmologists better understand balance control issues in patients who have glaucoma. The cross-sectional study, published in 

, presented and validated a novel paradigm that assesses postural reactivity to dynamic visual stimuli using a virtual reality environment.

	Using standard automated perimetry, the researchers studied 42 patients who had glaucoma and repeatable visual field defects. The study had 38 control healthy subjects. All participants completed a standard questionnaire about their history of falls.

	While wearing stereoscopic head-mounted goggles, the doctors evaluated patients’ postural stability using a force platform as static and dynamic visual stimuli were introduced. “The dynamic visual stimuli presented rotational and translational ecologically valid peripheral background perturbations,” they wrote. The investigators also tested postural stability in a completely dark field so they could gauge somatosensory and vestibular contributions postural control.

	The authors measured torque moments around the center of foot pressure on the force platform, and they calculated standard deviations of the torque moments (STD) as a measurement of postural stability; they were reported using Newton meters (Nm). Poisson regression models were used to determine the association with history of falls. Confounding factors included age, gender, body mass index, severity of visual field defect, best-corrected visual acuity and STD on dark field condition.

	During both translational and rotational stimuli, study participants with glaucoma had larger overall STD than did controls. Postural metrics obtained during dynamic visual stimuli better explained history of falls compared with metrics obtained in static and dark field condition, the researchers said.. “In the multivariable model, STD values in the mediolateral direction during translational stimulus were significantly associated with a history of falls in patients with glaucoma,” according to the authors.

Corneal asphericity, OCT angiography, and balance control issues in glaucoma patients are analyzed in this industry update roundup.

Analyzing corneal asphericity, OCT angiography, and balance control issues in glaucoma patients

	In a 1-year comparison of intravitreous aflibercept, bevacizumab and ranibizumab therapy for centre-involved diabetic macular oedema (DME), aflibercept was more effective at improving vision among patients who started treatment at lower levels of visual acuity. In patients with milder baseline levels of visual acuity loss, however, there were no differences, on average, between the three medications.

, the Diabetic Retinopathy Clinical Research Network randomly assigned 660 adults with DME involving the macular centre to receive 2.0 mg of intravitreous aflibercept (224 participants), 1.25 mg of bevacizumab (218 participants), or 0.3 mg of ranibizumab. The study took place at 89 clinical sites. Following a protocol-specified algorithm, drugs were administered as often as every 4 weeks.

	The researchers used a mean visual-acuity letter score for their analysis. Higher scores on a range of 1 to 100 indicate better visual acuity, with a score of 85 indicating approximately 20/20 vision.

	From baseline to 1 year, the mean visual-acuity letter score improved by 13.3 among patients who received aflibercept, by 11.2 among patients who received ranibizumab, and by 9.7 among patients who received bevacizumab.

	The researchers noted, however, that despite the apparent greater improvement with aflibercept, the driver was eyes with worse visual acuity at baseline, making the difference not clinically meaningful. Among the 51% of participants who had a baseline initial visual-acuity letter score of 78 to 69, the mean improvement was 8.3 with ranibizumab, 8.0 with aflibercept, and 7.5 with bevacizumab.

	Among patients who had an initial letter score of less than 69, the mean improvement was 18.9 with aflibercept, 14.2 with ranibizumab, and 11.8 with bevacizumab.

	The researchers concluded that “intravitreous aflibercept, bevacizumab, and ranibizumab were effective and relatively safe treatments for DME causing vision impairment,” and that “when initial visual-acuity loss was mild, there was, on average, little difference in visual acuity at 1 year among the three agents. However, at worse levels of initial visual acuity, aflibercept was more effective at improving vision.”

In a 1-year comparison of intravitreous aflibercept, bevacizumab and ranibizumab therapy for centre-involved DME, aflibercept was more effective at improving vision among patients who started treatment at lower levels of visual acuity.

Comparing anti-VEGFs for DME

	Anterior capsulotomy is the main trigger for an increase of prostaglandins in the aqueous humour that occurs immediately after femtosecond laser-assisted cataract surgery (FLACS), according to researchers from the Institute for Vision Science and the Experimental Eye Research Institute, Ruhr University Eye Hospital, Bochum, Germany.

, the researchers collected the aqueous humour from 67 patients twice: once after the pretreatment for FLACS (only capsulotomy, only fragmentation, or both) and again at the beginning of routine cataract surgery. They then used an enzyme-linked immunoassay to measure total prostaglandin levels in all four groups.

	Significantly higher levels of aqueous humour prostaglandins were detected immediately after the procedure in patients who underwent both capsulotomy and fragmentation (330.6 ± 110.6 pg/mL) or only laser capsulotomy 362.4 ± 117.5 pg/mL), compared to the control group (52.5 ± 8.1 pg/mL).

	Patients who underwent only FLACS fragmentation did not demonstrate a prostaglandin increase (186.8 ± 114.0 pg/mL).

	The researcher concluded that it may be possible to reduce laser-induced miosis by optimizing the laser’s energy settings and using nonsteroidal anti-inflammatory drugs.

Anterior capsulotomy triggers an increase of prostaglandins in the aqueous humour immediately after FLACS, according to researchers from Ruhr University Eye Hospital, Bochum, Germany.

Author | Ron Rajecki

Articles

Analyzing corneal asphericity, OCT angiography, and balance control issues in glaucoma patients

Comparing anti-VEGFs for DME

Capsulotomy triggers prostaglandin release in FLACS

Lens opacity AREDS score predicts progression