Low-power microwave disinfection of soft contact lenses.

PURPOSE: To evaluate the effectiveness of low-power microwave irradiation on the disinfection of contaminated contact lenses. METHODS: We infected 24 soft contact lenses with Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa. Each contact lens was placed into a vial containing 10 mL of contaminated, non-preserved saline. Each vial was then exposed to 2, 4, 6, 9, 12, 15, or 18 minutes of microwave irradiation in an oven (2,450 MHz 600W) set at 10% power. RESULTS: We found all contact lenses to be disinfected after 15 minutes of exposure. All lenses remained hydrated and revealed no apparent damage when examined under the slit-lamp biomicroscope. CONCLUSIONS: Low level microwaving in a home microwave oven can result in effective and non-damaging disinfection of soft contact lenses.

Mardi Gras eye injury survey, 1998-1999.

BACKGROUND: We studied the nature of associated ocular trauma during the 1998 and 1999 New Orleans parade seasons and whether trends were observable from previous surveys. METHODS: A prospective survey and retrospective analysis included 18 emergency rooms (ERs) in the New Orleans area. RESULTS: Sixteen surveys representing eight ERs were completed between February 19 and 24, 1998, and 32 surveys representing five ERs were completed between February 5 and 17, 1999. In both years, the most common ocular complaints were pain, blur, foreign body sensation, tearing, and photophobia. The most common slit lamp findings in 1998 were within normal limits, corneal abrasion, and conjunctival hyperemia. In 1999, the most common findings were subconjunctival hemorrhage, corneal abrasion, cell and flare, and lid laceration. CONCLUSIONS: Projectile injuries of the eyes are common during Mardi Gras due to the nature of interaction between paradegoers and float riders. We found no identifiable trend in the number or type of injuries reported in 1986, 1987, and 1998 Mardi Gras surveys.

Assessing health-related quality of life in cataract patients: the relationship between utility and health-related quality of life measurement.

The relationship between health-related quality of life (HQL) measures and patient preference for their health status was studied. Study subjects consisted of 132 patients at four hospitals who were scheduled for cataract surgery. Generic and disease-specific health status measures were determined in study subjects. The Medical Outcomes Study Short-form 36 (SF-36) item health status instrument was used to measure generic health status and the Visual Function 14 (VF-14) item visual health status instrument was used as the disease-specific health measure. Preference for general health and visual health was measured by assessing utilities assigned by patients to certain health states. Utilities assigned for general health were correlated with all categories of the SF-36 and VF-14 scores. Utilities assigned for visual health were correlated with four categories of the SF-36 (role limitation due to emotional health, general health, physical functioning, and vitality) and VF-14 scores. Utilities assigned for visual health were more strongly correlated with VF-14 scores than generic measures of health. Verbal ratings for visual health were correlated with Snellen visual acuity (SVA) (r = 0.20), utilities assigned for visual health (r = 0.58), VF-14 scores (r = 0.74), all categories of the SF-36 (r values ranging from 0.21 to 0.28), utilities assigned for general health (r = 0.19), and verbal ratings for general health (r = 0.29). Utility measures and verbal ratings for general and visual health were shown to be appropriate HQL measures. These measures were strongly correlated with other established generic and disease-specific health measures and should be included in the array of health status measures.

Contact lens articles in the literature: an update.

PURPOSE: To determine if the pattern of publication of contact lens articles in the ophthalmic literature has changed in recent years. METHODS: We searched the literature of the past 5 years and reviewed the abstracts of all published papers that presented information on contact lenses. The journals reviewed included the American Journal of Ophthalmology, Archives of Ophthalmology, Ophthalmology, and The CLAO Journal. We determined whether articles were positive, negative, or neutral. RESULTS: We reviewed a total of 1,189,451 articles and 48,811 (4.10%) eye articles; of the latter, 987 (2.02%) discussed contact lenses. Only 86 total contact lens articles were published in the three major ophthalmology journals, of which almost 40% presented negative information (e.g., complications of contact lens usage). The CLAO Journal published 136 contact lens articles during the same time period (39.7% were positive and 30.1% were negative). CONCLUSIONS: In the past 5 years, fewer contact lens articles have appeared in the ophthalmic literature than had appeared in the previous five years, and, in addition, more of these articles were negative. The CLAO Journal continues to publish the largest number of contact lens articles, although the percentage of positive articles has decreased somewhat, from 50% to 39.7%.

Rigid gas permeable contact lens fitting after radial keratotomy.

PURPOSE: The purpose of our study was to determine whether radial keratotomy (RK) patients could be fit with rigid gas permeable (RGP) contact lenses based on postoperative keratometry measurements. METHODS: Thirteen eyes from eight post-RK patients were fit with RGP lenses for residual refractive errors. Since these patients were self-referred and were operated on elsewhere, preoperative keratometry readings were not available. We used postoperative keratometry readings for base curve selection; and spherical polymethylmethacrylate diagnostic lenses were used for fitting. RESULTS: Visual improvements averaged 3.85 Snellen lines (range: 1-8 lines). Prefitting visual acuities were: 20/30 (5 eyes); 20/40 (1 eye); 20/ 50 (1 eye); 20/60 (1 eye); 20/70 (3 eyes); 20/150 (1 eye); and 20/200 (1 eye). Final visual acuities were 20/20 (7 eyes), 20/25 (4 eyes), 20/30 (1 eye), and 20/40 (1 eye). CONCLUSION: We found that when fitting post-RK eyes with RGP contact lenses preoperative keratometry was unnecessary, and an empirical fitting method based on postoperative keratometry was successful.

Exophthalmometry: a comparative study of the Naugle and Hertel instruments.

Exophthalmometry is frequently used as a tool in the evaluation of proptosis. The purpose of this study was to compare the clinical usefulness of the newly developed Naugle superior and inferior orbital rim-based exophthalmometer with that of the Hertel exophthalmometer, as well as to obtain normal values and analysis of possible race and sex differences. In the first part of this study, we measured 135 patients in a double-blind study in order to evaluate the repeatability of serial measurements using each instrument. Comfort was also evaluated in this series of patients. In the second part, a single observer measured 205 patients in order to obtain information for a multifaceted analysis. In the first part of the study, we found the Hertel measurement to be more variable in terms of coefficients of variation. We further found the Hertel base measurements to vary more between observers than those of the Naugle instrument. In the second part, we found that the mean values of globe position were not statistically different (mean Naugle, 17.23; mean Hertel, 18.61; p = 0.909). A significant difference was noted between black and white patients when using the Naugle instrument. A difference between white and black women was noted with the Hertel instrument. The results of this analysis strongly suggest that the values obtained from the Naugle exophthalmometer are more repeatable in serial measurements compared with the Hertel values. However, single measurements of globe position from all patients were statistically similar. We conclude that the Naugle instrument is comparable in accuracy to the Hertel instrument for measuring ocular position, as well as being more comfortable for the patient. The Naugle instrument has the advantage of measuring hyperophthalmos and hypoophthalmos with a vertical gradient scale.

Bausch & Lomb CW 79 aphakic extended wear contact lens: long-term follow-up.

PURPOSE: The purpose of our study was to assess the long-term tolerance of aphakic contact lenses in an elderly male population. METHODS: We conducted a follow-up study of Bausch & Lomb CW 79 aphakic extended wear contact lenses fit since 1982. A total of 109 patients (115 eyes) were identified. Records of 37 patients (43 eyes) were available to determine the course of contact lens wear. RESULTS: Thirty-six eyes were contact lens dropouts. The average time to failure was 22 months. Seventeen eyes from the failure group elected to receive secondary intraocular lenses (IOLs). Seven eyes were still wearing CW 79 contact lenses at the conclusion of the study. The average length of wear in these seven eyes was 91 months. CONCLUSIONS: We concluded that the CW 79 aphakic extended wear contact lenses were successful in selected cases. However, a high failure rate was found on long-term follow-up, and approximately half of the failure were converted to secondary IOLs.

Bitoric rigid contact lens with prism fitting in rare cases of moderate corneal and residual astigmatism.

We reviewed all records of bitoric rigid gas permeable (RGP) contact lenses with prism ballast fittings performed at Tulane University Hospital and affiliated clinics from 1985 to 1993. We found eight eyes of six patients fit were fit with this lens, which is indicated for the patient with a moderately astigmatic cornea in addition to residual refractive astigmatism. In this design, a small amount of prism is added to a standard bitoric design to achieve rotational stability. All patients achieved 20/25 or better vision. We provide an outline for fitting bitoric RGP contact lenses with prism ballast.

Rigid gas permeable extended wear.

We have reviewed the pertinent literature on rigid gas permeable (RGP) extended wear contact lenses, and we discuss the benefits and adverse reactions of this contact lens modality, drawing conclusions from reviewed studies. We suggest parameters for success with these lenses and guidelines for the prevention of adverse reactions.

Contact lens articles in the literature.

We searched the ophthalmic literature of the past 5 years looking for patterns in the publication of contact lens articles. Contact lens articles constituted 2.59% of all ophthalmology articles. We found that a substantial percentage of the articles published in The CLAO Journal and selected optometric journals concerned contact lenses; this, however, was not the case with the major ophthalmology journals (American Journal of Ophthalmology [AJO], Ophthalmology, and Archives of Ophthalmology [Archives]). One recent contact lens development, disposable lenses, was covered by both The CLAO Journal and the major ophthalmology journals, but the coverage differed in that the orientation of the articles in the major ophthalmology journals was essentially negative. Articles about another recent development (rigid gas permeable contact lenses for extended wear), although found in The CLAO Journal, could not be found in the other ophthalmology journals. Finally, when the abstracts of all contact lens articles were reviewed, we found a negative slant to articles published in AJO and Archives. We believe that the major ophthalmology journals present a rather negative view of contact lenses; this, we think, impedes unbiased dissemination of information about new contact lens developments.

Ocular infections associated with Comamonas acidovorans.

Comamonas acidovorans (Pseudomonas acidovorans) is a ubiquitous gram-negative rod. Although generally considered nonpathogenic, we found C. acidovorans to be associated with six cases of ocular infections. The organism was the only isolate in three cases, whereas an association of other organisms was present in three cases. The multiple resistance patterns of these strains to antibiotic susceptibility testing emphasizes the need for culturing ocular infections. We recommend the identification and susceptibility testing of all ocular gram-negative rod isolates.

Ocular effects and detection in tears of aerosolized intranasal cocaine and fluorescein.

Ocular effects of intranasal cocaine were investigated. Twenty-nine outpatients from an otolaryngology clinic received 1 mL of aerosolized cocaine 4% (40mg) in each nostril. Intraocular pressure, corneal sensitivity, pupil size, and tear cocaine concentration were assessed before and after cocaine administration. Pupil size was unchanged; intraocular pressure increased in 75% of patients (not statistically significant). Corneal sensitivity decreased by 11% (P less than .05). Cocaine, however, was not detectable in tears using high-performance liquid chromatography. Since corneal sensitivity decreases after intranasal cocaine administration, it may travel retrograde through the nasolacrimal duct. In addition, three pathways of pharmacologic absorption using fluorescein were explored because of its ease of detection. We measured tear fluorescein concentrations in five patients undergoing intravenous angiograms with fluorescein 25% and in six patients who received aerosolized fluorescein 2% intranasally. Fluorescein concentration was 29 times higher per mg dose in intranasal subjects. This finding suggests that reflux occurs through the nasolacrimal duct.

Is the quality of vision with contact lenses adequate? Not in all instances.

There are several circumstances in which contact lenses (CLs) provide vision inferior to that possible with spectacles. Over time, both soft and rigid gas-permeable (RGP) lenses accumulate deposits that can cloud vision. RGP lenses are especially prone to scratching; some varieties may even become crazed, giving a spiderweb quality to vision. Certain uncommon corneal complications associated with lens wear--infection, neovascularization, ulcers, and severe epithelial edema--may also impair vision, sometimes permanently. CLs often provide less than optimal vision for patients with presbyopia or severe astigmatism. Difficulties with axis stabilization arise with both soft and rigid toric lenses, and these can take several attempts to resolve. Monovision fitting currently offers the best option for presbyopes, but it has an effect on stereopsis, compromising depth perception. Furthermore, patients often require considerable time before adapting to monovision lens use. Finally, even under normal circumstances, certain inherent features of CLs can diminish visual acuity. The water in soft lenses diffuses light; the loss of visual crispness is particularly notable with high-water-content lenses. On the other hand, the small diameter of RGP lenses often contributes to ghosting--a phenomenon in which the edge of the lenses is visible whenever the pupils are widely dilated.

Fluoroperm extended wear RGP contact lenses: II. Front toric fitting.

Seventeen eyes (10 patients) were fit with front toric rigid gas permeable (RGP) Fluoroperm lenses as part of an extended wear study. These 17 eyes required 40 fittings (an average of 2.35 fittings per eye); only six eyes were fit successfully the first time. What occasioned the large number of fittings was unacceptable visual acuity due to incorrect lens axis. Most fittings had been done with a polymethylmethacrylate (PMMA) fitting set; and it became obvious that the final Fluoroperm lenses rotated differently from the PMMA diagnostic lenses. Ultimately, the use of a Fluoroperm prism-ballasted fitting set resulted in 16 of 17 eyes (94%) seeing well with a front toric lens. We advise that, for front toric fittings, the diagnostic lens be of the same material as the final lens.

Bausch & Lomb CW 79 aphakic extended wear contact lens: multi-year follow-up.

We undertook a follow-up case study of 126 patients (146 eyes) to determine success rate and replacement rate of the Bausch & Lomb CW 79 aphakic extended wear contact lens. One hundred eighteen eyes (81%) were successful in wearing the contact lens, and 16 eyes (11%) were reported as contact lenses dropouts. Twelve eyes (8%) elected to receive intraocular lenses (IOLs). A total of 134 lenses were replaced, yielding a replacement rate of 0.3 lenses per eye per year. The average length of follow-up for successful patients was 3.7 years.

Fluoroperm extended wear RGP contact lenses for myopia, hyperopia, aphakia, astigmatism, and keratoconus.

One hundred fifteen eyes of 62 patients were fit with paflufocon-A (Fluoroperm) rigid gas permeable (RGP) contact lenses. Patients included myopes, hyperopes, aphakes, and keratoconic and astigmatic patients; the latter patients were fit with bitoric designs for large amounts of corneal astigmatism or front toric designs for residual astigmatism. Thirty of the 52 patients (58%) who completed the study were able to wear the lenses continuously without complications; six (12%) were able to achieve extended wear for up to one month. The average visual acuity across the study was 20/20. Three complications were observed, resulting in a complication rate of 6%.