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Karla Zadnik

Publications and source records attributed to Karla Zadnik.

At least 37 records · Page 2Linked to original sources
PubMed2004

Use of the experience sampling method to measure nearwork.

PURPOSE: The purpose of this study was to use the Experience Sampling Method (ESM) to evaluate the daily visual activities of a group of optometry students and to determine whether the ESM could detect differences in visual activities when a difference was thought to exist. METHODS: Sixty-two optometry students, at four different levels of training, at The Ohio State University College of Optometry were tested using the ESM during a 14-day period. A subgroup of 18 subjects in their fourth year of study was asked to repeat the 14-day ESM on a second occasion. The two ESM periods were specifically chosen at times when the subjects were expected to have markedly different nearwork profiles. RESULTS: A comparison of members from the four optometry classes when the fourth-year students were taking final written examinations showed no significant differences in the proportion of nearwork among groups (p = 0.170); however, when the fourth-year students were primarily performing eye examinations during clinical rotations, there was a significant difference in the proportion of nearwork among training levels (13.8% for fourth-year students compared with 24.9%, 23.7%, and 30.4% for the other optometry classes; p = 0.0001). The percentage of time spent doing nearwork and performing eye examinations was significantly different between two ESM periods (paired t-test, p = 0.0001 for each activity). CONCLUSIONS: The ESM is capable of detecting differences in the proportion of time spent doing nearwork and performing eye examinations among groups of optometry students in different levels of training with different daily visual demands and between two ESM periods when these activities were expected to differ. The ESM can be used as an alternative method for nearwork quantification in future studies.

Adult↗
PubMed2004

Variables affecting rigid contact lens comfort in the collaborative longitudinal evaluation of keratoconus (CLEK) study.

PURPOSE: To identify factors associated with rigid contact lens comfort in keratoconus. METHODS: Baseline data from the 16 Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study clinical sites were analyzed for all patients wearing a rigid contact lens in their more severely keratoconic eye (as determined by steep keratometry). Corneal transplant patients, patients who did not wear a rigid contact lens in either eye, patients who did not wear a rigid lens in their worse eye, and patients with missing contact lens comfort data were excluded from the sample. A total of 751 eyes were included. Variables assessed included measures of disease severity, visual acuity through the patients' habitual rigid contact lenses, contact lens wearing time, the apical fitting relationship of the contact lens, the degree of peripheral clearance, and the presence of corneal scarring and staining. Comfort was measured by asking the patients "In general, how comfortable are your contact lenses?" (1 = very comfortable through 5 = very irritating). RESULTS: Measures of disease severity (steep keratometry and the first definite apical clearance lens) were not associated with lens comfort. There was no difference in self-reported contact lens comfort between patients fitted with apical touch vs. apical clearance. Patients with a peripheral clearance rating of "minimal unacceptable" (more common among patients with milder keratoconus) were approximately half as likely to report good contact lens comfort compared with patients with "average" peripheral clearance (unadjusted odds ratio, 0.39; 95% confidence interval, 0.19 to 0.79). There was no association between contact lens comfort and the other peripheral clearance ratings compared with ratings of average. CONCLUSIONS: There does not appear to be an association between decreasing patient-reported rigid lens comfort and increasing disease severity as measured by steep keratometry or first definite apical clearance lens in this sample. The apical fitting relationship (flat vs. steep) does not appear to be associated with patient-reported comfort. Minimal peripheral clearance may contribute to decreased rigid contact lens comfort in keratoconus.

Adult↗
PubMed2004

Daily disposable contact lens wear in myopic children.

PURPOSE: To determine whether 8- to 11-year-old myopic children are able to wear daily disposable contact lenses. METHODS: Subjects were examined for eligibility and fitted with 1-Day Acuvue contact lenses at the baseline visit. They underwent noncycloplegic manifest refraction, keratometry, slitlamp biomicroscopic examination, contact lens fitting, standardized visual acuity measurement, and contact lens application and removal training. The subjects attended visits 1 week, 1 month, and 3 months after the initial dispensing visit. At each of these visits, the subjects underwent spherical over-refraction, keratometry, slitlamp examination, and standardized visual acuity measurement, and they completed surveys about contact lens wear. The contact lens with the base curve that exhibited the most appropriate amount of movement and centration or the contact lens with the flatter base curve, if the movement and centration of the two contact lenses were similar, was dispensed. RESULTS: Ten of the 12 subjects completed the 3-month investigation. One subject decided not to wear contact lenses before the 1-week visit, and one subject moved from the area after the 1-month visit. At the 3-month visit, 6 (60%) of the 10 subjects wore the 9.0 mm base curve contact lens, and 6 (60%) of the 10 subjects required one power change to optimize vision. At the 3-month visit, all subjects but one reported that their vision was "pretty good" or "perfect." All subjects also reported that their eyes were "always comfortable" or "usually comfortable." Eighty percent of the subjects reported that they "never had a problem" or "usually did not have a problem" putting on their contact lenses. All subjects reported that they "usually did not have a problem" or "never had a problem" taking out their contact lenses, and 90% of the subjects reported that they "usually did not have a problem" or "never had a problem" handling their contact lenses. CONCLUSION: Eight- to 11-year-old subjects are able to independently care for daily disposable contact lenses and wear them successfully. Daily disposable contact lenses eliminate the need for cleaning and disinfecting contact lenses, so they should be strongly considered as a contact lens treatment option for children.

Child↗
PubMed2004

Refractive astigmatism and the toricity of ocular components in human infants.

PURPOSE: Many studies have characterized astigmatism in infancy, but few have been longitudinal or contained ocular component data. This study characterized the frequency, orientation, and longitudinal change with age of infant astigmatism. Additional factors investigated were the influence of early astigmatism on emmetropization and its relation to corneal and lenticular toricity. METHODS: Three hundred two infants were enrolled in the study. Of these, 298 provided data for at least one visit at 3 +/- 1 months, 9 +/- 1 months, 18 +/- 2 months, and 36 +/- 3 months. Testing included cycloplegic retinoscopy (cyclopentolate 1%), video-based keratophakometry, and ultrasonography over the closed eyelid. RESULTS: Astigmatism > or =1.00 DC was common at 3 months of age (41.6%) but decreased in prevalence to 4.1% by 36 months (p < 0.0001). The most common orientation was with-the-rule at 3 months (37.0% compared with 2.7% for against-the-rule) but against-the-rule at 36 months (3.2% compared with 0.9% for with-the-rule). Most of the change in the average value of the horizontal/vertical component of astigmatism (J0) occurred between 3 and 9 months (-0.26 +/- 0.36 D; p < 0.0001) with no significant change between 9 and 36 months (-0.05 +/- 0.36 D; p=0.09). Spherical equivalent refractive error was not correlated with J0 at 3 and 9 months (R=0.002, p=0.48 and R=0.001, p=0.56, respectively). The two were only weakly correlated at 18 and 36 months (R=0.06 for each age, p <0.0001, p=0.0002, respectively). Changes in spherical equivalent between 3 and 9 months were unrelated to either the initial value of J0 (partial R for J0=0.0001; p=0.85) or the change in J0 (partial R for change in J0=0.0031; p=0.31). Across all the ages, corneal toricity was with-the-rule, and lenticular toricity was against-the-rule (produced by the toricity of the posterior lens surface). The cornea and anterior lens surface became more spherical with age, contributing to the shift away from with-the-rule refractive astigmatism. Toricity of all the refractive surfaces became less variable with age. CONCLUSIONS: Consistent with many reports, astigmatism was common in early infancy but decreased in prevalence with age, particularly when with-the-rule in orientation. The reduction in percentage of infants with astigmatism appeared to be caused by decreases in the toricity of the cornea and the anterior lens combined with decreases in the variability of corneal and lenticular surfaces. Astigmatism in infancy appeared to be unrelated to emmetropization of spherical equivalent refractive error.

Age Distribution↗
PubMed2004

Normal eye growth in emmetropic schoolchildren.

PURPOSE: The purpose of this report is to describe the normal growth pattern of the optical components of the eye in a cohort of emmetropic, school-aged children. METHODS: Emmetropia was defined as refractive error (measured by cycloplegic autorefraction) in the vertical and horizontal meridians of the right eye between +1.00 D and -0.25 D at all the visits. This definition resulted in a sample of 194 children enrolled in the Orinda Longitudinal Study of Myopia (OLSM) between ages 6 and 14 years with at least 2 years of follow-up evaluation (across three annual visits) between 1989 and 2000. The optical components measured included corneal power, anterior chamber depth, crystalline lens thickness, Gullstrand lens power, calculated lens power, crystalline lens index, vitreous chamber depth, and axial length. RESULTS: Corneal power and anterior chamber depth were best modeled as quadratic functions of ln (age). The model involving the square of the inverse of age best described calculated lens power and crystalline lens index. The relationship between age and crystalline lens thickness was best described using a linear function of age with a point of inflection. A linear function of ln (age) with a point of inflection best described the relationship between age and axial length, Gullstrand lens power, and vitreous chamber depth. For five of the eight components (crystalline lens thickness, Gullstrand lens power, calculated lens power, corneal power, and crystalline lens index), the line modeling the data was negative in overall direction, indicating that the component value decreased with age. The upward trend of the line modeling axial length, anterior chamber depth, and vitreous chamber depth reflected the continued growth of the eye from age 6 years to age 15 years. CONCLUSIONS: A picture of normal eye growth in emmetropes from ages 6 to 15 years is provided based on a combination of cross-sectional and longitudinal data. Axial elongation, crystalline lens flattening and thinning, and decrease in lens power are its hallmarks.

Adolescent↗
PubMed2003

Refractive error and ethnicity in children.

OBJECTIVE: To report the baseline prevalence of refractive error in the study population. DESIGN: A multicenter, longitudinal, observational study of refractive error and ocular development in children from 4 ethnic groups. PATIENTS AND METHODS: The study population included 2523 children (534 African American, 491 Asian, 463 Hispanic, and 1035 white) in grades 1 to 8 (age, 5-17 years). Myopia was defined as -0.75 diopters (D) or more and hyperopia as +1.25 D or more in each principal meridian, and astigmatism was defined as at least a 1.00-D difference between the 2 principal meridians (cycloplegic autorefraction). RESULTS: Overall, 9.2% of the children were myopic, 12.8% were hyperopic, and 28.4% were astigmatic. There were significant differences in the refractive error prevalences as a function of ethnicity (chi2, P<.001), even after controlling for age and sex (polychotomous logistic regression, P<.001). For myopia, Asians had the highest prevalence (18.5%), followed by Hispanics (13.2%). Whites had the lowest prevalence of myopia (4.4%), which was not significantly different from African Americans (6.6%). For hyperopia, whites had the highest prevalence (19.3%), followed by Hispanics (12.7%). Asians had the lowest prevalence of hyperopia (6.3%) and were not significantly different from African Americans (6.4%). For astigmatism, Asians and Hispanics had the highest prevalences (33.6% and 36.9%, respectively) and did not differ from each other (P =.17). African Americans had the lowest prevalence of astigmatism (20.0%), followed by whites (26.4%). CONCLUSION: There were significant differences in the prevalence of refractive errors among ethnic groups, even after controlling for age and sex (P<.001).

Adolescent↗
PubMed2003

Reliability and validity of refractive error-specific quality-of-life instruments.

OBJECTIVE: To evaluate the reliability and validity of the National Eye Institute Refractive Error Quality of Life Instrument (NEI-RQL-42) and the Refractive Status and Vision Profile survey (RSVP). METHODS: Eighty-one participants with good visual acuity (better than 20/30 best-corrected acuity in each eye) completed the NEI-RQL-42 and RSVP on 2 occasions. Noncycloplegic, subjective refractions and high-contrast visual acuity assessments were also performed. Statistical analyses addressed internal consistency, test-retest reliability, and validity (ie, concurrent and construct validity) of the 2 instruments. OUTCOME MEASURES: The NEI-RQL-42, RSVP survey, subjective refraction, and visual acuity. RESULTS: The internal consistency for the overall NEI-RQL-42 was excellent (Cronbach alpha = 0.91); and for the overall RSVP, good (Cronbach alpha = 0.81). Likewise, the test-retest reliability for the overall NEI-RQL-42 was excellent (intraclass correlation coefficient [ICC], 0.91; 95% limits of agreement, -9.1 to 10.1); and for the RSVP, fair (ICC, 0.76; 95% limits of agreement, -12.1 to 12.5). The NEI-RQL-42 overall score showed good concurrent validity as it correlated significantly with subjective refraction, whereas the RSVP overall score did not. The NEI-RQL-42 and RSVP showed similar construct validity in terms of refractive error discrimination, but the NEI-RQL-42 showed better construct validity when discriminating by the type of refractive correction used by patients. Between-instrument convergent and divergent validity was good. CONCLUSIONS: The NEI-RQL-42 and RSVP generally have good reliability and validity in this sample of patients with refractive error. However, other factors such as content should be considered in choosing 1 of these instruments for studies of refractive error correction.

Adult↗
PubMed2003

Patient satisfaction and visual symptoms after laser in situ keratomileusis.

PURPOSE: To examine preoperative risk factors for decreased satisfaction and symptoms of glare, halos, and/or starbursts after laser in situ keratomileusis (LASIK). DESIGN: Retrospective, case-control study. PARTICIPANTS: Participants were 604 previously myopic patients who underwent LASIK at least six months prior to completing the questionnaire. METHODS: Questionnaires about satisfaction and night vision symptoms were mailed to 2100 patients from the Northeastern Eye Institute, UCLA, and the University of Pittsburgh. Preoperative and postoperative ocular variables were collected from the medical charts of the 841 subjects who returned the questionnaire. MAIN OUTCOME MEASURES: Responses to various satisfaction and night vision symptom questions were compared to demographic and preoperative ocular variables using multivariate logistic regression. RESULTS: The questionnaire return rate was 42.9%. The mean age for all subjects was 43.0 +/- 10.6 years, and 63% of the subjects were women. Overall, 97% of the subjects would recommend LASIK to a friend. Among subjects who would not recommend LASIK to a friend, a significantly larger percentage reported that they experienced glare, halos, or starbursts (13 of 16 (81.3%) vs. 206 of 388 (53.1%), chi(2) = 4.9, p = 0.03). Also, subjects with flatter preoperative minimum corneal curvature values were more likely to report that they would not recommend LASIK to a friend (OR = 0.71, 95% confidence interval (CI) = (0.52, 0.96), p = 0.03). The median score for satisfaction with vision was 100%, or the maximum value of 127 mm on the visual analog scale. Increasing age was significantly associated with dissatisfaction with vision after LASIK (OR = 1.68, 95% CI = (1.10, 2.56), P = 0.02). Halos were reported by 30%, glare by 27%, and starbursts by 25% of all subjects. Subjects who reported starbursts had a significantly flatter preoperative minimum corneal curvature (43.54 +/- 1.60 D versus 43.92 +/- 1.69 D, t = 2.15, p = 0.03). Also, subjects who had surgical enhancement were more likely to experience glare, halos, and/or starbursts (OR = 2.14, 95% CI = (1.33, 3.46), p = 0.002). CONCLUSIONS: Most subjects are satisfied with their vision after LASIK. Our study suggests, however, that certain factors are associated with decreased satisfaction and night vision symptoms after LASIK. Some of these factors include: increasing age, flatter preoperative minimum corneal curvature, and surgical enhancement.

Adult↗
PubMed2003

Use of a run-in period to decrease loss to follow-up in the Contact Lens and Myopia Progression (CLAMP) study.

Rigid gas permeable (RGP) contact lenses are initially less comfortable to wear than spectacles. In previous studies evaluating the use of RGP contact lenses to control myopia, more subjects randomly assigned to wear RGP contact lenses have been lost to follow-up than spectacle wearers. Previous rigid contact lens myopia control studies have lost 44% and 47% of the rigid contact lens wearers. This unequal loss to follow-up may compromise the results of the study, so we conducted a run-in period prior to randomized treatment-group assignment to ensure that all participants could adapt to RGP contact lens wear. We enrolled 147 children ages 8-11 years with myopia in the run-in period. Of the 147 subjects, 116 (78.9%) were able to wear RGP contact lenses for at least 40 hours per week and reported that they were "usually comfortable" or "always comfortable." After 3 years, no subjects were lost to follow-up. The run-in period greatly reduced the loss to follow-up suffered by previous RGP contact lens myopia progression studies and may help provide more definitive answers regarding myopia control with RGP contact lenses.

Child↗
PubMed2003

Ocular component data in schoolchildren as a function of age and gender.

PURPOSE: To describe the refractive error and ocular components of a large group of school-aged children as a function of age and gender. METHODS: In this report, we describe the refractive error and ocular components of 2583 school-aged children (49.3% girls, overall mean [+/-SD] age 10.0 +/- 2.3). Measurement methods included cycloplegic autorefraction, autokeratometry, videophakometry, and A-scan ultrasonography. For statistical comparisons across gender and age, a critical point of alpha = 0.005 was used to assess significance because of the large sample size and the large number of comparisons made. RESULTS: Of these 2583 children, 10.1% were myopic (-0.75 D or more myopia in both meridians), and 8.6% were hyperopic (+1.25 D or more hyperopia in both meridians). As would be expected, there was a significant effect of age on refractive error (spherical equivalent, p < 0.0001), toward less hyperopia/more myopia. There was no significant difference in the average refractive error between girls and boys (p = 0.0192). Girls had steeper corneas than boys (0.74 D steeper in the vertical meridian and 0.63 D steeper in the horizontal meridian, p < 0.0001). There were no significant differences in corneal power with age (p = 0.16). Both older age and male gender were significantly associated with deeper anterior chambers (p < 0.0001 for both). The crystalline lens showed significant thinning with age (p < 0.0001), however, there was no significant difference in the lens thickness between girls and boys (p = 0.66). Both Gullstrand lens power and calculated lens power showed significant effects of age and gender (p < 0.0001 for both). Girls, on average, had Gullstrand lens powers that were 0.28 D steeper and calculated lens powers that were 0.80 D more powerful than boys. Axial length also showed significant effects of age and gender (p < 0.0001 for both). Girls' eyes were, on average, 0.32 mm shorter than those of boys. CONCLUSIONS: These cross-sectional data show a general pattern of ocular growth, no change in corneal power, and crystalline lens thinning and flattening between the ages of 6 and 14 years. Girls tended to have steeper corneas, stronger crystalline lenses, and shorter eyes compared with boys.

Adolescent↗
PubMed2002

Genetic loci for pathological myopia are not associated with juvenile myopia.

The purpose of this study was to evaluate chromosomal regions previously linked to pathological myopia for linkage to juvenile myopia in a sample of myopic children and their families. Of 125 families with a myopic child participating in the Orinda longitudinal study of myopia, 53 submitted 221 buccal swab samples for genetic analysis. Myopia in proband children was defined as -0.75 D or more myopia in both meridians on cycloplegic autorefraction (1% tropicamide). Affected status in parents and siblings was obtained by survey. DNA was extracted from buccal mucosal cells, amplified by polymerase chain reaction (PCR), and then analyzed with seven markers for chromosome 12 and five markers for chromosome 18 in the regions previously associated with pathological myopia. LOD scores were not significant for any marker tested. The largest positive LOD score was 0.15 for GATA30F04. Model-free methods using a SimIBD approach suggested a possible linkage at one marker, GATA6H09 (P = 0.003), but these results were not supported by transmission disequilibrium test (TDT) analysis. The statistical power to detect LOD scores of > or =1.0, assuming homogeneity, was estimated at 93.2%. We found no confirmatory evidence of linkage between juvenile myopia and regions of chromosomes 12 and 18 previously associated with pathological myopia.

Child↗
PubMed2002

Levels of agreement between parents' and children's reports of near work.

PURPOSE: To assess whether parents and children report the same information regarding children's near vision activities when given similar questionnaires. METHODS: Data from questionnaires administered to 406 children and their parents were analyzed to evaluate the agreement between parent and child reports. The questionnaires were completed during the 1994 testing of the Orinda Longitudinal Study of Myopia. Each child and parent was asked to categorize how often the child reads for pleasure. In addition, each subject was asked to estimate how many hours per week were spent in each of five visual activities. The weighted kappa statistic, paired t-tests, and polytomous logistic regression were used for analyses. RESULTS: A weighted kappa = 0.42 (moderate agreement) was found in the comparison of child-reported vs. parent-reported classification of reading. Agreement between parent- and child-reported number of hours spent doing homework (0.21), reading for pleasure (0.31), watching television (0.31), playing video games (0.31), and engaging in sports/outdoor activities (0.26) was fair for each activity. CONCLUSIONS: Although the results indicate fair to moderate levels of agreement, better methods of reporting near-work activities are needed for future myopia research.

Adolescent↗
PubMed2002

Performance and repeatability of the NEI-VFQ-25 in patients with dry eye.

PURPOSE: The use of the National Eye Institute Visual Function Questionnaire (NEI-VFQ) has increased as a method of assessing patients' impressions of their vision-specific quality of life. The purpose of this study was to assess the performance and test-retest repeatability of the 25-question format of the NEI-VFQ in patients with dry eye. METHODS: The self-administered NEI-VFQ-25 was administered to 75 patients with dry eye on two occasions in a university-based optometry practice. Dry eye severity was assessed with use of the European criteria for dry eye. The weighted kappa statistic (kappa(w)) was used to evaluate test-retest repeatability of the NEI-VFQ-25 individual test questions, and the 95% limits of agreement and the intraclass correlation coefficients were calculated for the overall VFQ and subscale scores. RESULTS: With use of the European dry eye criteria, 21.9% of participants were classified with moderate to severe dry eye. For the sample, the ocular pain subscale score was lower (indicating more ocular pain) than published normative values. Repeatability of individual NEI-VFQ-25 questions ranged from moderate to substantial (kappa(w) values: 0.42 [pain and discomfort] to 0.90 [stay home because of vision]). The intervisit mean (+/- standard deviation) difference in the overall VFQ score was -0.66 +/- 4.26 (95% limits of agreement: -9.02, 7.69), and the intraclass correlation coefficient for the ocular pain subscale was 0.57. CONCLUSION: Patients with dry eye have lower ocular pain subscale scores. The repeatability of the overall NEI-VFQ score and the subscale scores was moderate to high, and it may be influenced by the number of questions in each subscale.

Adult↗
PubMed2002

Between-eye asymmetry in keratoconus.

PURPOSE: To report baseline differences between eyes on key variables in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study cohort compared with a retrospectively assembled group of myopic contact lens wearers without ocular disease. METHODS: A total of 1,079 keratoconus patients who had not undergone a penetrating keratoplasty in either eye before their baseline visit were enrolled and examined at baseline. Records from 330 contact lens-wearing myopes were reviewed. Corneal curvature (keratometry), visual acuity, refractive error (manifest refraction), and corneal scarring were measured. RESULTS: The mean differences between keratoconic eyes are as follows (better eye-worse eye for each variable, separately). Flat keratometry: -3.59 +/-4.46 D and steep keratometry: -4.35 +/-4.41 D; high-contrast best-corrected visual acuity: 7.30 +/-6.83 letters; low-contrast best-corrected visual acuity: 8.53 +/-7.51 letters; high-contrast entrance visual acuity: 9.03 +/-8.40 letters; low-contrast entrance visual acuity: 9.43 +/-7.88 letters; spherical equivalent refractive error: 3.15 +/-3.84 D; and refractive cylinder power 1.55 +/-1.42 D. Twenty-one percent of the keratoconus patients had corneal scarring in only one eye. There is an association between patient-reported unilateral eye rubbing and greater asymmetry in corneal curvature, and between a history of unilateral eye trauma and greater asymmetry in corneal curvature and refractive error, with the rubbed/traumatized eye being the steeper eye most of the time. CONCLUSIONS: Keratoconus is asymmetric in the CLEK Study sample.

Adult↗
PubMed2002

Visual performance and comfort with the Rose K lens for keratoconus.

PURPOSE: The "Rose K Lens for Keratoconus" is a proprietary rigid contact lens design that has been reported and marketed as a lens that provides better visual acuity and comfort than other rigid contact lens designs for keratoconus. METHODS: Twenty patients with keratoconus who were wearing rigid contact lenses were refitted into the Rose K lenses. Visual acuity measurements were taken with habitual lenses at the baseline visit and with the Rose K lenses at the completion of the study. Questionnaires were used to assess vision-specific quality of life, contact lens comfort, and self-reported assessment of vision. RESULTS: There were no statistically significant changes in high- or low-contrast visual acuity with the Rose K lenses. There was statistically significant improvement in self-reported assessment of vision and self-reported assessment of comfort in the eyes with more advanced keratoconus. At the conclusion of the study, 72% of patients preferred the Rose K lenses over their habitual lenses, and 87% reported that they would continue wearing the Rose K lenses. CONCLUSIONS: There was no difference in the visual acuity with the Rose K lenses compared with the patients' habitual lenses. Subjective assessment of vision and comfort indicate a statistical improvement for more advanced keratoconus with the Rose K lens. We could not rule out a placebo effect as a source of subjective improvement in vision and comfort. Nevertheless, the successful fit rate and patient preference demonstrate the usefulness of the Rose K lens in clinical practice.

Adult↗
PubMed2002

A retrospective study of myopia progression in adult contact lens wearers.

PURPOSE: To study retrospectively the frequency of myopia progression and risk factors for progression in a sample of adult contact lens wearers. METHODS: From a database of 815 soft contact lens wearers, patients were identified whose age was between 20 and 40 years, who had at least -0.50 D spherical equivalent of myopia in both eyes, three or more refractions, and > or =5 years of follow-up. Only data from the right eye were used. Progression was defined as an increase of at least -1.00 D over 5 years. Subjects were also asked to complete a questionnaire regarding their ocular history, demographics, family history, and the amount of time spent performing different tasks at home and at work. RESULTS: Two hundred ninety-one subjects met the eligibility criteria with a mean baseline refractive error of -3.29 +/- 1.92 D and a mean age of 28.5 +/- 5.0 years. Of these, 21.3% progressed by at least -1.00 D over the 5-year period. The 5-year rate of progression decreased with increasing age (chi(2) = 12.44, P = 0.006). One hundred ninety-seven subjects (67.6%) completed and returned questionnaires. "Progressors" (N = 41) did not differ from "nonprogressors" (N = 156) in terms of hours per day spent reading and writing, computer use, education level, family history of myopia, age of onset of myopia, and contact lens wear. CONCLUSIONS: In this database of soft contact lens wearers, myopia progression was common for subjects in their twenties and less common for those in their thirties.

Adult↗