Brien Holden

Potential lost productivity resulting from the global burden of uncorrected refractive error

OBJECTIVE To estimate the potential global economic productivity loss associated with the existing burden of visual impairment from uncorrected refractive error (URE). METHODS Conservative assumptions and national population, epidemiological and economic data were used to estimate the purchasing power parity-adjusted gross domestic product (PPP-adjusted GDP) loss for all individuals with impaired vision and blindness, and for individuals with normal sight who provide them with informal care. FINDINGS An estimated 158.1 million cases of visual impairment resulted from uncorrected or undercorrected refractive error in 2007; of these, 8.7 million were blind. We estimated the global economic productivity loss in international dollars (I

Interactions of lens care with silicone hydrogel lenses and effect on comfort.

) associated with this burden at I

Myopia, an underrated global challenge to vision: where the current data takes us on myopia control

427.7 billion before, and I

Validation of the Flush Method as an Alternative to Basal or Reflex Tear Collection

268.8 billion after, adjustment for country-specific labour force participation and employment rates. With the same adjustment, but assuming no economic productivity for individuals aged > 50 years, we estimated the potential productivity loss at I

The TFOS International Workshop on Contact Lens Discomfort: report of the definition and classification subcommittee.

121.4 billion. CONCLUSION Even under the most conservative assumptions, the total estimated productivity loss, in

Risk factors for corneal inflammatory and mechanical events with extended wear silicone hydrogel contact lenses.

I, associated with visual impairment from URE is approximately a thousand times greater than the global number of cases. The cost of scaling up existing refractive services to meet this burden is unknown, but if each affected individual were to be provided with appropriate eyeglasses for less than I

The role of optometrists in India: An integral part of an eye health team

1000, a net economic gain may be attainable.

Real cost of recycled spectacles

Purpose. The purpose of this study was to investigate the effect of lens care products on short-term subjective and physiological performance silicone hydrogel lenses. Methods. Ten subjects wore either lotrafilcon B or galyfilcon A silicone hydrogel contact lenses soaked in a lens care product containing either Polyquad/Aldox or PHMB or control lenses inserted directly from the pack. Subjects wore the lenses for 6 h. Ocular comfort (graded on a 1 to 10 scale) and ocular physiology were assessed. Unworn but soaked lenses were analyzed for metrological changes, release of excipients into phosphate buffered saline, and changes to their surface chemical composition. Results. None of the lens metrology measures or clinically observed conjunctival or limbal redness changed. Corneal staining was significantly (p < 0.008) raised, albeit to low levels, after 6 h wear for either lens type when soaked in the PHMB solution compared with the control lens (lotrafilcon B 0.4 to 0.9 ± 0.7 to 0.4 vs. 0.1 to 0.4 ± 0.3 to 0.5; galyfilcon A 0.2 to 0.3 ± 0.2 to 0.4 vs. 0.0 ± 0.0). For lotrafilcon B lenses, there were decreases in comfort (p = 0.002), increases in burning/stinging (p = 0.002) after 1 h of wear, and increases in lens awareness on lens insertion (p = 0.0001) when soaked in PHMB. However, lotrafilcon B lenses soaked in Polyquad/Aldox showed increases in burning/stinging after 1 and 6 h (p < 0.008) of lens wear. For galyfilcon A lenses, most significant (p ≤ 0.002) changes to symptomatology occurred after soaking in Polyquad/Aldox solution. More PHMB was released from lotrafilcon B lenses, and more MPDS material was released from galyfilcon A lenses. The surface of galyfilcon A lenses changed but irrespective of lens solution type, whereas the changes to the lens surface was dependent on solution type for lotrafilcon B lenses. Conclusions. Lens care products can change corneal staining and comfort responses during wear. These changes may be associated with release of material soaked into lenses or changes to the lens surface composition.

Towards better estimates of uncorrected presbyopia

Myopia is the most frequent cause of distance impairment in the world and is creating an alarming global epidemic with deleterious ramifications for the quality of life and economic health of individuals and nations as a whole. In addition to being immediately disadvantageous, myopia increases the risk of serious disorders such as myopic macular degeneration, retinal detachment, glaucoma, and cataract and is a leading cause of visual impairment and blindness across many countries. The reduction in age of onset of myopia is of great concern since the earlier the onset, the more myopic the individual will become, with all the attendant increased risks of accompanying debilitating eye conditions. The economic burden is great; both in consequences of uncorrected refractive error and also in the provision of devices for correcting visual acuity. Earlier onset of myopia increases the lifetime economic burden related to loss of productivity and independence, leading to a reduced quality of life. Recent data suggest addressing accommodation per se has little direct amelioration of myopia progression. Pharmacological interventions that effect changes in the sclera show promising efficacy, whereas optical interventions based on a myopic shift in the retinal image are proving to effect up to 55% reduction in the rate of progression of myopia. Early contact lens and spectacle interventions that reduce the rate of progression of myopia are able to significantly reduce the burden of myopia. These non-pharmacological interventions show profound promise in reducing the overall associated morbidity of myopia.

Visual performance of single vision and multifocal contact lenses in non-presbyopic myopic eyes

Purpose: To validate the more easily applicable “flush” tear collection technique as a viable alternative to basal and reflex tear collection. Materials and Methods: Total protein content (TPC) and immunoglobulin A (IgA) concentrations were determined in the basal, reflex, and flush tears of 16 healthy non-contact lens wearers. The overall protein profile was established using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry (MS). Results: Collection-rates were 4.6 ± 6.7 μl/min, 13.9 ± 11.1 μl/min, and 25.7 ± 12.4 μl/min for the basal, reflex, and flush tears, respectively. TPC was 7.14 ± 2.22 mg/mL, 6.01 ± 2.11 mg/mL, and 3.79 ± 1.51mg/ mL for basal, reflex, and flush tears, respectively, with flush tears being significantly less concentrated than basal (p = 0.001) and reflex (p = 0.008). IgA concentration was 1.04 ± 0.29 mg/ mL, 0.64 ± 0.26 mg/mL, and 0.65 ± 0.23 mg/mL for basal, reflex, and flush tears, respectively, with basal tears being significantly more concentrated (p < 0.001). As a percentage of TPC, IgA represented 19.8 ± 14.9%, 11.4 ± 3.9%, and 19.8 ± 8.7% for basal, reflex, and flush, respectively. The flush was not significantly different to basal (p = 1.00) but significantly greater than reflex (p = 0.02). SDS-PAGE showed the same tear profiles for basal and flush tears. MS identified the most abundant proteins in all tear types. Conclusions: The flush method allows much faster collection than basal secretion sampling but returns essentially the same spectrum of proteins in similar proportions. This behavior is confirmation that the flush technique has utility as a more convenient alternative to basal tear sampling in studies involving composition analysis.