Purpose: To determine changes in refractive state and corneal parameters after CYCLOPLEGIA with cyclopentolate hydrochloride 1% using a dual Scheimpflug imaging system. Methods: In this prospective cross‑ sectional study patients aged 10 to 40 years who were referred for optometric evaluation enrolled and underwent autorefraction and corneal imaging with the Galilei dual Scheimpflug system before and 30 minutes after twice instillation of medication. Changes in refraction and astigmatism were investigated. Corneal biometrics including anterior and posterior corneal curvatures, total corneal power and corneal pachymetry were compared before and after CYCLOPLEGIA. Results: Two hundred and twelve eyes of 106 subjects with mean age of 28 ± 5 years including 201 myopic and 11 hyperopic eyes were evaluated. Mean spherical equivalent refractive error before CYCLOPLEGIA was ‑ 3. 4 ± 2. 6 D. A mean hyperopic shift of 0. 4 ± 0. 5 D occurred after CYCLOPLEGIA (P < 0. 001). The astigmatism power did not significantly change (P = 0. 8), however, 26. 8% of eyes with significant astigmatism experienced a change of more than 5 degrees in the axis of astigmatism. Changes in posterior corneal curvature were scant but statistically significant (P = 0. 001). Moreover, corneal thickness was slightly increased in the central and paracentral regions (P < 0. 001 and P < 0. 001, respectively). Conclusion: CYCLOPLEGIA causes a hyperopic shift and astigmatism axis changes, along with an increase in central and paracentral corneal thickness and change in posterior corneal curvature. The effects of CYCLOPLEGIA on refraction and corneal biometrics should be considered before cataract and refractive surgeries.

Purpose: The present study sets out to investigate the effect of cyclopentolate-induced CYCLOPLEGIA on distance and near deviation and the accommodative convergence/accommodation (AC/A) ratio. Methods: This prospective study was performed on 30 subjects. The inclusion criteria included a lack of any active ocular pathology and systemic diseases, no history of ocular surgery, and nonuse of various medications. Refraction, near and distance deviation were measured for all subjects, and the same examinations were repeated after the administration of two drops of cyclopentolate 1% to both eyes. Results: The obtained data from 30 subjects, including 19 males, with a mean age of 22. 53 ± 1. 74 years were analyzed. The mean ± SD of near deviation in dry and cycloplegic conditions were – 6. 9 ± 8. 1 and +6. 4 ± 9. 1 prism diopters, respectively, which were statistically significant (P < 0. 001). Distance deviation in cycloplegic conditions demonstrated an average difference of 0. 8 prism diopters, compared to dry conditions (P < 0. 001). AC/A ratios were 4. 7 ± 2. 5 and 9. 7 ± 3. 9 (Δ/D) in non-cycloplegic and cycloplegic conditions, respectively, which was a statistically significant difference (P < 0. 001). The multiple regression indicated that among all under study variables, refraction (B coefficient: –2. 4,P < 0. 001) and near pre-cycloplegic deviation (B coefficient: 0. 56,P < 0. 001) were significantly associated with post-cycloplegic near deviation. Conclusion: The results of this study indicated that CYCLOPLEGIA causes a considerable esophoric shift in near deviation and a negligible esophoric shift in distance deviation. As a result, the AC/A ratio demonstrated a significant increase due to unequal changes in near and distance deviation.

Background: Cycloplegic refraction is an important test in strabismus patients and any patient with decreased vision.The most commonly used drugs for this test are Atropine and Cyclopentolate. The drug which was more popular in the past was Atropine, which is still the standard against which other cycloplegic agents are compared. Nowadays Cyclopentolate is the drug of choice because it has many advantages as compared to atropine, including faster onset, shorter duration, reduced toxicity and ease of use.This is now an open question as to what is an appropriate regimen of cyclopentenlote. In different references and among specialists, different opinions exist. Some believe that a single drop of cyclopentolate produces the adequate CYCLOPLEGIA and some believe in two or even three drops to be adequate.Purpose: In this research we tried to define how many drops of cyclopentolate can produce adequate CYCLOPLEGIA without producing unwanted side effects.Materials & Methods: We used data obtained from the 3 to 20 year old patients referring to strabismus clinic during one year (2003-2004). We divided the patients randomly into three groups and compared the results between one and two drops, one and three drops and two and three drops.We also considered the factors that could be potential confounders, including age, sex, color and darkness of iris, type and amount of strabismus and the kind and amount of refractive error.Results: 96 patients (192 eyes) were studied including 32 patients in group 1 and 33 patients is group 2 and 31 patients in group 3. They included 40 males (41.7%) and 56 females (58.3%) with mean age 11±5.7 years. 50 patients (52%) did not have strabismus but 46 patients (48%) had strabismus including 26 patients( 27.1%) with ET and 18 patients (18.8%) with XT. Two patinas (2.1%) had only hypertropia. 142 eyes (74%) were hyprope an 30 eyes (15.6%) were myope and 20 eyes (10.4%) were between a little hyperopia and myopia in two stages of the study. The effect of all factors including age, sex, iris color and darkness, presence of strabismus and its magnitude and type of refractive error and its magnitude and spherical equivalent were evaluated and were not significant in different groups. The study also showed that side effects were more prevalent using more frequent drops.Conclusion: The study showed that considering all these factors that could have been potential confounders, the adequate dose of cyclopentolate is one drop, meaning that in any patient who is candidate for doing cycloplegic refraction, using a single drop of cyclopentolate 1% suffices. We also reached the conclusion that there are less side effects using one drop of cyclopentolate, compared to two or three drops.

Purpose: To determine refractive state and corneal parameter changes after CYCLOPLEGIA with cyclopentolate 1% using dual scheimpfluge imaging system.Methods: Healthy volunteers between the ages of 10 and 40 years who were referred for ophthalmic evaluation in a 3-month period were included. Complete ophthalmic examination, auto-refraction and corneal imaging with the Gallilei dual scheimpfluge system was performed before and after 30 minutes of applying 1% cyclopentolate. Changes in refractive and corneal parameters were evaluated.Results: One hundred and six patients with mean age of 28±5 years or 212 eyes (201 myopic and 11 hyperopic) were evaluated. The mean spherical equivalent before CYCLOPLEGIA was -3.4 ± 2.6 D (diopter), after CYCLOPLEGIA the mean hyperopic shift was 0.4±0.5 D (P<0.001). The astigmatism power change was not significant (P=0.8), but in 26.6% of 127 eyes, with more than 0.5D astigmatism, the axis changed more than 5 degrees after CYCLOPLEGIA. Anterior corneal curvature change was not statistically significant (p=0.5) but posterior corneal curvature change was statistically significant (P=0.001) and in the direction of hyperopic shift (diff=-0.02).Corneal thickness increased statistically and significantly in the central and para-central areas, respectively {(diff=3.2 micron (P<0.001) and 3.9 micron (P<0.001)}.Conclusion: The refractive state, posterior corneal curvature and corneal thickness changed statistically and significantly after CYCLOPLEGIA, so it is recommended not to measure these parameters in cycloplegic state for clinical judgment, in IOL power calculation and refractive surgery.

Accurate measurement of refractive errbrin uncooperative patients and young children, requires CYCLOPLEGIA. The aim of the present study was to determine whethere cyclopentolate by itself or in combination with 4 times instillation of atropine can be used as a substitute for 10 tims instillation of atropine. From 1994 to 1996, 39 patients aged 2-12 years were included in this study. CYCLOPLEGIA was undertaken by four different methods in subsequent visits: cyclopentolate 1% 4 times instillation of atropine, 10 times instillation of atropine plus tropicamide and 10 times instillation of atropine. 26 pationts (53% male, mean. age: 6.4 years) completed the four stages of the study, Spheric refraetion was significantly different between cyclopentolate. and 4 times and 10 times atropine grpups, but We didn"t find any significant difference in cylindric refraction between group. It seems that 10 times instillation of atropine is still the best method of CYCLOPLEGIA in pediatric eye examination.

Introduction: The goal of this study was to compare the level of difference between cycloplegic and noncycloplegic refraction in different age groups.Materials and Methods: This correlation study was performed on 400 eyes of 200 participants in Khatam Al-Anbia hospital. For all participants, non cycloplegic refraction was done. CYCLOPLEGIA was performed, using Cyclopentolate 1%. Then cycloplegic refraction was done with the same autorefractometer. The amount of accommodation suppressed by the drug and possible effects of age, gender, type of refractive error and occupation on this amount was compared in different age groups. SPSS ver.13 statistical software was used for data analysis. P-value less than 0.05 considered as significant.Results: Average age of participants was 20.11±15.50 (range 2-59). The amount of accommodation suppressed by cyclopentolate 1% was significantly different among various age groups (p<0.001). The amount of accommodation suppressed by Cyclopentolate 1% showed no difference between myopic and hyperopic patients in any age groups (p>0.10 for each eye). Also, there was no correlation between occupation, sex and the amount of accommodation suppressed during CYCLOPLEGIA (p=0.45 and p>0.10 respectively). Conclusion: Cycloplegic refraction is an effective procedure for patients under 50 years old. The type of refractive error, sex and occupation had no effect on the amount of accommodation suppressed by Cyclopentolate 1%.

Accurate measurement of refractive errors in children is of great importance. It is time-consuming and difficult, especially in the presence of astigmatism. This study was conducted to compare the new generation of objective autorefractometers with retinoscope in terms of their efficacy in measuring refractive errors in astigmatic children.After induction of CYCLOPLEGIA with cyclopentolate 1%, 175 eyes of 4-10 year-old children with refractive errors, including ≥1 diopter of astigmatism, were initially refracted by retinoscope and later by objective auto refractometer (C-R30). Corrected Snellen acuities were measured for both refraction methods in the cycloplegic state and were compared.Geometric mean visual acuity measured 0.8)(1.17 by retinoscopy and 0.95)(1.09 by autorefractometry (P<0.001). An acceptable correlation was observed between results of the two methods of measurement (R=0.995).Cycloplegic objective autorefractometry with a third-generation instrument is comparable, or superior to cycloplegic retinoscopy in astigmatic children. It is a less time-consuming and easier procedure.

Purpose: To determine the accuracy of photorefraction and autorefraction as compared to cycloautorefraction and to detect the repeatability of photorefraction.Methods: This diagnostic study included the right eyes of 86 children aged 7-12 years. Refractive status was measured using photorefraction (PlusoptiX SO4, GmbH, Nurnberg, Germany) and autorefraction (Topcon RM800, USA) with and without CYCLOPLEGIA. Photorefraction for each eye was performed three times to assess repeatability.Results: The overall agreement between photorefraction and cycloautorefraction was over 81% for all refractive errors. Photorefractometry had acceptable sensitivity and specificity for myopia and astigmatism. There was no statistically significant difference considering myopia and astigmatism in all comparisons, while the difference was significant for hyperopia using both amblyogenic (P=0.006) and nonamblyogenic criteria (P=0.001). A myopic shift of 1.21 diopter (D) and 1.58 D occurred with photorefraction in nonamblyogenic and amblyogenic hyperopia, respectively. Using revised cut-off points of+1.12 D and+2.6 D instead of+2.00 D and+3.50 D improved the sensitivity of photorefractometry to 84.62% and 69.23%, respectively. The repeatability of photorefraction for measurement of myopia, astigmatism and hyperopia was acceptable (intra-cluster correlation [ICC]: 0.98, 0.94 and 0.77, respectively). Autorefraction results were significantly different from cycloautorefraction in hyperopia (P<0.0001), but comparable in myopia and astigmatism. Also, noncycloglegic autorefraction results were similar to photorefraction in this study.Conclusion: Although photorefraction was accurate for measurement of myopia and astigmatism, its sensitivity for hyperopia was low which could be improved by considering revised cut-off points.Considering cut-off points, photorefraction can be used as a screening method.