Comparison of photorefraction by Plusoptix A12 and cycloplegic autorefraction in children

BACKGROUND

Plusoptix photoscreeners are capable of measuring refractive errors of children from 1 meter distance, without cyloplegia. We aimed to compare refractive data obtained from the newest version of Plusoptix (model 12) with cycloplegic autorefraction.

METHODS

We examined 111 consecutive children aged 3-7 years first by Plusoptix A12C under manifest condition and subsequently for cycloplegic refraction by Topcon KR-1 tabletop autorefractometer. Sphere, spherical equivalent, cylinder and axis of astigmatism measured by the two methods were analyzed to determine correlation, agreement and differences.

RESULTS

Binocular examination of 111 children aged 4.86±1.27 years revealed good agreement between refractive data obtained by Plusoptix and cycloautorefraction, according to Bland-Altman plots. Significant (p < 0.001) and strong correlation was found between all refractive measurements (Pearson's r value of 0.707 for sphere, 0.756 for pherical equivalent, and 0.863 for cylinder). Plusoptix mean sphere, spherical equivalent and cylinder were 1.22, 0.56, and -1.32 D, respectively. Corresponding values for cycloautorefraction were 1.63, 1.00, and -1.26 D. The difference between axis of cylinder measured by the two methods was < 10° in 144 eyes (64.9%).

CONCLUSIONS

Considering the significant agreement and correlation between Plusoptix photoscreener and cycloplegic autorefraction, the need for cycloplegic drops in refractive examination of children may be obviated. The mean difference between cylinder measurements are considerably trivial (0.06 D), but sphere is approximately 0.4 D underestimated by Plusoptix compared to cycloautorefraction, on average.

Effects of cycloplegia on crystalline lens morphology and location in acute acquired concomitant esotropia

PURPOSE

The study aims to compare morphology and location of crystalline lens between acute acquired concomitant esotropia (AACE) patients and control subjects, both before and after cycloplegia.

METHODS

This is a prospective and observational clinical study. Morphological and locational parameters of the crystalline lens in 53 AACE patients and 32 control subjects were assessed before and after cycloplegia using CASIA2 system, which represents the latest swept-source anterior segment optical coherence tomography. Cycloplegic refraction was recorded by administering 1% atropine in patients younger than 12 years and 1% cyclopentolate in those > 12 years old. Morphological parameters included anterior radius of curvature (ARC), posterior radius of curvature (PRC), lens thickness (LTH), and equivalent diameter of lens (LED). Locational parameters comprised lens decentration (LD) and lens tilt (LT). Comparison of these parameters before and after cycloplegia were conducted between AACE and controls. Additionally, the study analyzed and compared the changes in these parameter post-cycloplegia.

RESULTS

Our findings suggest no significant difference in morphological parameters including ARC, PRC, LTH and LED between AACE patients and controls before or after cycloplegia. However, 2D-modeling data in the 0° meridian revealed that variation post-cycloplegia of LD (lens shift) in right eyes was different in AACE patients, measuring - 0.03(0.08) [median(interquartile range)] which was significantly distinct from the control group, exhibiting a measurement of 0.01(0.06) (z =  - 2.373, p = 0.018). In left eyes, a similar trend was observed with lens shift in the 0° meridian being 0.02(0.06) in AACE, significantly differing from control group's measurement of - 0.02(0.08) (z =  - 2.809, p = 0.005). Further, correlation analysis revealed that larger temporal shift of lens was associated with greater changes in ARC (r = 0.294, p = 0.006) and LTH (r =  - 0.230, p = 0.031).

CONCLUSIONS

The morphological features of the crystalline lens were similar in AACE patients and controls; however, the change of lens location by cycloplegia was observed only in AACE patients, suggesting an association with excessive accommodation.

Evaluation of cycloplegic and noncycloplegic performance of spot vision screener in detection of amblyopia risk factors using 2021 AAPOS guidelines

PURPOSE

This research evaluates the effectiveness of the Spot Vision Screener (SVS) before and after cycloplegia to detect amblyogenic refractive errors in children.

METHODS

Children ages 3 to 10 years old were screened by the SVS before and after cycloplegia. Sensitivity, specificity, positive and negative predictive value, paired t-test, Bland-Altman plot and receiver operating characteristic area under the curve were evaluated by comparing the results of the SVS (v3.0.05) measurements with the results of the cycloplegic Topcon autorefractometer according to the 2021 guidelines of the American Association for Pediatric Ophthalmology and Strabismus.

RESULTS

Both eyes of 211 patients aged 3 to 10 years old were included. Regarding the amblyopia risk factors, the noncycloplegic SVS had 65.7 % sensitivity, 94.9 % specificity, 81.2 % positive predictive value and 89.3 % negative predictive value. The SVS's sensitivity increased from 65.7 % to 81.9 % with cycloplegia compared to noncycloplegic SVS results. The sensitivity detection of hyperopia was improved from 4.2 % to 100 % after cycloplegia. Areas under the receiver operator characteristic curve for noncycloplegic SVS and cycloplegic SVS were 0.506 (95 % CI, 0.395 to 0.646, p = 0737) and 0.905 (95 % CI, 0.915 to 0.971, p < 0.001) for hyperopia, respectively. Using the +1.64 D revised cutoff criteria for hyperopia increased sensitivity from 4.2 % to 78 %.

CONCLUSION

Noncycloplegic SVS measurements showed relatively high specificity in detecting amblyopia risk factors. The fact that noncycloplegic measurements have a very low sensitivity for hyperopia is an important weakness of the SVS, especially because hyperopia is the most frequently encountered refractive error in very young children. It should be noted that amblyogenic hyperopia may be overlooked by an SVS without cycloplegia.

Mean cycloplegic refractive error in emmetropic adults - The Tehran Eye Study

PURPOSE

In children under 20 years, refractive development targets a cycloplegic refractive error of +0.5 to +1.5D, while presbyopes over 40 years generally have non-cycloplegic errors of ≥ +1D. Some papers suggest these periods are separated by a period of myopic refractive error (i.e., ≤ -0.50D), but this remains unclear. Hence, this work investigates the mean cycloplegic refractive error in adults aged between 20 - 40 years.

METHODS

In 2002 a cross-sectional study with stratified cluster sampling was performed on the population of Tehran, providing cycloplegic and non-cycloplegic refractive error data for the right eyes of 3,576 participants, aged 30.6 ± 18.6 years (range: 1-86 years). After grouping these data into age groups of 5 years, the refractive error histogram of each group was fitted to a Bigaussian function. The mean of the central, emmetropized peak was used to estimate the mean refractive error without the influence of myopia.

RESULTS

The mean cycloplegic refractive error at the emmetropized peak decreased from +1.10 ± 0.11D (95 % confidence interval) to +0.50 ± 0.04D before 20 years and remains stable at that value until the age of 50 years. The non-cycloplegic refractive error also sees a stable phase at 0.00 ± 0.04D between 15 - 45 years. After 45 - 50 years both cycloplegic and non-cycloplegic refractive error become more hypermetropic over time, +1.14 ± 0.12D at 75 years.

CONCLUSIONS

The cycloplegic refractive error in adults is about +0.50D between 20 - 50 years, disproving the existence of the myopic period at those ages.

Comparison between wavefront-derived refraction and auto-refraction

BACKGROUND

This study aimed to compare objective refractive errors and keratometry measurements obtained using the Nidek OPD-Scan II aberrometer/topographer and Topcon KR 8900 autorefractokeratometer.

METHODS

The right eye medical records of 176 patients aged 18-35 years who were admitted to our clinic as refractive surgery candidates were tested for refractive status and keratometry measurements with a Nidek OPD-Scan II aberrometer/topographer and a standard table-top autorefractokeratometer (Topcon KR 8900) before and after the induction of cycloplegia. Patients who had undergone any eye surgery and had hereditary, ectatic, or acquired corneal pathology were excluded. Refractive data were compared as spheres, cylinders, spherical equivalents, and power vectors before and after the induction of cycloplegia. Flat and steep keratometry (K1-K2) readings were recorded in diopters (D) and axis degrees, respectively, for each eye.

RESULTS

The spherical, cylindrical, spherical equivalence, J0-J45 vector values and K1-K2 readings (D, axis) between the two devices were statistically significant before and after the induction of cycloplegia (p<0.05). Bland-Altman analysis identified mean differences (95%CI of limits of agreement) of 0.77 (-0,57 to 2,11) in sphere, 0.74 (-0,54 to 2,01) in spherical equivalent, -0,07 (-0,41 to 0,26) in J0 vector, 0,06 (-0,31 to 0,43) in J45 vector, -0,16 (-0,66 to 0,33) in K1, -0,23 (-0,79 to 0,33) in K2 values before induction of cycloplegia.

CONCLUSION

The refractive and keratometry results of the Nidek OPD Scan II system and Topcon KR 8900 standard table-top autorefractokeratometer are not interchangeable in healthy adult population before and after induction of cycloplegia.

Effects of atropine and tropicamide on ocular biological parameters in children: a prospective observational study

BACKGROUND

The effectiveness of cycloplegia in delaying the progression of myopia and its application in refractive examination in children have been extensively studied, but there are still few studies on the effects of atropine/tropicamide on ocular biological parameters. Therefore, the purpose of this study was to explore the effects of atropine/tropicamide on children's ocular biological parameters in different age groups and the differences between them.

METHODS

This was a prospective observational study in which all school children were examined for dioptres and ocular biological parameters in the outpatient clinic, and 1% atropine or tropicamide was used for treatment. After examination, we enrolled the patients grouped by age (age from 2 to 12 years treated by atropine, 55 cases; age from 2 to 10 years treated by tropicamide, 70 cases; age from 14 to 17 years treated by tropicamide, 70 cases). The ocular biological parameters of each patient before and after cycloplegia were measured, and the difference and its absolute value were calculated for statistical analysis using an independent-samples t test.

RESULTS

We compared the value and the absolute value of the differences in ocular biological parameters before and after cycloplegia in the same age group, and we found that the differences were not statistically significant (P > 0.05). There were significant differences in the corresponding values of AL, K1 and ACD among the different age groups (P < 0.05). Before cycloplegia, there were significant differences in AL, K, K1, K2 and ACD in different age groups (P < 0.05). However, the differences in AL, K, K1, K2 and ACD among different age groups disappeared after cycloplegia (P > 0.05).

CONCLUSIONS

This study demonstrated that atropine/tropicamide have different effects on cycloplegia in children of different ages. The effects of atropine/tropicamide on ocular biological parameters should be fully considered when evaluating the refractive state before refractive surgery or mydriasis optometry for children of different ages.

Randomized Trial to Evaluate the Efficacy of the Nanodropper Device for Pupillary Dilation and Cycloplegia in Children

PURPOSE

We evaluated the noninferiority of 10.4 μl of eye drops eluted with a commercially available eye drop adapter, the Nanodropper (Nanodropper, Inc), on pupillary dilation and cycloplegia in children compared with the standard of care (SOC), 50 μl of eye drops.

DESIGN

Prospective randomized trial.

PARTICIPANTS

Pediatric patients scheduled for routine pupillary dilation at the University of California, San Francisco, at the Pediatric Ophthalmology Clinic were enrolled. Each participant provided 1 eye for the intervention group (Nanodropper) and 1 eye for the control group (SOC).

METHODS

Participants were randomized to receive small-volume dilating drops in 1 eye (Nanodropper) and SOC dilating drops in the other eye. Dilation was performed using 1 drop each of 1% cyclopentolate, 1% tropicamide, and 2.5% phenylephrine. Refraction and pupillometry were obtained before and 30 minutes after dilation. A noninferiority analysis was performed to assess change from before to after dilation in spherical equivalent and in pupil constriction percentage and maximum pupil diameter after dilation.

MAIN OUTCOME MEASURES

Spherical equivalent, maximum pupil diameter, and pupil constriction percentage.

RESULTS

One hundred eyes of 50 patients were included, with a mean ± standard deviation age of 9 ± 3 years. After controlling for baseline measurements, the spherical equivalent after dilation was 0.05 diopter (D) more (95% confidence interval [CI], -0.28 to 0.37 D) in the Nanodropper arm, which did not achieve noninferiority. Maximum pupil diameter after dilation was lower in the Nanodropper group (mean, -0.01 mm; 95% CI, -0.20 to -0.03), which did achieve noninferiority. Constriction percentage after dilation was 0.57 percentage points more (95% CI, -1.38 to 2.51 percentage points) in the Nanodropper group, which did not achieve noninferiority.

CONCLUSIONS

Administration of eye drops using a small-volume adapter demonstrated similar efficacy to SOC in a pediatric population. Strict noninferiority was met only for pupillary dilation and not for cycloplegia or constriction percentage; however, the small differences in the effect of the Nanodropper versus SOC on all primary outcomes were not clinically significant. We conclude that small-volume eye drops have the potential to decrease unnecessary medical waste and medication toxicity while maintaining therapeutic effect.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Noncycloplegic Compared with Cycloplegic Refraction in a Chicago School-Aged Population

PURPOSE

To evaluate differences between autorefraction measurements with and without cycloplegia among school-aged individuals and to explore factors associated with significant differences.

DESIGN

Cross-sectional, retrospective study.

PARTICIPANTS

Individuals between 3 and 22 years of age evaluated at the Illinois College of Optometry from September 2016 through June 2019 who underwent same-day noncycloplegic and cycloplegic autorefraction of the right eye.

METHODS

Demographic information including age, sex, and race or ethnicity were collected during the eye examination. Autorefraction was performed before and after cycloplegia. Myopia, defined as at least -0.50 diopter (D) spherical equivalent (SE), hyperopia, defined as at least +0.50 D SE, and astigmatism of at least 1.00 D cylinder were determined using noncycloplegic and cycloplegic autorefractions. Factors associated with at least 1.00 D more myopic SE or at least 0.75 D cylindrical difference by noncycloplegic autorefraction were assessed using logistic regression models.

MAIN OUTCOME MEASURES

Differences between noncycloplegic and cycloplegic autorefraction measurements.

RESULTS

The mean age was 10.8 ± 4.0 years for the 11 119 individuals; 52.4% of participants were female. Noncycloplegic SE measured 0.65 ± 1.04 D more myopic than cycloplegic SE. After adjusting for demographic factors and refractive error, individuals with at least 1.00 D of more myopic SE refraction by noncycloplegic autorefraction (25.9%) were more likely to be younger than 5 years (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.18-1.79) and 5 to younger than 10 years (OR, 1.32; 95% CI, 1.18-1.48) than those 10 to younger than 15 years. This difference of at least 1.00 D of more myopic SE was more likely to be observed in Hispanic people (OR, 1.23; 95% CI, 1.10-1.36) and those with hyperopia (OR range, 4.20-13.31). Individuals with 0.75 D or more of cylindrical difference (5.1%) between refractions were more likely to be younger than 5 years, to be male, and to have mild-moderate-high myopia or moderate-high hyperopia.

CONCLUSIONS

Three quarters of school-aged individuals had < 1 D of myopic SE difference using noncycloplegic compared with cycloplegic autorefraction. Understanding measurement differences obtained for refractive error and associated factors may provide useful information for future studies or programs involving refraction in school-aged children.

Correlation and agreement between the Mohindra and cycloplegic retinoscopy techniques in children

PURPOSE

As an objective technique to assess refractive status, retinoscopy is particularly useful in children. The Mohindra technique (RM) is an alternative for those patients not good candidates for cycloplegic retinoscopy (RC). The aim of the present research was to compare both techniques and to determine the correlation and agreement of their measurements.

MATERIAL AND METHODS

A total of 47 boys and girls of ages ranging from 3 to 11 years old were included in the study. Cycloplegic (cyclopentolate 1%) and Mohindra retinoscopy were conducted in both eyes, and refraction was also assessed with an autorefractometre (AR). The results from the three techniques were compared and a correction factor between RM and RC was calculated.

RESULTS

Statistically significant differences were found between RM and RC (median of -0.42 D; p < 0.001) and between RM and AR (median of -0.42 D; p = 0.008), but not between RC and AR (median of 0.00 D; p = 0.758). A strong correlation was found between RM and RC (rho = 0.846; p < 0.001), although the Bland-Altman test revealed a larger difference between these techniques in patients with larger hyperopic refractive errors, with a correction factor of RC = 1.15 RM + 0.42.

CONCLUSIONS

The Mohindra technique may be considered a valid alternative to cycloplegic retinoscopy in patients of young age, with a good correlation between both techniques, albeit less agreement in patients with high hyperopic refractions.

Effect of Topical Cyclopentolate 1% on Ocular Ultrasonographic Features, Intraocular Pressure, Tear Production, and Pupil Size in Normal Donkeys (Equus Asinus)

This study was performed to investigate the effects of cyclopentolate on ultrasonographic parameters of eye structures, intraocular pressure (IOP), tear production, and pupil size in normal donkeys. Sixteen eyes of eight clinically healthy adult donkeys (2-2.5 years old) weighing 295 ± 34 kg (mean ± standard deviation) were used in this study. Cyclopentolate hydrochloride 1% was instilled in a randomly selected eye and the other eye received normal saline drops as a control. The effect of cyclopentolate was evaluated by ultrasonography. Additionally, changes in IOP and tear production were evaluated for 2 hours post-instillation by tonometry and Schirmer tear test (STT), respectively. Vertical and horizontal pupil diameters were recorded pre-instillation (0), and 15, 30-, 45-, 60-, and 120-minutes post-instillation. After cyclopentolate 1% instillation, iridocorneal angle and width of the entry of ciliary cleft were significantly increased as observed by ultrasonography. IOP was significantly increased starting from 30 minutes till 60 minutes post-instillation of cyclopentolate 1%. Non-significant alteration in the STT was observed in the cyclopentolate-treated eyes compared to the control eyes. Both vertical and horizontal pupil diameters began to significantly increase 30 minutes after cyclopentolate 1% instillation compared to the control saline group. In conclusion, cyclopentolate 1% could be used as a potent cycloplegic drug in donkeys without systemic or ocular side effects.

Subtle changes of the crystalline lens after cycloplegia: a retrospective study

BACKGROUND

The purpose of this study was to evaluate the shape of the crystalline lens in terms of biometry and diopters before and after cycloplegia using the CASIA2 swept-source (SS) optical coherence tomography (OCT) system on the anterior segment.

METHODS

This was a retrospective study. Children and adolescents (26 males and 29 females, aged 4-21 years) with simple ametropia were selected for optometry and CASIA2 imaging at 2 separate visits before and after cycloplegia. Diopter values were derived from the spherical power (S) obtained by optometry. Biometric parameters of the crystalline lens, including the anterior chamber depth (ACD), anterior and posterior curvature of the lens (ACL and PCL), lens thickness (LTH), lens decentration (LD), lens tilt (LT), and equivalent diameter of the lens (LED), were measured by the CASIA2 system. The differences in these parameters after compared with before cycloplegia were determined, and their relationships were analyzed.

RESULTS

Fifty-five participants (106 eyes) were initially enrolled. There was a significant difference (P < 0.05) in the S (t=-7.026, P < 0.001), ACD (t=-8.796, P < 0.001), ACL (t=-13.263, P < 0.001) and LTH (t = 7.363, P < 0.001) after compared with before cycloplegia. The change in the PCL (t = 1.557, P = 0.122), LD (t = 0.876, P = 0.383), LT (t = 0.440, P = 0.661) and LED (t=-0.351, P = 0.726) was not statistically significant (P > 0.05). There was a significant (P < 0.05) correlation of the change in the S with that in the ACL (r = 0.466, P < 0.001), LTH (r=-0.592, P < 0.001), and LED (r = 0.223, P = 0.021) but not the PCL (r = 0.19, P = 0.051), LD (r=-0.048, P = 0.0628) or LT (r=-0.022, P = 0.822). Furthermore, the change in the ACD was closely related to the change in crystalline morphology. However, in children and adolescents, we found that the change in crystalline morphology was unrelated to age.

CONCLUSIONS

Changes in lens morphology after compared with before cycloplegia are mainly related to the ACL and LTH, but there is no difference in the PCL, LD, LT, or LED. In the adolescent population, change in the S is related to change in the ACL, LED and LTH. However, age is unrelated to the shape and tendency of the crystalline lens. Further research is required to determine whether the same conclusion applies to different age groups and different refractive states (myopia, hyperopia, emmetropia) .

[Significant Increase in Astigmatism after Cycloplegia in Two Children]

Two cases with high corneal astigmatism and mixed astigmatism were reported. Both cases showed significantly increased astigmatism after cycloplegia. Combined with the patients' refractive error, corneal topography and wavefront aberration changes, the possible causes were analyzed. Aberration changes caused by pupil dilation, corneal astigmatism differences in different diameter ranges, and changes in lens astigmatism before and after cycloplegia may lead to increased astigmatism after cycloplegia. It was found that cycloplegic refraction may not accurately reflect the refractive status in daily life for children with high corneal astigmatism, especially mixed astigmatism. Because children need refractive correction in the state of natural pupil, it is recommended that the cycloplegic refraction result could not be directly used as prescription for such children. The final prescription should be based on the topography and the refraction result under natural pupil.

The Effect of Cycloplegia on the Ocular Biometric and Anterior Segment Parameters: A Cross-Sectional Study

Introduction

To evaluate the effects of cycloplegia on the biometric components and anterior segment parameters of the eye.

Methods

In this cross-sectional study, changes to axial length (AL), anterior chamber depth (ACD) lens thickness, anterior chamber angle (ACA) and volume, corneal thickness in the pupil center (PC), corneal curvature (CC) and white-to-white (WTW) following cycloplegia induced by tropicamide 1% in 42 eyes of patients aged 23–58 years were assessed. Biometric components and anterior segment parameters were measured using an IOLMaster 700 (Carl Zeiss Meditec, Jena, Germany) and a Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany), respectively.

Results

Significant statistical changes in ACD (increased by 0.06 ± 0.05 mm; p < 0.001), anterior chamber volume (increased by 15.19 ± 10.32 mm³; p < 0.001), ACA (decreased by 2.18 ± 10.20°; p = 0.029) and lens thickness (decreased by 0.02 ± 0.03 mm; p < 0.001) were observed post-cycloplegia, while the changes in CC, corneal thickness in the PC, WTW and AL were not statistically different (p > 0.05). Also, a significant inferior displacement of the PC along the vertical axes was seen (p = 0.020).

Conclusion

Cycloplegia resulted in a deeper ACD and thinner lens thickness. These changes should be considered in determining intraocular lens (IOL) power to prevent refractive surprises in cataract surgery and also in the phakic IOL implantation.

[Amblyopia-Basic principles and current diagnostic and therapeutic standards]

Amblyopia is a visual deficit that occurs during childhood and results in an abnormal development of the normal cortical visual pathway. It is defined as the reduction of best corrected visual acuity of one or rarely both eyes, which is not explained by structural abnormalities of the eye alone. During the sensitive period amblyopia is completely or partially reversible. The main causes of amblyopia are strabismus and refractive errors. Congenital cataracts are less common but if present may cause pronounced amblyopia. In Germany the prevalence of Amblyopia is approximately 5%, which is relatively high in relation to other countries, even though data are not completely comparable. As amblyopia can only be successfully treated during the first years of life, early detection of amblyogenic factors is important. Screening tests help in identifying children at risk of amblyopia, while only a thorough ophthalmological examination including cycloplegic refraction reliably detects all risk factors of amblyopia. Treatment consists of removal of the amblyogenic factors and stimulation of the amblyopic eye.

Evaluation of ocular motility deviation changes in exotropic patients after cycloplegic eye drops versus prism adaptation test

PURPOSE

To evaluate changes in ocular motility deviation with cycloplegic eye drop examination compared to the prism adaptation test in patients with strabismus.

METHODS

The medical charts were reviewed of all patients who underwent primary strabismus surgery in our center from December 2013 to July 2015. Data collected included demographics, medical history, and findings on pre-operative ophthalmic/orthoptic examination. Ocular motility deviation was measured before instillation of cycloplegic eye drops, immediately after maximal dilation (end point), and 10 and 20 min later. Prism adaptation test readings were taken at baseline, immediately after prism removal (end point), and 10 and 20 min later.

RESULTS

A total of 43 patients had complete pre- and post-operative evaluations. Our analysis focused only on the exotropic patients (n = 33). On cycloplegics, there was no significant difference in ocular motility deviation between baseline and end point for distance and near (p = 0.584, p = 0.468, respectively). On prism adaptation test, comparison of ocular motility deviation between baseline and end point was statistically significant for distance and near (p = 0.002, p = 0.001, respectively). Changes remained significant 10 min after the end point for near (p = 0.011). Comparison at the end points between the tests revealed statistical significance for distance and near, favoring the prism adaptation test (p = 0.001 and p < 0.001, respectively). This significance was maintained even after 10 min for near (p = 0.036).

CONCLUSION

The prism adaptation test is preferred over cycloplegic eye drops for the evaluation of maximal reserve of distance/near motility before surgical correction of exotropia.

Comparison of cyclopentolate versus tropicamide cycloplegia: A systematic review and meta-analysis

PURPOSE

The aim of the present meta-analysis is to compare the efficacy of cyclopentolate and tropicamide in controlling accommodation during refraction.

METHODS

A comprehensive literature search was performed in PubMed, Scopus, Science direct and Ovid databases by the key words: "tropicamide"; "cyclopentolate"; "cycloplegia" and "cycloplegic" from inception to April 2016. Methodological quality of the literature was evaluated according to the Oxford Center for Evidence Based Medicine and modified Newcastle-Ottawa scale. Statistical analyses were performed using Comprehensive Meta-Analysis (version 2; Biostat Inc., USA).

RESULTS

The present meta-analysis included six studies (three randomized controlled trials and three case-control studies). Pooled standardized difference in the mean changes in the refractive error was 0.175 D [lower and upper limits: -0.089; 0.438] more plus in the cyclopentolate group compared to the tropicamide group; however, this difference was not statistically significant (p=0.194; Cochrane Q value=171.72 (p<0.05); I²=95.34%). Egger's regression intercept was -5.33 (p=0.170). Considering type of refractive errors; refractive assessment procedure and age group; although cycloplegic effect of cyclopentolate was stronger than tropicamide; however, this effect was only statistically significant in children; hyperopic patients and with retinoscopy.

CONCLUSION

We suggest that tropicamide may be considered as a viable substitute for cyclopentolate due to its rapid onset of action. Although these results should be used cautiously in infants and in patients with high hyperopia or strabismus when using tropicamide as the sole cycloplegic agent especially in situations that the findings are variable or there is no consistency between the examination results and clinical manifestations of the visual problems.

Effect of Cycloplegia on Corneal Biometrics and Refractive State

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.

Increase in esodeviation under cycloplegia with 0.5% tropicamide and 0.5% phenylephrine mixed eye drops in patients with hyperopia and esotropia

Backgroud

To evaluate the manifestations of increased esodeviation under cycloplegia with 0.5% tropicamide and 0.5% phenylephrine in children with hyperopia and esotropia.

Methods

We reviewed the medical record of 34 children with hyperopia and esotropia who underwent a prism alternate cover test before and after instillation of mixed eye drops containing 0.5% tropicamide and 0.5% phenylephrine between November 2014 and October 2015. Increased angle of deviation was defined as 10 prism diopters (PD) or greater deviation after cycloplegia. The factors related to increased angle of deviation were evaluated using univariable and multivariable logistic regression analysis.

Results

The median age was 5.0 years (interquartile range, 3.75 to 5.0) and 12 patients (35.3%) were male. The median manifested refractive (MR) was +2.13 diopters (D) (+0.92 to +4.47) and cycloplegic refractive (CR) was +3.50 D (+1.72 to +5.66). The median difference between MR and CR was +0.88 D (+0.50 to +1.28). Thirteen patients (38.2%) showed increased esodeviation under cycloplegia and all had accommodative esotropia. A larger difference between MR and CR was the only significant factor affecting increased esodeviation in both univariable (OR = 4.72, P = 0.029) and multivariable (OR = 5.22, P = 0.047) analyses.

Conclusion

Children with hyperopia and esotropia often showed an increased angle of deviation after instillation of 0.5% tropicamide and 0.5% phenylephrine. This phenomenon reminded the clinicians that cycloplegics can have a different effect on esodeviation and suggested that increased angle of esodeviation may help to reveal the latent deviation in some patients with hyperopia and esotropia.

Onset and duration of cycloplegic action of 1% cyclopentolate - 1% tropicamide combination

PURPOSE

To study the time course (onset, time and duration of maximal cycloplegia, and the full duration) of cycloplegic action of 1% Cyclopentolate - 1% Tropicamide.

METHODS

Seventy-seven students, aged 15-24 years were purposively sampled from the University of Cape Coast and Cape Coast Technical Institute. Subjective near addition (ADD) determination and pupil diameter measurement before and after a drop of the test agent (1% Cyclopentolate - 1% Tropicamide combination in the right eye) and the control (1% Cyclopentolate in the left eye) were performed. Measurements of subjective near ADD and pupil diameter were made after the initial reading at 5 minutes interval for the first hour and every 30 minutes for the next 7 hours for each participant. Time of onset, time of peak cycloplegia, duration of peak cycloplegia and duration of total cycloplegic effect was indirectly determined.

RESULTS

1% Cyclopentolate - 1% Tropicamide combination had rapid onset of cycloplegia (5-10 minutes), shorter time of maximal cycloplegia (55 versus 90 minutes), and recovery (7 versus ≥ 8hours) in the majority (79.2%) of subjects.

CONCLUSION

Cyclopentolate -Tropicamide combination was comparable to Cyclopentolate in depth of cycloplegia produced, and clinically superior to 1% Cyclopentolate in rapidity of cycloplegic onset, time of maximal cycloplegia and recovery from cycloplegia.

Evaluating relaxed ciliary muscle tone in presbyopic eyes

PURPOSE

Studies of age-related changes in ciliary muscle (CM) morphology and contractility have variously reported that CM weakens or strengthens with age. In response, the aim of this study was to evaluate relaxed CM tone in vivo in pre-presbyopic and presbyopic patients using a predictor value (P_CM).

METHODS

Two groups of eyes-40 eyes of 40 healthy volunteers with a mean age of 28.1 ± 5.8 years and 40 eyes of 40 healthy volunteers with a mean age of 56.6 ± 7.3 years-formed the sample for this prospective, observational cross-sectional study. Used to evaluate relaxed CM tone, P_CM was calculated as the difference between the change in mean anterior chamber depth (ACD) and lens thickness (LT) before and after cycloplegia, as measured with swept-source optical biometry.

RESULTS

The P_CM for relaxed CM tone was 0.04 ± 0.04 mm in pre-presbyopic participants, 0.06 ± 0.03 mm in presbyopic ones, and significantly greater in presbyopic patients (p = .018).

CONCLUSION

The statistical significance of P_CM between pre-presbyopic and presbyopic eyes might not signify clinical significance, since the difference was close to the repeatability limits for swept-source optical biometry. When relaxed, CM tone does not diminish with presbyopia according to changes in anterior chamber parameters due to cycloplegia.

Does astigmatism alter with cycloplegia?

PURPOSE

To determine the effect of the cyclopentolate 1% on the cylindrical and spherical components of the refraction.

METHODS

Three hundred seventy-five eyes of 195 subjects, including 74 males and 121 females, aged from 3 to 59 years were refracted before and 30 min after cyclopentolate 1% eye drop instillation. To compare cylindrical data, power vector analysis (J0 and J45 cross cylinder) was applied.

RESULTS

A statistically significant difference between the J0 values of the noncycloplegic and cycloplegic refraction was revealed (P = 0.006) while the J45 values did not significantly differ. 95% limit of agreement for dry and cycloplegic values of the J0 and J45 were -0.22 to 0.25 and -0.19 to 0.20, respectively. Astigmatism difference was separately analyzed in emmetropic, myopic and hyperopic eyes. The J0 difference was significant (P = 0.014) only in hyperopic eyes. Spherical equivalent (SE) values in cycloplegic refraction were significantly more hyperopic than those yielded in dry refraction by mean difference of +1.16 ± 1.20 diopters (P < 0.0001). Spherical equivalent difference (SED) values were negatively correlated with age.

CONCLUSIONS

Our findings indicated that cycloplegic drops caused a statistically significant shift in the "with the rule" and "against the rule" astigmatisms, although the oblique astigmatisms remained unaffected. Further research with larger sample sizes are needed to answer what mechanisms are involved in changing cylinder with cycloplegia.

Accuracy of PlusOptix A09 distance refraction in pediatric myopia and hyperopia

Background

The PlusOptix photoscreeners (PlusOptix GmbH, Nuremberg, Germany) is used in many vision screening programs. The purpose of the present study was to further explore the accuracy of the PlusOptix A09 photoscreener in children with ametropia (myopia or hyperopia).

Methods

A total of 70 eyes (35 children) were prospectively included. Before administration with the cycloplegia treatment 1 % cyclopentolate hydrochloride, children underwent refraction measurement with the PlusOptix A09. A refraction was then performed after cycloplegia with either Retinomax hand-held or Nidek autorefractor before and after 3 years old, respectively.

Results

The median (interquartile range) age was 58 (18 to 86) months. The mean (SD) spherical equivalent differed between PlusOptix A09 and cycloplegic autorefraction (+0.54 [1.82] D vs +1.06 [2.04] D, p = 0.04). PlusOptix A09 refraction was positively correlated with cycloplegic autorefraction (r = 0.81, p < 0.001) with higher coefficient in myopic than in hyperopic children (r = 0.91, p = 0.0002 and r = 0.52, p = 0.01, respectively). The mean (SD) difference between PlusOptix A09 and cycloplegic autorefraction was higher with hyperopia than myopia (0.73 [1.34] vs 0.05 [0.66], p = 0.01). The proportion of children with < 1-D difference between cycloplegic and PlusOptix A09 refraction was 68.8 %, higher with myopia than hyperopia (90 % vs 54.5 %, p = 0.01).

Conclusion

The spherical equivalent value with non-cycloplegic PlusOptix A09 refraction is closer to that with cycloplegic autorefraction than non-cycloplegic autorefraction. The PlusOptix A09 photoscreener underestimated the hyperopia of 0.73 D and slightly overestimated myopia of 0.05 D. The PlusOptix A09 could be used for screening with higher accuracy in myopic than hyperopic children.

Effect of tropicamide and homatropine eye drops on a-scan parameters of the phakic normal eyes

OBJECTIVES

A prospective study to evaluate the changes in A-Scan axial parameters of phakic normal eyes before and after instillation of 1% topical Tropicamide and 2% Homatropine eye drops.

METHODS

Anterior chamber depth, lens thickness, vitreous chamber length, and ocular axial length were measured in 76 eyes before and after cycloplegia induced by 1% topical Tropicamide, and in 28 eyes with 2% Homatropine eye drops.

RESULTS

Anterior chamber depth demonstrated increase from baseline readings with Tropicamide and Homatropine eye drops, while lens thickness showed decrease from the baseline readings with both eye drops. Effect of both the eye drops on over all axial length and vitreous chamber length is statistically seen, but is clinically negligible and not significant.

CONCLUSION

Cycloplegia induced by 1% Tropicamide eye drops and 2% Homatropine eye drops has a significant measurable influence on anterior chamber depth and lens thickness, while vitreous chamber length and overall axial length demonstrated negligible statistical difference on A-Scan parameters of the normal phakic eyes.