Optometry and vision science: official publication of the American Academy of Optometry

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Online ISSN: 1538-9235
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Article
As optometric practitioners, we all gather and then analyze large quantities of clinical data every day. We understand that some of these data will be normal (or negative), and some will be abnormal (or positive); some will even be questionable (unreliable or suspicious). However, all clinical data used to prevent, diagnose, treat, and/or rehabilitate our patients are important; therefore, patients--as well as third-party payors--should be reminded of this fact.
 
Article
To investigate the effect of a new non-selective muscarinic antagonist, 0.05% racanisodamine eye drop, on pupil size and accommodative response in children. Twenty healthy myopic children aged between 9 and 12 years were enrolled in the study. They were given two successive drops of 0.05% racanisodamine solution in one eye. Scotopic pupil sizes of both eyes were evaluated with an infrared open-field autorefractor before and 10, 20, 30, 45, 60, 90, 120, 180, 240, 300, and 360 min after treatment. Accommodative responses to a Maltese cross at a distance of 50, 33, and 20 cm were measured at the same time intervals as pupil sizes. Subjective evaluation of photophobia and reading difficulty were recorded by questionnaires. Pupil sizes and accommodative responses were compared across time using repeated measurements of analysis of variance. The minimum pupil size of the treated eye came at 10 min after the second drop and maintained for the next 20 min. Then, it recovered to baseline value at 45 min and continued to enlarge to a peak size of about 0.75 ± 0.22 mm larger than baseline value at 120 min (p = 0.036), followed by a recovering process. No significant change occurred to the contralateral untreated eye. Accommodative responses to near targets did not significantly change at any time during the procedure for both eyes. Only one subject experienced photophobia in the treated eye at the 120 and 180 min time points after treatment. None reported reading difficulty at any time. As a non-selective muscarinic antagonist, 0.05% racanisodamine has a significant but clinically moderate impact on pupil size and no effect on accommodative response.
 
Article
The Non-Contact Corneal Aesthesiometer (NCCA) was used to monitor the effect of topical anesthesia on corneal sensitivity loss and recovery. In a single masked randomized study, one drop of nonpreserved 0.4% benoxinate hydrochloride was instilled in either the right, left, or both eyes of 20 subjects on separate days, and measurements were made of the central corneal sensitivity in the right eye over a 60-min period. As controls, 10 subjects were retested, without any anesthetic instillation, over the same time period. No significant differences were found between these two benoxinate treatments, nor between the contralateral treatment and controls. Results indicate that there is no contralateral effect of benoxinate anesthesia, and that full recovery does not occur until 60 min after instillation. No effect on the depth and duration of anesthesia was found for iris color.
 
Article
The TGDc-01 "PRA" (Ryazan State Instrument, Ryazan, Russia) tonometer is a new portable small-sized tonometer that measures intraocular pressure (IOP) through the eyelid. The purpose of this study is to assess the repeatability of the TGDc-01 IOP measurements by comparing them against those obtained with Goldmann tonometer and with those from Perkins applanation tonometer, Xpert (Reichert, Depew, NY) noncontact tonometer, and Tono-Pen XL (Medtronic Solan, Jacksonville, FL) digital tonometer. Fifty-eight right eyes of 58 young subjects were measured with each of the tonometers. Noncontact tonometry was performed first, followed by Goldmann and Perkins applanation tonometer (in random order), digital Tono-Pen XL, and finally TGDc-01 tonometer (sitting and supine position). Correlation analysis was used to evaluate the relationship between the Goldmann tonometer and the remaining tonometers used in this study. Plotting the difference between the methods against mean was also done to compare the tonometers. The hypothesis of zero bias was examined by a paired t-test. The 95% limits of agreement (LoA) were also calculated. TGDc-01 showed no statistical difference between the IOP measurements obtained in sitting and supine positions. A poor relationship between the TGDc-01 and Goldmann tonometer was found (r = 0.173; p = 0.001). Although the mean differences between Goldmann and Tonopen XL, Xpert, and TGDc-01 IOP measurements were statistically significant, the wider 95% LoA was observed when comparing the Goldmann and TGDc-01 tonometers. Computation of the 95% LoA resulted in a wide bias range when comparing the TGDc-01 with all the tonometers used in this study. The TGDc-01 "PRA" tonometer was not comparable with the other techniques used in the study. The wide dispersion range of the values obtained shows low repeatability of the TGDc-01 for screening purposes. These results could be because of the technique of measurement and/or interindividual variables.
 
Article
Purpose: This observational case series investigated the occurrence and distribution of proptosis in Japanese patients with dysthyroid ophthalmopathy (DO). The relationship among lid retraction, lid swelling, and enlargement of extraocular muscles was also analyzed. Methods: From 1993 to 2002, 10 931 patients (2240 men and 8691 women, average age; 39.9 ± 14.0 years) with abnormal thyroid function were examined for proptosis. Proptosis was measured using a Hertel exophthalmometer, and lid swelling and retraction were classified. Orbital magnetic resonance imaging or computed tomography was used to quantify enlargement of the extraocular muscles. Results: Clinically significant proptosis (≥15 mm) was present in 74.2% patients and was classified as mild (15-17 mm, 39.1%), moderate (18-20 mm, 25.9%), or severe (>20 mm, 9.2%). The average exophthalmometer reading was 17.2 ± 3.2 mm, with proptosis less pronounced with age (p < 0.001) and more pronounced in men than women (18.2 ± 3.4 mm vs. 17.0 ± 3.1 mm; p < 0.001). Lid retraction was present in 57.7% of patients, lid swelling in 46.9%, and muscle enlargement in 40.8% of patients. Multiple regression analysis revealed proptosis was strongly correlated with a young age and the male gender, followed by extraocular muscle enlargement and lid retraction and swelling (p < 0.001). Conclusions: This study assessed the measurable features of proptosis in Japanese patients with DO and contributes to the understanding by correlating symptoms and signs of DO.
 
Article
Test-retest reliability of the CSV-1000 (Vector Vision) has only been reported for one adult sample. We measured the reliability of this instrument in both children and adults and also investigated the effect of changing the examiner on test-retest reliability. Test-retest log contrast sensitivity (CS) measurements were obtained for 19 young adults and 15 children by the same examiner. Test-retest log CS data were obtained from 21 young adults with different examiners. Reliability was calculated using the Bland-Altman limits of agreement, the coefficient of repeatability (COR), and the intraclass correlation coefficient. All three estimates of reliability for the CSV-1000 chart are low for both children and adults using the standard recommended testing protocol. If the test-retest log CS data are obtained from the same examiner then the reliability is improved, but not significantly so. The reliability of the CSV-1000 is low, even if the same examiner obtains test-retest data. The data indicate that this test is unlikely to be sensitive enough to provide useful information for the clinician as is, but we suggest modifications of the procedure that may significantly increase test reliability.
 
Article
To demonstrate the ability of a new high-speed polarization-sensitive optical coherence tomography (PS-OCT) system for retinal imaging at 1040 nm. A new polarization-sensitive swept source OCT system in the 1 μm wavelength range is used to image the retina of healthy volunteers. The instrument is operated at an A-scan rate of 100 kHz which is about three times faster than previously reported PS-OCT instruments in this wavelength region. The increased imaging speed can be used to record densely sampled volumes of the retina. Moreover, it enables averaging of several B-scans recorded at the same location to obtain high-definition B-scans without the use of an eye tracker. Polarization-sensitive images of healthy volunteers clearly show the retinal pigment epithelium as a depolarizing layer. In addition, the good tissue penetration of the system allows the visualization of the sclera, which is highly birefringent and therefore shows increased image contrast with PS-OCT. PS-OCT in the 1 μm wavelength region shows similar polarization effects as in the 840 nm wavelength range. The high speed enables averaging of several B-scans to obtain high-definition polarization-sensitive images. The new system provides excellent penetration depth into the choroid and sclera.
 
Article
To observe and analyze corneal asphericity and its related factors in Chinese subjects. The corneal asphericity of 1052 right eyes from a Chinese population was determined using the Wavelight-ALLEGRO Topographer. The corneal asphericity coefficient Q describes the rate of curvature variation of the cornea from its center to the periphery and specifies the type of conicoid that best represents its shape. All cases were grouped by age in years (A: ≤ 9; B: 10 to 19; C: 20 to 29; D: 30 to 39; E: 40 to 49; F: ≥50), and 223 myopic cases were grouped by magnitude in spherical equivalent (SE) refractive error (low myopia, > -3.0 diopters (D); moderate myopia, -6.0 D < SE ≤ -3.0 D; high myopia, -8.0 D < SE ≤ -6.0 D; and super high myopia, SE ≤ -8.0 D). In addition, corneal asphericity was analyzed by corneal quadrant (nasal, temporal, superior, and inferior) and two meridians (vertical and horizontal). The mean Q value of 1052 right eyes was -0.30 ± 0.12. Although statistical differences were found between some age groups, no statistical correlation between Q values and age was found in this study (r = -0.58, p = 0.06). Q values of the nasal and superior corneal quadrant were significantly more oblate than that of the temporal and inferior quadrants, respectively (both p < 0.0001). A trend toward more oblate Q values was found as the level of myopia increased (r = 0.166, p = 0.013). There was a negative relationship between Q value and central corneal radius in this entire study population (r = -0.09, p = 0.004). Corneal asphericity in this population is related more to corneal quadrant location than to age. The results from this study suggest that degree of myopia and central corneal radius both have a significant though weak association with corneal asphericity in Chinese eyes.
 
Article
Thirty-two children who had been refracted in early infancy were re-refracted at the age of 7 to 8 years. Refraction comprised cycloplegic retinoscopy at the mean age of 11 weeks and noncycloplegic retinoscopy and subjective examination at the mean age of 94 months. The change in spherical equivalent refraction (SER) was highly negatively correlated with the initial refraction (-0.863), demonstrating emmetropization; however, the correlation between the refractive error at age 7 to 8 years and the refractive error in infancy was much weaker (+0.225). The SER was significantly less and the astigmatism was greater in infancy in children who were myopic at age 7 to 8 years. There was, however, extensive overlap in range between the SER for the two groups and the initial SER was not a good predictor of myopia at 7 to 8 years, although it may help to identify children who are unlikely to become myopic. One hyperopic child with bilateral ptosis failed to emmetropize.
 
Article
The 12th International Myopia Conference held in Queensland, Australia on July 8-11, 2008 included 11 separate symposia, each with 3-5 presentations. Here, in a single paper, the authors of those Symposia describe the scientific advances noted at the conference and include the full abstracts of the individual myopia papers presented in each symposium. The symposia included molecular studies in humans and animals; twin studies; prevalence, progression and risk factors; outdoor activity and near work; lens compensation and emmetropization; therapies for myopia based on optical strategies; accommodation and ocular aberrations as causative links; eye shape and peripheral refraction relation to myopia; sclera and its role in regulating myopia; signalling cascades in developing myopia; and animal models in understanding myopia.
 
Article
The aim of this article was to report the prevalence of refractive errors, mainly myopia, among 12- to 13-year-old children in a metropolitan setting in Mexico. A total of 1035 schoolchildren were examined in a field study in Monterrey, Mexico. The examination included best-corrected visual acuity and refraction during cycloplegia. A sample of the children was sent to a pediatric eye clinic and underwent cycloplegic refraction with an autorefractor. We found a prevalence of myopia (>/=-0.5 D SE) of 44%, whereas bilateral myopia was present in 37% of the children. In the total sample, high myopia (>/=-5D) was found in 1.4%. The prevalence of myopia was significantly higher in girls. Only 20% of children with bilateral myopia used prescription glasses; 8% had prescribed glasses, but did not use them. Hyperopia (>/=+1 D) was present in 6.0% of the total population, and astigmatism (>/=-1.5 D) was present in 9.5%. The prevalence of myopia among 12- to 13-year-old children in Mexico is high. The majority of cases are low grade, and a large number of the myopic children do not have, or do not use, prescription glasses.
 
Article
To evaluate factors that may affect mesopic pupil size in refractive surgery candidates. Medical records of 13,959 eyes of 13,959 refractive surgery candidates were reviewed, and one eye per subject was selected randomly for statistical analysis. Detailed ophthalmological examination data were obtained from medical records. Preoperative measurements included uncorrected distance visual acuity, corrected distance visual acuity, manifest and cycloplegic refraction, topography, slit lamp examination, and funduscopy. Mesopic pupil size measurements were performed with Colvard pupillometer. Relationship between mesopic pupil size and age, gender, refractive state, average keratometry, and pachymetry (thinnest point) were analyzed by means of ANOVA (+ANCOVA) and multivariate regression analyses. Overall mesopic pupil size was 6.45 ± 0.82 mm, and mean age was 36.07 years. Mesopic pupil size was 5.96 ± 0.8 mm in hyperopic astigmatism, 6.36 ± 0.83 mm in high astigmatism, and 6.51 ± 0.8 mm in myopic astigmatism. The difference in mesopic pupil size between all refractive subgroups was statistically significant (p < 0.001). Age revealed the strongest correlation (r = -0.405, p < 0.001) with mesopic pupil size. Spherical equivalent showed a moderate correlation (r = -0.136), whereas keratometry (r = -0.064) and pachymetry (r = -0.057) had a weak correlation with mesopic pupil size. No statistically significant difference in mesopic pupil size was noted regarding gender and ocular side. The sum of all analyzed factors (age, refractive state, keratometry, and pachymetry) can only predict the expected pupil size in <20% (R = 0.179, p < 0.001). Our analysis confirmed that age and refractive state are determinative factors on mesopic pupil size. Average keratometry and minimal pachymetry exhibited a statistically significant, but clinically insignificant, impact on mesopic pupil size.
 
Article
On July 26 to 29, 2010, the 13th International Myopia Conference was held in Tübingen, Germany, and featured 4 key note lectures, 17 targeted symposia, and 98 poster presentations. This article provides the full listing of keynote lectures, the 7 myopia topics, 17 symposia and abstract titles within these 7 topics, followed by the posters presented at the symposium. The on-line version of this article has direct links to 60 of the color posters.
 
Article
Previous studies have shown a relation between refractive status and tonic accommodation (TA), with corrected hyperopes displaying a significantly higher TA than corrected myopes. TA measurements in those studies were made on adult subjects, under laboratory conditions with an infrared or laser optometer. The study reported here used a different measurement method and younger subjects. The TA of 113 (19 hyperopic, 61 emmetropic, 33 myopic) children, ages 6 to 14 years, was measured by a clinical method described earlier. Analysis of variance indicated significant (p less than 0.25) between-group mean differences similar to the adult-subject data cited above. Clinical implications of the data and the measurement method are discussed.
 
Article
The purpose of this study was to document the adult age progression of myopia and the incidence of visual impairment in a representative sample of Danish adolescents with high myopia. This study consisted of a scheduled regular ophthalmic follow-up over 40 years of 39 otherwise unselected Copenhagen 14 year olds with uni- and bilateral myopia of at least -6 D, as screened from a 1948 birth-year school cohort comprising 9243 pupils. Thirty-six of the 39 had satisfactory refractive and corrected visual acuity data for a longitudinal analysis. Myopia progression for the full period ranged from 0 to 14 D, and the peak myopia value increased from -14 to -26 D. The mean progression from age 16 to 26 years was 2.09 D, and from age 26 and on it was 1 D. Using both eyes and relevant correction, at the preliminary end point of 54 years, 32 of the 36 had a corrected visual acuity (VA) of 0.5 or better. Four had a corrected VA of < or = 0.3, but the visual loss was partly explained by other eye pathology. Significant visual reduction in single eyes mainly affected the subgroup of eyes with unilateral high myopia (n = 9). With only a slight overrisk recorded as associated with high myopia (in three or four of 36 subjects), the adult visual prognosis for working age appeared better than usually claimed. There seems to be a correlation between degree of myopia at age 14 and consecutive visual loss, but it was not possible to identify subjects at high risk at that early age.
 
Article
To describe distributions of ocular biometry and their associations with refraction in 7- and 14-year-old children in urban areas of Anyang, central China. A total of 2271 grade 1 students aged 7.1 ± 0.4 years and 1786 grade 8 students aged 13.7 ± 0.5 years were measured with ocular biometry and cycloplegic refraction. A parental myopia questionnaire was administered to parents. Mean axial length, anterior chamber depth, lens thickness, central corneal thickness, corneal diameter, corneal radius of curvature, axial length/corneal radius of curvature ratio, and spherical equivalent refraction were 22.72 ± 0.76 mm, 2.89 ± 0.24 mm, 3.61 ± 0.19 mm, 540.5 ± 31 μm, 12.06 ± 0.44 mm, 7.80 ± 0.25 mm, 2.91 ± 0.08, and +0.95 ± 1.05 diopters (D), respectively, in 7-year-old children. They were 24.39 ± 1.13 mm, 3.42 ± 0.41 mm, 3.18 ± 0.24 mm, 548.9 ± 33 μm, 12.03 ± 0.43 mm, 7.80 ± 0.26 mm, 3.13 ± 0.14, and -2.06 ± 2.20 D, respectively, in 14-year-old children. Compared with 7-year-old children, the older group had significantly more myopia (-3.0 D), longer axial length (1.7 mm), deeper anterior chamber depth (0.3 mm), thinner lens thickness (-0.2 mm), thicker central corneal thickness (10 μm), and greater axial length/corneal radius of curvature ratio (0.22) (all p < 0.001), as well as smaller corneal diameter (-0.03 mm, p = 0.02) and similar corneal radius of curvature. Sex differences were similar in both age groups, with boys having longer axial length (0.5 mm), deeper anterior chamber depth (0.1 mm), shorter lens thickness (0.03 mm), greater central corneal thickness (5 μm), greater corneal diameter (0.15 mm), and greater corneal radius of curvature (0.14 mm) than girls (all p < 0.01). The most important variables related to spherical equivalent refraction were vitreous length, corneal radius of curvature, and lens thickness. The 14-year-old group had larger parameter dimensions than the 7-year-old group except for corneal radius of curvature (unchanged) and lens thickness and corneal diameter (both smaller). Boys had large parameter dimensions than girls except for lens thickness (smaller). Axial length, corneal radius of curvature, and lens thickness were the most important determinants of refraction.
 
Article
The fitting characteristics of 1-day Acuvue disposable soft contact lenses (SCLs) [base curve (BC) 9.0 mm, diameter 14.2 mm] and 14-day Acuvue disposable SCLa (BC 8.8 mm, diameter 14.0 mm) were evaluated and compared with respect to lens centration and post-blink movement in primary gaze and in upgaze. In this double-blind study 25 successful daily wearers of either the 1-day lens or the 14-day lens with the same parameters were randomly fit with three 1-day lenses and three 14-day lenses for a total of 6 lenses per eye. The lene fit was evaluated 5 min after insertion. Lens centration was assessed by measuring temporal, nasal, superior and inferior limbal coverage, and then comparing the net horizontal centration (temporal minus nasal coverage) and the net vertical centration (superior minus inferior coverage) of the 1-day and 14-day lenses. There was no significant difference between the two lenses in terms of temporal, superior, and inferior limbal coverage (p > 0.05). However, the 1-day lens showed statistically more nasal coverage (p < 0.05). No statistically significant difference in movement or in horizontal and vertical differences in centration were found (p > 0.05). Although our findings indicate a subtle statistical difference in fitting characteristics, clinically the two lenses should provide similar fits.
 
Article
Leber hereditary optic neuropathy (LHON) is characterized by an acute, painless, sequentially bilateral reduction in vision that usually occurs in young men. It is a maternally inherited mitochondrial genetic disease. This case report details the chronology of the bilateral vision loss of a patient found to have LHON with a mutation at nucleotide site 14484. A spontaneous recovery of visual acuity and decrease in disability occurred without a corresponding improvement in color vision, contrast sensitivity, or pattern visual evoked potential (VEP's) over a period of 6 years. The abnormal pattern VEP's were one of the indicators of the neural damage to the spatial frequency channels of the visual system. The normal flash VEP's, as determined by the critical frequency of photic driving (CFPD), suggested that most of the fibers in the luminance channels were unaffected by LHON.
 
Article
The purpose of this study is to determine the ability of single-value metrics of retinal image quality of the eye to predict visual performance as measured by high (HC) and low (LC) -contrast acuity at photopic (P) and mesopic (M) light levels in eyes with 20/17 and better visual acuity. Forty-nine normal subjects in good health ranging in age from 21.8 to 62.6 with 20/17 or better monocular high-contrast logarithm of the minimum angle of resolution (logMAR) acuity served as subjects. Wavefront error through the 10th Zernike radial order over a 7-mm pupil was measured on each test eye using a custom-built Shack/Hartmann wavefront sensor. For each eye, 31 different single-value retinal image quality metrics were calculated. Visual acuity was measured using HC (95%) and LC (11%) logMAR at photopic (270 cd/m) and mesopic (0.75 cd/m) light levels. To determine the ability of each metric of retinal image quality to predict each type of logMAR acuity (P HC, P LC, M HC, and M LC), each acuity measure was regressed against each optical quality metric. The ability of the metrics of retinal image quality to predict logMAR acuity improved as luminance and/or contrast is lowered. The best retinal image quality metric (logPFSc) accounted for 2.6%, 15.1%, 27.6%, and 40.0% of the variance in P HC, P LC, M HC, and M LC logMAR acuity, respectively. In eyes with 20/17 and better P HC acuity, P HC logMAR acuity is insensitive to variations in retinal image quality compared with M LC logMAR acuity. Retinal image quality becomes increasingly predictive of logMAR acuity as contrast and/or luminance is decreased. Everyday life requires individuals to function over a large range of contrast and luminance levels. Clinically, the impact of retinal image quality as a function of luminance and contrast is readily measurable in a time-efficient manner with M LC logMAR acuity charts.
 
Article
The purpose of this study was to evaluate the longitudinal changes in ocular physiology, tear film characteristics, and symptomatology experienced by neophyte silicone hydrogel (SiH) contact lens wearers in a daily-wear compared with a continuous-wear modality and with the different commercially available lenses over an 18-month period. Forty-five neophyte subjects were enrolled in the study and randomly assigned to wear one of two SiH materials: lotrafilcon A or balafilcon A lenses on either a daily- (LDW; BDW) or continuous-wear (LCW; BCW) basis. Additionally, a group of noncontact lens-wearing subjects (control group) was also recruited and followed over the same study period. Objective and subjective grading of ocular physiology were carried out together with tear meniscus height (TMH) and noninvasive tear breakup time (NITBUT). Subjects also subjectively rated symptoms and judgments with lens wear. After initial screening, subsequent measurements were taken after 1, 3, 6, 12, and 18 months. Subjective and objective grading of ocular physiology revealed a small increase in bulbar, limbal, and palpebral hyperemia as well as corneal staining over time with both lens materials and regimes of wear (p < 0.05). No significant changes in NITBUT or TMH were found (p > 0.05). Subjective symptoms and judgment were not material- or modality-specific. Daily and continuous wear of SiH contact lenses induced small but statistically significant changes in ocular physiology and symptomatology. Clinical measures of tear film characteristics were unaffected by lens wear. Both materials and regimes of wear showed similar clinical performance. Long-term SiH contact lens wear is shown to be a successful option for patients.
 
Article
To assess the validity and reliability of the Convergence Insufficiency Symptom Survey (CISS) in children aged 9 to 18 years. The CISS is the primary outcome measure for a pilot study evaluating two different treatments for convergence insufficiency (CI). Children with CI were given the CISS twice to assess reliability. CISS scores for the first administration were also compared with scores from children with normal binocular vision to assess the validity of the CISS. Forty-seven children with CI and 56 children with normal binocular vision participated in the study. Reliability was assessed using intraclass correlation and 95% limits of agreement for the children with CI. For children with CI, the intraclass correlation was 0.77 (95% confidence interval, 0.613 to 0.873), and the 95% limits of agreement were -10.2 to +12.1. The mean (+/-SD) CISS score was 30.8 +/- 8.4 for the children with CI and 8.4 +/- 6.4 for the children with normal binocular vision. These means were significantly different (p < 0.0001). Good discrimination (sensitivity, 96%; specificity, 88%) was obtained using a score of >/=16. Children with CI showed a significantly higher CISS symptom score than children with normal binocular vision. The results of the study indicate that the CISS is a valid and reliable instrument to use as an outcome measure for children aged 9 to 18 who are enrolled in clinical research concerning CI.
 
Article
Forced choice operant preferential looking (OPL) was used to evaluate stereopsis in children between 18 and 35 months of age. Eighty-three children who passed a vision screening were tested with a ring-shaped random dot target that stood out in depth. Food was used to reinforce looking at the target. Children were also administered the Random Dot E (RDE) as a comparison measure. Four children were unable to complete testing with OPL compared with 31 who were unable to complete testing with the RDE. This difference was most apparent in children under 24 months of age. This new procedure appears to be a useful technique to evaluate stereopsis in very young children.
 
Article
For over 50 years, graduate programs in physiological optics (vision science) have been the primary source of supply to schools and colleges of optometry of Master of Science and Doctor of Philosophy degree recipients who teach and conduct research. To determine the supply of M.S. and Ph.D. degree recipients from 1938 through 1989 and the career pursuits of these recipients, a computerized data base was developed. A total of 456 degrees were awarded (287 M.S. and 169 Ph.D.). Among the M.S. recipients, 56 also completed a Ph.D. Although there was a steady increase in the number of degree recipients, the number who pursued optometric education as a career steadily declined, especially among those who received only a M.S. degree. Further analysis suggests that a loss of optometry faculty with graduate degrees, in particular those with Ph.D.'s, due to attrition will likely occur during this decade and become substantial during the first decade of the next century. Clearly, efforts need to be increased by schools and colleges of optometry in the very near future to foster graduate level study of physiological optics, and to encourage the pursuit of optometric education as a career.
 
Article
In 1971, Rempt et al. reported peripheral refraction patterns (skiagrams) along the horizontal visual field in 442 people. Later in the same year, Hoogerheide et al. used skiagrams in combination with medical records to relate skiagrams in emmetropes and hyperopes to progression of myopia in young adults. The two articles have spurred interest in peripheral refraction in the past decade. We challenge the understanding that their articles provide evidence that the peripheral refraction pattern along the horizontal visual field is predictive of whether or not a person develops myopia. First, although it has been generally assumed that the skiagrams were measured before the changes in refraction were monitored, Hoogerheide et al. did not state that this was the case. Second, if the skiagrams were obtained at an initial examination and given the likely rates of recruitment and successful completion of training, the study must have taken place during a period of 10 to 15 years; it is much more likely that Hoogerheide et al. measured the skiagrams in a shorter period. Third, despite there being many more emmetropes and hyperopes in the Rempt et al. article than there are in the Hoogerheide et al. article, the number of people in two types of "at risk" skiagrams is greater in the latter; this is consistent with the central refraction status being reported from an earlier time by Hoogerheide et al. than by Rempt et al. In summary, we believe that the skiagrams reported by Hoogerheide et al. were taken at a later examination, after myopia did or did not occur, and that the refraction data from the initial examination were retrieved from the medical archives. Thus, this work does not provide evidence that peripheral refraction pattern is indicative of the likely development of myopia.
 
Article
Section 504 of the Rehabilitation Act of 1973 is an antidiscrimination law that covers those persons with handicaps who are otherwise qualified to participate in and benefit from the programs or activities receiving Federal financial assistance. This article discusses the qualified handicapped applicant, especially individuals who have been identified as learning disabled, who meets the academic and technical standards requisite to admission to a school or college of optometry. The learning characteristics and handicaps that have been associated with this disability are discussed. The "reasonable accommodations" that educational institutions are expected (and not expected) to provide students are explained. Results of a survey of 15 colleges of optometry revealed that there are numerous inconsistencies in compliance with Section 504 involving reasonable accommodations in the classroom, clinic, and testing procedures involving learning disabled professional students. Recommendations to improve required services are proposed.
 
Article
The nation's first one-year, Council on Optometric Education accredited hospital-based optometry residency program began at the Kansas City Veterans Affairs Medical Center in 1975. As part of the 25th anniversary review, past residents were surveyed to determine whether the residency had met their goals and influenced their postresidency activities. This is the first in-depth study of a single residency program. A 34-question survey was developed based on one previously used in a 1987 national study of Veterans Affairs residents. The survey was designed to provide data comparable to that found in other residency surveys. Forty-eight of 50 former residents responded, and at least one survey was returned for every year from 1975 through 2000. One hundred percent of residents noted that the program met or exceeded expectations in patient diversity, workload, and level of responsibility. Additionally, almost 30% of residents currently or previously held Veterans Affairs staff positions, and they have collectively published 316 papers, 33 textbook chapters, and five textbooks. CONCLUSIONS Judged by these responses, the Kansas City Veterans Affairs Medical Center Optometry Residency Program offers an exceptional clinical training program that surpasses resident expectations. Finally, former graduates of the program have made a significant contribution to patient care and to the optometric profession as demonstrated by their clinical, academic, and research accomplishments.
 
Article
Contact lens materials over the last 20 years have progressed from polymethyl methacrylate (PMMA) through hydrogels to high Dk rigid and semi-soft lenses. Our understanding of how and why contact lenses affect the eye has also advanced considerably. We now know that: (1) the oxygen demands of the eye are high and (2) carbon dioxide accumulates and corneal acidosis occurs with most current contact lenses, especially with extended wear (EW). The effects of these perturbations on the epithelium include decreased metabolic rate, thinning, microcysts, and reduced adhesion. In addition, stromal edema and thinning and, with pressure, distortion occur with the long-term use of low to moderate oxygen transmissible lenses. Endothelial polymegethism also occurs and is a relatively permanent effect of inadequate oxygen permeability (Dk). The major consequence of chronic hypoxia and acidosis is, for a significant number of patients, corneal intolerance and discontinuation of lens wear. High permeability materials (100 Dk) that provide adequate gaseous exchange for daily wear and minimal changes in EW are now available and should be used where possible. The more obvious problems of contact lens-induced chronic inflammation, e.g., contact lens-induced papillary conjunctivitis (CLPC), and acute inflammation, e.g., acute red eye (ARE), are less well understood. Protein deposits, lens ageing, occlusion, mechanical effects, and bacterial contamination have all been implicated. The remaining frontiers include understanding and avoiding the stimuli to low grade irritation and inflammation by making contact lenses more comfortable and improving their compatibility with the ocular surfaces.
 
Article
This study assessed the impact of vision-related relicensing policies on traffic fatalities in the United States. There is a limited empirical basis for state vision testing policies for relicensing. Furthermore, it is uncertain whether contemporary vision standards for driver licensing achieve their implicit goal of protecting the public's health, or inappropriately restrict the mobility of competent drivers. The 48 contiguous states and the District of Columbia were the "subjects" in this investigation. During the study period (1989 to 1991), 10 states did not require vision testing for driver license renewal. Multiple regression modeling was used to assess the impact of vision-related relicensing policies on traffic safety and to estimate the number of avoidable vehicle occupant fatalities and corresponding economic costs associated with traffic crashes involving older drivers (> or = 60 years). The primary data source for this investigation was the Fatal Accident Reporting System (FARS) database. Vision-related relicensing policies were significantly associated (p < 0.05) with lower vehicle occupant fatality rates of older drivers. According to the final regression model, approximately 222 fewer vehicle occupant fatalities (-12.2%) associated with older drivers would be expected for the 3-year period if mandatory vision testing policies had been in effect in 8 of the 10 states without such policies. Conservatively, those avoidable deaths represent an estimated $31 million in avoidable economic costs. State-level mandatory vision testing for relicensure may enhance traffic safety and reduce the economic burden of fatal crashes. Vision testing requirements should be maintained by jurisdictions with such requirements, and jurisdictions without such requirements should consider the potential traffic safety benefits of vision testing for driver license renewal.
 
Article
Pupil centration is important to the optical blur on the retina. Using a dual Maxwellian view system we measured the centration of the pupil with respect to the achromatic axis of the eye as a function of pupil size. Significant shifts of the pupil center (up to 0.6 mm) with pupil dilation were measured in both nasal and temporal directions. The effect was usually symmetrical between the two eyes and the shift was linear with pupil size in one-half of the subjects. From their initial positions the linear pupil center shifts with dilation were in the direction of the achromatic axis.
 
Article
Classical color vision theory incorporates the concepts of hard-wired parallel independent processing and of hard-wired opponent-processing. These two powerful concepts can be applied more generally in visual psychophysics. The concept of parallel independent processing can help to understand two extremes of visual performance: disordered vision in patients and the extraordinary visual abilities of athletes and aviators. Three illustrations of this thesis are discussed. First, evidence for dissociations of spatial vision for low-contrast and high-contrast objects. Second, evidence that a binocular system for motion in depth runs in parallel with the classical disparity-driven binocular system for relative position in depth. Third, evidence that a visual system for motion-defined form parallels the well known system for contrast-defined form. However, in principle these two concepts have limited value because they do not incorporate the possibility that the functional organization of the visual pathway could be modified by descending task-dependent signals.
 
Article
The profession of optometry has been very successful in providing optical corrections for spherocylindrical refractive errors. In this paper, I examine one attempt to improve retinal image quality beyond that afforded by a standard refractive correction. Ocular chromatic aberration is one of the factors that prevent retinal image quality from reaching the upper limit set by the wave nature of light. It can be subdivided into three primary aberrations (wavelength-dependent differences in imaging plane, image position, and image size). We have been able to measure all three of these using psychophysical techniques. Although attempts to provide an optical correction for wavelength-dependent refractive errors have been optically successful, they have failed to improve vision. Several possible explanations are given for this failure.
 
Article
In this report I summarize recently reported studies which establish the existence of a previously undocumented diffusional pathway for plasma-derived proteins from the ciliary body stroma to the anterior chamber of the normal mammalian eye via the iris root. The data support the hypothesis that nearly all of the plasma-derived protein present in the aqueous humor of the anterior chamber arrives via this pathway, thus by-passing the posterior chamber. Additional studies suggest that some of the protein transported via the pathway is shunted directly into the trabecular meshwork and aqueous outflow pathways. Perfusion studies show how the perfused eyes were later immunohistochemically stained to reveal the distribution and qualitative amounts of serum albumin. These studies strongly suggest that the well-known "wash-out" effect, encountered in experimental studies of aqueous outflow, arises predominantly from wash-out of the protein depot that serves as the anterior diffusional pathway for proteins. Taken as a whole, these studies support the hypothesis that protein is a physiologically relevant and important element in the generation of normal aqueous outflow resistance, possibly more important than glycosaminoglycans (GAG's).
 
Article
The discovery that sunlight is the primary causal factor in a family of serious eye diseases is doubly significant because it offers a simple, safe, and inexpensive means of preventing all of them simultaneously. The need for prevention is underscored by the terrible expense of sunlight-related eye diseases--$50 billion for cataract surgery in the U.S. during the past decade, plus the added cost to society of visual impairment and blindness. There is widespread scientific agreement that the use of eyewear with lenses that preferentially absorb the high-energy components of the solar spectrum, including 100% of UV radiation, will substantially reduce the risk of all sunlight-related eye diseases without interfering with visual function. A program to preserve visual health by such means can be based primarily on public education. Because the method of preventing these diseases is the use of appropriate eyewear, this unprecedented opportunity falls within the field of expertise of optometry.
 
Article
The Orinda Longitudinal Study of Myopia is a 12-year project examining predictive factors for the onset of myopia, the underlying etiologies of myopia, and normal eye growth in school children. This paper reports on all measurements made of the ocular components (cycloplegic refractive error, corneal curvature, crystalline lens power, and axial ocular dimensions), parental history of myopia, and near work activity in children participating in the Orinda Longitudinal Study of Myopia between 1989 and 1993. An analysis of the interaction between parental history of myopia and children's near work is conducted on the cross-sectional study data from 1993. The cross-sectional and longitudinal data show a gradual decrease in refractive error from low hyperopia toward emmetropia, no shift in corneal curvature, a gradual decrease in crystalline lens power, thinning of the crystalline lens, and elongation of the eye between the ages of 6 and 14 years. Parental history is more contributory to a statistical model predicting myopia than is near work, but near work is a significant factor as well. We can find no evidence of statistical interaction between parental history and near work in explaining the presence or absence of myopia. The emmetropization process is evident in the gradual decrease in refractive error toward emmetropia, the axial elongation of the eye, and the compensating decrease in crystalline lens power. Both nature and nurture play a role in the etiology of myopia, although the predominant role appears to belong to a positive parental history of myopia. This role does not appear to be through an interaction between parental myopia status and children's near work activity.
 
Article
In order to understand and update the prevalence of myopia in Taiwan, a nationwide survey was performed in 1995. We stratified the cluster sampling by developmental grading of the city, using a size proportional to the population. Two cities were randomly selected from each city grading. The total number of students enrolled was 11,178, including 5,676 boys and 5,502 girls. The refractive status and corneal radius of each student were measured with an autorefractometer under cycloplegia and checked with retinoscopy. Axial length was measured with biometric ultrasound. The myopic rate was from 12% at the age of 6, it increased to 56% at the age of 12, and then to 76% at the age of 15. A myopic rate of 84% was found for the age range of 16 to 18. The prevalence of high myopia (over -6.0 D) at the age of 18 was 20% in girls and 12% in boys. The mean refractive status became myopic at the age of 9, then increased to -3.92 D in girls and -2.71 D in boys at the age of 18. The increase of axial length is correspondent with the progression of myopia. The anterior chamber depth (ACD) was deeper with age and the severity of myopia, whereas the corneal curvature remained unchanged. The lens thickness became thinner from age 7 to 13, then it became thicker with age and the severity of myopia after age 15. The prevalence and degree of myopia in girls was more severe than in boys. The prevalence of myopia in Taiwan increased year by year. The increase in severity and prevalence of high myopia may be due to earlier onset.
 
Top-cited authors
Lyndon W Jones
  • University of Waterloo
Brien A. Holden
  • Brien Holden Vision Institute
Mark Willcox
  • UNSW Sydney
Gladys Mitchell
  • The Ohio State University
Lisa A Jordan
  • The Ohio State University