IN THIS ISSUE:
• Does Changing the Contact Lens and Solution Really Help Comfort?
Discomfort is commonly experienced among contact lens wearers. It remains a big challenge. Practitioners often respond by changing the contact lens or solution (or both) for these patients to try and improve their comfort. How successful is this approach? It is not always clear. In a prospective, crossover, randomized clinical trial, our authors document that the comfort of symptomatic contact lens wearers was commonly improved by the clinician changing the lens and solution combination. (p. 411)
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• Does Contact Lens Wear Increase the Presence of Collagen-Degrading Enzymes in Tears?
Matrix metalloproteinase (MMP) enzymes can degrade the structural proteins of the extracellular matrix, with MMP-9 being the primary matrix-degrading enzyme. Agreater concentration ofMMP-9 has been associated with corneal erosions and corneal ulcers. The authors found that the initial period of overnight lens wear disturbs the tear film homeostasis as indicated by a significant increase in MMP-9 on awakening. The return to baseline levels by 1 month suggests that an adaptive process takes place. No comparable changes are seen with daily wear. (p. 419)
• Fusarium and Fresh Multipurpose Disinfectant Solutions
Although rare, fungal keratitis is a sight-threatening infection associated with contact lens wear, and an outbreak of Fusarium keratitis led to the global recall of a multipurpose disinfectant solution (MPDS) in 2006. The author compared the efficacy of MPDSs and oxidative systems (hydrogen peroxide and povidone iodine) against Fusarium strains. All MPDSs were effective against the ATCC 36031 strain of Fusarium solani, although there was reduced efficacy for some MPDSs against clinical isolates. Because peroxide and povidone iodine systems have no continued antimicrobial presence once neutralized by the platinum disc, lenses should be placed in fresh disinfection solutions if stored for extended periods. (p. 430)
• Orthokeratology, Spherical Aberration, and Myopia Control Related?
The authors simultaneously captured both the overall ocular aberrations and corneal aberrations after day 1 and day 7 of overnight orthokeratology (OK). They revealed that, although positive spherical aberration increased, the change to corneal spherical aberration was greater than for ocular spherical aberration after 7 nights of OK. The authors suggest that this could be explained through an accommodative response that would induce a negative shift in spherical aberration to neutralize some of the ocular spherical aberration, and that this possible mechanism could be influential in the myopia-controlling effect reported for OK. (p. 439)
• Is Consanguinity a Risk Factor for Keratoconus?
Yes, say our authors. They studied 70 keratoconus cases and 140 patient controls at the St. Johns Eye Hospital in Jerusalem. The patients were questioned regarding their parents’ relationship. Using logistic regression analysis, they found that children of consanguineous parents had a fourfold increased risk of keratoconus compared with children of unrelated parents. They see this as providing strong support for a genetic basis to keratoconus. (p. 448)
• Poor Handwriting from Altered Preferred Retinal Locus in AMD
Writing legibly is often difficult for people with bilateral scotomas from AMD. The authors were able to document this by having the participants place the pen tip at their preferred retinal locus (PRL). A scanning laser ophthalmoscope showed the image of the subject’s hand and pen on his retina for the authors to document while the participant wrote. The poor handwriting performance of those with macular scotomas appears primarily caused by difficulty in placing letters in the appropriate location.They speculate that more effective placement of the PRL may be trainable and improve handwriting. (p. 455)
• Taking Refractive Error Defocus Out of Visual Field Testing
Automated perimetric testing is an integral part of 21st century clinical practice, yet much of it relies on a stimulus developed 70 years ago. The reduced sensitivity of this stimulus to optical defocus contributes to concerns about reliability. The authors propose a low spatial frequency grating stimulus at 0.25 cpd where the effects of optical blur can be greatly reduced. This stimulus is blur resistant for central visual field testing. (p. 466)
• A Clinical Trial of Vision Therapy for Treatment of Amblyopia
The first randomized clinical trial of office-based vision therapy for the treatment of childhood amblyopia failed because of restrictive eligibility criteria necessitated by the standardized approach to therapy. However, it did prove feasible to obtain good compliance and train and certify therapists to administer a standardized program. A more flexible approach that customizes vision therapy based on subject age, visual acuity, and stereoacuity might be required for a future study to be successful. (p. 475)
• Computer Vision Syndrome and Blink Patterns
Computer vision syndrome (CVS) is frequently associated with both reduced blinking and dry eye disorders.This study found that participants having the lowest blink rate showed the highest CVS symptom scores.However, increasing blink rate with an auditory signal did not change the CVS symptoms. Incomplete blinks were also important in CVS; the percentage of incomplete blinks correlated with total symptom score. The authors wonder if achieving complete blinks may be a more fruitful approach to CVS alleviating symptoms. (p. 482)
• Depression and Stress Greater in Retinitis Pigmentosa Patients
People in Korea with retinitis pigmentosa (RP) exhibited poorer mental health than did the control participants in the authors’ study of almost 200 RP patients and a similarly sized group of controls. Stress, depressive moods, and suicidal thoughts were each significantly more frequent in the RP patient group, although there was no significant difference in the actual (low) number of suicide attempts. The authors call for more welfare services in Korea for patients with RP. (p. 488)
• Ready Made Glasses in Nicaragua
The authors measured the effectiveness and patient satisfaction with ready-made equal-sphere plus bifocals and ready-made readers. The ready-made bifocals and readers were well accepted and may be an acceptable and affordable alternative for patients with hyperopia and presbyopia in areas in the world with low income and minimal resources. (p. 494)
• Pathological Myopia and Inflammation Markers
Myopic choroidal neovascularization (CNV) is commonly a central component of pathological myopia. Here, our authors provide evidence that immunological/inflammatory markers, namely high-sensitivity C-reactive protein, C3, and CH50, may play an important role in the development of pathological myopia. Not surprisingly, their study of 53 patients with pathological myopia between 8 diopters and 25 diopters prompts the authors to suggest that the anti-inflammatory and the complement system may represent a new therapeutic target in myopic CNV. (p. 501)
• Parental Myopia Related to Nearwork-Induced Transient Myopia in Their Children?
Our authors could find no such relationship. To induce nearwork-induced transient myopia (NITM), 360 children aged 7 to 17 years, with full distance refractive correction, binocularly performed a sustained near task (5 diopters) for 5 minutes incorporating a cognitive demand. Neither paternal nor maternal refractive error was associated with either their children’s initial NITM magnitude or its decay time in the myopic, emmetropic, or hyperopic groups or the total group. The authors conclude that any change inmyopia induced transiently by nearwork is not likely to be genetic—at least not genetically related to the parents’ myopic refractive error. (p. 507)
• Has Optical Control of Myopia Come of Age?
A clinical perspective comes from a clinician in private practice and a well-known myopia researcher. The authors argue, based on research they cite, that the time has come for clinicians to begin to adopt some optical contact lens treatment intervention strategies in myopia development and progression. At the same time, they call for well-designed clinical trials of such approaches. (p. e135)
• Documenting Sectoral Myelinated Nerve Fiber Loss in AION: A First?
The authors report a case of focal myelinated nerve fiber (MNF) loss caused by anterior ischemic optic neuropathy (AION). A year later, there is myelinated nerve fiber loss superiorly with preservation of the inferior segment. This is documented by spectral-domain optical coherence tomography of the optic nerve head and posterior pole showing localized thinning of superior nerve fibers (axons) and retinal thickness. Their case highlights the focal nature of AION and may be the first patient in whom sectoral loss of MNF has been photographically documented. (p. e138)
• SD-OCT Documents Foveal Photoreceptor Loss in Myopia: Another First?
In these 4 clinical cases of highly myopic patients, our authors use spectral-domain optical coherence tomography (SD-OCT) to establish acute foveal photoreceptor damage. All resolved without treatment in 2 weeks to 3 months. To the best of the authors’ knowledge, this is the first report of acute foveal photoreceptor damage documented by SD-OCT. (p. e142)