Orthokeratology for Monovision is Viable for Presbyopia Correction
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Our authors applied hyperopic overnight orthokeratology (OK) in the non-dominant eye of emmetropic presbyopes. They discovered that, like younger patients, OK is effective within a week and it reverses to baseline corneal curvature within 1 week cessation of lens wears. The results suggest that hyperopic OK, creating steepened corneas, can provide a viable option for correcting presbyopia with monovision. |
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Customized Optical Correction of Advanced Keratoconus
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Customized correction of higher order aberrations into a scleral lens produces substantial visual acuity improvement in advanced keratotonic eyes. This wavefront-guided optical design not only improved vision, but the authors report that the optical aberrations in the keratoconus eyes were corrected to normal levels. The research offers the potential of customized scleral lenses to provide patients with abnormally aberrated corneas with nearly a normal level of optical and visual quality. |
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Some Common Optical Corrections be Applied to Keratoconus Patient Groups?
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The authors feel that the relatively common high-order aberrations in keratoconus (KC) can be characterized in sub-groups that will allow feasible correction for these sub-groups. The 110 KC eyes were studied to develop templates for the sub-groups. |
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Detecting Sub-Clinical Keratoconus with Indices Derived From Placido Images
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Irregularity metrics were computed directly from the digitized images of the Placido disks reflected on the cornea of three groups of patients, diagnosed with clinical and subclinical keratoconus, and a normal control group. The authors claim that these new corneal irregularity indices can be an effective tool for detection of keratoconic and keratoconus-suspect eyes. |
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Contact Lens Wear Responses From the Lens or the Solution?
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Despite the increasing popularity of daily disposable lenses, planned-replacement lenses continue to be most commonly prescribed. Our authors use data from 7 prospective clinical trials, involving 283 subjects. They report that a planned replacement silicone hydrogel CL, when worn on a daily disposable basis, reduces corneal surface adverse events and offers better ocular comfort, compared to when it is re-used with various lens care systems. They call for further research on the topic. |
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Contact Lens Replacement/ Compliance and Regular Eye Care Exams Go Hand in Hand
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Perhaps not surprisingly the interval between eye examinations (IEE) is longer for patients who are less compliant with manufacturer recommended replacement frequency. The authors' study also revealed that wearers of daily disposable lenses returned most frequently for eye examinations and contact lens wearers who purchased lenses from their eye care practitioner, had a higher household income, had insurance covering eye exams and were of female gender were also found to attend their practitioner for eye examinations at more regular intervals. |
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Measuring Tear Osmolarity on the Eye
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Our authors validate in situ tear osmolarity measurements by comparing the TearLab instrument to a traditional vapor pressure osmometer. On-eye measurements were repeatable and showed good agreement with vapor pressure measurements. Though tear osmolarity measured with the TearLab instrument was higher when measured on-eye than on collected tears the authors point to the advantages of in situ measurements over techniques requiring tears to be collected. |
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New Tear Evaporation Measure Repeatable
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Our authors demonstrated repeatability for a new method to measure tear evaporation based on infra-red thermography at two different humidities (45% and 65%) at a constant temperature of 30°C. |
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Effectiveness of Two Commercial Eye Drops in Reducing Tear Osmolarity
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Reducing tear osmolarity in dry eye patients is a desirable goal. Each of 20 consecutive patients with moderate dry eye administered one of the commercial eye drops in the right eye, and the other in the left eye. The drops were administered this same way 3 times daily for 21 consecutive days. Both eye drops showed significantly lower tear osmolarity soon after instillation of the drops as well as on day 22, one day after the subjects stopped using the drops. However, hypo osmotic drops with sodium hyaluronate reduced tear osmolarity at a greater and more sustained rate than the osmoprotectants glycerin and carboxymethylcellulose-based drops. |
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A Case for Uncorrected Astigmatism in Pseudophakes
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Because they found that uncorrected astigmatism of up to 1D in 15 otherwise emmetropic pseudophakic eyes implanted with monofocal intraocular lenses improves near vision while reducing distance vision. In contrast, uncorrected myopic astigmatism >1D results in a large loss of distance acuity at no additional benefit to near acuity. The authors suggest leaving myopic astigmatism slightly uncorrected after cataract surgery may be a cost-effective strategy for improving near vision of elderly pseudophakes where conventional forms of sphero-cylindrical bifocal corrections are not readily available or are too expensive. |
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Caution Advised in Choice of Toric IOL
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Consistent astigmatism correction with implantation of a toric intraocular lens (IOL) r equires accurate preoperative keratometry. This paper compares agreement between an autokeratometer (Topcon KR-7100) and a partial coherence interferometry keratometer (IOLMaster 500) in estimating corneal astigmatism. While the keratometers were generally concordant the choice of toric IOL cylinder power differed appreciably in 40% of eyes examined, suggesting to the authors that where there is a consistent difference in IOL power predicted by two different instruments verification is needed using a more robust technique such as corneal topography. |
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Patient Perceptions of Vision Disability and General Health Following Bilateral Cataract Surgery
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Bilateral cataract surgery improves measured vision but not general health (assessed by the CatQuest-9SF and the Short Formular-36), say our authors who followed 148 patients before, at 6 weeks post-surgery and one year later. Physical and mental health improved following surgery but had returned to pre-surgery levels after twelve months. The authors also report some mismatch between measured vision and the assessment of vision disability assessed using the shortened 9-item Rasch-scaled version of the Cataract Questionnaire (Catquest-9SF). |
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Risk Factors for Myopia in Taiwanese Children Under 12
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By age 11 almost 50% of children in Taiwan are myopic (at least -1D). Our authors studied almost 2,000 elementary school children (ages 6 to 11 in grades1 to 6) and found that, of the 20 myopization factors they looked at, two thirds (66%) of refractive error were associated with just 4 of those myopization factors. Those associated with decrease in myopic refractive error were daily outdoor spectacle wear, spectacles for different working distances, and weekend outdoor physical activities. |
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Treating Pigment Epithelium Iris Cyst with Trabeculoplasty Laser
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Management of iris cysts is not yet clearly defined, with many different treatments. Detection is often difficult because they are hidden. Our authors report a case of a peripheral pigment epithelium iris cyst successfully treated with selective trabeculoplasty laser, noting it as potentially useful and relatively less invasive technique. |
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Metamorphopsia and Choroidal Excavation Differences a Clue to Pathogenesis
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Symptomatic and morphological differences between focal choroidal excavations suggest anatomical alterations between the photoreceptor tips and the retinal pigment epithelium, or location of choroidal excavation, as the cause of reported metamorphopsia. Using 2 different clinical cases the authors propose that pathogenesis of focal choroidal excavation involves outward traction on the macula caused by choroidal vascular abnormalities due to failed embryonic development. The availability of spectral-domain optical coherence topography will likely increase the understanding of this condition. |
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Intraocular Yolk Sac Tumor Misdiagnosed as Retinoblastoma
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A case of intraocular yolk sac tumor (YST), misdiagnosed as retinoblastoma by several hospitals. Ultimately the absence of calcification distinguished this condition as YST. The correct diagnosis is important for timely treatment of a dangerous condition. The patient, one year after treatment at 3 years old, is in good health. |
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