Change In Accommodative Amplitude Research Articles

Is 0.01% Atropine an Effective and Safe Treatment for Myopic Children? A Systemic Review and Meta-Analysis.

Several conflicting results regarding the efficacy of 0.01% atropine in slowing axial elongation remain in doubt. To solve this issue and evaluate the safety of 0.01% atropine, we conducted a systematic review and meta-analysis with the latest evidence. The review included a total of 1178 participants (myopic children). The efficacy outcomes were the mean annual progression in standardized equivalent refraction (SER) and axial length (AL). The safety outcomes included mean annual change in accommodative amplitude, photopic and mesopic pupil diameter. The results demonstrated that 0.01% atropine significantly retarded SER progression compared with the controls (weighted mean difference [WMD], 0.28 diopter (D) per year; 95% confidence interval (CI) = 0.17, 0.38; p < 0.01), and axial elongation (WMD, −0.06 mm; 95% CI = −0.09, −0.03; p < 0.01) during the 1-year period. Patients receiving 0.01% atropine showed no significant changes in accommodative amplitude (WMD, −0.45 D; 95% CI = −1.80, 0.90; p = 0.51) but showed dilated photopic pupil diameter (WMD, 0.35 mm; 95% CI = 0.02, 0.68; p = 0.04) and mesopic pupil diameter (WMD, 0.20 mm; 95% CI = 0.08, 0.32; p < 0.01). In the subgroup analysis of SER progression, myopic children with lower baseline refraction (>−3 D) and older age (>10-year-old) obtained better responses with 0.01% atropine treatment. Furthermore, the European and multi-ethnicity groups showed greater effect than the Asian groups. In conclusion, 0.01% atropine had favorable efficacy and adequate safety for childhood myopia over a 1-year period.

Change and Recovery of Choroid Thickness after Short-term Application of 1% Atropine Gel and Its Influencing Factors in 6-7-year-old Children

ABSTRACT Purpose To investigate the change and recovery of choroid thickness after short-term application of 1% atropine gel and its influencing factors in 6-7-year-old children. Materials and Methods 71 right eyes of 71 children were enrolled and divided into myopia and control group. 1% atropine gel was administered twice a day for one week and then stopped. Spherical equivalent (SE), accommodative amplitude (AA), keratometry (K), axial length (AL), and choroidal thickness (CT) were obtained at baseline and 1st, 4th, and 8th weeks. CT was measured at subfovea and 1 mm, 2 mm, and 3 mm temporal, superior, nasal, and inferior from the fovea using spectral-domain optical coherence tomography. Results In both groups, all CTs increased following the change in SE, AA, and AL after administration of 1% atropine for one week. They gradually recovered to baseline levels seven weeks after withdrawal. The change (Δ) in CT at 3 mm superior from the fovea was significantly higher in the myopia group than in the control group. In both groups, ΔCT at subfovea had no significant correlation with SE, AA, and AL, both at baseline and one week. However, ΔCT at subfovea was negatively correlated with ΔAL in the control group. Conclusions One-week application of 1% atropine gel may increase CT in 6-7-year-old Chinese children. Meanwhile, the recovery process after withdrawal lasts seven weeks. During the recovery process, the changes in structural parameters (AL, CT) and functional parameters (AA, SE) in both groups occurred synchronously. The SE, AA, and AL at baseline may not predict the extent of atropine’s effect on CT.

The Effect of Retinal Illuminance on the Subjective Amplitude of Accommodation.

We show that the amplitude of accommodation decreases with retinal illumination even under photopic reading conditions and a constant pupil size. This result provides a basis for clinical approaches that are not based on an optical explanation. We investigated the effect of retinal illuminance on the amplitude of accommodation while the pupil of the eye remained constant. The amplitudes of accommodation of 10 young subjects (from 20 to 38 years of age) and that of 10 presbyopic subjects (from 45 to 54 years of age) were measured subjectively through an artificial pupil of 5 mm using a Badal optometer and for four values of retinal illuminance: 222, 821, 2138, and 5074 trolands. Phenylephrine was instilled to all the subjects to ensure that their natural pupil was greater than the artificial one in all experimental runs. Linear mixed-effects model for repeated measures with age and log luminance as covariates were used to check whether changes in amplitude of accommodation with retinal illumination were statistically significant. In the range of illuminances tested, the amplitude of accommodation decreased on average from 6.34 to 4.35 D in the young subjects and from 1.69 to 1.04 D in the presbyopic subjects. Illuminance was associated with the amplitude of accommodation in both young and presbyopic groups, with P < .01. The reduction in the amplitude of accommodation with target illumination (a phenomenon named night presbyopia) under photopic light conditions is not only due to a reduction in the depth of focus as a consequence of pupil dilation; it is strongly affected by the decrease of retinal illumination.

Effect of low-dose atropine on myopia progression, pupil diameter and accommodative amplitude: low-dose atropine and myopia progression

PurposeTo evaluate the effects of 0.01% and 0.02% atropine eye drops on myopia progression, pupil diameter and accommodative amplitude in myopic children.MethodsA cohort study assessed 400 myopic children divided into...

Diurnal variations of amplitude of accommodation in different age groups.

Clinical assessment of amplitude of accommodation (AA) involves measuring the ability of the eye to change its optical power and focus on near tasks/objects. AA gradually decreases with increasing age. However, details of age-related diurnal changes in AA are not well known. This study compared diurnal changes in AA in the adolescents, the twenties, and the forties age groups. Measurement of AA using the push-up method was performed in six sessions at two-hourly intervals for 154 subjects (48, 56, 50 subjects for the adolescents, twenties, and forties age groups, respectively); the first measurements were taken from 9:00-10:00 a.m. and the final measurements from 7:00-8:00 p.m. The mean AA was 14.67 D (highest: 16.15 D in the 3:00-4:00 p.m. session, lowest: 13.35 D in the 9:00-10:00 a.m. session) for the adolescent group; 11.13 D (highest: 11.69 D in the 3:00-4:00 p.m. session; lowest: 10.61 D in the 9:00-10:00 a.m. session) in the twenties group; and 5.53 D (highest: 5.80 D in the 1:00-2:00 p.m. session, lowest: 5.11 D in the 7:00-8:00 p.m. session) in the forties age group. The measured AA showed significant difference between sessions; however, diurnal variations were greater in the younger groups. The measured AA was low at the beginning of the day in the adolescents and twenties groups and low at the end of the day in the forties age group. All age groups showed a high AA during the afternoon hours of the day (1:00-4:00 p.m.). Since the difference between each session was larger in younger subjects, AA should be evaluated while taking the age-related diurnal variations into account.

Mechanism of accommodation assessed by change in precisely registered ocular images associated with concurrent change in auto-refraction

Our purpose was to determine the changes in anterior chamber depth (ACD) and central lens thickness (CLT) during pharmacologically induced accommodation. Following pupillary dilation with phenylephrine 10%, baseline auto-refractions and swept-source optical coherence tomographic biometric images (Zeiss IOLMaster 700) were obtained from the right eyes of 25 subjects aged 19 to 24years. Pilocarpine 4% and phenylephrine 10% were then instilled into these right eyes. One hour later, auto-refractions and biometric imaging were repeated. Only data from eight of 25 subjects met the following stringent criteria to be included in the study analysis: pre and post-pilocarpine biometric foveal images were registerable, the images of the corneal centers were shifted by ≤100μm, pupils >5mm and the pharmacologically induced refractive change was ≥ -7 diopters. The mean auto-refractive accommodative change for the eight included subjects was -12.45 diopters (± 3.45 diopters). The mean change in CLT was 81μm (± 54μm) and the mean change in ACD was -145μm (± 86μm). Superimposition of the registered pre and post-pilocarpine biometric images of the sagittal sections of the whole eye from each subject demonstrated that the position of the whole lens did not shift either anteriorly, posteriorly or vertically during pharmacologically induced accommodation. A small increase in lens thickness was associated with a large change in accommodative amplitude and no significant change in lens position as predicted by the Schachar theory.

Accommodative Amplitude in School-Age Children

Abstract In children, intensive near-work affects the accommodation system of the eye. Younger children, due to anatomical parameters, read at smaller distance than older children and we can expect that the accommodation system of younger can be affected more than that of older children. We wanted to test this hypothesis. Some authors showed that the norms of amplitude of accommodation (AA) developed by Hofstetter (1950) not always could be applied for children. We also wanted to verify these results. A total of 106 (age 7-15) children participated in the study. Distance visual acuity was measured for all children and only data of children with good visual acuity 1.0 or more (dec. units) were analysed (73 children). Accommodative amplitude was measured before and after lessons using subjective push-up technique (with RAF Near Point Ruler). The results showed that the amplitude of accommodation reduced significantly (p &lt; 0.05) during the day and decrease of AA was similar in different age groups (about ~0.70 D). Additional measurements are needed to verify that the observed changes in AA were associated with fatigue effect. The results showed lower accommodation values compared to average values calculated according to the Hofstetter equation (p &lt; 0.05).

Evaluation of ocular accommodation, convergence and fusional vergence changes during Ramadan

Introduction: There are a few researches regarding the effects of Islamic fasting on visual system. The aim of this study was to investigate the effects of Ramadan fasting on the amplitude of accommodation (AA), near point of convergence (NPC), positive and negative fusional vergences (PFV and NFV, respectively) in visually healthy fasters. Methods: AA, NPC, PFV and NFV at far (6m) and near (40cm) were measured in 30 male students. Nutritional habits in a week before each examination visit were assessed with the Food Frequency Questionnaire (FFQ). Results: Mean age and fasting average experience were 23.9 and 10 years, respectively. AA and NPC showed significant changes (p<0.05) during Ramadan; but there was no significant difference before and after Ramadan in these parameters. NFV blur, break and recovery points at far significantly reduced in Ramadan than before (p=0.003, p=0.005, p=0.003, respectively) with insignificant compensation after Ramadan. Results showed that there was no significant correlation between changes in diet pattern and AA, NPC and distant NFV variations (p<0.05). Conclusion: Some visual problems may be reported at far and near visual tasks during Ramadan; but most of the problems may be resolved after it. Some visual preparations may be needed for more effective visual activities during Ramadan; essentially for students with intensive visual tasks. Vision therapy may be suggested along with nutrient pattern improvement during Ramadan.

Accommodative Changes After Photorefractive Keratectomy in Myopic Eyes

To determine the changes of amplitude of accommodation (AA) and facility of accommodation (FA) in myopic patients after photorefractive keratectomy (PRK). Using Technolas 217Z excimer laser, 160 myopic eyes of 80 patients underwent PRK. The patients were categorized into two age groups: <30 and ≥30 years. Changes in AA and FA were observed before PRK and at 2 weeks, 1 month, and 3 months after PRK. The role of preoperative AA, FA, refractive spherical equivalent, age, and sex on postoperative AA and FA was evaluated. In younger patients, the preoperative AA and FA values 7.77 ± 1.75 D and 7.75 ± 3.97 cpm changed to 8.36 ± 1.26 D and 11.57 ± 4.20 cpm (p < 0.001), respectively, at 3 months after PRK. In older patients, the preoperative AA and FA values 6.66 ± 1.41 D and 5.05 ± 3.26 cpm changed to 6.72 ± 1.26 D (p = 1.000) and 9.58 ± 4.29 cpm (p < 0.001), respectively. Two weeks after surgery, preoperative AA and spherical equivalent had a significant effect on postoperative AA, whereas preoperative AA and age had a significant effect on postoperative AA after 3 months (p < 0.001). Postoperative FA was positively related to preoperative FA and female sex (p < 0.05). This study suggests that some of the near-vision problems in younger myopes in early postoperative days after PRK might be due to decrease in AA and FA, which will eventually increase. However, in older patients, despite increase in FA, AA did not change.

New methodology to measure the dynamics of ocular wave front aberrations during small amplitude changes of accommodation

We present a methodology to measure the systematic changes of aberrations induced by small changes in amplitude of accommodation. We use a method similar the one used in electrophysiology, where a periodic stimulus is presented to the eye and many periods (epochs) of the stimulus are averaged. Using this technique we have measured changes in higher order aberrations from 0.006 mum to 0.02 mum and correlated them with amplitude changes of accommodation as small as 0.14D. These small changes would have been undetectable without epoch averaging. The correlation coefficients of Zernike terms with defocus were calculated, demonstrating higher values of correlation for epoch averaging. The accurate monitoring of defocus at the start of the accommodation response has shown some interesting trends that may be related with the mechanisms behind accommodation.

Anterior ciliary sclerotomy for treatment of presbyopia: A prospective controlled study

Purpose To examine the safety and efficacy of anterior ciliary sclerotomy to restore accommodation in the presbyopic eye. Design Prospective nonrandomized comparative single-center clinical trial. Participants Nine presbyopic subjects with no prior ocular surgery except corneal refractive procedures were enrolled. Methods One eye from each subject was chosen, in consultation with the patient, to undergo anterior ciliary sclerotomy. The contralateral eye of each subject served as a control. Examinations were performed preoperatively, and at 1 day, 1 week, 1 month, and 6 months after surgery. Main outcome measures (1) Accommodative amplitude, measured by two methods, (2) Jaeger reading vision at 14 inches wearing best distance correction, (3) manifest refraction, (4) assessment of operative complications. Results For the nine study eyes, there was no statistically significant change between the average accommodative amplitude at the preoperative visit (1.11 diopter [D]) and the 1-month postoperative visit (1.19 D, P = 0.55) nor at the 6-month postoperative visit (1.31 D, P = 0.21) in the study eyes. There was no significant difference between the study and control eyes’ change in accommodative amplitude at 6 months ( P = 0.43). Logarithm of the minimum angle of resolution equivalent of Jaeger reading vision in the study eyes at 14 inches wearing best distance correction showed no statistically significant change from the preoperative visit (0.53 [20/70]) at the 1-month postoperative visit (0.41 [20/50], P = 0.07) or at the 6-month postoperative visit (0.48 [20/60], P = 0.22). There was no significant change in manifest refraction spherical equivalent in the study eyes at 1 and 6 months postoperatively. One eye experienced a perforation of the anterior chamber during surgery. A second eye experienced mild postoperative anterior segment ischemia manifested by sectoral iris akinesis. Conclusions Anterior ciliary sclerotomy does not restore accommodation in presbyopic eyes and can cause significant complications.

Predicting results in the orthoptic treatment of accommodative dysfunction.

A retrospective analysis of the records of 114 orthoptic patients diagnosed as having accommodative dysfunction (accommodative insufficiency, fatigue of accommodation, infacility of accommodation, or spasm of accommodation) has allowed the construction of models of the results of orthoptic treatment. Discriminant analysis completed on various samples of the group provides linearized discriminant functions for the success of the treatment (either total or partial/none) and for the change in accommodative amplitude. These data indicate that linearized discriminant functions using the age and AC/A ratio of the patient are effective in postpredicting the success category of 60% of a calibration sample of 99 patients. Similar functions using the patient's age, initial accommodative amplitude, and blur value of the near positive vergences allow the postprediction of the category of change in accommodative amplitude with treatment (3 D or more vs. 2 D or less). Seventy-eight percent of a sample of 68 patients were correctly classified. The application of these models in predicting the results of treatment of similarly afflicted subjects is discussed.