INTERESTING EYE NEWS & CLINICAL PEARLS

Report in JAMA suggests oral glucosamine supplements, used for osteoarthritis, may raise intraocular pressure, leading to higher risk for glaucoma.

This study aimed to compare the 24 hour intraocular pressure control obtained with bimatoprost-timolol fixed combination (Ganfort) vs. latanoprost in newly diagnosed, previously untreated patients with exfoliative glaucoma patients with baseline IOP greater than 29mmHg.  It concludes: As first choice therapy in high-pressure, at-risk exfoliation patients, bimatoprost-timolol controlled mean 24 hour intraocular pressure significantly better than latanoprost monotherapy. 

According to this study in Ophthalmology : The corneal hysteresis (CH) measurements were significantly associated with risk of glaucoma progression. Eyes with lower CH had faster rates of visual field loss than those with higher CH. The prospective longitudinal design of this study supports the role of CH as an important factor to be considered in the assessment of the risk of progression in patients with glaucoma.

This is the abstract from a study in Experimental Eye Research : Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree shrew) have found that light levels (similar to being in the shade outdoors) that are mildly elevated compared to indoor levels, slow form-deprivation myopia and (in chick and tree shrew) lens-induced myopia. Normal chicks raised in low light levels (50 lux) with a circadian light on/off cycle often develop spontaneous myopia. We propose a model in which the ambient illuminance levels produce a continuum of effects on normal refractive development and the response to myopiagenic stimuli such that low light levels favor myopia development and elevated levels are protective. Among possible mechanisms, elevation of retinal dopamine activity seems the most likely. Inputs from intrinsically-photosensitive retinal ganglion cells (ipRGCs) at elevated light levels may b...

This study in the Journal of Cornea and External Disease determined whether or not chalazion affects refractive error.  It concludes:  Chalazion increases higher-order aberrations, as measured by the Hartmann–Shack aberrometer, which could affect the preoperative evaluation and results of refractive surgery, especially wavefront-guided approaches. Chalazion excision could reduce ocular aberrations and is recommended before refractive surgeries. My personal experience is the same with dermatochalasis. That means we should delay corrective refraction if a person is considering surgery.

Abstract in Clinical Ophthalmology : Developmental dyslexia affects almost 10% of school-aged children and represents a significant public health problem. Its etiology is unknown. The consistent presence of phonological difficulties combined with an inability to manipulate language sounds and the grapheme–phoneme conversion is widely acknowledged. Numerous scientific studies have also documented the presence of eye movement anomalies and deficits of perception of low contrast, low spatial frequency, and high frequency temporal visual information in dyslexics. Anomalies of visual attention with short visual attention spans have also been demonstrated in a large number of cases. Spatial orientation is also affected in dyslexics who manifest a preference for spatial attention to the right. This asymmetry may be so pronounced that it leads to a veritable neglect of space on the left side. The evaluation of treatments proposed to dyslexics whether speech or oriented towards the visual an...

This is the abstract from a study published in The British Journal of Ophthalmology Background  To analyse the relationship of clinically significant cystoid macular oedema (CME after phacoemulsification to blood–aqueous barrier breakdown as determined by aqueous flare, visual acuity and retinal thickness in optical coherence tomography (OCT). Materials and methods  30 eyes of 30 consecutive patients with clinically significant CME and vision loss were included. 46 pseudophakic and 45 phakic eyes without CME served as controls. Clinical data included age, gender, best-corrected visual acuity (BCVA) and spectral domain OCT volume scans. Retinal thickness measuring of the foveal central subfield was determined. Aqueous flare was measured quantitatively with the Kowa FM-500 Laser Flare-Cell Meter. Results  Patients with CME had significantly higher flare values compared with pseudophakic patients (p s =0.4, p=0.041), while there was no correlation with retinal ...