Optometry and Vision Science (OVS) Announces - May 2015
Coming in the May 2015 Optometry & Vision Science
Here are brief highlights. The online and printed copy will be available early-May. E-Publication Ahead-of-Print now available for all these articles at http://journals.lww.com/optvissci
Anthony J. Adams, OD, PhD, FAAO Editor-in-Chief
Two Automated Perimeters Compared with SITA
The Matrix perimeter was compared with the Humphrey Field Analyzer II (HFA) using the Swedish Interactive Thresholding Algorithm (SITA) over the range of contrast sensitivities each machine could estimate. The 24-2 test was repeated 5 times on 5 different days for 50 glaucoma eyes and 3 without disease. Variability of sensitivity determinations is affected more by the sensitivity level with HFA than with Matrix. Duplicate measurements for baseline and follow-up evaluation could be important, especially for Matrix. Further information on learning effects is needed, as is commercially available progression software for Matrix.
Challenge of Non-Adherence and Side Effects in Glaucoma Treatment
Almost 300 glaucoma patients from six ophthalmology clinics, and videotape analyses following the glaucoma office visits, were used to identify patients who expressed problems with medication side effects, eye drop administration, and non-adherence. As might have been anticipated, the authors found patients with lower health literacy are less likely to express problems with side effects and eye drop administration. And expressing these problems to a research assistant or the ophthalmologist was equally unlikely. The authors advocate that clinicians work more with patients to assess medication-related problems in order to mitigate barriers to medication adherence.
300 Year Old Proposal for Anomalous Binocularity Has Merit
Our author revisits issues of anomalous binocular correspondence (ABC) and with astute observations finds merit for a head-centric disparity model. A head-centric model of ABC elaborates on the anomalous- projection model of Verhoeff and Brock, originally described by Wells, late in the 18th century. The model describes how strabismics perceive 3-D space with two separate eyes, without binocular retinal correspondence. It captures several of the perceptual-motor characteristics associated with ABC that are unexplained by the retino-centric model (anomalous retinal correspondence) of Von Graefe and Burian, and it incorporates two sensory fusion mechanisms suggested by Hallden.
Using the Pupil for Amblyopia Diagnosis?
The authors note that amblyopes do not reliably show relative afferent pupillary defects with full-field stimulation, but they are able to show that stimuli that engage cortex do reveal pupil defects. While the full-field flash fails to elicit the defect, targets of appropriate pattern, brightness and contrast, that select for cortical contributions to the pupil response, may be useful for eliciting pupil defects. They may possibly identify those who will respond best to treatment.
Standardizing Mesopic VA Testing
It is well established that visual acuity (VA) decreases with luminance but the specific factors that are responsible remain unclear. Despite this, our authors find conditions (2 log units light level less than standard photopic testing) that yielded repeatable VA measures, and where accommodation and pupil size, optical aberrations and accommodation have little impact.
Ocular Components of Children in Central China
In a first systematic report of ocular biometry in children in central China, our authors find male and female differences in biometry but no age differences in corneal curvature between a 7-year old (n= 2271) and 14-year old group (n= 1786). Compared with 7-year-old children, the older group did have significantly more myopia (-3.0D), longer axial length (1.7mm), deeper anterior chamber depth (0.3mm), thinner lens thickness (-0. 2mm), and thicker central corneal thickness (10μm). Their study enables comparisons with other groups.
High Myopes Have More Elastic Retina-Choroid-Sclera Complex
Using a novel technique, ocular ultrasound elastography, our authors show that high myopia (>5D) is associated with a more elastic posterior vitreous and the elasticity of posterior retina-choroid-sclera complex increases as the axial length increases. They suggest the use of ocular ultrasound elastography in clinical practice.
Orthokeratology Increases Peripheral Myopic Focus Without Choroidal Thickening
Animal and human studies suggest that myopic defocus may thicken the choroid. The authors studied 9 children wearing orthokeratology lenses over 9 months and found no choroidal thickening by OCT despite successfully inducing a myopic periphery. They consequently doubt that peripheral myopic defocus slows the progression of myopia through a mechanism involving choroidal thickening to monitor progression.
IOP Measures Compared
The authors compared postoperative intraocular pressure (IOP) from the Corvis ST Tonometer (CST), ocular response analyzer (ORA), and Goldmann applanation tonometry (GAT) in eyes undergoing laser in situ keratomileusis (LASIK). Although the new CST was found to yield higher postoperative IOP readings, its measurements were well correlated with both the GAT and the ORA in patients after LASIK and remained close to the preoperative GAT readings. The ORA-derived corneal biomechanical parameters (corneal hysteresis and the corneal resistance factor) showed significant correlations with CST-derived parameters, including the maximum deformation amplitude at the corneal apex and the time from start until the first applanation.
Peripheral Myopic Defocus Induced with Novel RGP Lens
Inducing myopic peripheral defocus is now a goal for reducing myopia progression. Our authors produced an experimental rigid gas permeable lens, which induced at least -2.00 D of peripheral myopic defocus change in 60% of over 50 myopic eyes. With the lens, 85% of the eyes presented at least 1.00 D of peripheral myopia, and the effect was independent of the baseline axial myopia.
Astigmatic Aging with Ocular Aberrations
Despite of the high prevalence of myopia and astigmatism in Hong Kong Chinese, little is known about its effects on the corneal shape and aberration of the aging eyes. Our authors found that astigmatism had significant effects on the corneal shape factors and aberrations in this myopic aging population (almost fifty 50 to 70 year olds). The significant correlation between the corneal shape factors and ocular aberrations underscores the importance of taking corneal shape into account when correcting the optical defects in myopic Chinese.
Optometric Services in India
Due to lack of available care, close to 90% of vision impairment in India is avoidable. Optometrists have a major role to play in alleviating vision impairment and preventing blindness; however, there is little information available about the range of services optometrists provide in India. The authors set out with the first systematic survey on the practice patterns and range of services provided by optometrists in India and places the services in the context of the current and emerging eye health challenges.
Visuo-motor and Visual Perceptual Skills in Hong Kong Preschoolers
Using Visual-Motor Integration (VMI) and a Test of Visual-Perceptual Skills (TVPS) to establish a normative data base for Hong Kong preschoolers our authors discover that their study group (174) outperformed their US and Mainland China peers in the VMI and visual memory/ spatial relationships of the TVPS.
A New Handheld Videoscreener Pilot Tested
The authors report a pilot study of 86 young adults with the handheld 2Win videorefractor measures compared to a table mounted Topcon KR8800 autorefractor. They found better sphere than cylinder reproducibility but conclude that the 2Win was nevertheless a reliable, easy to use instrument, with acceptable reproducibility ranges if used only as a screening device.
White Dot Syndromes Better Understood with OCT and Autofluorescence Imaging
OCT and fundus autofluorescence (FAF) offer new opportunities to non-invasively image white dot syndromes, a group of inflammatory conditions of the retina which have been difficult to detect in the past using traditional clinical techniques. OCT and FAF findings for white dot syndromes however are fragmented across case reports and small scale studies making it difficult to incorporate findings into clinical practice. This review summarizes the clinical presentation of white dot syndromes using OCT and FAF and highlights the new information revealed by these technologies. This has helped in understanding the underlying mechanisms of these diseases.
New Insights on Rare Keratitis After Anterior Lamellar Keratoplasty
Our authors report a case of early-onset interface keratitis after anterior lamellar keratoplasty (DALK) by Candida glabrata, which occurred 4 days after DALK. They describe its clinical, confocal, histological and microbiological characteristics. With the popularization of DALK, they believe this case will add new insight into this rare complication.
Intravitreal Aflibercept Successful After Bilateral Bevacizumab Induced Iritis
The authors detail a single case of a patient with wet macular degeneration who was successfully treated with intravitreal aflibercept after developing iritis from two consecutive treatments with bevacizumab in separate eyes.
OCT Can Guide Diagnosis of Macroglobulinemia
This report highlights a characteristic spectral domain optical coherence tomography (SD OCT) pattern that guided the diagnosis of Waldenstrom's macroglobulinemia in a sixty year old male patient. The presentation was bilateral sudden onset vision loss with bilateral exudative retinal detachment involving the macula. SD OCT revealed neurosensory detachment with a very regular and harmonious cystoid pattern in outer retina and also deposits around the photoreceptors. Subsequent serum protein electrophoresis, bone marrow biopsy and immunophenotype scattergram of lymphoplasmacytic proliferative cells of bone marrow confirmed the diagnosis.
Uveal Effusion Following Chemotherapy
The authors describe believed to be the first case of uveal effusion and outer retinal disruption following gemcitabine and docetaxel chemotherapy for stage IV sarcoma. Early detection and close ophthalmic monitoring may allow modified concurrent cancer treatment and prevention of possible chemotherapy-induced ocular side effects.
American Academy of Optometry | 2909 Fairgreen Street, Orlando, FL 32803 | 321-710-EYES(3937) | Membership@aaoptom.org