Accuracy and validity of IK4 handheld video keratometer measurements in children

The infant keratometer (IK4) is a custom handheld instrument that was designed specifically to allow measurement of corneal astigmatism in infants as young as 6 months of age. In this study, accuracy of IK4 measurements with the use of standard toric surfaces was within 0.25 D. Validity measurements obtained in 860 children aged 3-7 years demonstrated slightly greater astigmatism measurements in the IK4 than in the Retinomax K+. Measurement success was 98% when the IK4 was used. The IK4 may prove to be clinically useful for screening children as young as 3 years of age at high risk for corneal astigmatism.     

Disparities in hypertension and cardiovascular disease in blacks: The critical role of medication adherence

Blacks are two to three times as likely as whites to die of preventable heart disease and stroke. Declines in mortality from heart disease have not eliminated racial disparities. Control and effective treatment of hypertension, a leading cause of cardiovascular disease, among blacks is less than in whites and remains a challenge. One of the driving forces behind this racial/ethnic disparity is medication nonadherence whose cause is embedded in social determinants. Eight practical approaches to addressing medication adherence with the potential to attenuate disparities were identified and include: (1) patient engagement strategies, (2) consumer‐directed health care, (3) patient portals, (4) smart apps and text messages, (5) digital pillboxes, (6) pharmacist‐led engagement, (7) cardiac rehabilitation, and (8) cognitive‐based behavior. However, while data suggest that these strategies may improve medication adherence, the effect on ameliorating racial/ethnic disparities is not certain. This review describes the relationship between disparities and medication adherence, which likely plays a role in persistent disparities in cardiovascular morbidity and mortality.     

Comparison of two artificial tear formulations for dry eye through high-resolution optical coherence tomography

Purpose: The aim was to determine the efficacy of two artificial eye‐drop formulations by analysing the lower tear film meniscus volume through a commercial high‐resolution spectral‐domain optical coherence tomographer. Methods: Twenty dry eye patients (12 men, eight women, aged 57.5 ± 8.4 years) with refractive errors from ‐2.50 to +0.75 D (mean ‐1.34 ± 1.02 D) and cylinders lower than 1.00 D were examined. Tear meniscus volume was measured before, immediately after and 10, 30 and 60 minutes after instillation using the Copernicus high‐resolution spectral‐domain optical coherence tomographer (Optopol Tech SA, Zawiercie, Poland). Volume was calculated from the local area obtained from tomograms considering a regular distribution of the tear meniscus across the eyelid. Ten subjects were randomly assigned to first receive either polyethylene glycol (Blink Intensive, Abbot Medical Optics Inc, CA, USA) or hypromellose (Artific, Farma‐Lepori SA, Barcelona, Spain) three times daily in both eyes for one month. Measures were then repeated and after a one‐week wash‐out period they were switched to the other eye‐drop for another month. Results: Mean baseline volume was 0.38 ± 0.10 µL, while mean baseline volume after the wash‐out period was slightly higher, 0.39 ± 0.10 µL (p = 0.638). Analysis of variance showed significant differences in meniscus volume with time after instillation with both formulations (p < 0.001), mean volume decreasing with time. At 30 and 60 minutes following instillation, values decreased to almost baseline (average difference 0.02 ± 0.03 µL at t₃₀, p = 0.016 and 0.01 ± 0.01 µL at t₆₀, p = 0.098). Conclusion: An increase in tear film meniscus volume in dry eyes from the use of eye‐drops has been shown. High resolution imaging of lower tear film meniscus with clinical optical coherence tomography systems provides useful measures of tear volume. Both formulations assessed in the present study are efficient in increasing tear meniscus volume and reducing dry eye signs and symptoms, although results in terms of increase in meniscus volume were higher with the polyethylene glycol formulation.     

Community‐based diabetic retinopathy screening in Hong Kong: ocular findings

Background: Diabetic retinopathy is one of the most common causes of blindness. Timely retinal evaluation is known to prevent or minimise visual loss. This study compared the prevalence of ocular disorders in patients who have and have not undergone a retinal examination since diagnosis of their type 2 diabetes mellitus (T2DM). Such data might be useful for planning purposes by health care authorities and agencies in Hong Kong. Methods: Patients with T2DM aged 30 years or over presented for standardised interviews and screening for diabetic retinopathy. The presence of ocular disorders was recorded and the severity of the retinopathy, if any, was graded using the Early Treatment Diabetic Retinopathy Study (ETDRS) classification. Results: For the 1058 subjects who participated in this study, the mean age at examination was 61.8 ± 10.5 (SD) years (range, 31–93 years). For the 891 subjects with known diabetes for one year or longer, 62.7 per cent had never undergone an evaluation for diabetic retinopathy since diagnosis of their T2DM. Of the 891 subjects, gradable fundus photographs were available for 853 subjects and nearly 2.0 per cent of these had sight‐threatening retinopathy based on the ETDRS classification. Those who had not had an eye examination since diagnosis of their T2DM were more likely to have sight‐threatening retinopathy than those who had a retinal evaluation (2.6 versus 0.6 per cent; p = 0.04). Conclusion: In our sample, over 60 per cent of patients with T2DM for one year or longer had not had a retinal assessment since diagnosis. The risk of developing sight‐threatening diabetic retinopathy appears to be higher for those who have not had a retinal assessment.     

7 Tesla MR imaging of the human eye in vivo

Purpose:

To develop a protocol which optimizes contrast, resolution and scan time for three‐dimensional (3D) imaging of the human eye in vivo using a 7 Tesla (T) scanner and custom radio frequency (RF) coil.

Materials and Methods:

Initial testing was conducted to reduce motion and susceptibility artifacts. Three‐dimensional FFE and IR‐TFE images were obtained with variable flip angles and TI times. T₁ measurements were made and numerical simulations were performed to determine the ideal contrast of certain ocular structures. Studies were performed to optimize resolution and signal‐to‐noise ratio (SNR) with scan times from 20 s to 5 min.

Results:

Motion and susceptibility artifacts were reduced through careful subject preparation. T₁ values of the ocular structures are in line with previous work at 1.5T. A voxel size of 0.15 × 0.25 × 1.0 mm³ was obtained with a scan time of approximately 35 s for both 3D FFE and IR‐TFE sequences. Multiple images were registered in 3D to produce final SNRs over 40.

Conclusion:

Optimization of pulse sequences and avoidance of susceptibility and motion artifacts led to high quality images with spatial resolution and SNR exceeding prior work. Ocular imaging at 7T with a dedicated coil improves the ability to make measurements of the fine structures of the eye. J. Magn. Reson. Imaging 2009;30:924–932. © 2009 Wiley‐Liss, Inc.     

Clinical outcomes following the dispensing of ready‐made and recycled spectacles: A systematic literature review

Uncorrected refractive error is the leading cause of global visual impairment. Given resource constraints in developing countries, the gold standard method of refractive error correction, custom‐made spectacles, is unlikely to be available for some time. Therefore, ready‐made and recycled spectacles are in wide use in the developing world. To ensure that refractive error interventions are successful, it is important that only appropriate modes of refractive error correction are used. As a basis for policy development, a systematic literature review was conducted of interventional studies analysing visual function, patient satisfaction and continued use outcomes of ready‐made and recycled spectacles dispensed to individuals in developing countries with refractive errors or presbyopia. PubMed and CINAHL were searched by MESH terms and keywords related to ready‐made and recycled spectacle interventions, yielding 185 non‐duplicated papers. After applying exclusion criteria, eight papers describing seven studies of clinical outcomes of dispensing ready‐made spectacles were retained for analysis. The two randomised controlled trials and five non‐experimental studies suggest that ready‐made spectacles can provide sufficient visual function for a large portion of the world's population with refractive error, including those with astigmatism and/or anisometropia. The follow‐up period for many of the studies was too short to confidently comment on patient satisfaction and continued‐use outcomes. No studies were found that met inclusion criteria and discussed recycled spectacles. The literature also notes concerns about quality and cost effectiveness of recycled spectacles, as well as their tendency to increase developing countries' reliance on outside sources of help. In light of the findings, the dispensing of ready‐made spectacles should be favoured over the dispensing of recycled spectacles in developing countries.