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PubMed1991

Ocular trauma. Triage and treatment.

Many types of ocular trauma can be diagnosed and treated in the primary care office, particularly if a slit lamp is available. Treatment for corneal abrasions consists of applying a cycloplegic medication, antibiotic ointment, and a patch (unless a corneal ulcer is suspected). Iritis can be treated with cycloplegics and topical corticosteroids; the prescribing physician should be familiar with the potential ocular side effects and complications. Hyphemas are treated with bed rest, topical atropine sulfate drops and topical corticosteroids, as well as measures to prevent rebleeding. A slit lamp, topical anesthesia, and a foreign-body spud greatly facilitate the removal of foreign bodies from the cornea. Acid and alkali burns should be irrigated until the pH is normal and then should be treated like a corneal abrasion. Lid lacerations must be repaired with care to preserve proper functioning of the lid. Ruptures of the globe are serious injuries requiring surgical repair and long-term follow-up.

Burns, Chemical↗
PubMed2004

Examination of preschool children for ametropia: first experiences using a new hand-held autorefractor.

INTRODUCTION: Over the last decades, various methods have been investigated for preschool screening for amblyogenic ametropia. The SureSight is a new hand-held wavefront-analyzing autorefractor designed for screening. METHODS: A total of 338 children (3 1/2 - 4 1/2 years-old) were examined in their kindergartens without cycloplegia using the new instrument. Of these, 56 had a cycloplegic retinoscopy as a reference measurement. Hyperopia > or =3 dpt, myopia > or =1 dpt, astigmatism > or =1 dpt and anisometropia > or =1 dpt were considered amblyogenic ametropia. RESULTS: Testability was 99.4%. Accuracy was high for cylinder power and axis but poor for the spherical equivalent. Sensitivity was 41% for the detection of amblyogenic hyperopia, 95% for astigmatism and 75% for anisometropia, with specificity values of 92, 79 and 73%. CONCLUSION: The high testability and accuracy for cylinder power and axis are the strong points. The poor accuracy for the spherical equivalent is probably caused by the lack of cycloplegia. At present, non-cycloplegic autorefractor screening cannot be recommended due to the low specificity. Our findings support the advice that objective refraction in childhood must be performed with cycloplegia.

Child, Preschool↗
PubMed2004

Comparison between two hand-held autorefractors: the Sure-Sight and the Retinomax.

PURPOSE: To compare the results of manifest refraction obtained with two different hand-held autorefractors (Sure-Sight, Welch Allyn Co. and Retinomax 1, Nikon Inc.) and with the Topcon RMA 6000 on-table autorefractor in order to estimate any potential bias between these refractometers and to compare the diagnostic performances of these two hand-held autorefractors as screening devices. METHODS: Ninety-eight children were refracted under manifest conditions with the three above-mentioned refractometers and under cycloplegic conditions with the Topcon on-table autorefractor, or by means of retinoscopy. The agreement between the manifest measurements obtained with the three different autorefractors was studied using the method of Bland and Altman. The validity of several thresholds of manifest refractive anomalies as measured with the Sure-Sight and with the Retinomax was estimated by receiver operating characteristic (ROC) curves using cycloplegic measures as reference. results There is a spherical positive bias of 1 D between the Sure-Sight and the Retinomax and better agreement between the Topcon and the Retinomax. The surface area indexes of the ROC curves and the diagnostic performances in term of sensitivity and specificity are better with the Retinomax in cases of hyperopia, astigmatism and anisometropia. For myopia, the Sure-Sight has better performance. CONCLUSIONS: The results suggest that either device may be sufficient for assessing refractive errors in children in a screening setting. However, because of a bias between both refractometers in measuring the sphere, distinctive referral criteria must be chosen for the detection of hyperopia and myopia. The diagnostic performance is slightly in favor of the Retinomax.

Adolescent↗
PubMed2004

Ketorolac for the regression of myopic LASIK overcorrection.

OBJECTIVE: To determine whether ketorolac (Acular) treatment and other factors influence regression after LASIK-induced consecutive hyperopia. METHODS: Seventy-two eyes of 51 patients who had undergone LASIK for myopia and compound myopic astigmatism and who experienced consecutive hyperopia of at least +0.50 diopters within the first postoperative week were analyzed. The consenting patients were treated with ketorolac (Acular). Data were collected over a period of 2 months. Primary preoperative variables included age, eye, preoperative manifest and cycloplegic refractions, and pachymetry. Postoperative variables included presence of microstriae and treatment with ketorolac. Treatment success was measured as reduction of consecutive hyperopia. RESULTS: Thirty-seven eyes were treated, and 35 eyes were in the control group. Mean start time for treatment with ketorolac was 9 days after surgery (range 3-35 days). Mean treatment time was 24.5 days (range 10-63 days). Both groups were matched for all preoperative variables except for age, including manifest and cycloplegic refraction, eye treated, and pachymetry. Treated patients were on average 9 years older than the control group. There was no significant difference in the overall rate of regression between the 2 groups at the 1-month and 2-month periods. Thicker preoperative corneas in all eyes had a sporadic association with reduction of consecutive hyperopia. CONCLUSIONS: Ketorolac does not improve consecutive hyperopia after LASIK for myopia and compound myopic astigmatism when compared with a matched control group. Pachymetry appears to be a determining factor in the degree of regression experienced after consecutive hyperopia. This finding warrants further investigation.

Adult↗
PubMed1994

Early signs of myopia in Chinese schoolchildren.

We looked for the earliest signs of the onset of myopia in 194 emmetropic (-0.25 to +0.75 D) eyes by following them for 1 to more than 2 years. Visual acuity examination, cycloplegic retinoscopy, and A-scan ultrasonography were performed at intervals of 6 to 12 months. Of the 194 eyes 64 became myopic during the observation time. Our results show that during the progression from emmetropia to myopia the change in visual acuity is not a good indicator of the onset of myopia. When visual acuity decreased to below 6/6 (20/20) cycloplegic retinoscopy showed that most of the 64 eyes had become truly myopic and A-scan ultrasonography revealed a significant increase in vitreous chamber depth and axial length as compared to the non-myopic eyes. In the early stage of myopia development the anteroposterior diameter of the eye elongates. However, changes in anterior chamber depth and lens thickness did not differ between the myopic and non-myopic group. Our results suggest that routine ocular refraction should be conducted in addition to the school vision screening. For those who have visual acuity 6/6 (20/20) and ametropia of -0.25 D or more minus we would like to be able to prevent or at least retard the development of myopia.

Child↗
PubMed1994

A comparison of drop instillation and spray application of 1% cyclopentolate hydrochloride.

We compared the objective cycloplegic refractive error of 37 hyperopic children (ages 18 months to 6 years). Cycloplegia was by spray application to the closed eye, or by a one-drop instillation to the open eye. Patients were initially screened for hyperopia using a masked noncycloplegic retinoscopy with loose trial lenses. Spray and drop cycloplegias (1% cyclopentolate hydrochloride; 1% Spectro Pentolate) were administered to each patient in random order within a 2-week period. A masked cycloplegic retinoscopy was performed 20 min after drug administration for patients with "light" iris coloration and after 40 min for those with "dark" irides. One examiner conducted all cyclopentolate administrations; a separate examiner (masked to application method) conducted all refractive testing. For right eyes, the mean spherical equivalent refractive error after spray application was 1.76 D (SD = 1.63 D) and after drop instillation 1.78 D (SD = 1.85 D). Results were similar for the left eyes. These small differences were not statistically significant (ANOVA, F = 0.05, p = 0.82). The absolute difference in spherical equivalent was 0.50 D or less in 93% of all subject eyes. A scaling system was used to rate the ease of administration and the patient's response to each method. Using an exact test of marginal homogeneity, the response rating for the spray method was significantly better (p = 0.038). The spray application of cyclopentolate hydrochloride is easier to administer and is an effective alternative to traditional drop instillation.

Child↗
PubMed1994

Dark focus of accommodation and vergence posture.

We evaluated the dark focus of accommodation and vergence posture in 20 boys and girls, 10 with and 10 without accommodative esotropia, before and after they wore glasses for at least 1 month. Refractive error was measured by Nidek Autorefractometer AR1600. We used two definitions of the dark focus, DFcus (Non-Cyclo R) and DFcus (Cyclo R). DFcus (Non-Cyclo R) = Dark R - Non-Cyclo R. DFcus (Cyclo R) = Dark R - Cyclo R. (Dark R: refractive state in the dark; Non-Cyclo R: non-cycloplegic refractive error; Cyclo R: cycloplegic refractive error.) Vergence posture was measured by prism cover test during distance fixation while uncorrected. DFcus (Cyclo R) was significantly greater in esotropic subjects than in non-esotropic subjects, although DFcus (Non-Cyclo R) did not differ significantly. A significant hyperopic shift in Dark R was observed after wearing glasses. DFcus (Cyclo R) was significantly decreased after wearing glasses, suggesting that wearing glasses is an important variable of the dark focus. Unlike the dark focus, the vergence posture did not change in either group after wearing glasses. The dissociation of the dark focus from vergence posture seems to be inconsistent with previous findings. It is postulated that change in dark vergence after wearing glasses is responsible for the results.

Accommodation, Ocular↗
PubMed1996

Changes in myopia, visual acuity, and psychological distress after biofeedback visual training.

The effects of auditory biofeedback training on myopia, visual acuity (VA), and psychological distress were evaluated in a controlled prospective study involving 55 mildly myopic (< or = -3.5 D) high school students. These myopes were divided into 2 groups, matched for age and dioptric defect: 33 were treated with visual training and 22 were not; 27 emmetropic subjects formed a further control group. Subjects were evaluated at the baseline (T0), at 10 weeks after the end of the treatment (T1), and after an interval of 12 months (T2) from the baseline for: (1) manifest and cycloplegic refraction, and the difference between them (cycloplegic tonus); (2) VA measured with a conventional optotype in all subjects, and also with a computer-generated optotype in the treated group; and (3) psychometric values and personality profile. At T2, myopia had significantly worsened both in the treated and in the control myopes; VA in the treated myopes appeared significantly improved when measured by the conventional optotype, but unchanged when measured by computer. Psychometric scores improved significantly in the treated myopes and in the emmetropic controls. Objectively the autorefractometer showed that 38% of the myopes had voluntary control of positive accommodation, i.e., the ability to increase spherical defect; no voluntary control of negative accommodation was observed. An increase in VA was associated with a significant increase in the foveation time (i.e., the period of time when the target is imaged on the fovea and the eye is motionless), and was partly attributable to a learning effect. In conclusion, biofeedback visual training had a positive effect on psychological distress and subjective VA improvement, but failed to reduce the existing myopia or delay its evolution.

Adolescent↗
PubMed2000

Measurement of refractive error in Native American preschoolers: validity and reproducibility of autorefraction.

PURPOSE: To examine (1) reproducibility of cycloplegic retinoscopy (C-RNS), cycloplegic autorefraction (C-Autoref), and noncycloplegic autorefraction (NC-Autoref), and (2) validity of C-Autoref and NC-Autoref compared with C-RNS in preschoolers with astigmatism. METHODS: Subjects were 36 Native American preschoolers. Three measurements of right eye refractive error were obtained with each of three methods: C-RNS (by three different retinoscopists), C-Autoref, and NC-Autoref (Nikon Retinomax K+). Vector methods (vector dioptric distance, VDD) were used in the analyses. RESULTS: Mean reproducibility was 0.41 D (SD = 0.18) for C-RNS, 0.25 D (SD = 0.17) for C-Autoref, and 0.37 D (SD = 0.21) for NC-Autoref. Mean agreement between C-Autoref and C-RNS ranged from 0.51 to 0.61 VDD (SD = 0.24 to 0.35), and ranged from 1.66 to 1.74 VDD (SD = 1.11 to 1.25) for agreement between NC-Autoref and C-RNS. Mean bias was -0.07 +0.21 x 149 and -1.33 +0.34 x 178 for C-Autoref and NC-Autoref, respectively. CONCLUSIONS: C-Autoref provided reliable and valid measurements of refractive error in young children. NC-Autoref measurements were reliable within subjects, but there was large variability in validity among subjects.

Arizona↗
PubMed2003

The manifestation of noncycloplegic refractive state in pre-school children is dependent on autorefractor design.

PURPOSE: To investigate the factors that govern the manifestation of hyperopic refractive errors of pre-school children when tested with and without the application of cycloplegics. METHODS: Forty-three pre-school children (mean age, 3.68 +/- 0.59 years) were tested before and during cycloplegia in the following order: retinoscopy with optical fogging; Retinomax K plus; Welch Allyn SureSight (DAV SureSight), and PowerRefractor. In the case of the PowerRefractor, the children viewed a difference of Gaussian target (0.20 cpd) at 3.5 m in addition to viewing the instrument LED sources. RESULTS: Instruments with close working distances (Retinomax) showed the greatest underestimation of hyperopia and the largest variation, followed by the instruments having a greater working distance (PowerRefractor LED view and retinoscopy). The addition of a far target (PowerRefractor difference of Gaussian view) showed the least underestimation, whereas DAV SureSight showed a mean overestimation of the refractive state. CONCLUSION: When autorefractors are applied to vision screening of pre-school children without the use of cycloplegics, autorefractor designs must be developed that both stabilize and relax the child's accommodation. Our results suggest that designs should include large working distances and distant fixation targets.

Accommodation, Ocular↗
PubMed2003

Refractive state of tree shrew eyes measured with cortical visual evoked potentials.

PURPOSE: To determine the refractive state of tree shrew eyes using visual evoked potentials (VEP's) recorded from primary visual cortex and compare the values with those obtained with streak retinoscopy and with an autorefractor. METHODS: VEP's were recorded in seven normal tree shrews and three animals in which approximately 5 D of myopia (relative to control eye) was induced by monocular -5 D lens wear. While the animals were awake, refractive correction was measured with an autorefractor before and after cycloplegia (1% atropine and 2.5% phenylepherine). When anesthetized, cycloplegic refractive correction was measured with streak retinoscopy. Then VEP's were produced with square-wave counterphased (1 Hz) high-contrast checkerboard patterns near the animals' high spatial frequency cutoff. Spherical lenses (2 D steps) were placed before the eye, and the VEP (average of 128 sweeps) was measured to determine the lens that produced the largest first positive peak (P1). RESULTS: VEP's were obtained over a broad range of trial lenses. Tuning was narrower when check sizes were small. In normal and control eyes, the P1 amplitude was largest, on average, for a trial lens of (mean +/- SD) -0.6 +/- 1.6 D (corrected for working distance but not vertex distance). The mean streak retinoscopy value (spherical equivalent at the corneal plane) was 7.0 +/- 0.8 D, and mean autorefractor values were 4.0 +/- 1.1 D (cycloplegic) and 3.7 +/- 1.2 D (noncycloplegic). In the eyes that compensated for a -5 D lens, the largest P1 values occurred with lenses with a power of -6.3 +/- 3.2 D. Thus, the VEP measure showed a similar treated vs. control eye difference as did streak retinoscopy (treated eyes, 4.7 +/- 0.4 D myopic) and the autorefractor (treated eyes, 4.8 +/- 0.5 D myopic). CONCLUSIONS: Normal tree shrew eyes are approximately emmetropic. The hyperopic values obtained with streak retinoscopy and the autorefractor are consistent with the presence of a "small-eye artifact" in tree shrews. Eyes that have compensated for a -5 D lens are myopic by approximately the value of the lens.

Animals↗
PubMed2004

A survey of clinical prescribing philosophies for hyperopia.

BACKGROUND: Prescribing philosophies for hyperopic refractive error in symptom-free children vary widely because relatively little information is available regarding the natural history of hyperopic refractive error in children and because accommodation and binocular function closely related to hyperopic refractive error vary widely among children. We surveyed pediatric optometrists and ophthalmologists to evaluate typical prescribing philosophies for hyperopia. METHODS: Practitioners were selected from the American Academy of Optometry Binocular Vision, Perception, and Pediatric Optometry Section; the College of Vision Development; the pediatric and binocular vision faculty members of the colleges of optometry; and the American Association for Pediatric Ophthalmology and Strabismus. Surveys were mailed to 314 participants: 212 optometrists and 102 ophthalmologists. RESULTS: A total of 161 (75%) of the optometrists and 59 (57%) of the ophthalmologists responded. About one-third of optometrists surveyed prescribe optical correction for symptom-free 6-month-old infants with +3.00 D to +4.00 D hyperopia, but fewer than 5% of ophthalmologists prescribe at this level. Most eye care practitioners prescribe optical correction for symptom-free 2-year-old children with +5.00 D of hyperopia, and this criterion for hyperopia decreases with age. Most ophthalmologists (71.4%) prescribe the full amount of astigmatism and less than the full amount of cycloplegic spherical component, and most optometrists (71.6%) prescribe less than the full amount of both components. When prescribing less than the full amount of astigmatism, eye care practitioners do not tend to prescribe a specific proportion of the cycloplegic refractive error. CONCLUSION: Pediatric eye care providers show a lack of consensus on prescribing philosophies for hyperopic children.

Data Collection↗
PubMed2006

Intrastromal corneal ring implantation (360 degrees ring) for myopia: a 5-year follow-up.

PURPOSE: Stability of correction is a major factor for successful refractive surgery. Intrastromal corneal rings were placed for the correction of low to moderate myopia beginning 10 years ago. The purpose of this study was to evaluate findings in patients 5 years after ring placement and to compare these findings with 1-year results to assess the stability of effect. METHODS: Seventy-two patients (113 eyes) with myopia (range, -0.75 to -4.50 diopters [D]) were treated with the placement of intrastromal corneal rings (360 degrees ), in a multicenter clinical trial between 1993 and 1994 under U.S. Food and Drug Administration phase II and phase III clinical trials. Six insert sizes were evaluated: 0.21, 0.25, 0.30, 0.35, 0.40, and 0.45 mm. The long-term results that were evaluated were uncorrected visual acuity, best spectacle-corrected visual acuity, cycloplegic refraction spherical equivalent at 5 years and proximity of this value to the target refraction determined preoperatively, induced manifest refraction cylinder, and slitlamp findings. RESULTS: Data at the 5-year follow-up showed that uncorrected visual acuity was 20/40 or better in 83% of eyes and 20/20 or better in 64% of eyes, compared to 88% and 43%, respectively, at the first year of follow-up. Only 7% of eyes lost two or more lines of preoperative best spectacle-corrected visual acuity at 5 years, compared to 11% at the first year. No eyes at the 1- or 5-year follow-up had a best spectacle-corrected visual acuity worse than 20/40. Cycloplegic refraction spherical equivalent was within 1.00 D of target refraction in 68% of eyes at 5 years, compared to 71% at the 1-year follow-up. Induced manifest refraction cylinder greater than 1.00 D was reduced to 5% of eyes in the fifth year, compared to 12% of eyes at year 1. CONCLUSIONS: Intrastromal corneal rings are a safe, effective, and stable method of correcting mild to moderate myopia, and most patients continue to be satisfied with the results after 5 years. There was no clinically significant change in refractive effect and the central corneas remained clear at the 5-year follow-up in all eyes studied. Further data are currently being collected for 10-year follow-up periods. It is hypothesized that the use of intrastromal corneal rings as a refractive option for mild to moderate myopia will be supported by these additional longitudinal data.

Corneal Stroma↗
PubMed2006

The Adolescent and Child Health Initiative to Encourage Vision Empowerment (ACHIEVE) study design and baseline data.

PURPOSE: The purpose of this study was to describe the baseline characteristics of subjects and methods for a multicenter, randomized clinical trial to compare the effects of contact lens wear and spectacle wear on children's self-perception. METHODS: Eligible subjects are randomly assigned to wear glasses or contact lenses throughout the 3-year study. Self-perceptions are measured 1 month after randomization and every 6 months using the Self-Perception Profile for Children (SPPC). Children's satisfaction with spectacles and refractive error-related visual quality of life are also measured using surveys developed for the study. Visual acuity, cycloplegic autorefraction, corneal curvature, and axial dimensions are measured annually. RESULTS: Five clinical sites enrolled 484 subjects with a mean (+/- standard deviation [SD]) age of 10.4 +/- 1.1 years. Approximately three-fifths of the subjects are girls, 47.1% of the subjects are white, 21.5% are black, and 21.5% are Hispanic. The mean (+/- SD) cycloplegic spherical equivalent autorefraction of the right eye is -2.38 +/- 1.04 D, and the average (+/- SD) axial length of the right eye is 24.32 +/- 0.77 mm. The average (+/- SD) Global Self-Worth score on the SPPC is 3.20 +/- 0.62 on a scale from one (low perceived competence) to 4 (high perceived competence). The average (+/- SD) spectacle satisfaction is 59.1 +/- 26.6 on a scale from zero (no satisfaction) to 100 (perfect satisfaction). The average refractive error-related quality of life score is 63.5 +/- 12.8 on a scale from zero (poor quality of life) to 100 (excellent quality of life). CONCLUSIONS: Subjects enrolling in the ACHIEVE Study are an ethnically diverse group of young myopic children. Ocular characteristics of the sample are consistent with data presented in other randomized clinical trials evaluating treatments for myopic children. The data reported here represent the baseline data for a 3-year randomized clinical trial to investigate the effects of contact lens vs. spectacle wear on children's self-perceptions.

Adolescent↗
PubMed2006

Refraction and aberration across the horizontal central 10 degrees of the visual field.

PURPOSE: The purpose of this study was to measure refraction and aberrations across the horizontal central visual field. METHODS: Cycloplegic refraction was measured on eight subjects at 13 points across the horizontal central 10 degrees of the retina using a Hartmann-Shack wavefront sensor. Refractions were converted into mean sphere (M), 90 degrees to 180 degrees astigmatism (J180), and 45 degrees to 135 degrees astigmatism (J45) components. For five subjects, higher-order aberrations were determined at the center and edges of the field. RESULTS: Subtle changes in refraction were found to exist across the central 10 degrees of the retina, with changes in mean best sphere varying by up to half a diopter across this region and with smaller changes in astigmatism. Horizontal coma, but no other higher-order aberrations, varied systemically across the visual field; it varied linearly with angle but at different rates for the different subjects. CONCLUSION: Subtle changes in cycloplegic refraction exist across the horizontal central 10 degrees of the retina. The results indicate the need for correct alignment when measuring objective refraction.

Adult↗
PubMed1993

Plasma concentrations and ocular effects of cyclopentolate after ocular application of three formulations.

1. Eight volunteers received in randomized order two 30 microliters drops of either 1% w/v cyclopentolate hydrochloride or a corresponding amount of cyclopentolate polygalacturonate in saline or in acetate buffer in one eye. Cyclopentolate concentrations in plasma were measured by a radioreceptor assay. 2. Peak plasma drug concentrations of about 3 ng ml-1 occurred within 30 min after all formulations. Occasionally, a second concentration peak in plasma, probably reflecting drug absorption from the gastrointestinal tract, was seen after 2 h. The mean elimination half-life of cyclopentolate was 111 min when all subjects and formulations were considered together. There were no statistically significant differences between the formulations with respect to the time-course of plasma drug concentration. 3. The maximal mydriatic effect was reached within about 15 min and was maintained for several hours, often being 1/3 of its peak value after 30 h. Similarly, an intense cycloplegic response was achieved within a few minutes, the peak changes in the near-point of vision being 9 to 10 dioptres. The cycloplegic response was more intense after one of the polygalacturonate complexes, especially at later time points.

Adult↗
PubMed1987

The effects of thymoxamine, phenylephrine and cyclopentolate on the accommodative process in man.

Accommodation of the eye was measured in a cross-over study in 11 healthy volunteers (20-35 years). In 5 subjects the near point was determined before and after topical instillation of 5 microliter of 0.1% and 0.5%, and 5 x 5 microliter 0.5% thymoxamine, 5 microliter of 2% and 10%, and 5 x 5 microliter 10% phenylephrine and 5 microliter of 0.04%, 0.2%, and 1% cyclopentolate. All concentrations of thymoxamine increased the accommodative amplitude by about 1.5 dioptres. Accommodation decreased by about 0.5 dioptre after instillation of 5 x 5 microliter 10% phenylephrine. The cycloplegic effects of 0.2% and 1% cyclopentolate were similar. Accommodation was also determined after application of 5 microliter 1% cyclopentolate followed by either 5 x 5 microliter 0.5% thymoxamine or 10% phenylephrine. Addition of thymoxamine did not alter the cycloplegic response of cyclopentolate alone. Addition of phenylephrine caused a more prolonged but similar maximum response compared to that of cyclopentolate alone. In the 6 other test subjects, the accommodation was compared before and after topical instillation of 5 microliter of 0.2% and 1% and 40 microliter (one standard eye-drop) of 1% cyclopentolate and followed during 6 h. There was no difference between the maximum value of 5 microliter and 40 microliter 1% cyclopentolate. We conclude from these data that alpha-stimulation by phenylephrine decreases and alpha-inhibition by thymoxamine increases the accommodative amplitude in man.(ABSTRACT TRUNCATED AT 250 WORDS)

Accommodation, Ocular↗
PubMed1988

Myopia prevention and therapy. The role of pharmaceutical agents. Japanese studies.

In order to normalize the condition of pseudomyopia, the following can be summarized: One percent cyclopentolate was effective in 63%, and 0.4% tropicamide was effective in 59% of the cases. With a value of 68% after labetalol eye drops there were no significant differences in efficacy between this drug and the above cycloplegics. In subjects treated only with placebo, 4 out of 16 eyes, i.e. 25% were relieved. A significant difference (P less than 0.01) was found between the results with the above 3 drugs and placebo. On the other hand, the efficacy of 0.25% timolol (effect in 28%) and chemical X (effect in 37%) were not significantly different from the effect of placebo, though the results with chemical X encourage further trials. It can be postulated that by releasing an abnormal tension cycloplegics reduce the myopic condition. Regarding the hypotensive action of beta-adrenergic blockers on intraocular pressure, it presumably depends mainly on inhibition of secretion in the ciliary body. The fact that labetalol appeared effective, and timolol not, in treatment trials of slight myopia might imply that the mechanism behind an effect of labetalol on slight myopia is not merely a beta-adrenergic blocking action.

Adolescent↗