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Lens Wearers (lens + wearer)
Kinds of Lens Wearers Selected AbstractsConservative management of Pseudomonal infectious sclerokeratitisCLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 3 2008Timothy C Smith MBBS Pseudomonal sclerokeratitis is an uncommon infection with the potential for loss of vision and the eye. A 66-year-old male contact lens wearer presented with a painful red eye diagnosed as sclerokeratitis. An intensive regimen of topical, subconjunctival and oral antibiotics as well as oral steroids was used as primary treatment. An overlying, focal collection of pus was incised and drained on two occasions. After three months of treatment, the infection had resolved and the treatment ceased. The involved sclera demonstrated a focal area of scleromalacia, which has remained stable. Infectious sclerokeratitis can be managed with conservative treatment without the need for surgical debridement and scleral grafting. [source] Randomised controlled trial of the effects of two rigid gas permeable (RGP) contact lens materials and two surface cleaners on straylight valuesOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 5 2009Marten F. Fortuin Abstract 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 ,m. 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. [source] Microbial contamination of contact lenses and lens care accessories of soft contact lens wearers (university students) in Hong KongOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2007M. S. Yung Abstract Purpose:, This study aimed to examine the rates of microbial contamination, and identify contaminants associated with contact lenses and lens care accessories used by a group of young contact lens wearers. Methods:, Collected contact lenses, lens cases, and lens care solutions were studied by bacterial culture. Contamination rates of these samples were recorded and compared with those reported in previous studies. Results:, Of the samples tested, 9% of lens extracts, 34% of case extracts and 11% of solution samples were contaminated with ocular pathogenic microorganisms. Serratia spp., Staphylococcus aureus and coagulase-negative staphylococci were the most common microorganisms isolated. Lens cases were the most frequently contaminated item. Lens cases also yielded the widest range of bacterial isolates. Contact lenses used by occasional wearers were associated with a higher contamination rate. Using either saline or multipurpose solution to rinse lenses before use appeared to be effective in reducing incidence of contamination. Conclusion:, Our findings demonstrate that contact lenses and lens care accessories are not well maintained by contact lens wearers. Regular reviews and reinforcement of lens care procedures for the usage and care of contact lenses and lens care accessories is therefore important and essential. [source] Incidence of corneal pigmented arc and factors associated with its appearance in orthokeratology,OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2005Pauline Cho Abstract Purpose:, To determine the incidence of the corneal pigmented arc in orthokeratology (ortho-k) lens wearers over 12 months of lens wear and the factors associated with its appearance. Method:, Thirty-five ortho-k subjects were recruited; refractive and corneal changes after lens wear (single-lens protocol) were monitored over 12 months. The incidence of the pigmented arc after 3, 6 and 12 months of lens wear was determined. Results:, The incidence of corneal pigmented arc was 17% (27%), 49% (49%) and 90% (93%) after 3, 6 and 12 months lens wear respectively in the left and right eyes. For subjects with arcs observed in the left eye within the first 6 months of lens wear, the mean ± S.D. period of lens wear before initial detection of the arc was 14 ± 7.4 weeks, and no correlation was found between this factor and the baseline spherical and cylindrical refractive errors (i.e. refractive sphere and cylinder, respectively), spherical equivalent refractive error (SERE), the target myopia reduction, the amount of refractive sphere (or SERE) reduction and changes in central and peripheral corneal curvatures after 6 months of lens wear. Baseline refractive sphere, baseline SERE, target, amount of myopia reduction, and change in central corneal curvature were significantly larger (p < 0.05) in those subjects with pigmented arcs after about 6 months of lens wear. The intensity of the observed pigmented arcs after about 6 months of lens wear was significantly related to the time when it was first observed (p = 0.003). Significant correlation was also found between the intensity of the arcs and the following parameters: baseline refractive sphere and SERE, target, change in central corneal curvature, and amount of myopia reduction (p < 0.006). After about 12 months of lens wear, the intensity of observed arcs was significantly related to the baseline refractive sphere, SERE and the target (p < 0.006). Conclusion:, The incidence of ortho-k-associated pigmented arc increases from 17% after 3 months of lens wear to over 90% after 12 months of lens wear. The intensity of the arc is related to the time when the arc first appeared. Both the incidence and the intensity of the arc are related to the period of lens wear, baseline refractive sphere, SERE and the target. [source] Clinical grading of corneal staining of non-contact lens wearersOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2001Morven Dundas Summary To distinguish normal from pathological corneal fluorescein staining requires knowledge of background levels of staining among otherwise healthy individuals. Corneal staining of 102 non-contact lens wearing subjects was assessed using a photographic grading scale that uses a generic (0 to 4) scale to score corneal staining. Some degree of corneal staining was found on 79% of the corneas. Low inter-observer variability suggests that the corneal staining grading scale can be used successfully with decimal rather than integer scale increments. [source] 3223: Dry eye syndrome and omega-3 fatty acidsACTA OPHTHALMOLOGICA, Issue 2010T KAERCHER Purpose Dry eye disease is characterized by an inflammatory component of the ocular surface. Pathways to modulate inflammation include corticoids and cyclosporine. Omega-3 fatty acids like eicosapentaenoic acid and docosahexaenoic acid represent an alternate pharmacologic way to influence the inflammatory cascade. Methods Clinical studies. Results An epidemiologic study in 32.470 healthy women showed that those with a higher intake of omega-3 fatty acids had a 68% decreased prevalence of dry eye syndrome. Hyposecretory dry eye was tested after intake of omega-3 fatty acids for 45 days. Symptoms, signs and inflammatory markers like HLA-DR improved. Hyperevaporative dry eye improved after a long-term supplementation with omega-3 fatty acids with respect to symptoms, break-up time and meibom score. Patients with refractive surgery (PRK) improved after omega-3 fatty acids intake; this was derived from the OSDI-score, Schirmer I test and tear clearance. In 102 contact-lens wearers the symptoms and signs of dry eye improved after 12 weeks therapy with omega-3 fatty acids. Conclusion Nutricionals with omega-3 fatty acids show evidence-based effects on the inflammatory component of ocular surface disease and tear film disorder. Their beneficial effect was tested for hypovolemic and hyperevaporative dry eye. Patients after refractive surgery and contact lens wearers improved after supplementation, too. In contrast to the available anti-inflammatory therapy the supplementation is apt for a long-term application. [source] 2166: Clinical applications of corneal Scheimpflug densitometry in DSAEK and cornea guttata patientsACTA OPHTHALMOLOGICA, Issue 2010M WEYNS Purpose The aim of this project is to study clinical applications of corneal Scheimpflug densitometry. In the first part of the study a correlation between corneal Scheimpflug densitometry and endothelial cell count in cornea guttata will be studied. The second part will investigate a possible correlation between the smoothness of the corneal graft and postoperative visual acuity in DSAEK patients. Methods Cross-sections of corneal Scheimpflug images will be analyzed by means of custom written software. Parameters such as average densitometry profile, position and intensity of the Bowman membrane and corneal endothelium peaks, as well as the position and intensity of the interface between an acceptor cornea and the DSAEK graft (if present) will be calculated. Results The method to analyze the corneal densitometry has already been developed and tested on corneas of contact lens wearers and post refractive surgery patients. A small number of DSAEK en cornea guttata eyes have been analyzed as well, demonstrating the potential of this technique in these patients. Conclusion Corneal Scheimpflug densitometry may be complementary to endothelial cell count in monitoring the disease progression in cornea guttata patients. Corneal Scheimpflug images may also be considered a predictor for visual outcome after DSAEK if the postoperative visual acuity variations in DSAEK patients can be linked to wrinkles in the posterior surface of the graft. [source] Serotype and adhesion of Pseudomonas aeruginosa isolated from contact lens wearersCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 3 2001Sophy J Thuruthyil PhD ABSTRACT The purpose of the present study was to correlate the serotypes of Pseudomonas aeruginosa to the bacterial adhesion to contact lenses and human corneal epithelial cells. Twenty-three strains isolated from contact lens wearers were used for the study. The bacterial serotypes were examined with a P. aeruginosa antisera kit. The attachment of bacteria on contact lenses or human corneal epithelial cells was determined by counting the number of adhered bacteria after incubation of the bacteria with contact lenses or corneal epithelial cells. The 23 ocular isolates belonged to seven serotypes. Strains of serotypes I, G and E were the three dominant serogroups and were more adhesive to contact lenses compared with other groups of the bacteria. The bacterial serotypes and the clinical sequelae were not strongly related. These results indicate that the surface characteristics of bacterial serotypes are related to the bacterial adhesion to the surface, but the pathogenesis of the bacteria may result from multiple factors. [source] Could the coefficient of variation (COV) of the corneal endothelium be overestimated when a centre-dot method is used?CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 1 2008Michael J Doughty PhD Background:, Little has been published on the reliability of estimates of the coefficient of variation (COV) in cell area for human corneal endothelia. The present study compares two methods. Methods:, A non-contact specular micrograph (Topcon SP-2000P) was obtained from the central region of the corneal endothelium of 20 healthy myopic white European subjects, aged from 32 to 53 years, half of whom were successful long-term soft contact lens wearers. The captured image file was either assessed using a machine-based algorithm, in which 25 cells in the middle of the image were marked and their areas reported (designated as ,centre-dot' method) or by a manual method, by which all the cells in the image were outlined on very high magnification prints of the endothelia and the cell areas measured by a manual digitiser in stream mode. The average cell area was used to calculate the endothelial cell density (ECD), while the COV was calculated from the standard deviation (SD) of the cell area measures. Results:, Identical mean cell area values were found (392 µm2) with the two methods, a marginally higher ECD estimate (2,594 versus 2,569) with the centre-dot method (p = NS) but a much higher COV with the centre-dot method (43.8 versus 29.0 per cent). This highly statistically significant difference in COV (p < 0.001) was seen in both contact lens wearers and non-contact lens wearers. A Bland-Altman analysis reveals a bias in the centre-dot method, especially for the COV estimates, that appears to be linked to erroneous definition of a single large cell domain on any individual image. Conclusions:, A centre-dot method can be reliably used to generate useful data on cell area and ECD but it should be used cautiously for estimates of polymegethism (COV). [source] | ||||||||||