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Scleral gas-permeable lenses are rapidly gaining international popularity. Unlike corneal gas-permeable lenses, scleral lenses are fitted to the bulbar conjunctiva and settle into the tissue after insertion. To date, we are unaware of any studies examining the settling behavior of three varying scleral lens designs. The purpose of this study was to quantify the mean total settling and mean rates of settling for three scleral lens designs: Onefit PA (Blanchard Contact Lens, Inc), Mini Scleral Design (msd) (Blanchard Contact Lens, Inc), and Jupiter (Visionary Optics).A randomized, repeated-measures study of Onefit PA, msd, and Jupiter was performed. Subjects were fitted from a trial lens set, according to the manufacturer's guidelines. After insertion, lens settling was measured at 0 minutes, 15 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 6 hours, and 8 hours. Statistical analyses were performed using analysis of variance and two-stage, nonlinear regression analyses of settling over time.On average, the Onefit PA, msd, and Jupiter lenses settled a total of 113.7, 133.7, and 88.1 μm, respectively. Although the rates of settling were not linear, analysis of variance revealed a significant difference in the average settling rates (p0.05) among the groups. Tukey analyses revealed a significant difference in the settling rates for msd and Jupiter comparison (p0.05). Nonlinear regression analyses predicted that the lenses settled to about 80% of the final estimated values for the Onefit PA lens, 90% for msd, and 99% for the Jupiter, after 8 hours.We concluded that the amount of settling varied significantly among the three lens designs. Settling rates were greatest shortly after insertion. Larger lenses were estimated to be settled by 8 hours. Based on the results of this short-term study, careful consideration to the settling patterns of individual scleral lens designs should be given.

Purpose This study aims to address the clinical performance of a large diameter rigid gas permeable lens (LRGP) in a group of subjects with low-to-moderate (0.75-2.75 D) refractive astigmatism. An additional goal was to determine whether soft toric or LRGP contact lenses performed better objectively in the correction of astigmatism and to determine which modality is preferred by subjects. Methods This was a multisite prospective cross-over clinical study. Ten asymptomatic contact lens wearers per site (four university clinics) were recruited and randomly assigned to group A or group B. Group A was assigned to start wearing Comfilcon A soft toric lens first, for two weeks, and then crossed over to LRGP lenses (Boston XO, 14.3 mm diameter miniscleral lens). Group B initially wore LRGP lenses and then crossed over to soft toric lenses. For each type of lens worn, low-contrast and high-contrast visual acuity (VA) were evaluated at distance. At the conclusion of the study, after two months, all subjects completed a questionnaire in which they were asked to indicate their preference for one type of lens (soft toric or LRGP) and to rate the quality of vision in day-to-day activities. Results Thirty-six of 38 (94.7%) subjects completed the study with 75% preferring the vision of the LRGP lens as compared to the soft toric lenses worn in the study. 52.7% expressed a preference to continue with this modality despite only 38.8% reporting that these LRGP lenses are easy or very easy to handle. Wear time, subjective comfort, and subjective vision ratings exhibited no significant difference between the two groups. Conclusions In a population of asymptomatic contact lens wearers, LRGP lenses can be considered as a good alternative to soft toric lenses for the correction of refractive astigmatism.

The contact lens wearing presbyopic population is underserved worldwide. There are several available options, including single vision contact lenses and spectacle over-correction for near, monovision, rigid gas permeable (GP) multifocal and bifocal lens designs and soft bifocal lens designs. This paper presents an overview of the latest research and clinical experience as it pertains to these forms of correction. Recent comparative studies concluded that contact lens multifocals perform better in many different forms of visual measurements, in some cases performing similar to best spectacle correction, than monovision wearers. The future appears to be very promising for multifocal GP and soft lens modalities.

Background A 58-year-old female with a history of hypertension and asthma presented to an internist for a routine physical examination. A grade II/VI systolic ejection murmur and electrocardiogram abnormalities were noted. She was referred to a cardiologist for further assessment. Investigations Transthoracic echocardiography, transesophageal echocardiography, contrast-enhanced CT and MRI, exploratory laparotomy. Diagnosis Intracardiac leiomyomatosis. Management Surgical excision.

During the past 20 years, transesophageal echocardiography (TEE) became an important diagnostic technique. Indications for TEE include: defining the cause and severity of native valve disease, particularly mitral regurgitation; detecting vegetations and other sequelae of endocarditis; assessing prosthetic valve function; and identifying a potential cardiac source for emboli.(1) TEE is usually well tolerated and is associated with few adverse events. However, structural abnormalities of the esophagus such as diverticula, stenoses, tumors, and advanced varices are relative contraindications to TEE because of the technical difficulties associated with probe advancement and the risk of esophageal perforation.(2) This report describes the successful performance of TEE in a patient with a Zenker's diverticulum. The patient was severely symptomatic of atrial fibrillation and was a poor candidate for long-term anticoagulation. Therefore, it was necessary to rule out a thrombus before cardioversion. Because the Zenker's diverticulum was large, a novel approach was taken using a balloon to occlude the orifice allowing safe passage of the TEE probe.

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.

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 patient's personality and the practitioner's 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 (x 2 = 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.

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).

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 patient's 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.

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.

The RGP Lens Institute (RGPLI) was established 4 years ago for the purpose of educating practitioners about the design, fitting, and applications of rigid gas permeable contact lenses. Since 1986, it has been under the sponsorship of the Contact Lens Manufacturers Association (CLMA). As hydrogel lenses have predominated in the 198Os, concern has been expressed that student, resident, and practitioner education may benefit from supplemental programs-particularly, from innovative practical education. The purpose of the RGPLI is to assist in meeting this need and to help contact lens practitioners develop more confidence and experience in fitting RGP lenses; therefore, the choice of what type of lens material to fit a given patient will be made based on what the practitioner sincerely believes will be most beneficial to that individual. Several educational programs have either been introduced in 1989 or will be introduced in 1990. These include the following

Background The purpose of this study was to survey Diplomates in the Section on Cornea and Contact Lenses of the American Academy of Optometry (AAO) to determine their fitting preferences for astigmatic patients, lens materials used, and their perception of simplicity or complexity of bitoric fitting. Methods A total of 180 practitioners, representing all active Diplomates in the Cornea and Contact Lens Section, were sent a survey of 11 questions pertaining to their astigmatic contact lens prescribing habits. Sixty-eight (38%) of those surveyed responded to the questionnaire. Results The results of this survey included the following: (1) gas permeable (GP) lenses represented 28.7% of all contact lenses fit; (2) a spherical power effect (SPE) bitoric lens was preferred (versus four other options) by 58.8% of respondents for a 3.5 diopter (D) refractive astigmat with no residual astigmatism, whereas a cylinder power effect (CPE) bitoric was preferred by 55.9% for a 3.5 D refractive astigmatic with more than 1 D of residual astigmatism; (3) only 10.4% of responding practitioners consider GP torics to be difficult to fit. Conclusions (1) Back surface toric and bitoric GP lenses are considered easy to design and fit by most Diplomates. (2) The Mandell-Moore guide is the preferred empirical method, and the Polycon SPE is the preferred diagnostic fitting method for bitoric lenses for those responding to the survey.

Testing for tree pollen hypersensitivity typically requires the use of several tree pollens. Identifying patterns of cross-sensitivity to tree pollens could reduce the number of trees used for testing. The goal of this study was to relate reported tree pollen levels to hypersensitivity patterns. Three hundred seventy-one allergy patients were tested serologically for hypersensitivity toward prevalent tree pollens in the surrounding New York area over the years 1993-2000. Specific tree pollens that were examined included oak (Quercus alba), birch (Betula verrucosa), beech (Fagus grandifolia), poplar (Populus deltoides), maple (Acer negundo), ash (Fraxinus americana), hickory (Carya pecan), and elm (Ulmus americana). Statistical analysis of the levels of hypersensitivity was performed to identify correlations and grouping factors. Pollen levels, obtained from published annual pollen and spore reports, were characterized and related to the prevalence of hypersensitivity for the various trees. The highest prevalence of hypersensitivity (scoreor = class 1) was for oak (34.3%), birch (32.9%), and maple (32.8%) tree pollens. Lower prevalences were observed for beech (29.6%), hickory (27.1%), ash (26%), elm (24.6%), and poplar (20.6%) trees. Significant correlations were observed between oak, birch, and beech radioallergosorbent test scores. Factor analysis identified two independent pollen groups with oak, birch, and beech consisting of one group and the other five tree pollens constituting the other group. Peak pollen counts clearly were highest for oak, birch, and maple trees. The peak pollen counts corresponded roughly to seropositivity prevalences for the tree pollens. When elm, poplar, and beech test scores were not used to identify patients who were allergic to tree pollens, only 1 of 106 patients with any positive tree radioallergosorbent test score was missed. It is concluded that in the New York City area, hypersensitivity to tree pollens most often is manifested with allergy to oak, birch, and maple tree pollens. Identifying beech, poplar, and elm hypersensitivity adds little toward identifying patients who are allergic to tree pollens. This may relate in part to cross-reactive epitopes. These data suggest that these three trees can be eliminated from testing with only a1% loss of sensitivity.

Correspondence: edward S Bennett College of Optometry, University of Missouri-St. Louis, One University Boulevard, St. Louis, MO 63121, USA Tel +1 314 516 6258 Fax +1 314 516 6708 email ebennett@umsl.edu Abstract: A current area of great consumer interest, as well as potential for practice growth, pertains to the contact lens correction of presbyopia. In particular many recent innovations with gas permeable multifocal lens designs have resulted in them comparing favorably – and often superiorly – to both soft multifocal lenses and monovision lenses, notably in the area of quality of vision. Gas permeable (GP) back surface aspheric multifocal designs have become increasingly popular because newer designs often are able to incorporate higher add powers than their predecessors, often via the addition of add power to the front surface of the lens. In addition, several front surface lens designs have recently been introduced which have the benefits of minimizing any corneal topography changes as they are typically fit in alignment with the cornea, while also providing a higher add than can be provided on the back surface of the lens. Some high specific gravity materials have been introduced which potentially allow for thinner lenses which have less mass and may exhibit more consistent centration than aspheric multifocal designs in conventional materials. New segmented, translating designs are available with the ability to provide an intermediate correction while the introduction of a hybrid design provides the practitioner with a viable option when a GP lens results in either poor centration of excessive subjective awareness.

To prevent corneal edema in most patients, contact lenses must transmit oxygen to the following minimum degree: (a) in daily wear, 24.1 x 10(-9) (cm x ml O2)/(s x ml x mm Hg), and (b) in extended wear, 34.3 x 10(-9) (cm x ml O2)/(s x ml x mm Hg). High Dk/L ratings are particularly important for patients wearing extended wear lenses and for those with exceptionally high corneal oxygen demand. Nevertheless, it is well known that other lens performance properties can be compromised by manipulating material or design parameters to increase the Dk/L rating. Increasing the Dk/L of hydrogel lenses, for example, may lead to problems such as fragility, dehydration, and corneal adherence. Similarly, high-Dk/L, rigid gas-permeable lenses may exhibit poor surface wettability and flexural resistance, base curve radius changes, and possible corneal adherence. Because such problems can compromise visual acuity, affect ease of handling, or decrease comfort, nonoxygen factors may exert a stronger influence on successful lens wear than high oxygen transmissibility alone for most patients. Among the nonoxygen factors important for contact lens wear are good movement, surface wettability, resistance to deposit buildup, and flexural resistance. Clinicians must consider these properties, along with oxygen transmission ratings, when fitting patients with contact lenses. Lenses that exhibit good overall performance, in my view, provide the greatest probability of successful wear.