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PubMed2006

Correlation between hemifield visual field damage and corresponding parapapillary atrophy in normal-tension glaucoma.

PURPOSE: To evaluate the correlation between the superior or inferior half area of parapapillary atrophy (PPA) and the corresponding hemifield visual field damage (VFD) in normal-tension glaucoma. DESIGN: Cross-sectional study. METHODS: patients: One hundred nine eyes of 109 consecutive patients with normal-tension glaucoma. observation procedures: Topography parameters of the optic nerve head and PPA (zone beta) area were obtained with the Heidelberg Retina Tomograph (HRT), and VFD was evaluated with the 30 to 2 program of Humphrey Field Analyzer. The HRT parameters and PPA area were determined separately in superior and inferior half regions. main outcome measures: Partial correlation coefficients of the superior and inferior areas of PPA with refractive error, axial length, HRT parameters, and corresponding hemifield VFD. RESULTS: In simple correlation analyses, significant correlation was found between the inferior PPA area and the superior hemifield VFD (Spearman rank correlation coefficient; Rs = -0.32; P < .001) but not between the superior PPA area and the inferior hemifield VFD (Rs = 0.05; P = .6). Age, refractive error, axial length, and height variation contour were associated significantly with the total, superior, and inferior areas of PPA, respectively (P < .01). Multiple regression analyses showed that the superior PPA area was associated significantly with only axial length (P < .001), and the inferior PPA area was associated significantly with the axial length and the superior hemifield VFD (P < .001). CONCLUSIONS: In patients with normal-tension glaucoma, only the inferior half area of PPA correlated significantly with glaucomatous VFD. Axial length and myopia were associated with both the superior and inferior half areas of PPA.

Cross-Sectional Studies↗
PubMed2002

The Sivaganga eye survey: I. Blindness and cataract surgery.

PURPOSE: To assess the prevalence of visual acuity impairment, blindness, and cataract surgery among older adults in rural southern India. METHODS: Random selection of village- and urban-based clusters was used to identify a cross-sectional sample of persons 50 years of age or older from the Sivaganga district of Tamil Nadu. Subjects in 25 selected clusters were enumerated through a door-to-door survey and invited to examination sites for measurement of uncorrected, presenting, and best-corrected visual acuity and ocular examination in 1999. The principal cause was identified for eyes with presenting visual acuity worse than 6/18. Quality assurance monitoring of visual acuity measurements took place in five of the study clusters. RESULTS: A total of 5081 persons in 3517 households were enumerated, and 4642 (91.4%) were examined. Thirty-six percent presented with visual acuity worse than 6/18 in the better eye. The prevalence of blindness, based on visual acuity worse than 6/60 in both eyes, was 6.0% (95% confidence interval [CI]: 5.1% to 6.9%) with presenting vision, and 2.5% (95% CI: 1.8% to 3.1%) with best correction. Blindness with presenting visual acuity was associated with older age and illiteracy. Cataract was the principal cause of blindness in one or both eyes in 69.4% of those presenting blind, and uncorrected aphakia and other refractive error affected 35.6% in at least one eye. The prevalence of cataract surgery was 14.7% (95% CI: 13.0% to 16.4%); low surgical coverage among the cataract blind was associated with illiteracy. CONCLUSIONS: It appears that much has been done in the prevention of blindness in Sivaganga. Nevertheless, blindness remains an important public health problem, mainly because of cataract and refractive error. Prevention of blindness programs in the area should target these two causes, with special emphasis on the elderly and the illiterate.

Age Distribution↗
PubMed1997

Significance of refractive status in branch retinal vein occlusion. A case-control study.

PURPOSE: To evaluate the significance of refractive error in cases of branch retinal vein occlusion. METHODS: Of 354 patients with branch retinal vein occlusion who attended our clinic between 1989 and 1995, 75 patients with unilateral branch retinal vein occlusion were compared with an equal number of matched controls with similar inclusion and exclusion criteria. The spherical equivalents of the refractive errors of patients in both groups were compared using the chi-square test, student's t test, and multivariate logistic regression. RESULTS: Hypermetropia was present in 53 patients with branch retinal vein occlusion (70.7%) and in 33 control patients (44.0%; P = 0.0001). Myopia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 30 controls (40.0%; P = 0.0005). Emmetropia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 12 controls (16.0%; P = 0.820). The odds ratio of developing branch retinal vein occlusion among patients with hypermetropia was 3.42 (95% Confidence Interval [CI], 1.62-7.2; P = 0.001) when compared with patients with no hypermetropia and 5.3 (95% CI, 2.1-13.3; P = 0.0003) when compared with patients with myopia alone. CONCLUSION: Hypermetropia is significantly more common in patients with branch retinal vein occlusion than in the general population, whereas myopia is significantly less common in these patients.

Aged↗
PubMed1975

The depth-of-focus of the human eye for Snellen letters.

Snellen acuity is determined as a function of refractive error for two subjects under cyploplegia, using randomised test charts, constant test chart luminance and a series of artificial pupils. These results allow determination of the depth-of-focus of the eye for Snellen targets, and it is shown that both optical and retinal factors influence the depth-of-focus achieved. Depth-of-focus is found to increase with decreasing pupil diameter and visual acuity. The clinical significance of these results, particularly with respect to the precision with which refractive error may be determined, is discussed.

Accommodation, Ocular↗
PubMed1999

Photorefractive keratectomy for hyperopia: long-term nonlinear and vector analysis of refractive outcome.

PURPOSE: To characterize the refractive changes after excimer laser photorefractive keratectomy for the correction of hyperopia over a follow-up up to 3 years and to assess refractive stability and changes in astigmatism. DESIGN: Noncomparative, nonrandomized, retrospective, interventional case series. PARTICIPANTS: Thirty-eight hyperopic eyes of 28 patients (age range, 33-62 years) with refraction in the range +1.00 to +8.00 diopters (D). Mean attempted correction was +3.33+/-0.98 D (range, +1.00 to +4.00 D). Data were compared to those from 216 eyes treated for myopia in the range -1.00 to -12.70 D. INTERVENTION: The hyperopic correction was made using an erodible mask inserted in the laser optical pathway to produce a circular ablation measuring 6.5 mm in diameter. An axicon was then used to create a blend transition zone from 6.5 mm up to 9.4 mm in diameter. Eyes were evaluated 3 to 11 times (5.5+/-2.4) over a 3- to 34-month follow-up (16.8+/-8.4 months). MAIN OUTCOME MEASURES: Vector analysis of refractive error, applying a nonlinear statistical model fitting the spherical equivalent, and the sphere component data. The fit parameters were the long-term error at stabilization (epsilon(infinity)), the amount of regression (epsilon0), being the difference of refractive errors immediately after surgery and at stabilization, and the time constant (T1/2) giving the temporal scale length by which the overcorrection halves (regression half-life). Cylinder was analyzed by a linear regression. RESULTS: The initial overcorrection was much larger after hyperopic treatments than myopic ones (epsilon0 = -3.26+/-0.35 D vs. +1.43+/-0.35 D), and it takes typically four times longer to regress (T1/2 = 3.30+/-0.91 months). Refractive stabilization is reached after more than 1 year, with a satisfactory refractive result. The hyperopic treatment induces a mean astigmatism of 1.00 D, which remains constant throughout the follow-up, and tends to be aligned along the with-the-rule meridian. CONCLUSIONS: The advantages of a reasonably well-designed algorithm to correct hyperopia (epsilon(infinity) = +0.20+/-0.23 D) are counterbalanced by the long time to refractive stabilization and by the induced astigmatism.

Adult↗
PubMed1999

Evaluation of relationships among refractive and topographic parameters.

PURPOSE: To examine the relationships among several refractive and topographic parameters. SETTING: Cullen Eye Institute Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA. METHODS: Using computerized videokeratography (EyeSys Corneal Analysis System), 287 corneas of 150 patients were retrospectively analyzed. The Holladay Diagnostic Summary (HDS) refractive maps were used to evaluate relationships among variables of the HDS and refractive error. RESULTS: Myopic spherical equivalent refraction (P = .0003) and more negative asphericity (Q-values) (P = .0119) were correlated with steeper corneas. The Q-values were less negative in eyes with moderate myopia (2.0 to 6.0 diopters [D]) than in those with hyperopia (1.0 D or greater). The Q-values below -0.3 were correlated with less favorable values for predicted corneal acuity and corneal uniformity index values. Mean corneal curvature measurements obtained by computerized videokeratography and standard keratometry showed a strong degree of correlation (P = .0001). CONCLUSION: As the degree of myopia and negative asphericity increased, the corneal radius of curvature decreased. Corneal Q-values less than -0.3 were associated with reduced optical performance of the cornea.

Adolescent↗
PubMed1984

Overcorrection as a means of slowing myopic progression.

Thirty-six subjects (18 males and 18 females) ranging in ages from 7.38 to 15.82 years received an overcorrection of 0.75 D over the power required to correct their myopia exactly. These 36 experimental subjects were matched by control subjects selected at random from the files of the Indiana University Optometry Clinics. The criteria used in matching were sex, beginning age, beginning refractive error, and duration of time covered by the record. The mean rate of change of refractive error for the experimental group was (minus indicating increase of myopia) -0.49 D/year (range, +0.37 to -1.95 D/year) on retinoscopy and -0.52 D/year (range, +0.21 to -1.32 D/year) on subjective refraction. The mean rate of change for the control group was -0.47 D/year (range, +0.06 to -2.03 D/year) on retinoscopy and -0.47 D/year (range, +0.28 to -1.72 D/year) on subjective refraction. Rates for the experimental and control groups were not significantly different. The results of this study do not support the hypothesis that an overcorrected myope has a lower rate of increase of myopia than a myope wearing a conventional spectacle correction.

Adolescent↗
PubMed2003

[Study of refractive changes inTimiş.county].

The aim of the study was to assess the prevalence of common refractive errors în children investigated at the "Louis Turcanu" Hospital's Ambulatory from Timisoara. This was a cross-sectional study done from January to June 2002 în the Ophthalmologic Medical Office. The target group was those of children from Timis County. We examined 646 children with a mean age of 10.7 years (from 0 to 18 years). A cycloplegic refraction examination was performed on all the children, using a computerized Humphrey-Zeiss autorefractometer. The statistical analysis was performed using CDC's Epi Info 2002. în the analysis, we used the Odds Ratio, the exact Fisher test and the chi-squared test. Among the 646 children, 407--63% (CI95 = 59.1-66.7) had refraction errors, of which 1.5% (CI95 = 0.8-2.9) were myopic whereas 49.8% (CI95 = 45.9-53.8) were hyperopic. Astigmatism was found în 11.8% (CI95 = 9.4-14.6). The study showed higher prevalence for the 14-16 age, emphasizing the importance of these examinations.

Adolescent↗
PubMed2002

A population based eye survey of older adults in Tirunelveli district of south India: blindness, cataract surgery, and visual outcomes.

AIMS: To assess the prevalence of vision impairment, blindness, and cataract surgery and to evaluate visual acuity outcomes after cataract surgery in a south Indian population. METHODS: Cluster sampling was used to randomly select a cross sectional sample of people > or =50 years of age living in the Tirunelveli district of south India. Eligible subjects in 28 clusters were enumerated through a door to door household survey. Visual acuity measurements and ocular examinations were performed at a selected site within each of the clusters in early 2000. The principal cause of visual impairment was identified for eyes with presenting visual acuity <6/18. Independent replicate testing for quality assurance monitoring was performed in subjects with reduced vision and in a sample of those with normal vision for six of the study clusters. RESULTS: A total of 5795 people in 3986 households were enumerated and 5411 (93.37%) were examined. The prevalence of presenting and best corrected visual acuity > or =6/18 in both eyes was 59.4% and 75.7%, respectively. Presenting vision <6/60 in both eyes (the definition of blindness in India) was found in 11.0%, and in 4.6% with best correction. Presenting blindness was associated with older age, female sex, and illiteracy. Cataract was the principal cause of blindness in at least one eye in 70.6% of blind people. The prevalence of cataract surgery was 11.8%-with an estimated 56.5% of the cataract blind already operated on. Surgical coverage was inversely associated with illiteracy and with female sex in rural areas. Within the cataract operated sample, 31.7% had presenting visual acuity > or =6/18 in both eyes and 11.8% were <6/60; 40% were bilaterally operated on, with 63% pseudophakic. Presenting vision was <6/60 in 40.7% of aphakic eyes and in 5.1% of pseudophakic eyes; with best correction the percentages were 17.6% and 3.7%, respectively. Refractive error, including uncorrected aphakia, was the main cause of visual impairment in cataract operated eyes. Vision <6/18 was associated with cataract surgery in government, as opposed to that in non-governmental/private facilities. Age, sex, literacy, and area of residence were not predictors of visual outcomes. CONCLUSION: Treatable blindness, particularly that associated with cataract and refractive error, remains a significant problem among older adults in south Indian populations, especially in females, the illiterate, and those living in rural areas. Further study is needed to better understand why a significant proportion of the cataract blind are not taking advantage of free of charge eye care services offered by the Aravind Eye Hospital and others in the district. While continuing to increase cataract surgical volume to reduce blindness, emphasis must also be placed on improving postoperative visual acuity outcomes.

Age Distribution↗
PubMed2003

Comparison of the Retinomax autorefractor with hand-held retinoscopy in 1-year-old infants.

This study aimed to determine the accuracy (and usability) of the Retinomax, a hand-held autorefractor, compared to measurements taken from hand-held retinoscopy (HHR) in a sample of normal 1-year-old children. The study was a method comparison set at four Community Child Health Clinics. Infants (n = 2079) of approximately 1 year of age were identified from birth/immunization records and their caregivers were contacted by mail. A total of 327 infants ranging in age from 46 weeks to 81 weeks (mean 61 weeks) participated in the study. The children underwent a full ophthalmic examination. Under cycloplegia, refraction was measured in each eye by streak retinoscopy (HHR) and then re-measured using the Retinomax autorefractor. Sphere, cylinder, axis of cylinder and spherical equivalent measurements were recorded for HHR and Retinomax instruments, and compared. Across the range of refractive errors measured, there was generally close agreement between the two examination methods, although the Retinomax consistently read around 0.3 D less hyperopic than HHR. Significantly more girls (72 infants, 47.7%), struggled during examination with the Retinomax than boys (52 infants, 29.5%) (P < 0.001). Agreement deteriorated between the two instruments if the patient struggled during the examination (P < 0.001). In general, the Retinomax would appear to be a useful screening instrument in early childhood. However, patient cooperation affects the accuracy of results and is an important consideration in determining whether this screening instrument should be adopted for measuring refractive errors in early infancy.

Female↗
PubMed2005

Vision loss in Australia.

OBJECTIVE: To assess the prevalence and causes of vision loss in Australia and to project these data into the future. DESIGN: Synthesis of data from two cross-sectional population-based cohort studies--the Melbourne Visual Impairment Project and the Blue Mountains Eye Study--and extrapolation to the entire Australian population. SETTING AND PARTICIPANTS: 8376 community and 533 nursing home residents recruited between 1992 and 1996 in urban and rural Victoria and New South Wales. MAIN OUTCOME MEASURES: Age-standardised prevalence of low vision (visual acuity < 6/12) and blindness (visual acuity < 6/60) (both measured in the best eye, with spectacles if usually worn for distance vision), and their causes for the Australian population for 2000 to 2024, projected from Australian Bureau of Statistics population data. RESULTS: In 2004, 480,300 Australians were estimated to have low vision, including 50,600 with blindness. The most common causes of low vision were undercorrected refractive error (62%), cataract (14%) and age-related macular degeneration (10%). The latter was responsible for almost half of all cases of blindness. The numbers of people with low vision and blindness are projected to almost double by 2024. CONCLUSIONS: Vision loss in Australia is a much bigger problem than is usually recognised; 76% of low vision is caused by uncorrected refractive error or cataract, both readily treatable. However, the prevention and treatment of macular degeneration poses a major challenge.

Adult↗
PubMedDate not supplied

Amblyopia detection by camera: Gateway to portable, inexpensive vision screening (calibration and validation of inexpensive, pocket-sized photoscreeners).

BACKGROUND: Photoscreening can allow early detection of amblyopia. The Gateway DV-S20, and similar models of miniature, digital flash cameras, have similar optical dimensions to existing photoscreeners for less than $200. METHODS: These cameras were calibrated on known, threshold amblyogenic refractive errors induced by placing minus and toric contact lenses on a normal subject's left eye. The DV-S20 was then applied to known amblyopic patients. Students under age 7 were vision screened with patched acuity and sequential photoscreeners (MTI and Gateway). RESULTS: The digital cameras and the MTI photoscreeners produced similar magnitude interpretable crescents for amblyopiagenic refractive errors. They had very similar validation with sensitivities of 80-90% and specificities of 98% for serious eye disorders in known patients and school-aged children. CONCLUSION: Combined with careful interpretation, pocket-sized, digital flash cameras provide a portable and inexpensive digital alternative for pediatric photoscreening. A category 3 CPT code (0065T) can be used for this valid, public health technique: Amblyopia Detection By Camera (ADBC).

Alaska↗
PubMed2003

Weaning children with accommodative esotropia out of spectacles: a pilot study.

BACKGROUND/AIM: Many children with accommodative esotropia must continue spectacle use throughout life. This study was undertaken to determine which factors are predictive of successfully weaning children with accommodative esotropia out of spectacles. METHODS: A retrospective review of 10 children with accommodative esotropia, who were gradually weaned from their hyperopic correction, and three age matched controls was performed. The main outcome measure was resolution or non-resolution of esotropia following weaning and eventual discontinuation of spectacles. Secondary outcome measures were final refractive error and the final esotropic or esophoric angle without correction. RESULTS: Six patients were successfully weaned from spectacles. At the completion of the weaning period one child was orthophoric and the other five children had well controlled esophorias. The other four patients remained spectacle dependent because of persistent esotropia or decreased vision without spectacles. The baseline and final refractive errors were significantly lower in the children successfully weaned from spectacles (p = 0.014). While the children who were successfully weaned from spectacles were older when initially diagnosed with accommodative esotropia (4.6 v 2.5 years), this difference was not statistically significant (p = 0.09). CONCLUSION: Some children with accommodative esotropia may be weaned out of spectacles during the grade school years with resolution of their esotropia. It is likely that gradual reduction of the hyperopic correction increases divergence amplitudes, but it is unclear whether this facilitates emmetropisation.

Accommodation, Ocular↗
PubMed1989

Genetic and environmental effects on oculometric traits.

Twenty twin pairs (9 monozygotic and 11 dizygotic) were examined to test the effect of genetic and environmental factors on the etiology of refractive error, axial length of the eyeball, and total astigmatism. The twins pairs were ascertained from the nationwide Finnish Twin Cohort Study (FTCS). The monozygosity was confirmed for nine pairs by a blood group analysis adopted for paternity testing procedures. The mean ages of the monozygotic twin pairs was 69 years and of the dizygotic twin pairs 63 years. Spherical equivalent of refractive error and axial length of the eyeball showed higher intrapair correlations among monozygotic pairs than among dizygotic pairs. This suggests, at least in part, a genetic etiology of these traits. Total astigmatism measured by retinoscopy did not show a significant difference in intrapair correlations between monozygotic and dizygotic twin pairs.

Aged↗
PubMed2005

Corticosteroid treatment of periorbital haemangioma of infancy: a review of the evidence.

AIM: To systematically review the literature for corticosteroid treatment of periorbital haemangioma of infancy (HOI) and determine the relative efficacy and safety of oral, topical and intralesional corticosteroids. METHODS: PubMed and the Cochrane Library were queried using keywords, and further articles were obtained by reviewing bibliographies. Inclusion and exclusion criteria were applied to create a subset of literature for analysis. RESULTS: Systematic review revealed 81 original reports of periorbital HOI cases treated with steroids. Most studies and case series failed to document refractive error or visual acuity before and after treatment. Of cases meeting inclusion criteria, five patients received topical steroids and 25 patients received intralesional steroids. Patients receiving intralesional injections tended to demonstrate reduced astigmatism at follow up after treatment (21 of 28). The lack of studies with relevant objective ophthalmological end points prevented statistical meta-analysis. CONCLUSION: Intralesional injections may reduce refractive error, while the efficacy of topical steroids is unclear. Studies measuring objective ophthalmic data before and after treatment are sparse, and more studies are needed to determine the relative efficacy of different steroids. There are insufficient data to estimate the incidence of steroid side effects in patients treated with steroids for periorbital HOI or complications of intralesional injections in particular.

Administration, Oral↗
PubMed2005

Guidelines for prescribing optical correction in children.

As the eye grows, the axial length increases while the cornea and lens flatten. High refractive errors which are common in the neonatal period, reduce rapidly during the first year of life through the process called emmetropization. The possibility that long-term full- time glasses wear may impede emmetropization must be considered. Hyperopia greater than 5.00 diopters (D) in young children is associated with an increased risk of amblyopia and strabismus, therefore optical correction should be prescribed. When hyperopia is associated with esotropia, full correction of the cycloplegic refractive error should be prescribed. Myopia greater than 8.00 D and astigmatism greater than 2.50 D are common causes of isometropic amblyopia. Patients with hyperopic anisometropia with as little as l D difference between the eyes may develop amblyopia while the difference should reach 3-4 D for myopic anisometropia to develop amblyopia. Full cycloplegic refractive difference between two eyes should be given to the anisometropic child in spite of age, strabismus and degree of anisometropia. Myopia control is the attempt to slow the rate of progression of myopia such as cycloplegic agents, plus lenses at near, and rigid contact lenses.

Adolescent↗
PubMed2001

Emmetropization in chicks uses optical vergence and relative distance cues to decode defocus.

When visual information is confined to one object plane, the emmetropization end-point is adjusted in accord with the corresponding incident optical vergence at the eye [Proceedings of the 7th International Conference on Myopia (2000) 113]. We now report the effect of adding extra visual information beyond the target plane. Visual conditions were controlled using a cone-lens system: black Maltese cross targets on white opaque backgrounds (OMX) were attached to the open faces of 2.5 cm translucent cones fitted with either 0, +25 or +40 D imaging lenses. An alternative target (TMX) was made by substituting the opaque target background for a transparent background, which allowed access to visual information beyond the target plane. The imaging devices were applied to 7-day-old chicks and worn for 4 days. Prior to this treatment, on day 2, some chicks underwent ciliary nerve section (CNS) to preclude accommodation. All treatments were monocular. Refractive errors and axial ocular dimensions were measured using retinoscopy and A-scan ultrasonography under halothane anesthesia. Treatment effects were specified as mean ( +/-S.D.) interocular differences. Eyes with the OMX/+40 D lens combination remained emmetropic (+0.73 +/-3.57 D), consistent with the target plane being approximately conjugate with the retina. Switching to the TMX caused a hyperopic shift in refractive error (+3.78 +/-3.41 D). This relative shift towards hyperopia in switching from the OMX to the TMX target also occurred for the other two lens powers. Thus, the OMX/+25 D lens induced myopia (-7.00 +/-5.88 D), corresponding to the imposed hyperopic defocus (target plane now imaged behind the retina), and switching to the TMX resulted in a reduction in myopia (-1.73 +/-5.36 D). The OMX/0 D lens combination produced the largest myopic shift, and here, switching to the TMX condition almost eliminated the myopic response (-15.50 +/-6.62 D cf. -0.56 +/-1.24 D). This relative hyperopic shift associated with switching from the OMX to the TMX target was eliminated by CNS surgery. Thus, the two CNS/TMX groups were both more myopic than the equivalent no CNS/TMX groups (+40 D lens: -2.66 +/-2.34 D; +25 D lens: -7.97 +/-6.87 D). When the visual information is restricted to one plane, incident optical vergence appears to direct emmetropization. Adding visual information at other distances produces a shift in the end-point of emmetropization in the direction of the added information. That these effects are dependent on the integrity of the accommodation system implies that accommodation plays a role in emmetropization and represents the first reported evidence of this kind.

Accommodation, Ocular↗
PubMed1976

Normal values in clinical electrooculography. II. Analysis of potential and time parameters and their relation to other variables.

The following EOG potential and time parameters from 72 normal subjects were analysed: base value B, dark trough D, light peak L, light induced potential rise L-D, interval between beginning of dark adaptation and occurrence of dark through d and interval between dark trough and light peak l. Their relations to sex, age pupillary diameter, degree of iris pigmentation, refractive error, axial length, corneal curvature and diameter, ocular protrusion and interpupillary distance were assessed. Right eye and left eye samples of the EOG parameters were congruent, although individual differences were sometimes appreciable. The levels of B and D were higher in the female half of the sample. A positive correlation existed between age and D level. L-D was negatively correlated to the degree of refractive error and positively correlated to the ocular protrusion. A positive correlation was found between d and the four potential parameters, and there was a positive correlation between age and l. Practical consequences of the statistical analysis relating to the interpretation of such EOG data are discussed.

Action Potentials↗