Vinita Allee Henry

Clinical Investigation of the Paraperm Ew Rigid Gas-permeable Contact Lens

ABSTRACT Paraperm EW is a high oxygen flux silicone/acrylate rigid lens material currently under clinical investigation for extended wear. The purpose of this paper is to report the clinical findings after 12 months of a 2‐year investigation of 18 patients fitted with this material. Fifteen were successfully wearing Paraperm EW lenses at 1 year. The only significant clinical finding was keratometric flattening at the 1‐month visit. It was concluded that the Paraperm EW lens was durable, comfortable, and provided excellent visual acuity during the course of this investigation without inducing any of the ocular complications sometimes associated with extended wear of hydrogel lenses.

Effect of topical anesthetic use on initial patient satisfaction and overall success with rigid gas permeable contact lenses.

Background. Rigid gas permeable (RGP) contact lenses have numerous benefits; however, RGP lens use is not increasing in the United States. An important factor for this trend has been initial comfort. Studies have demonstrated that how RGPs are presented to patients, in addition to lens design, can play an important role in the initial comfort process. Another important factor could be the use of a topical anesthetic during the fitting and dispensing visits. The purpose of this study was to use a multicenter format to determine if topical anesthetic use increased the likelihood of patient satisfaction and success. Methods. A total of 80 subjects, with no previous rigid lens wear experience, was entered into this 1 -month study, including 20 subjects from each of 4 institutions. Subjects were randomly divided into the following two groups: (A) anesthetic or (B) placebo, with the former group receiving one drop of a topical anesthetic before lens insertion at both the diagnostic fitting and dispensing visits, whereas the latter group received a placebo. Subjects completed a questionnaire on their perception of rigid lens wear both immediately before fitting and at the 1-month visit. After diagnostic fitting with rigid lenses, subjects completed an adaptation questionnaire after 15 min, 1 week, 2 weeks, and 1 month of lens wear. Results. Seventy of the 80 subjects completed the study and, of the 10 subjects who discontinued, 8 were in the placebo group. In all categories evaluated, the anesthetic group experienced a more optimum adaptation experience at each visit vs. the placebo group. Specifically, overall comfort was rated significantly higher at both dispensing and 2 weeks. In addition, the anesthetic group exhibited significantly greater overall satisfaction with rigid lens wear at 2 and 4 weeks. Also, the anesthetic group perceived their adaptation, sensitivity, and adaptation time to be significantly better at the 1 -month visit. There was no significant difference in corneal staining between these two groups at each visit, with the exception of a greater amount of staining in the central quadrant for the placebo group at the 1 -month visit. Conclusions. The use of a topical anesthetic at the fitting and dispensing visits for first-time wearers of RGP lenses resulted in significantly fewer dropouts, improved initial comfort, an enhanced perception of the adaptation process, and greater overall satisfaction after 1 month of lens wear as compared to the use of a nonanesthetizing placebo at those visits. This result, in combination with both presenting RGP lenses in a nonthreatening manner and optimizing the lens design and fitting relationship, should result in a positive adaptation process and successful wear of RGP contact lenses.

Effect of patient personality profile and verbal presentation on successful rigid contact lens adaptation, satisfaction and compliance.

Background. Rigid gas permeable (RGP) lenses have numerous benefits, including quality of vision, ocular health, and reduction of myopic progression in young people. Nevertheless, RGP lens use is not increasing in the United States. It is possible that certain patient personality characteristics and/or how a practitioner presents RGP lenses to a new patient may affect satisfaction and success. The purpose of this study was to evaluate the effect of individual patients personality and the practitioners method of presenting RGP lenses to new patients on their ability to adapt to these lenses. Methods. Forty-nine subjects, all noncontact lens wearers, were entered into this 1-month study, which was conducted at both the University of Missouri-St. Louis School of Optometry and the Pacific University College of Optometry. All subjects initially completed standardized questionnaires pertaining to locus of control, openness to new experiences, and motivation/expectations. After diagnostic fitting with a RGP lens material, the subjects were placed into one of the following three groups: (1) Fear-Arousing Non-Enthused; (2) Neutral Content Non-Enthused; or (3) Neutral Content Enthused. They observed one of three video presentations on RGP lens wear. Subjects submitted daily questionnaires providing their evaluation of such factors as comfort, wearing time, and handling. Results. The results showed that there was a significant difference (x2=6.99; p<0.05) among the different groups in the number of dropouts: 6/19 with the Fear-Arousing Non-Enthused group, 2/17 with the Neutral Content Non-Enthused group, and 0/13 with the Neutral Content Enthused group. There was also a significant difference (ANOVA F=4.1, p<0.05) among the groups on compliance, with the Neutral Content Enthused group demonstrating greater compliance. In terms of satisfaction, there was no significant difference among presentation groups. Conclusion. It was concluded that the method of presentation is important for successful RGP contact lens wear. If presented with genuine interest and a positive and realistic attitude, patients are more likely to succeed in RGP lens wear during the initial critical period.

An evaluation of the 8.4 mm and the 8.8 mm base curve radii in the Ciba NewVe vs. the Vistakon Acuvue

Abstract As practitioners, we have often fit soft contact lenses using the medium or flattest base curve radius as our first choice of base curve radius; however, it is important to realize that identical base curve radii in different lens materials may fit differently. In addition, the flattest or medium base curve radius may not always provide optimal comfort. When fitting soft lenses, it is important to achieve a good fit and provide good performance. In this study, completed at the University of Missouri-St. Louis, School of Optometry, the NewVue (Ciba Vision Corp.) and the Acuvue (Vistakon) 8.4 and 8.8 mm base curve radii were compared based on comfort, visual acuity, contrast sensitivity, lens movement, and ease of handling in a double-blind study. The results showed that subjects performed similarly among NewVue and Acuvue lenses. The Acuvue 8.4 mm base curve radius was perceived as being more comfortable than the patients current contact lenses and showed optimal centration and best distance Snellen visual acuity. The Acuvue 8.8 mm base curve radius showed optimal lens movement. The NewVue 8.4 mm base curve radius showed optimal lens movement and demonstrated excellent handling and lens centration. The NewVue 8.8 mm base curve radius demonstrated excellent lens handling. When fitting a disposable contact lens candidate, our first choice for lens selection would be the Acuvue 8.8 mm base curve radius or the NewVue 8.4 mm base curve radius. If these lenses are not adequate, appropriate changes may be made.

RGP lens power change with abrasive cleaner use

The introduction of the so-called superpermeable rigid gas permeable (RGP) lens materials has greatly reduced contact lens complications associated with hypoxia. In addition, the incorporation of fluorine into most RGP lens materials has permitted higher siloxane contenttherefore, higher oxygen permeability-with minimal compromise in surface wettability. The important clinical problem presented by this new generation of fluorosilicone/acrylate lens materials, however, is stability. Reports of warpage,iV2 flexure,3 and radical flattening4 with high Dk RGP lens materials have been reported in the literature due to the softness and flexibility of these materials relative to PMMA and low Dk RGP polymers. These stability-related complications often result in unacceptable visual acuity and/or a compromised lensto-cornea fitting relationship. This is especially problematic in former PMMA wearers who often maintain the same vigorous cleaning technique with their RGPs; the result is a much higher incidence of warpage than present with nonPMMA lens wear.4 The purpose of this article is to report on another related RGP material and patient compliancerelated problem-specifically, an increase in minus power occurring over time with an abrasive cleaner in combination with excessive digital pressure.

Daily disposable hydrogel contact lenses: a comparative study

Abstract This open-label study compares three daily disposable hydrogel contact lenses, Focus® Dailies® (Ciba Vision), 1-Day Acuvue® (Vistakon, a division of Johnson & Johnson), and SofLens® one day disposable (Bausch & Lomb). Comparisons were made by soliciting participant preference among factors such as overall satisfaction, comfort, satisfaction with vision, dryness, eye strain, ease of handling, irritation upon insertion, frequency of solution use, and rate of damage of contact lenses. Subjects were randomly given appropriate Focus® Dailies®, 1-Day Acuvue®, and SofLens® one day disposable to use on both eyes for 2-week periods. After use of each of the three lens designs, the participants filled out a questionnaire about their wearing experience and their eyes were evaluated for contact lens complications. They also filled out a final questionnaire. Fifty percent of the participants favored Focus® Dailies® in a forced-choice comparison although 1-Day Acuvue® and SofLens® one day disposable scored higher in overall satisfaction. We find that participant preference appears to be influenced by factors other than performance on the eye. Factors such as packaging (easy to open) and lens designs that enhance handling strongly influence patient lens preference.

The effectiveness of typical hand-cleaning methods on hydrogel contact lenses

Abstract Contamination of hydrogel contact lenses occurs during handling of the lenses. A survey was conducted to determine the hand-cleaning methods used by hydrogel contact lens wearers prior to insertion and removal of the lenses. This study was implemented to evaluate the relative effectiveness of several methods: no hand washing, use of water only, Ivory (bar), and Dial (antibacterial liquid). Microbial contamination of the lenses was evaluated by culturing the contact lenses after employing various hand-cleaning techniques. The presence of bacteria, subsequent surface area of growth, density of growth, and types of bacteria were evaluated. The results suggested that use of antibacterial liquid soap significantly reduced the bacterial contamination of lenses as compared to use of non-antibacterial soap, water only, or no hand washing prior to lens handling (p = 0.001) (t-test).

Rigid extended wear problem solving

Abstract Numerous rigid extended wear lens materials have been introduced in recent years. Selecting the specific lens material for a given patient depends on numerous factors including stability, wettability, and oxygen permeability—not on Dk alone. The lens design is typically larger in diameter, flatter in base curve radius and greater in center thickness than daily wear lenses. The importance of careful verification, notably base curve radius, center thickness, and edge design are paramount. One of the major complications is poor surface wettability, and both the diagnosis and management of nonwetting lens materials are discussed. Material-induced stability problems including flexure and warpage are also emphasized. Corneal problems, including edema, adhesion, abrasion, desiccation, and vascularized limbal keratitis are described. A case format is used to describe representative examples of these complications and reinforce effective management plans.

Optima 38 versus optima EW: A daily wear comparison study

Abstract Improvements in soft lens technology have provided practitioners with increasingly greater oxygen permeable materials. The importance of oxygen transmission to the cornea is well documented. This paper describes the efficacy of using a soft extended wear lens design on a daily wear basis. A daily wear clinical investigation was conducted using 20 patients over a 6-month period wearing an Optima 38 daily wear lens on one eye and an Optima EW lens on the other eye. No significant differences were noted pertaining to ocular signs or symptoms between the two lenses. It was concluded that, with the knowledge that it provides for enhanced corneal transmission and, therefore, physiology, the Optima EW lens material employed on a daily wear basis appears to provide comfort, visual acuity, and handling properties equivalent to that of the Optima 38 daily wear lens.