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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]

Copyright of Journal of Optometry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

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]

Copyright of Investigaciones ANDINA is the property of Fundacion Universitaria del Area Andina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a scenario by which a 25-year old right-handed male patient, who has been presented for a routine eye care, desiring contact lenses. The patient accordingly disclosed that he had been told he had a problem with his pupils and has been experiencing muscular parenthesis, which he described as jumping and twitching in his right hand fingers. Pupillary anomalies are said to be challenging due to its underlying cause that can range from benign conditions to potentially life-threatening disorders. It is further stated that patients with any pupillary abnormality, even without associated neurological symptoms, need to be further evaluated.

Background: Several studies have suggested that bifocal and progressive spectacles can reduce progression of myopia in esophoric children. This study compared myopic progression with bifocal (BSCL) and single vision soft contact lenses (SVSCL) in identical twins with near point esophoria. Methods: Two 12-year-old myopic girls were randomly assigned to wear either BSCL or SVSCL for one year using a double-masked design. Both twins then wore BSCLs for another year. Ocular measurements included cycloplegic and manifest refractions, corneal curvature and axial length. Distance and near phorias were measured through distance corrections and near associated phorias, with both types of contact lenses. Results: Through their SVSCLs, both children exhibited near associated esophorias, which were neutralised by the BSCLs. The child wearing SVSCLs over the first year showed significant myopic progression, increasing -1.19 D (binocular average), while the child wearing BSCLs showed no progression (+0.13 D). The latter child showed limited progression (-0.28 D) over the second year, while switching from SVSCLs to BSCLs arrested progression in the other child (+0.44 D after one year). Axial length data were consistent with the refractive findings; the child exhibiting more myopia at the end of the first 12 months of the study had longer eyes (by 0.64 mm) than her sister, although their corneas also had steepened more (by 0.44 D compared to 0.18 D). The children showed similar, small increases in eye size over the second year when both wore BSCLs (binocular averages: 0.05, 0.09 mm, respectively). Conclusion: The apparent inhibitory effect of BSCLs on myopic progression reported in this twin study argues for further study of their efficacy as a control treatment for myopes with near esophoria. [ABSTRACT FROM AUTHOR]

Purpose: The aims were to determine the level of compliance of contact lens wearers, to identify which procedures have highest levels of non-compliance and to study the effectiveness of a compliance enhancement strategy on the level of compliance. Methods: The level of compliance for each subject was evaluated with a self-administered questionnaire together with microbiological examination of their contact lenses, lens cases and lens care solutions. The effect of an intervention to improve the level of compliance was determined by a controlled trial. A regular self-review exercise on proper lens handling was given to the test group once every three months for 12 months. The levels of compliance and contamination of contact lenses and lens care accessories between test and control groups were compared at the end of the 12-month period to evaluate the effect of the intervention. Results: Sixty-five subjects who were experienced contact lens wearers were recruited and 60 completed the study. All showed some degree of non-compliance in the care of their contact lenses and lens accessories. Most (about 60 per cent) were non-compliant with at least six of a total of 15 lens care procedures. The most common non-compliant behaviour among contact lens wearers was associated with the care of the lens case. By the end of the study period, our compliance enhancement strategy did not appear to have had a significant effect on the behaviour of our subjects, except for improvement in the care of lens cases. Compliance for other procedures improved in both test and control groups. Conclusion: All subjects showed some degree of non-compliance and the spectrum of non-compliance was wide. The poorest levels of compliance were associated with care of the lens case, which was also the most frequently contaminated item. Our compliance enhancement strategy showed a significant difference in improvement in compliance between the intervention and control groups only in the care of lens cases. [ABSTRACT FROM AUTHOR]

The aim of the present study is to determine the amount and time of water-content recovery of ionic contact lenses (Surevue® and Acuvue®) and non-ionic contact lenses (Soflens 38®, Soflens 66® and Optima 38®) when submerged in maintenance solution for 9 h. Using a hand-held refractometer, we measured the water content of the lenses upon removal from the eye, and after 15, 30, 45 min, 1, 2 and 9 h in soaking solution. Both ionic lenses presented pre-wear water content of 58%, while two of the non-ionic ones (Soflens 38® and Optima 38®) registered 38.6% and the third (Soflens 66®) had 66%. We found a significant increase ( p < 0.05) in water content after submersion in the Opti-Free® solution for all the time periods studied and for all lenses. The water-content recovery was faster in the non-ionic lenses (Soflens 38®, Soflens 66® and Optima 38®) than in the ionic ones (Surevue® and Acuvue®), especially at 15 min. After 9 h in the soaking solution, the Surevue® Acuvue®, Soflens 38®, Soflens 66® and Optima 38® lenses reached water-content recovery values of 99.7%, 99.6%, 99.8%, 99.8% and 99.6%, respectively, without significant differences ( p > 0.05) between ionic and non-ionic lenses, although the non-ionic lenses reached slightly higher water-content values at all the times studied. These results indicate that when the refractometer technique is used to measure water content, the lens types used in this study regain their initial water-content values after 9 h in soaking solution. These data indicate the time needed for hydrogel contact lenses to reach their maximum water content after removal from the eye and submersion in maintenance solution. By ensuring maximum water content and minimum reduction of oxygen for the cornea, the specialist can help avoid clinical signs and symptoms related to low water content in the lenses. [ABSTRACT FROM AUTHOR]

Practitioners have long recognised the importance of determining the extent of scratching on the surface of rigid contact lenses when deciding on lens replacement. Despite this, little research has been undertaken to define this problem. The extent of scratching of rigid contact lens materials was evaluated and this property was related to material oxygen permeability and refractive index. One hundred and forty lenses made from 28 different rigid materials were evaluated in a masked and randomised manner. Scratches were created on the front surface of the lenses using an apparatus that was specifically designed and constructed for this experiment. The extent of scratching was quantitatively evaluated using a computer- based scanning and image analysis system. The oxygen permeability of all materials was measured using the polarographic method. An Atago N3000 hand-held refractometer was used to measure the refractive index of these materials. Three significant correlations were revealed: an inverse relationship (r = -0.813, P < 0.0001) between oxygen permeability and refractive index; a positive relationship (r = 0.51 1, P < 0.008) between oxygen permeability and the extent of scratching; and an inverse relationship (r = -0.539, P < 0.0058) between refractive index and the extent of scratching. The information generated in this study concerning scratch resistance of rigid contact lens materials may assist the contact lens industry and contact lens practitioners in developing and prescribing rigid lenses with optimal performance characteristics. Copyright © 1996 The College of Optometrists. Published by Elsevier Science Ltd [ABSTRACT FROM AUTHOR]

A novel approach and the equilibrium sessile drop (laser assisted) method were used to determine the wettability of hydrated and unhydrated PMMA, Polycon II, Boston IV, Equalens and Boston RXD rigid contact lens materials. In the new method the ability of the contact lens surface to attract the liquid is evaluated by measuring the adhered mass of liquid on the front lens surface. The mass has a direct relationship to contact lens wettability, so the greater the lens surface hydrophilicity the more liquid adheres to the contact lens surface. In the hydrated state, Equalens and Boston IV showed the greatest hydrophilicity of all five materials, although there was no significant difference between them (P > 0.9). Boston RXD had a lower ability to attract liquid and there was a significant difference between it and the next higher material which was Boston IV (P < 0.005) and also the next lowest Polycon II (P < 0.00001). PMMA had the lowest capability to adhere liquid and there was a significant difference between PMMA and Polycon II (P < 0.00001). The new method is simple and quick to use and gives greater discrimination and repeatability than other current methods. [ABSTRACT FROM AUTHOR]

The issue of possible adverse effects of contact lens care solutions on ocular health has been raised in the literature. Possible effects of a multipurpose contact lens care solution (Bausch & Lomb ReNu® ) on eight measures of ocular function were evaluated relative to the effects of physiological saline (Bausch & Lomb Sensitive Eyes®). In a randomized, two-treatment, crossover design, all subjects were treated with each of the two solutions on successive weeks. In 73 subjects, comprised of contact lens and non-lens wearers, tear break-up time was measured using the keratometer mire and f luorescein techniques. Measures of autonomie function were vertical palpebral aperture size, amplitude of accommodation, intraocular pressure, pupil size, conjunctival injection, and pupil reactivity. The results indicated that this multipurpose solution provoked no adverse ocular response as determined by the tear breakup time and autonomie functions, and the multipurpose solution was clinically equivalent to physiological saline. These results apply to both contact lens wearers and non-lens wearers. Additional findings speak of the unreliability of the fluorescein method for measuring tear break-up time. [ABSTRACT FROM AUTHOR]

From a research programme comparing two photorefractive keratectomy (PRK) methods. Group S using Summit ExciMed UV 200, and Group V using the VisX 20:20 excimer laser system, 10 patients from each group were recruited. They were referred 6-12 months post- PRK for lens fitting to correct resultant ametropia or irregular astigmatism. Ablation zone diameters were: Group S, 4.5 mm; Group V, 4-6 mm. For Group S, best fit rigid gas permeable (RGP) lenses generally had a back optic zone radius (BOZR) 0.10 mm steeper than the mean keratometry reading (K) and overall diameter of 9.20-10.0 mm. For Group V best fit RGP lenses generally had a BOZR of 0.20 mm steeper than the mean K. The lenses often required large diameters to improve lens centration and extra negative power to compensate for the positive power of the central tear pool. Several patients required soft lens fitting to improve comfort and some finally opted for repeat PRK. [ABSTRACT FROM AUTHOR]

Thick, 0.34 mm, 38% water hydrogel lenses were fitted, under a pressure patch, to one eye of 18 type I diabetic patients (aged 18-40 years) to assess the acute response to hypoxia and hypercapnia; the response was compared with that in 18 healthy, aged-matched non- diabetic subjects; the closed-eye lens wear was started mid-morning. Pre-lens wear assessments were made of acuity, intraocular pressure OOP), central corneal thickness (CCT) and corneal appearance by biomicroscopy. The mean duration of the diabetes was 13 + 7 years and the average fasting blood glucose was 8.7 + 3.3mMl-1. Baseline CCT values were marginally greater in diabetic patients (600 +33 μm) compared with a group of non-diabetic control subjects (584 +26 ^m; P>0.5). A 7.7 + 2.1% increase in CCT was measured after 3 h lens wear in the diabetic patients while an average 10.6 + 2.4% increase in CCT was measured in the control subjects (P<0.05). The recovery of corneal thickness to baseline values in diabetic patients was slower (at 44.8 + 2.0% per hour) than the control subjects (53.9±2.1 per hour; P<0.05) although recovery of corneal thickness occurred in both groups within 2.5-3 h. I0P values (non-contact tonometry) were higher in the diabetic patients than in the controls (14.5 + 2.9 vs 12.4+1.7 mmHg; P<0.01). Overall, those corneas with greater baseline CCT values tended to swell less than those with lower baseline CCT values (r = 0.582). Positive correlations were also found between corneal thickness and IOP and blood glucose. The diabetic patients thus tended to have slightly thicker corneas (but this could be related to blood glucose or IOP rather than true corneal disease) and also had corneas that tended to swell less with a contact lens stress test (but this could be constitutively due to the slight oedema already present). The different corneal response in diabetic patients may thus be the result of physical determinants such as initial oedema and IOP and not the result of a disease of the cornea itself. [ABSTRACT FROM AUTHOR]

Previous studies have shown that soft lenses dehydrate during lens wear. The purpose of this study was to determine the dehydration time course of 38% water content non-ionic Medalist , 58% ionic Acuvue™and 74% non-ionic Permaflex™ lenses, and the relationship between dehydration and in vivo diameter, movement and symptoms of dryness. Nineteen subjects randomly wore three pairs of lenses, each for 7 h. Lens movement and diameter were measured in vivo and hydration after lens removal at 1, 3 and 7 h. Dryness was rated by the subjects using a visual analogue scale. A separate experiment was conducted to measure hydration changes after 7 continuous hours of lens wear. The water content of all three lens types decreased significantly over 7 h with Acuvue decreasing more than the Permaflex and Medalist lenses in the interrupted and continuous experiments (ANOVA P < 0.05). Dehydration of Acuvue was significantly greater in the 7 h continuous experiment (9.0 ± 2.6% H2O, ANOVA P = 0.0062) compared to the interrupted experiment. Hydration levels measured for Acuvue lenses on subjects for control purposes at 0, 1,3 and 7 h showed no difference over time (ANOVA P = 0.0711). Movement of Permaflex lenses decreased 0.60 + 0.57 mm (ANOVA P = 0.0005) over 7 h and the in vivo diameter of Acuvue lenses decreased by 0.12 + 0.16 mm (ANOVA P = 0.0569). Dryness ratings increased significantly and equally for all three lenses over 7 h (ANOVA P = 0.9833). No correlation was found between lens dehydration, movement, diameter and dryness with the exception of a weak significant (r = 0.5, P < 0.05) correlation between dehydration and dryness for Permaflex. The results of the study suggest that dehydration of soft lenses over a 7 h period does not significantly affect the clinical performance (dryness and movement) of the three lens types. [ABSTRACT FROM AUTHOR]

Non-compliance is emerging as a critical issue in the contact lens field. This problem has been studied at depth in general health care situations and is seen as the responsibility of both practitioner and patient (client) working in a health care partnership. The contact lens practitioner and patient present a specific case for the study of non-compliance in areas such as hygiene, solution use, appointment attendance and wearing times. From 40 to 91% of contact lens patients have been reported as non-compliant in the use of recommended care and maintenance regimens and many of these are confused or ignorant about their behaviour. In order to arrive at a general set of conclusions from the studies published to date, it is important to understand the methodology of each study, its purpose, the definition of non-compliance used and the way the results were analysed and described. This review summarizes the research into non-compliance in the contact lens field to date. A set of general conclusions is drawn and a model for compliance in the context of contact tens practice is proposed. [ABSTRACT FROM AUTHOR]

The effect of prismatic spectacle corrections on ocular rotation for different object distances is determined and evaluated. The same principles are applied for a correction fitted on the eye, that is, a contact lens correction. The latter must be considered as a thick lens system. The effects of different types of prismatic contact lenses on ocular rotation are considered. Assuming the contact lens to remain stationary and the eye behind the lens to rotate, it is shown that the theoretical effect on ocular rotation of prismatic contact lenses is practically equal to their prismatic effect in air. The effect for high-powered contact lenses is discussed. [ABSTRACT FROM AUTHOR]