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Vision screening and regular eye care can help detect and treat potentially irreversible vision impairment. This study aims to investigate the associations between sociodemographic and health characteristics and the receipt of eye care among children aged 17 years and younger in the United States. This cross-sectional study used data from the National Survey of Children's Health (NSCH), a nationally representative and population-based survey of randomly sampled households. Participants were children aged 0 to 17 years, residing in all 50 states and the District of Columbia, whose caregivers or parents answered an address-based survey by mail or online. Weighted prevalence calculations were applied to analyze the data, and logistic regression was performed to explore associations between reported eye care and demographic, health, and parent-related variables. Caregiver-reported vision screenings, referral to an eye doctor after vision screening, eye doctor visits, and prescription of corrective lenses. Caregivers reported that 53.2% of children had a vision screening at least once (if child ≤ 5 years) or within the past 2 years (if child > 5 years). Of those screened, 26.9% were referred to an eye doctor. Overall, 38.6% of all children had a previous eye doctor visit, and among them, 55.4% were prescribed corrective lenses during the visit. Factors associated with decreased odds of vision screening included younger age, lack of health care visits, no insurance coverage, parent education high school or less, and lower household income. Non-White ethnicities, households with a non-English primary language, and lower incomes were more likely to be referred to an eye doctor after vision screening. Lower rates of eye doctor visits were associated with younger age, lack of insurance coverage, and primary household languages other than English. Children from disadvantaged backgrounds are less likely to receive vision screening and eye care. Targeted strategies are needed to increase vision screening and access to eye care services in these vulnerable groups. Proprietary or commercial disclosure may be found after the references. [ABSTRACT FROM AUTHOR]

Background: To determine the spectacle reassessment rates of dissatisfied patients returning to the optical services department of a tertiary eye centre in India over a period of six years.Methods: A total of 169,567 spectacles were dispensed from the optical services department between January 2010 and December 2015. The spectacle reassessment forms of dissatisfied patients who returned to the optical services department with their spectacles were analysed.Results: A total of 797 spectacle reassessment forms were analysed. The overall spectacle reassessment rate during the study period was found to be 0.5% (95% CI: 0.467-0.472). The mean age of patients returning back for spectacle reassessment was 48 years (SD 19.9, range 3-97 years). Error in refractive correction measurement was found to be the most common reason for spectacle reassessment (54.7%), followed by dispensing error (21.1%), documentation errors while writing the prescription from the medical records in the tertiary eye care centre (12.7%), transcription error occurring at the optical services department (10.8%) and ocular pathologies (0.8%). No statistically significant difference was observed in the year-wise spectacle reassessment rates during the study period (p = 0.14).Conclusions: The frequency of spectacle reassessment rate in a tertiary eye care centre was low, with errors in measuring refractive errors contributing the most to the reassessment and reorder of spectacles. [ABSTRACT FROM AUTHOR]

Purpose: To review the microbiologic profile, clinical course, treatment, and outcome of patients with cosmetic contact lens (CL)-associated ulcerative keratitis. Materials and Methods: Observational noncomparative case series selected from an ongoing prospective series. Forty-six subjects examined at a corneal specialty practice in Abha, southern Saudi Arabia between April 2012 and June 2013, who presented with corneal stromal infiltrate on slit-lamp examination, were included in the study. Results: All patients were emmetropic, and lenses were worn solely for cosmetic purposes. Nine (19.5%) of 46 CL-wearing patients presented with laboratory-proven infectious keratitis. Pseudomonas was the most common organism (6/9; 66.6%). Staphylococcus species were the second most common, occurring in two (22.2%) of the nine cases. Streptococcus viridans in one case (11%). Laboratory-based medical therapy led to the healing of ulcers in all cases. Thirty-seven (80.4%) patients had sterile infiltrates. Conclusions: Over-the-counter use of cosmetic lenses is rapidly increasing. The easy availability of these lenses is resulting in severe sight-threatening complications in some young emmetropic individuals. Prompt treatment of microbial keratitis is important to prevent vision loss. [ABSTRACT FROM AUTHOR]

Background and objective: We describe a miniaturized lightweight high-refractive-index panretinal contact lens for diagnostic and therapeutic visualization of the peripheral retina. Instrument design: The miniaturized high-resolution wide-field contact lens includes three optical elements in a light (15 g) and miniaturized (16 mm footplate, 24 mm external aperture, and 21 mm vertical height) casing contributing to a total dioptric power of +171 diopters. This lens provides up to 165° visualization of the retina for diagnostic and therapeutic applications while allowing easier placement due to its miniaturization. Conclusion: This new lens (50% lighter and 89% smaller) improves upon earlier contact lenses for visualization of the peripheral retina. [ABSTRACT FROM AUTHOR]

Purpose To quantify the optical quality of various daily disposable contact lenses in vivo and to ascertain its variation in terms of wearing time by means of objective non-invasive determination of wavefront patterns. Methods The crx1 adaptive-optics system was used to measure the wavefront aberrations in 15 myopic eyes before and at 2-h intervals after contact lens fitting, over a 12-h wearing period. Seven types of contact lenses having different material, water content and lens design were evaluated in this study: Dailies Total1, Dailies Aqua Comfort Plus, Proclear 1 Day, 1-Day Acuvue Tru Eye, 1-Day Acuvue moist, Sof Lens daily disposable and Clariti 1-Day. The aberration data were analysed by fitting Zernike polynomials up to the 5th-order for 3 and 5-mm pupils. The optical quality under each condition and at each point in time was described by means of the Root-Mean-Square ( RMS) value of wavefront aberration, Modulation Transfer Function ( MTF), Point Spread Function and cut-off spatial frequency. Results A RMS increase was observed after contact lens fitting as well as over time, both for a 3-mm and a 5-mm pupil. Each type of lens induced a different amount of wavefront aberrations, which vary over time also in a different manner. Dailies Total1 showed the lowest RMS values both at baseline and at the end of the day. In addition, Dailies Total1 provided the best MTF out of all the contact lenses that were assessed. These observations were reflected in higher cut-off spatial frequencies and visual resolution both at baseline and after 12 h of wearing time. Conclusions Aberrometry makes it possible to analyse accurately and in vivo the optical quality of contact lenses and to assess how lenses having different characteristics - such as material or water content - behave for different wearing times. These variations across contact lenses may result in differences in visual performance. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of decorative lenses on ocular wavefront aberrations. Methods: A wavefront analyzer was used to measure higher-order aberrations (HOAs) in 20 right eyes of 20 participants while they were wearing Vistacon contact lenses of different designs, namely, clear 1-day Acuvue, ring-design circle 1-day Acuvue Define (Accent style), or spoke-design circle 1-day Acuvue Define (Vivid style). All of these lenses are made of the same materials and have the same lens parameters, except for the tinted design. HOAs induced by each contact lens were measured for 4- and 6-mm pupils. The coma-like, spherical-like, and total HOAs of each lens type were compared. HOAs of well- and poorly fitting lenses were also compared. Results: For a 4-mm pupil, the HOAs of the three lens types did not differ significantly. For the 6-mm pupil, coma-like and total HOAs were significantly larger with decorative lenses than with clear lenses ( P < 0.05, Bonferroni test). No significant differences were observed between the two types of decorative lenses. Poorly fitting decorative lenses showed significantly larger HOAs than did well-fitting decorative lenses. Conclusions: Poorly fitting decorative lenses may reduce the quality of vision. Consequently, care should be taken that these lenses are properly centered. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To determine the prevalence and the major types of ocular complications related with soft contact lenses (CL) in a tertiary eye care centre of Nepal. Methods: Medical files of 4064 soft CL wearers who started wearing CL between January 2003 and December 2010 in BP Koirala Lions Centre for Ophthalmic Studies (BPKLCOS) Kathmandu, Nepal, were retrospectively reviewed. Records of patients who visited the hospital with complications were analyzed. Patients with ocular complications non-related with CL wear were excluded. Results: Complications were found in 4.9% of the total soft CL wearers. Contact lens induced papillary conjunctivitis (CLPC) was the most common complication, comprising 36.9% of the total patients with complications. The other commonly found complications were superior punctuate keratitis (SPK) in 16.2%, conjunctivitis in 18.2%, meibomian gland dysfunction (MGD) in 8.6%, contact lens induced peripheral ulcer (CLPU) in 4%, corneal vascularization in 3.5% and microbial keratitis in 3%. The average time of first occurrence of complications after starting of contact lens wear was 14.3±11.4 months. Conclusion: CLPC, conjunctivitis and SPK were the most common types of soft CL related complications found in Nepal. Vision threatening complications like microbial keratitis was also found in some patients. Patient education in CL hygiene, after care schedule and frequent follow up examinations may help to minimize CL related complications. [Copyright &y& Elsevier]

Background: Acanthamoeba keratitis (AK) is ever more frequently reported in industrialized countries. The loss of the corneal surface integrity consequent to secondary microtrauma produced by the use of contact lens (CL) favors the penetration of the parasite into the corneal tissue. Objectives: A scientific review was performed to investigate the association of CL wear as an Acanthamoeba keratitis (AK) risk factor. Methods: A computerized screening of 7834 Medline articles (4623 from PubMed; 3211 from Scopus) used a strict selection criteria of case-control studies involving CL wear and/or trauma. Results: The search yielded five case-control studies published from 1995 to 2012. All studies included showed a statistically significant positive association between AK and CL use, with a combined odds ratio (OR) of 10.21 (95%, confidence intervals [CI]; 3.57-27.64). Statistical analysis: All studies included showed a statistically significant positive association between AK and CL use, though with differing OR values. Conclusion: Though rare, AK should be held in higher consideration when ophthalmologists are faced with CL users exhibiting simplex-like lesions associated with circular stromal infiltrates and disproportionate ocular pain in respect to the objective clinical picture. [ABSTRACT FROM AUTHOR]

Background: Normal vision is essential to interact with widespread digital technologies. Higher order aberrations (HOA) are one of the important causes of image degradation in patients suffering from keratoconus, pterygium, or irregular astigmatism. These aberrations cannot be corrected by common ways of refractive errors correction like spectacles. Besides, other methods of HOA correction (e.g. customized contact lenses) are not easily accessible in many regions and photo-refractive surgeries like laser-assisted in situ keratomileusis (LASIK) are expensive. A novel method to correct HOA is pre-compensation of images displayed on computer monitors to provide unaberrated images. We used total variation (TV) deconvolution to pre-compensate images and compared the results with previous methods based on Wiener deconvolution. Methods: MATLAB was used for simulations. Each HOA was reconstructed using single-index scheme for Zernike coefficients. Pupil diameter was assumed to be four millimeters. Root-mean-square error of simulated aberrations was greater than 0.35 micrometers. Point spread functions corresponding to each HOA were created and TV deconvolution was used to pre-compensate the images. Findings: Strehl ratio of TV pre-compensation is very close to the results of Wiener pre-compensation method. Besides, execution time for TV Pre-compensation algorithm is about 20% faster than Wiener. Conclusion: Simulations ascertain that TV based pre-compensation method is a fast and efficient way to pre-compensate the images, and it could improve the patient's perceived retinal image quality. One more advantage of using TV algorithm is that we could enhance the results just by altering one parameter. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the safety of bromfenac sodium eye drops from the standpoint of corneal sensitivity and tear secretion in healthy controls following instillation for 1 month. Methods: A prospective single-blind parallel clinical study was conducted in 20 eyes of ten healthy volunteers with no history of ocular or systemic allergic disease, dry eye, contact lens wear, or ocular surgery. Participants were instructed to instill either bromfenac sodium or artificial tears in each eye twice daily for 28 days. Corneal sensitivity tested using a Cochet-Bonnet esthesiometer was evaluated before and immediately after instillation at 7, 14, and 28 days after the initiation of treatment. Tear secretion was also evaluated by Schirmer's eye test before and at 28 days. Results: No significant difference in mean corneal sensitivity and tear-secretion rate was observed between the bromfenac and artificial-tear treatment groups at any time. Conclusion: These results indicate that bromfenac sodium eye drops are safe with respect to corneal sensitivity and tear secretion in subjects with a normal ocular surface condition. Further evaluation is still necessary to determine whether bromfenac is safe in pathological conditions, such as inflammatory disorders and postsurgical cases. [ABSTRACT FROM AUTHOR]

Purpose: To determine and compare corneal elevation and thickness indices, thereby formulating a reliable index to distinguish eyes with pellucid marginal degeneration (PMD) from keratoconus eyes and normal (control) eyes. Setting: LV Prasad Eye Institute, Hyderabad, India. Design: Initial model-building retrospective study. Methods: Anterior and posterior corneal elevations and thickness indices were obtained from the Orbscan IIz topographer. These values were analyzed and compared between PMD patients, keratoconus patients, and control subjects. Results: Of the indices, the mean values of anterior elevation (AE), ratio of the AE to the anterior best-fit sphere, ratio of the average power values of nasal quadrant to the average power values of inferior quadrant, and difference between maximum keratometry (K) and minimum K were significantly different between the 3 groups (P<.05). The highest area under the receiver-operating-characteristic (AROC) curve in discriminating PMD from keratoconus was for asphericity (0.974; cutoff ≥−0.07; sensitivity 93.3%; specificity 90.6%) followed by the ratio of average power values of the nasal and temporal quadrants to the average power values of the inferior and superior quadrants (Avg NT(D)/IS(D)) (0.959; cutoff ≥1.005; sensitivity 96.7%; specificity 90.6%). The PMD index (AROC curve, 0.935), with a cutoff of 3.45 or higher had 90% sensitivity and 93.7% specificity to distinguish PMD from keratoconus and had 100% sensitivity and 100% specificity to distinguish PMD from control eyes, with a cutoff of 2.46 or higher (AROC curve, 1.000). Conclusions: The PMD index appeared to be highly sensitive and specific for diagnosing PMD. Asphericity and Avg NT(D)/IS(D) were clinically relevant in discriminating PMD from other groups. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]

Citation information: Jinabhai A, Charman WN, O'Donnell C & Radhakrishnan H. Optical quality for keratoconic eyes with conventional RGP lens and simulated, customised contact lens corrections: a comparison. Ophthalmic Physiol Opt 2012, 32, 200-212. doi: 10.1111/j.1475-1313.2012.00904.x Abstract Purpose: To compare monochromatic aberrations of keratoconic eyes when uncorrected, corrected with spherically-powered RGP (rigid gas-permeable) contact lenses and corrected using simulations of customised soft contact lenses for different magnitudes of rotation (up to 15°) and translation (up to 1 mm) from their ideal position. Methods: The ocular aberrations of examples of mild, moderate and severe keratoconic eyes were measured when uncorrected and when wearing their habitual RGP lenses. Residual aberrations and point-spread functions of each eye were simulated using an ideal, customised soft contact lens (designed to neutralise higher-order aberrations, HOA) were calculated as a function of the angle of rotation of the lens from its ideal orientation, and its horizontal and vertical translation. Results: In agreement with the results of other authors, the RGP lenses markedly reduced both lower-order aberrations and HOA for all three patients. When compared with the RGP lens corrections, the customised lens simulations only provided optical improvements if their movements were constrained within limits which appear to be difficult to achieve with current technologies. Conclusions: At the present time, customised contact lens corrections appear likely to offer, at best, only minor optical improvements over RGP lenses for patients with keratoconus. If made in soft materials, however, these lenses may be preferred by patients in term of comfort. [ABSTRACT FROM AUTHOR]

Purpose: The aim was to determine the cytotoxic effects of three multipurpose solutions (MPS) on human corneal epithelial cells (HCEC) and to assess the metabolic rates of recovering cells at different levels of cell membrane damage. Method: The effects of one to 15 minutes exposure to multipurpose solutions containing polyquaternium-1 (MPS-A), polyaminopropyl biguanide (MPS-B) and polyhexanide (MPS-C) on HCEC were determined. Recovery rates at different levels of cell membrane damage were assessed after re-culture for two hours at 37°C. Cell viability and membrane integrity were assessed using Annexin V-FITC/7-AAD staining and flow cytometry. Effects of concentrations of 10 to 40 per cent multipurpose solutions on the metabolic rate of recovering HCEC were assessed using a Vybrant MTT cell proliferation assay kit. Results: The highest percentage of late necrotic cells resulted after exposure to MPS-A compared with other solutions and the control (p < 0.001). The percentages of early necrotic cells after 10 and 15 minutes of soaking in MPS-B were significantly higher than the control and other multipurpose solutions (p < 0.001). Although MPS-C exposure also resulted in statistically significant higher percentages of early necrotic cells than the control (p < 0.005), these differences were small. No recovery was noted when HCEC treated with multipurpose solutions were re-cultured, with numbers of dead cells in MPS-B-treated cultures increasing fourfold. The MTT assay showed significant dose-response decreases of 500 nm absorbance for all MPS-treated cells. In 40 per cent MPS-A-treated HCEC, lack of activity indicated the cells were non-viable. Conclusions: Multipurpose solutions induced varying levels of irreversible tissue sensitivity reactions, with MPS-A showing the greatest effects. The solutions damaged cell integrity and reduced metabolic rates suggesting delayed healing ability. The formulations of multipurpose solutions need to balance antimicrobial effectiveness with low cytotoxicity, which might not be currently possible to achieve. In light of our results, we suggest that contact lens wearers should be advised to rinse the soaked lenses with saline before lens insertion. [ABSTRACT FROM AUTHOR]

Purpose: The aim was to evaluate the disinfection properties of six multi-purpose contact lens disinfection solutions (MPDS) available in Iran against Fusarium solani and Candida albicans, based on the International Organization for Standardization (ISO) 14729 guidelines. Methods: Three lots each of six multi-purpose solutions, namely, Renu MultiPlus, Solo Care Aqua, All-Clean soft, Contact All In One Advanced, Hippia, Ginza Multi-Purpose Solution and 0.9% normal saline solution were inoculated with standard strains of Fusarium solani (ATCC 36031) and Candida albicans (ATCC 10231). Surviving fungi were determined by counting colony-forming units on recovery plates at specified times. The mean log reduction in fungal numbers at the manufacturer's minimum recommended disinfection time was determined and compared with the criteria for stand-alone disinfection products for each MPDS against each fungal strain. Results: Renu MultiPlus, Contact All In One Advanced and All-Clean Soft were effective in achieving the mean 1.0 log reduction in fungal numbers, based on ISO 14729 stand-alone primary acceptance criteria. Solo Care Aqua failed to achieve the ISO 14729 stand-alone primary acceptance criteria for Candida albicans. The other solutions were not effective against test microorganisms after the specified times. Conclusions: There were differences in the rates of disinfection efficacy. Generally, Renu MultiPlus, Contact All In One Advanced and All-Clean Soft exceeded the primary acceptance criteria of the ISO 14729 guidelines for stand-alone contact lens solutions. [ABSTRACT FROM AUTHOR]

Background: Contact lens-related infections are often associated with inadequate contact lens hygiene, and therefore, contact lens care products should be able to sufficiently minimise the amount of pathogens that are responsible for these infections. In 2001, the EN ISO 14729 was introduced to ensure adequate disinfection efficacy of contact lens care solutions, but this norm has recently been criticised. Methods: In this study, six frequently used contact lens care solutions were retested according to the Stand Alone Test of the EN ISO 14729 (2001). The Stand Alone Test is a quantitative suspension test. In addition, the products were tested in a modified setting adding an organic load. The load was a mixture of human blood serum, lysozyme, and mucine, which resembles tear fluid. Results: The criteria of the Stand Alone Test recommended in EN ISO 14729 were only met by Aosept Plus. This 3% hydrogen-peroxide-based contact lens care solution attained a reduction factor of > 5 log units for bacteria and > 4 for fungi in all cases. Two further contact lens care solutions, Blue Vision and Optifree Replenish, met the criteria of a reduction factor of > 3 log units for bacteria and > 1 log unit for fungi, but only in the presence of artificial tear fluid. The three remaining products did not exhibit adequate disinfecting efficacy, at least against one of the tested microorganisms. Conclusions: Through the observation that the artificial tear fluid used in this study influences the disinfecting efficacy of contact lens care solutions, especially that of multi-purpose solutions, in a different way than does albumin, mucine, or even the organic load suggested in EN ISO 14729, it becomes obvious that the test conditions in the EN ISO 14729 should be revised in order to create more realistic conditions, e.g., by using a more realistic artificial tear fluid. Furthermore, we suggest adapting the EN ISO 14729 to the European test hierarchy for chemical disinfectants and antiseptics, which consists of three test phases and also requests meeting stricter criteria in order to pass the test. Unless the test conditions guarantee a sufficient reduction of potential pathogens, the risk of contact lens-related microbial keratitis and other infections will remain for the users. [ABSTRACT FROM AUTHOR]

Purpose: We evaluated the usefulness of commercially available materials for protecting the cornea from drying during vitrectomy with a wide-angle viewing system. Methods: Three vitreoretinal surgeons evaluated fundus visibility during vitrectomy on the images of five study materials used on the cornea: balanced saline solution, a viscoelastic agent, a vitrectomy contact lens, a rigid gas permeable (RGP) contact lens, and a soft contact lens. Fundus visibility was graded using the following scale: grade 1, unclear; grade 2, slightly unclear; grade 3, clear; and grade 4, very clear. Results: Respective scores for each material used during core vitrectomy and membrane removal were: balanced saline solution, 3.3/3.3; viscoelastic agent, 3.8/3.3; vitrectomy contact lens, 3.3/4.0; RGP contact lens, 4.0/3.9; soft contact lens, 1.1/not applicable. Conclusion: The RGP contact lens provided visibility similar to or clearer than that obtained with other methods. Because of its ease of use and lower cost, use of the RGP contact lens is ideal during vitrectomy performed with a wide-angle viewing system. [ABSTRACT FROM AUTHOR]

Purpose: To assess the use of multipurpose lens care products via an online survey conducted among soft contact lens (SCL) wearers in Japan. Methods: The subjects were 1000 men and women aged 15--44 years who reported that they cleaned their SCL by using multipurpose solution at least twice a week. Via the internet, they were asked questions about SCL care, the use of a rubbing step when cleaning SCL, cleaning and replacing lens cases, and recommended SCL care methods. Results: Of the 1000 SCL wearers enrolled, 94.3% performed lens care every day lenses were worn, 64.2% reported rubbing the lenses every time, 57.9% rubbed the lenses for at least 10 seconds per side, and 64.7% reported they rubbed the lenses on both sides. Further, 61.2% reported that they had been given an explanation of SCL cleaning at an eye clinic or contact lens store. Only 49.8% of subjects reported that they cleaned the lens case every time and 61.7% replaced the case within 3 months. Only 19.5% had been given an explanation about lens case care. Half of the subjects reported they had been given no recommendation to use specific SCL care products or could not remember whether or not they had. The most common reason for the recommendation was good compatibility with their type of lens. Conclusion: More education is needed in Japan regarding methods of SCL care to ensure correct lens cleaning with inclusion of a rubbing step, as well as sufficient cleaning and replacement of the lens case. Of particular interest is the finding that many subjects were not given an explanation about proper SCL care and lens case cleaning and replacement at the time of lens purchase or prescription. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to assess whether differences in central corneal dendritic immune cell densities associated with combinations of soft contact lenses and lens care solutions could be detected by in vivo confocal microscopy. Methods: Participants were adults naïve to contact lens wear (n = 10) or who wore soft contact lenses habitually on a daily-wear schedule (n = 38) or on a study-assigned schedule for 30 days with daily disposable silicone hydrogel lenses (n = 15). Central corneas were scanned using an in vivo confocal microscope. Cell densities were compared among groups by demographic parameters, lens materials, and lens care solutions (polyhexamethylene biguanide [PHMB], polyquaternium-1 and myristamidopropyl dimethylamine [PQ/MAPD], peroxide, or blister pack solution [for daily disposable lenses]). Results: Among lens wearers, no associations were observed between immune cell densities and age, gender, or years of lens-wearing experience. Mean cell density was significantly lower (P < 0.01) in nonwearers (29 ± 23 cells/mm2, n = 10) than in lens wearers (64 ± 71 cells/mm2, n = 53). Mean cell density was lower (P = 0.21) with traditional polymer lenses (47 ± 44 cells/mm2, n = 12) than with silicone hydrogel lenses (69 ± 77 cells/mm2, n = 41). Lowest to highest mean density of immune cells among lens wearers was as follows: PQ/MAPD solution (49 ± 28 cells/mm2), blister pack solution (63 ± 81 cells/mm2), PHMB solution (66 ± 44 cells/mm2), and peroxide solution (85 ± 112 cells/mm2). Conclusion: In this pilot study, in vivo confocal microscopy was useful for detecting an elevated immune response associated with soft contact lenses, and for identifying lens-related and solution-related immune responses that merit further research. [ABSTRACT FROM AUTHOR]

Commonly associated with dry eye, blepharitis is the most commonly encountered disorder in general ophthalmologic practice. Although anti-infective and anti-inflammatory therapies are available, eyelid hygiene is the cornerstone of effective management. A variety of products have been used to assist and encourage eyelid cleansing and massage. The present study examines the ocular and periocular tolerability and acceptability of Blephagel, a cosmetic, poloxamer-containing gel designed specifically for cleansing the eyelid in subjects with sensitive skin or eyes or contact lens users. Subjects with blepharitis and sensitive skin or eyes, a history of atopy, or who use contact lenses applied Blephagel twice daily at home. Clinical ophthalmologic examinations were conducted before and 21 days after aqueous gel application, and subjects completed a questionnaire on the acceptability of the preparation. Thirty-three predominantly female subjects entered and completed the study. A total of 36% of the subjects had used similar products in the past, 21% regularly. Upon questioning by the ophthalmologist, 85% of the subjects reported acceptability of the preparation as good to very good, and 73% rated the efficacy as good to very good. There were minor but statistically nonsignificant changes in fluorescein tear breakup time and visual acuity before and after 21 days of aqueous gel application. The questionnaire results indicated that the subjects found the product to be effective for cleansing the eyelids of mucus and squama around eyelash roots. Moreover, cosmetic qualities, sensation in use, and acceptability were also appreciated. No subject reported any adverse event considered to be related to the aqueous gel. Although the safety of Blephagel has already been established in standard tests, the current results suggest that it is also pleasant to use and acceptable to blepharitis patients with sensitive skin as an aid to an eyelid hygiene regime. [ABSTRACT FROM AUTHOR]

Purpose: To report a case of aniridia in a pseudophakic patient following blunt trauma to the eye. Case report: The traumatized eye had cataract surgery through a 3.0 mm clear corneal incision 6 years prior to the incident. While there have been previous cases of traumatic aniridia in pseudophakic eyes, previous reports have all occurred closer to the time of the cataract surgery. We believe that the most likely mechanism of loss of iris tissue is through wound dehiscence, which would suggest the relative instability of clear corneal incisions several years postoperatively. The patient's visual acuity returned to 20/20 4 weeks post-trauma, with symptoms of glare which were managed by the use of a colored contact lens. Conclusion: The possibility of wound dehiscence should be recognized as an important clinical entity in the immediate postoperative period, but also several years following cataract surgery. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effect of intraocular lens (IOL) orientation (vertical versus horizontal) and haptic design (1-piece versus 3-piece) on centration and tilt using a Purkinje meter. Setting: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. Design: Randomized pilot study with intrapatient comparison. Methods: In part 1 of this study, patients received plate-haptic IOLs (Akreos Adapt) in both eyes that were positioned vertically in 1 eye and horizontally in the other eye. In part 2, patients received a 1-piece IOL (Acrysof SA60AT) in 1 eye and a 3-piece IOL (Acrysof MA60AC) in the contralateral eye. Decentration and tilt were measured 1 month and 3 months postoperatively with a new Purkinje meter. Results: In part 1 (n = 15), the mean decentration of plate-haptic IOLs was 0.4 mm ± 0.2 (SD) with vertical orientation and 0.4 ± 0.2 mm with horizontal orientation and the mean tilt, 1.5 ± 1.1 degrees and 2.9 ± 0.9 degrees, respectively. In part 2 (n = 15), the mean decentration was 0.4 ± 0.3 mm with 1-piece IOLs and 0.6 ± 0.8 mm with 3-piece IOLs and the mean tilt, 2.2 ± 7.2 degrees and 5.3 ± 2.4 degrees, respectively. Conclusions: Three-piece IOLs had a greater tendency toward more decentration than 1-piece IOLs, perhaps because of slight deformation of 1 or both haptics during implantation or inaccuracies in production when the haptics are manually placed into the optic. The IOL orientation for plate-haptic IOLs appeared to have no effect on IOL position. The Purkinje meter was useful in assessing the capsule bag performance of the IOLs. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes. [Copyright &y& Elsevier]

Background: The monitoring and assessment of the upper tarsal conjunctiva can be enhanced by the use of a grading scale. The aim of this study was to categorise the appearance of normal tarsal conjunctiva among young adults in Malaysia using the Institute for Eye Research grading scale and to investigate inter- and intra-observer agreement. Methods: The appearance of the upper tarsal conjunctiva of 416 non-contact lens wearing subjects aged between 19 to 24 years was assessed by two separate observers for roughness and redness in three separate zones using the Institute for Eye Research grading scale. The average grade for each zone and overall grade for roughness and redness were calculated. Inter- and intra-observer agreements were analysed. Results: Subjects were categorised for ethnicity and the roughness and redness were calculated. No significant differences were found between Malay and Chinese eyes (p > 0.05). The average grades for the upper tarsal conjunctiva redness and roughness were 0.90 ± 0.25 and 0.86 ± 0.43, respectively. Significantly higher roughness scores were found in zone 1 compared to the other two zones (p = 0.03). Significant association was also found between tarsal conjunctiva redness and roughness (Spearman ρ= 0.45, p < 0.001). Correlation between redness and roughness with age (p = 0.48, p = 0.65) and gender (p = 0.30, p = 0.79) were not significant. Only 2.2 per cent of subjects had scores higher than 2.0 for roughness or redness. Inter- and intra-observer analysis showed good agreement between two observers during the study. Conclusion: The roughness and redness of normal tarsal conjunctiva among young adults in Malaysia were found to be less than two units. Results of this study might be beneficial in clinical trials using contact lenses where changes in the tarsal conjunctiva are commonly used as an outcome measure. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to compare central and peripheral corneal thickness measurements in corneas with and without contact lens (CL)-induced corneal swelling, in order to establish the constancy of the Orbscan acoustic factor (AF) for reliability in detection of CL-induced corneal swelling. Methods: Corneal thickness was measured in five corneal locations (central, superior, inferior, nasal and temporal) using both ultrasonic and Orbscan pachymetry before and after one week of high Dk (lotrafilcon A) and low Dk (etafilcon A) contact lens continuous wear (CW). Lenses were randomly fitted for CW in the right and left eyes of 20 healthy subjects to induce various amounts of corneal swelling. Results: Etafilcon A contact lenses induced greater corneal swelling than the lotrafilcon A contact lenses (p < 0.05, paired Student t-test). Equal corneal swelling percentages (with and without the application of the acoustic factor) were determined from Orbscan measurements. Application of the 0.92 AF did not permit adjustment to all corneal locations. The correlations between Orbscan with and without the 0.92 AF and ultrasonic pachymetry were higher for central pachymetry (r² > 0.88; p < 0.01) and lower for peripheral pachymetry (r² < 0.58; p < 0.01) with similar trends in corneas with and without CL-induced swelling. Conclusions: The acoustic factor proposed by the manufacturer to obtain corneal thickness with the Orbscan compared with those from ultrasonic pachymetry was not valid for all corneal topographic positions. The AF is unnecessary when determining CL-induced corneal swelling. [ABSTRACT FROM AUTHOR]

PurposeWith a new Fourier domain optical coherence tomography (FD OCT) device, SL SCAN-1 (Topcon Europe Medical BV, Capelle a/d IJssel, The Netherlands), integrated into a slit-lamp OCT, scans can be obtained through a handheld lens. The necessary adjustment of the reference arm is possible by fast Z-alignment. This study was performed to prove the capability of SL SCAN-1 to scan through a three-mirror contact lens, scanning the peripheral retina and anterior chamber angle.MethodsDifferent representative pathologies of the peripheral retina and anterior chamber were simultaneously observed and scanned with the SL SCAN-1. The scans of peripheral retinal lesions were obtained both through a handheld lens and through a three-mirror contact lens. The anterior chamber angle was scanned directly with the SL SCAN-1 in anterior mode, and through the gonio-mirror of a three-mirror contact lens with the SL SCAN-1 in posterior mode.ResultsOCT scans could be obtained with the SL SCAN-1 of the peripheral retina through both, a common handheld lens and a three-mirror contact lens. The scans obtained through a three-mirror contact lens were of better quality, visualizing details of the different layers of the retina more clearly. The scans of the anterior chamber, obtained through the gonio-mirror of a three-mirror contact lens, visualized the open anterior chamber angle, with details of fine structures.ConclusionsThe SL SCAN-1 is a unique FD OCT system, which is able to scan not only the posterior pole and anterior segment but also the anterior chamber angle and the more peripheral retina. These four modalities combined into one device could make the SL SCAN-1 a very powerful aid in daily practice. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of toric and soft spherical contact lenses on the visual performance and wavefront aberrations in cases of low astigmatism. Material and Method: Twenty-four eyes of 14 contact lens users with cylindirical refractive error of -1.25 diopters or less were included in this prospective study. The subjects wore spherical (lotrafilcon B) and toric (galyfilcon A) lenses for eight hours with a one-week interval. The best-corrected visual acuity and contrast sensitivity were measured before and after 8 hours of contact lens wear. Corneal topography and wavefront analysis were also performed. Zernike coefficients were used to calculate the aberrations at a 6-mm pupil diameter. Total and higher-order root mean square (RMS) values as well as spherical and coma aberrations were measured. Result: The mean spherical refractive error of the cases was -2.52±1.25 (range: from -0.50 to -6.0) D. The mean best- corrected visual acuity was significantly higher with both types of contact lenses than with glasses (p=0.017), however, no statistical difference was observed between the two types of contact lenses (p=0.470). The mean high-frequency contrast sensitivity value was lower with toric lenses (p=0.038). The mean higher-order RMS value was higher with both types of contact lenses (p=0.021), but with no difference between them (p>0.05). The mean spherical aberration value did not differ among glasses, toric or soft spherical contact lenses (p>0.05). The mean coma aberrations were high with both types of contact lenses (p=0.041); no difference was observed between the two lens types (p>0.05). Discussion: In this study, it was demonstrated that in cases of low astigmatism, soft spherical and toric contact lenses increase visual acuity, total higher-order aberrations, and coma aberrations, but decrease high-frequency contrast sensitivity. There was no difference between the two types of contact lenses. [ABSTRACT FROM AUTHOR]

In this article, the materials used for glass (mineral) and plastic (organic) spectacle lenses and the properties of monofocal, bifocal, trifocal and multifocal spectacle lenses are investigated. On the other hand, the new generation personalized lenses, which were produced by freeform technology and customized high resolution (HD) wavefront-guided spectacle lenses and ongoing glass research studies are also discussed. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the possible impact of latanoprost, bimatoprost and travoprost on central corneal thickness (CCT) in the short term. Materials and Methods: A total of 66 newly diagnosed primary open angle glaucoma patients were randomly distributed into 3 groups to receive latanoprost, bimatoprost or travoprost. Patients with non-glaucomatous eye disease, history of trauma, contact lens use, topical drop/oinment use, lacrimal problems, or any pathology that could affect CCT were discluded from the study. All CCT measurements were recorded with ultrasonic pachymeter (Tomey, SP3000) at baseline and at 1st, 4th, and 12th weeks of treatment. Statistical analysis were conducted using SPSS 11.0 (Chicago, IL). Results: The 3 groups were similar regarding age (p=0,504) and baseline CCT (p=0.100). The mean CCT change was not significant at 1 week of treatment, but 4th and 12th week measurements showed considerable difference in all 3 groups. The mean change in CCT was 5,86 mm at 4th week and 8.39 mm at 12th week. Bimatoprost group at 12th week showed the highest percentage (52%) of CCT change when pachymetric difference of >10 mm was considered. Travoprost group exhibited a significant CCT thinning even at 1st week of treatment in patients with a baseline CCT of >545 microns. Conclusion: Latanoprost, bimatoprost ve travoprost similarly caused significant CCT thinning at 4th and 12th weeks of treatment. It may be important to obtain pachymetry measurements at each visit in the early period of primary open angle glaucoma treatment. [ABSTRACT FROM AUTHOR]

Trichiasis is a lid margin disorder in which the eyelashes are misdirected toward the ocular surface. It is a major cause of ocular morbidity. Trichiasis is secondary to inflammation and scarring of the eyelash follicles. There is a frequent association between trichiasis and cicatricial entropion and the correct diagnosis is mandatory for a successful treatment. There are several options for the management of trichiasis and the main purpose is to eliminate the anomalous cilia and improve the patient’s comfort. Temporary measures include eye lubricants, contact lenses, and mechanical epilation. Surgical treatments have initial success but long-term results are poor and recurrences are frequent. Definitive trichiasis treatments include bipolar electrolysis, radiofrequency ablation, cryotherapy and laser ablation, and surgical procedures. The techniques are described in detail along with possible complications and outcome. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To assess demographic profile and functional outcomes of patients with keratoconus attending contact lens clinic at a tertiary eye care centre. Materials and methods: Retrospective analysis of 77 patients (142 eyes) diagnosed with keratoconus attending contact lens clinic at Dr Shroff''s Charity Eye Hospital, New Delhi, from January 2008 to December 2008 was done. Data on age, gender, slit lamp examination, keratometry, topography, visual acuity with log MAR conversion, degree of visual success, type of contact lens and fitting characteristics were obtained. Results: One hundred and forty-two eyes of 77 patients were analyzed of which 49 (63%) were males and 28 (37%) were females; their median age was 24 years (15–36 years). Keratoconus reading based on keratometry was done. Twenty eyes (14.4%) were diagnosed to have mild keratoconus, 51 eyes (36.7%) had moderate, 45(32.4%) had advanced and 23 eyes (16.6%) had severe keratoconus. 113 eyes (79.5%) were visually rehabilitated with RGP lenses while 29 eyes (20.4%) fitted best with Rose-K lenses and in 1 patient (0.1%) Boston scleral lens was given in both eyes. With contact lens wear, visual acuity improved to 6/9 (0.18log MAR) or better in 91% (115 eyes) and 141 (99%) eyes improved to 6/18 (0.48log MAR) or better. Conclusion: We found that in India keratoconus presents at an early age as compared to the western population. Contact lenses offer a good modality to delay the requirement for penetrating keratoplasty. Newer philosophies for fitting contact lenses and newer materials can help in decreasing the contact lenses intolerance which still remains the major indication for undergoing penetrating keratoplasty. [Copyright &y& Elsevier]

Background: It is generally believed that the clinical performance of the original Czechoslovakian hydrogel contact lenses was poor but historical reviews provide very little explanation regarding their failings. There is a lack of information in the literature about their dimensions and, in particular, thickness, which is essential for the calculation of oxygen transmissibility. Until now no measurements on Czechoslovakian lenses have been reported. Methods: A literature search on Czechoslovakian lenses was made that spanned the first decade of their use and included peer-reviewed journals, non-refereed publications and a number of archived documents. In addition, the water content and dimensions of five Geltakt and four Spofa lenses were measured. Results: Lens packaging, lens lifetime, hygienic care, visual acuity, nominal lens dimensions, flexure, failure to correct astigmatism, corneal oedema, oxygen transmissibility, complications and wearing time are reviewed. Measurements on Czechoslovakian lenses indicate that the total diameter was similar to that of the cornea, the back optic zone radius was steep and the centre thickness was large. Conclusion: Problems associated with the Czechoslovakian lenses included packaging and an initial failure to require daily disinfection. Few complications of lens wear were reported, probably due to the comparatively small number of patients fitted and the limited wearing time that they achieved. Delayed disclosure of lens dimensions handicapped the development of a fitting technique. An acceptable visual acuity was attained in selected cases, while reduced acuity may sometimes have been due to uncorrected astigmatism or to poor lens quality. The most serious disadvantage was the very low oxygen transmissibility that could result in marked corneal oedema. [ABSTRACT FROM AUTHOR]

The visual outcomes for infants 18 months or younger with cataracts have improved dramatically over the past couple of decades. Earlier detection of infantile cataract and prompt surgical removal—with subsequent visual rehabilitation with contact lenses—mean that these patients now have a much better visual prognosis. Advances in contact lens technology have led to a significantly higher success rate with contact lenses and this has been a major factor in improving the visual outcomes for aphakic infants. This review outlines the contact lens management of infantile cataract, including a detailed analysis of the various contact lens options available and a discussion regarding the important factors that can cause issues with contact lens wear and affect the overall visual rehabilitation of the infant. [ABSTRACT FROM AUTHOR]

Purpose: Recent outbreaks of microbial keratitis have increased concerns about the efficacy of multipurpose solutions (MPS) against ‘real-world’ organisms. This study determined, in accordance with FDA/ISO standard methods, the effects of five MPS against clinical isolates and type strains of bacteria, and isolates of fungi from subjects’ ocular structures; and of three MPS against environmental fungal isolates. Method: MPS were challenged with bacteria (type strains (ATCC) and clinical isolates of bacterial pathogens obtained from a district hospital laboratory) and with fungal isolates from both the periocular and conjunctival structures and from environmental air. Results: All MPS demonstrated at least a 3-log reduction of challenged cell viability of all bacterial species tested, with the exception of MPS D against a canine infection Staphylococcus aureus isolate. Whilst all MPS tested were able to effect a 1.0-log reduction of viability of Fusarium solani (ATCC 36031), only two MPS had 90% viability reduction against all fungi of human origin and only one of these against all environmental fungal isolates. Effectiveness of these two solutions against fungal isolates compared to the remaining three MPS was found to be statistically significant ( p = 0.003). Conclusions: All MPS demonstrated a 99.9% viability reduction against a wide range of bacteria including major ocular pathogens not currently included in the FDA panel. The inability of three MPS to achieve a 90% reduction against fungal isolates is of concern as there has been a recent upsurge in reports of fungal keratitis. We would recommend extension of the current FDA testing panel for MPS to include more fungal isolates. [ABSTRACT FROM AUTHOR]

Recently, an alternate method for recovering the shape of the anterior surface of an intraocular lens (IOL) (by Purkinje images), and capable of returning a Zernike polynomial representation of that surface, was proposed ( Ophthal. Physiol Opt., 29, 2009, 80–91). However, in moving toward a clinically applicable method, it is important to estimate parameters such as surface radius, lens tilt and decenter. Previously, radius of curvature (for the anterior surface of an IOL) was estimated by finding the best-fit sphere. A methodology is presented here to recover lens tilt and decenter using this alternate method. The theory is developed and then tested in simulation. An IOL is added to the Navarro eye, and then recovered by assuming: (i) the same ‘full eye’, and (ii) a reduced two surface version (the ‘simplified’ eye). A number of decenter and tilt settings are tested, from which root mean squared (RMS) surface errors, best-fit spheres, tilt and decenter values are estimated. Mis-measurement of the axial position of the posterior surface of the IOL is also simulated. The full eye model produces low RMS surface and radii of curvature errors, that increase linearly with axial shift. The error behaviour is not greatly affected by changes in IOL decenter and/or tilt. The simplified eye ( n = 1.32 for aqueous) with n = 1.4760 (at λ = 880 nm) for the IOL, fits the ‘full eye’ results most consistently. Lens decenter is consistently estimated to within 0.015 mm (for a 1 mm decenter), and tilt <0.15 degrees (for a 5 degree tilt). [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the outcome of intraocular lens (IOL) implantation using capsular tension ring (CTR) in subluxated crystalline or cataractous lenses in children. Setting: Tertiary care setting Materials and Methods: We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 900 up to 2100 after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO). Results: Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA) in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Conclusions: Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of a customised manipulation of spherical aberration (SA) on the high and low contrast visual acuities and contrast sensitivity of young adult myopes. Methods: A placebo-controlled double masked trial of customised spherical aberration controlling soft contact lenses was undertaken in myopes aged 15–23. Participants wore customised soft contact lenses with either (i) zero spherical aberration or (ii) negative spherical aberration that resulted in a net SA (eye plus lens) of −0.1 micron. High and low contrast log MAR visual acuities and Pelli Robson contrast sensitivity were assessed in 196 eyes of 98 subjects after a period of 12 months wearing the lenses. Results: Both high and low contrast acuities were significantly better in the group wearing the contact lenses with negative spherical aberration (high contrast log MAR, p = 0.043; low contrast log MAR, p = 0.043) which was not due to differences in residual astigmatism or pupil size between the two groups. Pelli Robson contrast sensitivity was not significantly different in the two groups. Conclusions: Manipulation of spherical aberration, taking account of the participants’ baseline level of aberration, can cause statistically significant improvements in high and low contrast distance visual acuity although these improvements are too small in magnitude to be of clinical significance. [ABSTRACT FROM AUTHOR]

Purpose: A population based, cross-sectional telephone survey was conducted to estimate the total penetrance of contact lens wear in Australia. Methods: A total of 42,749 households around Australia were randomly selected from the national electronic telephone directory based on postcode distribution. Before contact was attempted, letters of introduction were sent. The number of individuals and contact lens wearers in each household was ascertained and lens wearers were interviewed to determine details of lens type and mode of wear using a structured questionnaire. Results: Of households contacted, 59.2% (19,171/32,405) agreed to participate. Response rates were only marginally higher amongst households that first received a letter of introduction. In these households, 35,914 individuals were identified, of which, 1,798 were contact lens wearers. The penetrance of contact lens wear during the study period was 5.01% (95% CI: 4.78-5.24). Soft hydrogel lenses had the largest penetrance in the community, (66.7% of all wearers), however, their market share decreased significantly over the study period with increased uptake of newly introduced lens types. Conclusions: The penetrance of contact lens wear concurs with market estimates and equates to approximately 680,000 contact lens wearers aged between 15 and 64 years in Australia. The low response rate obtained in this study highlights the difficulty in contemporary use of telephone survey methodology. [ABSTRACT FROM AUTHOR]

A wirelessly operated, minimally invasive retinal prosthesis was developed for preclinical chronic implantation studies in Yucatan minipig models. The implant conforms to the outer wall of the eye and drives a microfabricated polyimide stimulating electrode array with sputtered iridium oxide electrodes. This array is implanted in the subretinal space using a specially designed ab externo surgical technique that fixes the bulk of the prosthesis to the outer surface of the sclera. The implanted device is fabricated on a host polyimide flexible circuit. It consists of a 15-channel stimulator chip, secondary power and data receiving coils, and discrete power supply components. The completed device is encapsulated in poly(dimethylsiloxane) except for the reference/counter electrode and the thin electrode array. In vitro testing was performed to verify the performance of the system in biological saline using a custom RF transmitter circuit and primary coils. Stimulation patterns as well as pulse strength, duration, and frequency were programmed wirelessly using custom software and a graphical user interface. Wireless operation of the retinal implant has been verified both in vitro and in vivo in three pigs for more than seven months, the latter by measuring stimulus artifacts on the eye surface using contact lens electrodes. [ABSTRACT FROM AUTHOR]

In this paper, novel procedures were developed using a thin (0.17 mm) tactile piezoresistive pressure sensor mounted on a rigid contact lens to measure upper eyelid pressure. A hydrostatic calibration system was constructed, and the influence of conditioning (prestressing), drift (continued increasing response with a static load), and temperature variations on the response of the sensor were examined. To optimally position the sensor-contact lens combination under the upper eyelid margin, an in vivo measurement apparatus was constructed. Calibration gave a linear relationship between raw sensor output and actual pressure units for loads between 1 and 10 mmHg (R² = 0.96). Conditioning the sensor prior to use regulated the measurement response, and sensor output stabilized about 10 s after loading. While sensor output drifts slightly over several hours, it was not significant beyond the measurement time of 1 min used for eyelid pressure. The error associated with calibrating at room temperature but measuring at ocular surface temperature led to a very small overestimation of pressure. Eyelid pressure readings were observed when the upper eyelid was placed on the sensor, and removed during a recording. When the eyelid pressure was increased by pulling the lids tighter against the eye, the readings from the sensor significantly increased. [ABSTRACT FROM AUTHOR]

Purpose: In a double-masked randomized controlled crossover study we investigated both the retinal responses to straylight, and the effects of lens cleaners on straylight values, in two different RGP contact lens materials. Methods: Thirty patients (20–59 years) wearing RGP lenses were refitted with new lenses made of Boston XO material in one eye and made of Comfort O2 (ONSI-56) material in the other eye. Reported wetting angles for the Boston XO material (103°) and for the ONSI-56 material (7.2°) were obtained by sessile drop measurements. After refitting, the study comprised three 5-week trial periods. In Period 1 half of the participants (Group A) wore Boston XO lenses in their right eye and Comfort O2 (ONSI-56) lenses in their left eye, and the other half (Group B) vice versa. In Period 2 Group A wore Comfort O2 (ONSI-56) lenses in their right eye and Boston XO lenses in their left, and Group B vice versa. All participants used Miraflow cleaner during periods 1 and 2. In Period 3, during which all participants used Boston cleaner, Group A wore Boston XO lenses in their right eye and Comfort O2 (ONSI-56) lenses in their left eye and Group B vice versa. Straylight data (log S) were obtained with and without contact lenses using the Oculus C-Quant straylight meter in all three periods. Central corneal thickness (CCT) was measured in the second and third periods. Results: When not wearing lenses ( n = 60 eyes) at the end of the second 5 week trial period straylight was measured twice with averages of 1.07 log S, and the corrected CCT measurements averaged 546 μm. Straylight values with Comfort O2 (ONSI-56) reached 1.15 log S at the end of both the second ( n = 25 eyes) and third periods ( n = 23 eyes). Straylight values with Boston XO were 1.17 log S ( n = 26 eyes) at the end of the second period, and 1.16 log S ( n = 25 eyes) at the end of the third period. Conclusions: Existing RGP lens wearers refitted with new lenses with different contact angles, made of Boston XO and Comfort O2 (ONSI-56) showed, over three 5 week periods, relatively small increases in straylight, which were functionally comparable, irrespective of the type of lens material or lens cleaner used. At every visit, straylight values and CCTs returned to baseline levels after RGP lens removal, confirming that the straylight fluctuations were mainly due to scattering from the RGP lenses; or tear film interaction; or a combination of both. [ABSTRACT FROM AUTHOR]

Purpose: This study investigates how well the recently introduced Ocular Comfort Index (OCI) and the more established McMonnies Dry Eye Index are able to detect contact lens induced dry eye (CLIDE). Methods: Seventy volunteer contact lens wearers (mean age = 28.7 ± 8.0; 52 female, 18 male) were grouped as CLIDE positive or CLIDE negative depending on three sets of criteria: Method I: objective (tear meniscus height, lid parallel conjunctival folds, phenol red thread test and tear break-up time); Method II: objective and/or subjective [contact lens dry eye questionnaire (CLDEQ)] (i.e. being positive by Method I and/or Method III); Method III: subjective (CLDEQ). Symptoms were measured using the McMonnies Dry Eye Index and the OCI. Discrimination was analysed by the receiver operating characteristic (ROC) curves; positive predictive values (PPV) and cut-off values were calculated. Results: ROC results for Methods I and II were statistically significant only for the McMonnies ( p = 0.008; p < 0.001; respectively). In Method III ROC results were statistically significant for both the McMonnies ( p = 0.001) and OCI ( p = 0.005). The McMonnies showed the best prediction of Method I [0.646/10.5 (PPV/cut-off value)], while the OCI gave the best predictability in Method III only (0.518/30.6). Conclusion: A McMonnies scoring of ≥10.5 or an OCI scoring of ≥30.6 indicates CLIDE. The McMonnies performs better in prediction of CLIDE than the OCI. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Starting in mid-2005, an increase in fungal keratitis caused by Fusarium spp was observed among contact lens wearers in Hong Kong, Singapore, and the USA. The objective of this study was to describe the outbreak and to determine any association with the use of Bausch & Lomb (B&L) ReNu® contact lens solution. Methods: We defined a case as a disposable contact lens user with ophthalmologist-diagnosed keratitis and a positive culture of Fusarium spp reported to the Department of Health from January 1, 2005 to May 31, 2006. We identified cases through inpatient discharge data and the electronic laboratory databases of all public hospitals, and from physician reporting. Controls were recruited from three outpatient clinics. Risk factors were collected using a standardized questionnaire and analyzed by univariate analysis and binary logistic regression. Results: From January 2005 through May 2006, we identified 33 cases of Fusarium keratitis. Most were in young adults (mean age 28 years) who presented with eye pain (100%), redness (84%), photophobia (41%), and tearing (34%). Twenty-four cases and 86 controls were recruited in the case–control study. By logistic regression, B&L ReNu solution showed the strongest association with being a case (adjusted odds ratio 26.1, 95% confidence interval 3.0–225.3) after adjusting for potential confounders. Conclusion: Using B&L ReNu contact lens solution was strongly associated with Fusarium keratitis among disposable contact lens users in Hong Kong. B&L ReNu with MoistureLoc® was permanently withdrawn from the market globally in May 2006. [Copyright &y& Elsevier]

Matrix methods have a long tradition in paraxial physiological optics. They are especially suited to describe and handle optical systems in a simple and intuitive manner. While these methods are more and more applied to calculate the refractive power(s) of toric intraocular lenses (IOL), they are hardly used in routine IOL power calculations for cataract and refractive surgery, where analytical formulae are commonly utilized. Since these algorithms are also based on paraxial optics, matrix optics can offer rewarding approaches to standard IOL calculation tasks, as will be shown here. Some basic concepts of matrix optics are introduced and the system matrix for the eye is defined, and its application in typical IOL calculation problems is illustrated. Explicit expressions are derived to determine: predicted refraction for a given IOL power; necessary IOL power for a given target refraction; refractive power for a phakic IOL (PIOL); predicted refraction for a thick lens system. Numerical examples with typical clinical values are given for each of these expressions. It is shown that matrix optics can be applied in a straightforward and intuitive way to most problems of modern routine IOL calculation, in thick or thin lens approximation, for aphakic or phakic eyes. [ABSTRACT FROM AUTHOR]

Thus far there is little data available concerning Acanthamoeba associated amoebic keratitis (AK) from Italy. In order to understand the incidence of Acanthamoeba in patients with ocular infections and to characterize the isolates at the molecular level, ocular specimens and contact lenses or lens case solutions from 140 patients were analysed by culture and by an 18S rRNA ( Rns) gene-based PCR method. Nineteen (13.6%) patients showed Acanthamoeba culture positive samples. Eleven out of the 14 genetically characterized isolates were assigned to the T4 genotype. Three isolates, two of them from patients with keratitis responding to specific anti- Acanthamoeba therapy, were identified as belonging to the T15 genotype. This finding represents the first association between the T15 genotype and human amoebic keratitis. PCR amplification of the 18S ribosomal DNA proved to be a sensitive method, potentially able to detect Acanthamoeba without the need of long culture incubation, and thus considerably useful for clinical applications. [ABSTRACT FROM AUTHOR]

Background: Fungal keratitis is a painful and dangerous fungal infection of the cornea. Recently, use of a contact lens solution with a novel ophthalmic preservative was linked to an increased risk of fungal keratitis. This study investigated whether fungal contamination was present in bottles of a widely used moxifloxacin ophthalmic solution, and whether there was an association between the use of this solution and fungal keratitis in a corneal referral practice. Methods: Fungal cultures were obtained for 32 moxifloxacin bottles brought in by 32 keratitis patients referred to our cornea practice from June 2003 to March 2006. Demographic and clinical data were also collected for 29 patients with fungal keratitis and 82 patients with bacterial keratitis, referred to our practice for corneal ulcers between June 2003 and April 2006. These two groups were compared with respect to moxifloxacin use and other variables. Logistic regression was carried out to determine whether an association between fungal keratitis and moxifloxacin use was present after taking into account potential confounding variables. Results: Thirteen (41%) of the bottles of moxifloxacin solution grew fungus on culture. Patients with fungal keratitis were nearly twice as likely as patients with bacterial keratitis to report the use of moxifloxacin ophthalmic solution: 41% vs. 22% ( P = 0.043). The association between fungal keratitis and moxifloxacin use persisted after taking into account potential confounding variables. Conclusions: Fungal contamination is present in the moxifloxacin bottles used by some keratitis patients. There appears to be an association between the use of moxifloxacin ophthalmic solution and fungal keratitis. [ABSTRACT FROM AUTHOR]

A new method for noninvasive assessment of tear film surface quality (TFSQ) is proposed. The method is based on high-speed videokeratoscopy in which the corneal area for the analysis is dynamically estimated in a manner that removes videokeratoscopy interference from the shadows of eyelashes but not that related to the poor quality of the precorneal tear film that is of interest. The separation between the two types of seemingly similar videokeratoscopy interference is achieved by region-based classification in which the overall noise is first separated from the useful signal (unaltered videokeratoscopy pattern), followed by a dedicated interference classification algorithm that distinguishes between the two considered interferences. The proposed technique provides a much wider corneal area for the analysis of TFSQ than the previously reported techniques. A preliminary study with the proposed technique, carried out for a range of anterior eye conditions, showed an effective behavior in terms of noise to signal separation, interference classification, as well as consistent TFSQ results. Subsequently, the method proved to be able to not only discriminate between the bare eye and the lens on eye conditions but also to have the potential to discriminate between the two types of contact lenses. [ABSTRACT FROM AUTHOR]

Contact lens hygiene has long been recognised as key to the prevention of contact-lens associated infection and inflammation. Microbial keratitis (MK) is the only serious and potentially sight-threatening contact lens adverse event. International studies including recent research in Asia Pacific show that MK is rare but, as the consequences can be severe, it is important to minimise the risk factors. Studies continue to show that one of the key risk factors is lens and lens case hygiene. Therefore, it is also useful to review the behaviour of our patients, to see how closely they follow the recommended hygiene practices. Recent studies in various regions have shown that patients’ lens care habits do not meet a required standard. Patients can become complacent and thus non-compliant with lens care instructions. Furthermore, they do not understand the high risk of some behaviour and they are not hearing the practitioner when instructions and reminders are given. Further education is important to improve patient compliance and safety. The Asia Pacific Contact Lens Care Summit held in Singapore urged the industry and practitioners to restore the emphasis of proper lens care, including the ‘rub and rinse’ technique, and developed a new set of guidelines to help eye-care professionals educate their patients on the importance of proper contact lens care to avoid eye infections. The summit also presented the latest research on how to avoid corneal staining, another important element of contact lens care. This review provides a summary of the summit presentations and the science behind these guidelines. [ABSTRACT FROM AUTHOR]

Interested in star movement the founder of Heidelberg's astronomy observatory, Max Wolf, faced the dilemma that the hitherto used 'Blinkmikrosop' of his Institution was damaged beyond repair following the first world war. He therefore used a new method, stereoscopy, to systematically classify 1053 moving stars between 1915 and 1918. The key problem Wolf identified with the new method was that variation in brightness of the same star on different photographic plates gave rise to an illusory movement. This was a particularly frequent problem with smaller stars close to the very bright Milky Way such as those in the proximity of Cygni or “fade-out stars” such as R Coronae Borealis. Carl Pulfrich, the world-leading expert on stereoscopy at the time, picked up immediately on the technical limitations Wolf published on stereoscopy in 1920. Pulfrich, who was blind in one eye, could not see the effect himself and designed a projection device to demonstrate Wolf's serendipitous observation to an audience which was equipped with a monocular neutral density filter. Pulfrich performed detailed investigations on the relationship of spatial perception and object movement, naming the phenomenon “stereo effect,” but it became widely known as the “Pulfrich effect.” The neuro-anatomical basis of the Pulfrich effect lies in the joint encoding of motion and depth within the visual cortex. Recognising Pulfrich effect is relevant for the management of patients in whom pathology of the visual pathways impairs judgment of object movement/position (e.g., in traffic or sport). Fitting a unilateral tinted lens or contact lens in front of the good eye can abolish the problem. [ABSTRACT FROM AUTHOR]