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weekly e-journal by Art Epstein, OD, FAAO
Off the Cuff: Is Hubble in Trouble?
Founded by fast-track millennials Ben Cogan and Jesse Horwitz, Hubble Contacts was inspired by disruptive consumer specialty marketers Dollar Shave Club and Harry’s. Hubble sells what are essentially generic daily-disposable lenses for about $30 a month. And while cheap contact lenses are an attractive proposition for many patients, you might be wondering what brand Hubble sells so cheaply. Nothing you are likely to be familiar with. St. Shine Optical in Taiwan makes Hubble contact lenses. I know, you’ve never heard of St. Shine.
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Changes in Thickness of Central Macula and Retinal Nerve Fiber Layer in Severe Hypertensive Retinopathy: a One-year Longitudinal Study | ||||
This study analyzed the longitudinal changes in the thickness of the central macula and retinal nerve fiber layer (RNFL) in patients with hypertensive retinopathy (HTNR) using spectral-domain optical coherence tomography (SD-OCT). This was a prospective cohort study. Researchers studied 18 eyes of patients with HTNR of grade IV who had been followed for more than one year, and 36 normal eyes (without any relevant medical history; the control group). Antihypertensive treatment successfully normalized the blood pressure of HTNR patients. The RNFL thickness and that of the central macula of HTNR patients were measured using a Cirrus HD-OCT instrument, and compared with those of the control group.
At 12 months of follow-up, the mean thickness of the RNFL and central macula was significantly lower in the HTNR group than in the control group (the RNFL was measured first, and then the central macular thickness (CMT): 77.4 ± 9.1 μm and 233.8 ± 30.8 μm vs. 94.1 ± 7.8 μm and 256.3 ± 28.1 μm, respectively). With time, the RNFL thickness and CMT became significantly less than that at the initial diagnosis. Researchers concluded that severe HTNR caused a decrease in the thickness of the RNFL and central macula over time. Therefore, they added, the impact of retinal changes associated with systemic diseases such as hypertension should be considered in analyzing the thicknesses of the RNFL and central macula in ocular disorders, including retina, glaucoma and neuro-ophthalmologic diseases. |
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Lee HM, Lee WH, Kim KN, et al. Changes in thickness of central macula and retinal nerve fibre layer in severe hypertensive retinopathy: a 1-year longitudinal study. Acta Ophthalmol. 2017; Oct 4. [Epub ahead of print]. |
Evidence for Cerebrospinal Fluid Entry Into the Optic Nerve Via a Glymphatic Pathway | ||||
The purpose of this study was to determine whether cerebrospinal fluid (CSF) entered the optic nerve via a glymphatic pathway and whether this entry was size-dependent. Fluorescent dextran tracers (fluorescein isothiocyanate [FITC]) of four different sizes (10, 40, 70 and 500 kDa) and FITC-ovalbumin (45 kDa) were injected into the CSF of 15 adult mice. Tracer distribution in the orbital optic nerve at one hour after injection was assessed in tissue sections with confocal microscopy. Tracer distribution within the optic nerve was studied in relation to blood vessels and astrocytes identified by isolectin histochemistry and glial fibrillary acidic protein (GFAP) immunofluorescence, respectively. Aquaporin 4 (AQP4) immunostaining was performed to assess astrocytic endfeet in relation to CSF tracer.
One hour following the tracer injection into the CSF, all tracer sizes (10 kDa to 500 kDa) were noted in the subarachnoid space surrounding the orbital optic nerve. In all cases, 10 kDa (n=4/4) and 40 kDa (n=3/3) tracers were noted within the optic nerve, while 70 kDa tracer was occasionally noted (n=1/4). Tracer found within the nerve was specifically localized between isolectin-labeled blood vessels and GFAP-positive astrocytes or AQP4-labeled astrocytic endfeet. The 500 kDa tracer was not detected within the optic nerve. Investigators wrote that, to their knowledge, this was the first evidence of a glymphatic pathway in the optic nerve. CSF entered the optic nerve via spaces surrounding blood vessels, bordered by astrocytic endfeet. In addition, they determined that CSF entry into paravascular spaces of the optic nerve was size-dependent and that this pathway might be highly relevant to optic nerve diseases, including glaucoma. |
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SOURCE: Mathieu E, Gupta N, Ahari A, et al. Evidence for cerebrospinal fluid entry into the optic nerve via a glymphatic pathway. Invest Ophthalmol Vis Sci. 2017;58(11):4784-91. |
Tolerable Rates of Visual Field Progression in a Population-based Sample of Patients with Glaucoma | ||||
Participants with open-angle glaucoma (OAG) in the Thessaloniki Eye Study (cross-sectional, population-based study in a European population) were included in this analysis to provide population-based data on the maximum tolerable rate of progression to avoid visual impairment (maxTRoP_VI) and blindness (maxTRoP_BL) from OAG. Visual impairment was defined as mean deviation (MD) equal to or worse than -12 dB and blindness as MD equal to or worse than -24 dB. Additional thresholds for visual impairment were tested. For each participant, maxTRoP_VI was defined as the rate of progression that would not lead to visual impairment during expected lifetime. MaxTRoP_BL was defined accordingly. Both parameters were calculated for each OAG subject using age, sex, MD and life expectancy data. The eye with the better MD per subject was included in the analysis.
Among 135 subjects with OAG, 123 had reliable visual fields and were included in the analysis. The mean age was 73 years ± 6 years, and the median MD was -3.65 dB ± 5.28 dB. Among the participants, 69.1% were found to have a maxTRoP_VI slower than -1 dB/year and 18.7% were found to have a maxTRoP_VI between -1 dB and -2 dB/year. Also, 72.4% were found to have a maxTRoP_BL slower than -2 dB/year. For all tested thresholds for visual impairment, approximately 86% of the OAG participants would not be able to tolerate a rate of progression equal to or faster than -2 dB/year. The majority of patients with glaucoma in this study were found to have a maximum tolerable rate of progression slower than -1 dB/year in their better eye. Researchers concluded that patient-tailored strategies to monitor the visual field were important, but raised the issue of feasibility with regard to the number of visual field tests needed. |
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SOURCE: Salonikiou A, Founti P, Kilintzis V, et al. Tolerable rates of visual field progression in a population-based sample of patients with glaucoma. Br J Ophthalmol. 2017; Sep 28. [Epub ahead of print]. |
News & Notes | |||||||||||||||
Ennco Offers Multi-option Product Configuration Ennco Display Systems debuted a “product configurator” with a fully functional pricing module to its current ecommerce website. The company has been working to find a way to enable clients to select a basic item and then add color, frame display options, storage options, lighting options and more. Dispensing tables and complete panel systems are the first products to roll out with the new formats. Clients can shop options and price out dispensing tables and wall panel systems as they are made available. Read more. |
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SciFluor Releases Positive Phase I/II SF0166 Study Results
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IOPtima Launches Lipitear Phospholipid Microemulsion IOPtima announced the launch of Lipitear, a microemulsion formed by aqueous and lipidic phases that help to restore the proper microenvironment of the ocular surface, enhance the physiological process of corneal re-epithelization following ocular surgery, and reduce the typical symptoms and signs of ocular surface disorders. Read more. |
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Alcon AcrySof IOL Reaches 100 Million Implants
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AAOF Awards Korb - Exford Dry Eye Career Development Grant The American Academy of Optometry Foundation selected the inaugural recipient of the Korb - Exford Dry Eye Career Development Grant. Srihari Narayanan, OD, PhD, FAAO, professor at the University of the Incarnate Word Rosenberg School of Optometry, who is leading the study “Meibomian Gland Dysfunction management to relieve contact lens discomfort,” was chosen to receive the grant. Dr. Narayanan will be honored at the AAOF Celebration Luncheon during AAO’s annual meeting in Chicago. Read more. |
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Allergan Research Grant Recipient Named
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Optometric Physician™ (OP) newsletter is owned and published by Dr. Arthur Epstein. It is distributed by the Review Group, a Division of Jobson Medical Information LLC (JMI), 11 Campus Boulevard, Newtown Square, PA 19073. HOW TO ADVERTISE |