Changes In Anterior Chamber Depth Research Articles

Retinal image size in pseudophakia.

Approaches are developed to determine relative retinal magnifications in anisometropic patients undergoing cataract surgery; these can be used to balance between full spectacle corrections with equal intraocular lens (IOL) powers and a pure IOL power correction. The analysis started from the original and pseudophakic Navarro eye models, where in the latter case an IOL replaced the natural lens. A third model was a simplified Navarro-IOL model with a single surface cornea and a thin lens. These models were manipulated by altering vitreous length, corneal power and lens position. Retinal image sizes were determined for both full IOL corrections and full spectacle corrections by raytracing and approximate equations. Relative magnification (RM) was determined as the ratio of retinal image size of an eye to that of the appropriate standard eye. For raytracing and full IOL correction, vitreous length led to RM change of 5%/mm, while for corneal power and IOL position this was -0.4%/D and 1.4%/mm, respectively. For raytracing and spectacle correction, effects were 0%/D (vitreous depth), -1.6%/D (corneal power) and +1.0%/mm (IOL position). For full IOL correction, the approximate RM calculations were highly accurate. For spectacle correction, the approximate RM calculations were exact for vitreous length changes, reasonably accurate for corneal power changes but very inaccurate for changes in anterior chamber depth. Relative magnification approximations may be useful to assess the risk of aniseikonia in anisometropic patients targeted for postoperative emmetropia. Some of these patients would be corrected best by a combination of spectacles and IOLs.

Biometric assessment of pseudophakic subjects during objective accommodative stimulation: a prospective observational study

ABSTRACT Clinical relevance: Ultrasound biomicroscopy is an objective method for assessing changes in anterior segment biometry. There is a paucity of data on the reliability of this method. A reliable method for assessing anterior segment changes during physiologically driven accommodation can be a useful tool for clinicians, researchers, and industry. Background: To assess the test–retest reliability of ultrasound biomicroscopy for measurements of change in anterior chamber depth during a distance to near fixation task in pseudophakic subjects. Methods: Subjects were adults with monofocal intraocular lenses implanted in both eyes who completed a 6-month post-operative period and had monocular uncorrected distance visual acuity of 6/15 (0.4 logMAR) or better. The change in anterior chamber depth during a distance to near fixation task was measured with a 35-MHz VuMAX HD ultrasound biomicroscopy device (Sonomed Escalon, New Hyde Park, NY) during two separate visits. An asymmetrical vergence paradigm allowed evaluation of anterior segment biometry at 22-µm axial resolution in one eye, while the fellow eye fixated on the target. To assess the test–retest reliability, 2-sided 95% CI from a paired t test was calculated for the difference in anterior chamber depth change from distance to near between visits. Results: The mean (standard deviation) near-focused anterior chamber depth measured by ultrasound biomicroscopy was 4.331 (0.237) and 4.333 (0.241) mm at visits 1 and 2, respectively. In response to a change in fixation from distance (4 m) to near (40 cm), the mean anterior chamber depth change was −0.012 (0.038) and 0.003 (0.039) mm at visits 1 and 2, respectively. Analysis of the difference in the change in anterior chamber depth between visits was −0.015 mm (95% CI, −0.035 to 0.003). Conclusion: Ultrasound biomicroscopy is a repeatable, objective method for assessing change in anterior segment biometry during physiological changes in fixation from distance to near.

Anterior chamber changes assessment by Scheimpflug analysis after intravitreal dexamethasone implantation.

To evaluate structural changes in the anterior chamber and intraocular pressure (IOP) changes following intravitreal dexamethasone implantation. Forty-two eyes of 42 patients that received intravitreal dexamethasone implant for the management of macular edema secondary to diabetic retinopathy or branch retinal vein occlusion (BRVO) were included in the study. IOP was measured by Goldmann applanation tonometry. Anterior chamber depth (ACD) and iridocorneal angle (ICA) was measured by a Scheimflug camera (Sirius, CSO, Italy) the day before the injection of the dexamethasone implant and on postoperative day 1, first week, and first month. Mean IOP was 15.14 ± 2.77 mmHg before the procedure and, 15.67 ± 3.70 mmHg, 15.86 ± 3.11 mmHg, 16.21 ± 2.75 mmHg on day 1, first week, and first month following intravitreal dexamethasone implantation, respectively. Mean ICA and ACD were significantly higher in pseudophakic eyes compared to phakic eyes. However, there was no statistically significant change in ICA before and after the procedure (on postoperative day 1, first week, and first month) among both phakic and pseudophakic patients (p = 0.783). Similarly, ACD remained unchanged after the procedure (on postoperative day 1, first week, and first month) compared to the initial measurement (p = 0.802). This study confirmed that there was an increase in IOP. However, these changes were not accompanied with a change in ACD or ICA.

Impact of Pseudoexfoliative Syndrome on Effective Lens Position, Anterior Chamber Depth Changes, and Visual Outcome After Cataract Surgery.

PurposeTo compare the effective lens position (ELP), anterior chamber depth (ACD) changes, and visual outcomes in patients with and without pseudoexfoliation syndrome (PEX) after cataract surgery.DesignProspective, randomized, fellow-eye controlled clinical case series.MethodsThis prospective comparative case series enrolled 56 eyes of 56 consecutive patients with (n = 28) or without PEX (n = 28) and clinically significant cataract who underwent standard phacoemulsification and were implanted with single-piece acrylic posterior chamber intraocular lenses (IOLs). The primary outcome parameters were the ACD referring to the distance between the corneal anterior surface and the lens anterior surface, which is an indicator of the postoperative axial position of the IOL (the so-called ELP) and distance corrected visual acuity (DCVA).ResultsBefore surgery, the ACD was 2.54 ± 0.42 mm in the PEX group and 2.53 ± 0.38 mm in the control group (p = 0.941). Postoperatively, the ACD was 4.29 ± 0.71 mm in the PEX group and 4.33 ± 0.72 mm in the normal group, respectively (p = 0.533). There was no significant difference in ACD changes between groups (PEX group: 1.75 ± 0.74 mm, control group: 1.81 ± 0.61 mm, p = 0.806) and DCVA pre- (p = 0.469) and postoperatively (PEX group: 0.11 ± 0.13 logMAR, control group: 0.09 ± 0.17 logMAR, p = 0.245) between groups.ConclusionPreoperative and postoperative ACD, as an indicator of ELP, between PEX eyes and healthy eyes after cataract surgery showed no significant difference. Phacoemulsification induced similar changes in eyes with PEX compared to healthy eyes.

Refractive outcome of combined phacoemulsification and glaucoma surgery in patients of primary "open-angle glaucoma"

Introduction Glaucoma and cataracts are the leading causes of blindness worldwide. Treatment of either condition can influence the course of the other. Trabeculectomy induces changes to anterior chamber depth, axial length (AL), and corneal curvature, which could influence the accuracy of intraocular lens power calculations in combined surgery. Aim Assessment accuracy of intraocular lens calculation and refractive outcome after combined surgery versus cataract surgery (phacoemulsification) alone for coexisting cataract and glaucoma. Patients and methods Our study is a prospective nonrandomized comparative study of 43 consecutive patients (60 eyes) with cataract with coexisting glaucoma who had undergone phacotrabeculectomy (group 1) or phacoemulsification only (group 2). The biometry prediction error was determined for each case by the difference between the actual postoperative refraction and the preoperative predicted refraction in a spherical equivalent followed by comparative analysis of mean absolute refractive error, best-corrected visual acuity, and intraocular pressure (IOP) before and after surgery at 1, 3 months postoperatively. Results In both groups, best-corrected visual acuity was improved and IOP was decreased significantly. Mean absolute refractive error at 1, 3 months postoperatively was not significantly different between two groups (P>0.05) with more cylindrical changes and myopic shifts in group 1 due to high bleb, conjunctival or scleral suture, and changes in anterior chamber depth. Conclusion Phacotrabeculectomy may be an effective treatment with stable long-term outcomes of prediction error similar to phacoemulsification in patients with glaucoma. However, it is more effective in lowering IOP.

Changes in ocular morphology after cataract surgery in open angle glaucoma patients

The purpose of this study was to evaluate intraocular pressure (IOP) pre- and postoperatively, together with anterior chamber angle (ACA) parameters and biometrical results in cataract patients with or without open angle glaucoma (OAG). The prospective observational case–control study included 15 eyes with cataract and OAG in the glaucoma group and 25 eyes with only cataract in control group. Examination included full ophthalmic evaluation, IOP, ocular biometry and anterior segment optical coherence tomography measuring ACA pre- and 6 months postoperatively. OAG patients had a larger absolute IOP reduction compared to control group. Anterior chamber depth (ACD) and ACA width significantly increased in both groups. The OAG group had a tendency of narrower ACA preoperatively, but overall ACA parameters did not differ in either group pre- and postoperatively. The ACD change after surgery correlated with ACA parameters in the control group, but not in OAG group. Axial length was shorter postoperatively in the control group, but remained similar in the OAG group. Absolute IOP reduction was more pronounced in cataract patients with OAG than in cataract patients without glaucoma. ACD and ACA postoperatively increased in both groups and AL shortening was observed in non-OAG in cataract group.

The Role of Anterior Chamber Depth on Post-operative Refractive Error After Phacovitrectomy.

PurposeTo investigate the effect of phacovitrectomy on the post-operative anterior chamber depth (ACD) and refractive outcomes, and to analyze the potential differences between vitreous filling with BSS, air and gas.MethodsPatients who underwent phacovitrectomy were included in this study and invited for repeated post-operative examination including refraction and biometry at least 3 months after the surgery. Data retrieved included demographic information, indication for phacovitrectomy, surgical details, type of vitreous filling (BSS, air or gas), pre-operative and post-operative biometric data including K-readings, axial length (AL), and ACD, as well as spherical equivalent (SE) values of the target and final refraction.ResultsForty-three eyes of 43 patients were included in this study, including 10 eyes filled with BSS, 18 with air and 15 with gas. The mean difference between the final measured spherical equivalent (SE) and the SE of the intended target refraction was 0.61±0.68 D (p = 0.019). Only 58.1% of eyes had a final SE within ±0.5D of the target refraction. Following surgery, AL remained unchanged, while mean pre-operative ACD increased significantly from 3.11±0.34 mm to 4.77±0.47 mm (p < 0.001). There was no difference in refractive error between the vitreous fillings and no correlation with AL or ACD.ConclusionsPhacovitrectomy is associated with lower accuracy of post-operative refraction compared to cataract surgery. This may be attributed to a significant change in ACD, influencing the effective lens position of the IOL, and may require adjustment of the pre-operative calculations.

Influence of the “Inverted U Method” Nd: YAG Laser Posterior Capsulotomy on Anterior Segment Parameters, Decentration and Tilt of Intraocular Lens in Patients after Phaco-vitrectomy

ABSTRACT Purpose To investigate the effects of the “inverted U method” Nd:YAG laser posterior capsulotomy on anterior segment parameters, decentration and tilt of intraocular lens (IOLs) and visual acuity in posterior capsular opacification (PCO) patients after combined phaco-vitrectomy. Methods Seventy-six patients (76 eyes) were enrolled in this study, who were diagnosed as PCO and underwent “inverted U method” Nd:YAG laser posterior capsulotomy. All patients had undergone previous combined phaco-vitrectomy for rhegmatogenous retinal detachment. The parameters including IOL decentration, angle of IOL tilt, anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), keratometry, pupil size, axial length (AL), intraocular pressure (IOP), refractive status, corrected distance visual acuity (CDVA), objective scattering index (OSI) and Chinese version of Visual Function 14 (VF-14) index were obtained before and 3 months after capsulotomy. Results After capsulotomy, the tilt angle and decentration of the IOLs at both vertical (tilt: p = .004, decentration: p = .029) and horizontal meridian (tilt: p = .001, decentration: p = .017) were significantly decreased, ACA increased (p = .015), CDVA (p = .000), VF-14 score (p = .000) and OSI (p = .000) were significantly improved. There were a significant decrease in cylindrical error (p = .001) and a myopic shift in spherical error (p = .001) after the capsulotomy. No significant differences in ACD, ACV, CCT, keratometry, pupil size, AL and IOP were detected (p > .05 for all). Conclusion The “inverted U method” Nd: YAG laser posterior capsulotomy decreases tilt and decentration of the IOL, increases ACA and causes no change in ACD, ACV, CCT and IOP in patients after phaco-vitrectomy. These changes make a decrease in cylindrical error and a myopic shift in spherical error. Laser capsulotomy significantly improves visual acuity.

Effect of cyclopentolate versus tropicamide on anterior segment angle parameters in three refractive groups

ABSTRACT Clinical relevance Frequent clinical application of cycloplegia in clinical practice makes it essential to assess how this condition influences anterior segment angle parameters. Background This study aims to compare the effects of cyclopentolate and tropicamide on anterior segment angle parameters in three adult refractive groups. Methods Sixty healthy individuals were recruited and assigned into three refractive groups according to inclusion criteria. At baseline visit, anterior segment angle parameters were measured using anterior segment optical coherence tomography in the right eye. All measurements were repeated at two separate visits, one week apart, after administration of tropicamide 1% and cyclopentolate 1% at similar conditions. Main outcome measures were angle‐opening distance, trabecular iris angle, trabecular iris space area and anterior chamber depth. Anterior segment angle parameters were recorded at temporal areas (180 degrees). Results Sixty participants (29 men and 31 women, age: 27.82 ± 4.71-years) completed the experiment. Baseline mean spherical equivalents were +1.52 ± 1.20 D, −0.04 ± 0.33 D and −1.91 ± 0.91-D in hyperopic, emmetropic and myopic groups, respectively. No statistically significant differences were found between tropicamide and cyclopentolate for all angle parameters in three refractive groups. Both drops induced an increase in all parameters in three refractive groups. Analysis between refractive groups revealed that a more hyperopic refraction was associated with less trabecular iris angle, angle‐opening distance and anterior chamber depth parameters in baseline, after tropicamide and cyclopentolate instillations. Conclusions Topical application of cycloplegic eye drops in healthy individuals leads to small but significant changes in anterior chamber depth and anterior segment angle parameters, regardless of refractive status. Moreover, lower values of anterior chamber depth and anterior segment angle parameters in hyperopic individuals after administration of cycloplegic drops should be taken into account during biometric measurement and phakic intraocular lens implantation. Due to shorter effect and recovery time and less ocular/systemic reaction of tropicamide versus cyclopentolate, tropicamide could be a recommended cycloplegic agent for diagnostic and therapeutic procedures.

Accuracy of Intraoperative Aberrometry, Barrett True-K With and Without Posterior Cornea Measurements, Shammas-PL, and Haigis-L Formulas After Myopic Refractive Surgery.

To assess the accuracy of intraoperative aberrometry, the Barrett True-K No History (Barrett TKNH), Barrett TKNH with posterior corneal measurements (Barrett TKNH with PC), Shammas-PL, and Haigis-L formulas in patients with cataract who had prior myopic refractive surgery. This was a retrospective consecutive case series of patients with prior myopic refractive surgery undergoing cataract extraction. Mean absolute error (MAE) and median absolute error (MedAE) of refraction prediction were compared for each formula. Interactions of each biometry measurement were modeled for each formula to evaluate those with the most significant impact on refraction prediction. One hundred sixteen eyes of 79 patients were analyzed. MAE was 0.40 ± 0.33 diopters (D) for intraoperative aberrometry and 0.42 ± 0.31 D for the Barrett TKNH, 0.38 ± 0.30 D for the Barrett TKNH with PC, 0.47 ± 0.38 D for the Shammas-PL, and 0.56 ± 0.39 D for the Haigis-L formulas. Comparisons between formulas were significant for Barrett TKNH versus Barrett TKNH with PC formulas (P = .046), Barrett TKNH with PC versus Shammas-PL formulas (P = .023), and for all comparisons with the Haigis-L formula (P < .001), and not significant for all other comparisons (P > .05). Eyes were within ±0.50 D of prediction 73%, 72%, 69%, 62%, and 52% of the time for intraoperative aberrometry, the Barrett TKNH with PC, Barrett TKNH, Shammas-PL, and Haigis-L formulas, respectively. Corneal asphericity (Q value) was significantly associated with prediction error for all five methods. Changes in anterior chamber depth had a significant impact on Shammas-PL prediction errors. Newer technology using information from the posterior cornea modestly improved outcomes when compared to established methods for intraocular lens selection in eyes that had previous laser refractive surgery for myopia. [J Refract Surg. 2021;37(1):60-68.].

Long-Term Visual and Refractive Stability and Ocular Biometric Changes after Laser-Assisted Subepithelial Keratomileusis for Correction of Myopia: An 8-Year Follow-Up.

Purpose:To assess the long-term visual and refractive stability and ocular biometric changes in low to moderate myopic subjects treated by laser-assisted subepithelial keratomileusis (LASEK).Methods:It is a prospective, interventional study. Included were 70 eyes of 35 patients who underwent LASEK for correction of ≤6 diopters (D) myopia. The uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest refractions, and ocular biometric indices (by Lenstar-LS900, Haag-Streit AG, Koeniz, Switzerland) including keratometry, anterior chamber depth (ACD), aqueous depth (AD), axial length (AL), central corneal thickness (CCT), and lens thickness (LT) were assessed preoperatively and after 6 months and 8 years.Results:Mean preoperative spherical equivalent was −3.99 (standard deviation [SD] =1.38) D which improved to 0.02 (SD = 0.27, P < 0.001) D and −0.10 (SD = 0.31, P < 0.001) D at 6 months and 8 years, respectively. The preoperative AL was not different from postoperative measures at 6 months (P = 0.15) and 8 years (P = 0.47). The ACD and AD decreased during 8 years, while LT increased (all P ≤ 0.001). The changes of LT inversely correlated with changes of ACD (rs = −0.67, P = 0.001 at 6 months and rs = −0.87, P < 0.001 at 8 years) and AD (rs = −0.76, P < 0.001 at 6 months and rs = −0.86, P < 0.001 at 8 years). The CCT and keratometry values reduced at 6 months postoperatively (all P < 0.001) and then did not change up to 8 years (0.21 ≤ P ≤ 0.87).Conclusions:The post-LASEK myopic regression is 0.1 D over 8 years. Ocular biometric values like keratometry, CCT, ACD, AD, and LT have been changed for a long period after LASEK in low to moderate myopia except AL.

Acute Myopic Shift and Change in Anterior Chamber Depth after Intake of Zonisamide

Acute Myopic Shift and Change in Anterior Chamber Depth after Intake of Zonisamide

Changes of Anterior Chamber Depth and Refractive Error after Phacovitrectomy with and without Posterior Capsulotomy

Changes of Anterior Chamber Depth and Refractive Error after Phacovitrectomy with and without Posterior Capsulotomy

Influence of pupil dilation on the Barrett universal II (new generation), Haigis (4th generation), and SRK/T (3rd generation) intraocular lens calculation formulas: a retrospective study

BackgroundDespite the surge in the number of cataract surgeries, there is limited information available regarding the influence of pupil dilation on predicted postoperative refraction and its comparison with recommended various intraocular lens power calculated using the different parameters. We used three different IOL power calculation formulas: Barrett Universal II (Barrett) (5-variable formula), Haigis (3-variable formula), and SRK/T (2-variable formula), in order to investigate the potential effect of pupil dilation on the predicted postoperative refraction (PPR) and recommended intraocular lens (IOL) power calculation.MethodsThis retrospective study included 150 eyes. All variables were measured and calculated using a ZEISS IOL Master 700. The following variables were measured before and after dilation: anterior chamber depth (ACD), lens thickness (LT), white-to-white (WTW). PPR and recommended IOL power were calculated by Barrett, Haigis, and SRK/T IOL calculation formulas. The change in each variable before and after dilation, and the correlations between all changes were analyzed using the Wilcoxon signed-rank test and the Spearman’s rank-order correlation test, respectively.ResultsThe mean absolute change (MAC) in PPR before and after dilation was found to be highest in the Barrett formula. Significant differences were found between each MAC (P < 0.0001). Significant changes were observed before and after dilation in ACD and LT (P < 0.0001), but not in WTW. Using the Barrett and Haigis formulas, there was a significant positive correlation between the change in PPR and change in ACD (P < 0.0001), and a negative correlation between change in PPR and change in LT (P < 0.0001). The correlations were strongest with the Barret formula followed by the Haigis, particularly in terms of LT. Changes in PPR determined by the Barrett formula also demonstrated a significant positive correlation with changes in WTW (P = 0.022). The recommended IOL power determined using Barrett and Haigis changed before and after dilation in 23.3 and 19.3% cases respectively, while SRK/T showed no change.ConclusionsIn terms of PPR and recommended IOL power, pupil dilation influenced mostly the Barrett formula. Given the stronger correlation between the changes in PPR when using Barrett and the changes in ACD, LT, and WTW, changes in ACD, LT, and WTW significantly affect how dilation influences the Barrett formula. Determining how dilation influences each formula and other variables is key to improving the accuracy of IOL calculations.

Cluster analysis reveals patterns of age-related change in anterior chamber depth for gender and ethnicity: clinical implications.

PurposeTo identify patterns of age‐, gender‐ and refractive‐ related changes in Scheimpflug‐based anterior chamber depth across the central 8 mm of chamber width, to derive normative models, potentially useful for angle closure disease diagnosis.MethodsThis was a retrospective, cross‐sectional study. Scheimpflug photography was used to obtain anterior chamber depth measurements at 57 points across the central 8 mm of the chamber width from one eye of each healthy subject (male Caucasians (n = 189), female Caucasians (n = 186), male Asians (n = 165) and female Asians (n = 181)). Sliding window and nonlinear regression analysis was used to identify the age‐related changes in chamber depth. Hierarchical cluster analysis was used to identify test locations with statistically identical age‐related shifts, which were used to perform age‐correction for all subjects, resulting in normative distributions of chamber depth across the chamber width. The model was examined with and without the contribution of spherical equivalent refractive error.ResultsDistinct clusters, demonstrating statistically indistinguishable age‐related changes of chamber depth over time, were identified. These age‐related changes followed a nonlinear regression (fifth or sixth order polynomial). Females tended to have a greater rate of chamber depth shallowing. Incorporating refractive error into the model produced minimal changes to the fit relative to the ground truth. Comparisons with cut‐offs for angle closure from the literature showed that ageing alone was insufficient for identifying angle closure disease.ConclusionsAge‐, ethnicity‐ and gender‐related differences need to be acknowledged in order to utilise anterior chamber depth data for angle closure disease diagnosis correctly. Ageing alone does not adequately account for the angle closure disease process.

A study on post-operative change in intraocular presuure and anterior chamber depth after retinal detachment surgery

Effect of these procedures on the intra-ocular pressure has not received much attention, so it shall be the endeavour of this study to see how different steps in the surgical procedure for retinal detachment surgery influence the intraocular pressure both on the table and in the immediate post-operative period along with changes induced in the anterior segment. We have added an attempt to evaluate the post operative changes in the intra-ocular pressure and anterior chamber depth was analysed. The study was conducted in 50 consecutive cases of both phakic and aphakic retinal detachments, attending the retinal services at Dr VRK Womens Medical College &amp; Tertiary Hospital during the year June2018 – May 2019. The preoperative and immediate post operative intra ocular pressure and anterior chamber depth were measured and serial changes tabulated and analysed. We conclude that, No significant change in anterior chamber depth and width of the angle of the anterior chamber is observed.

Differential Effects on Ocular Biometrics by 0.05%, 0.025%, and 0.01% Atropine: Low-Concentration Atropine for Myopia Progression Study

To evaluate changes in ocular biometrics in groups receiving 0.05%, 0.025%, and 0.01% atropine compared with placebo over 1 year based on the Low-Concentration Atropine for Myopia Progression (LAMP) study. Double-blinded, randomized, placebo-controlled trial. Three hundred eighty-three children aged 4 to 12 years who were assigned randomly to receive 0.05%, 0.025%, 0.01% atropine, or placebo once daily in both eyes and completed the first year of the LAMP study. Cycloplegic spherical equivalent (SE), axial length (AL), corneal curvature (K), and anterior chamber depth (ACD) were measured by IOLMaster. Corneal astigmatism and lens power were calculated. The ocular biometric parameter changes were compared among groups. Contributions to SE progression from ocular parameters were determined and compared among groups. Changes in ocular biometrics and their associations with the changes in SE. Over 1 year, changes in AL were 0.20 ± 0.25 mm, 0.29 ± 0.20 mm, 0.36 ± 0.29 mm, and 0.41 ± 0.22 mm in the 0.05% atropine, 0.025% atropine, 0.01% atropine, and placebo groups, respectively (P < 0.001), with a concentration-dependent response. Corneal power remained stable, and its changes were similar across all atropine concentrations: -0.02 ± 0.14 diopter (D), -0.01 ± 0.14 D, -0.01 ± 0.12 D, and 0.01 ± 0.14 D in the 0.05% atropine, 0.025% atropine, 0.01% atropine, and placebo groups, respectively (P= 0.10). Lens power decreased over time in each concentration, but its changes also were similar across all concentrations: -0.31 ± 0.43 D, -0.38 ± 0.47 D, -0.40 ± 0.43 D, and -0.41 ± 0.43 D in the 0.05% atropine, 0.025% atropine, 0.01% atropine, and placebo groups, respectively (P= 0.24). Changes in ACD remained similar across all concentrations (P= 0.41). The contributions to SE progression from the ocular biometric changes after adjusting for age and gender in each concentration were similar across all groups (P > 0.05). Low-concentrations of atropine (0.05%, 0.025%, and 0.01%) have no clinical effect on corneal or lens power. Antimyopic effects of low-concentration atropine act mainly on reducing AL elongation, and therefore could reduce the risk of subsequent myopia complications.

The Effect of Cyclopentolate on Ocular Biometric Components.

It is apparent that a variety of biometric changes are caused by different types of cycloplegic eye drops. However, these effects are inconsistent and have not been reported in different refractive groups. The purpose of this study was to determine the effect of cyclopentolate 1% on ocular biometric components in different types of refractive errors in children. This cross-sectional study was conducted on 226 eyes of 113 schoolchildren in Shahroud, northeast Iran, with a mean ± standard deviation age of 9.20 ± 1.65 years. All participants had noncycloplegic and cycloplegic objective refraction using an autorefractometer. Cycloplegia was induced using cyclopentolate 1% eye drops. Biometric measurements were made with Allegro Biograph (WaveLight AG, Erlangen, Germany) before and after administering cycloplegic drops. Mixed-effect model regression was used to analyze the data. After cycloplegia, the vitreous chamber depth (VCD) (-0.043; 95% confidence interval [CI], -0.067 to -0.019 mm), lens thickness (-0.146; 95% CI, -0.175 to -0.117 mm), axial length (-0.009; 95% CI, -0.012 to -0.006 mm), and lens power (-0.335; 95% CI, -0.463 to -0.208 D) decreased significantly, whereas the anterior chamber depth (ACD) (0.183; 95% CI, 0.164 to 0.202 mm), anterior segment length (0.036; 95% CI, 0.014 to 0.058) mm), lens central point (0.109; 95% CI, 0.094 to 0.124 mm), and pupil diameter (1.599; 95% CI, 1.482 to 1.716 mm) increased (P value for all tests, <.001). For changes in VCD and ACD, a significant interaction was observed between different types of refractive errors and cycloplegia, such that the adjusted mean change for ACD was significantly lower and for VCD was significantly higher in hyperopes compared with emmetropes. Lens center moves backward in myopes (0.17 mm) and stays the same in hyperopes under cycloplegia. According to the findings of this study, cycloplegia reduces the thickness of the crystalline lens and subsequently causes an increase in the ACD. Cycloplegia-related ocular biometric changes were different by type of refractive error.

Short-Term Changes in Prediction Error after Cataract Surgery in Eyes Receiving 1 of 3 Types of Single-Piece Acrylic Intraocular Lenses

To compare short-term changes in refractive prediction error (PE) after phacoemulsification among eyes receiving different types of single-piece acrylic intraocular lenses (IOLs). Randomized clinical trial. A total of 195 eyes of 195 patients scheduled for implantation of a single-piece acrylic IOL were randomly assigned to receive 1 of 3 IOLs: 1) an Alcon model SN60WF, 2) a Hoya model XY-1, or 3) an AMO model ZCB00V. Manifest spherical equivalent (MRSE) value, PE, and changes in PE were examined at 1day and at 1 and 2months postoperatively and were compared among groups. The mean MRSE and PE significantly changed toward myopia between 1day and 2months postoperatively in all groups (P < .0001). The MRSE and PE did not differ significantly among groups at 1day and 1month postoperatively and were significantly smaller in the SN60WF group than in the XY-1 and ZCB00V groups at 2months (P ≤ .0006). The PE change between 1day and 2months postoperatively was significantly smaller in the SN60WF group than in the other groups (P= .0062). IOL type and changes in anterior chamber depth and corneal curvature independently correlated with PE changes. The MRSE and PE showed a significant myopic change for 2months postoperatively in eyes implanted with 1 of 3 types of single-piece acrylic IOLs and were significantly smaller in the SN60WF than in the XY-1 and ZCB00V groups. Changes in PE during the 2 postoperative months were smaller in the SN60WF IOLs than in the other IOLs, suggesting that postoperative refractive stability differs among single-piece acrylic IOLs.

Effect of capsular tension ring implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation syndrome.

To investigate the effect of capsular tension ring (CTR) implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation (PEX) syndrome. This double-blind randomized clinical trial was conducted on 60 patients with PEX syndrome referring to Imam Khomeini Hospital affiliated to Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran, for undergoing cataract surgery. The study population was divided into two groups, namely CTR group (n=30) and non-CTR group (control group; n=30). The refractive error and anterior chamber depth (ACD) were measured 1wk, 1mo, and 3mo after phacoemulsification (PE) surgery. The results indicated no statistically significant difference between the two groups in terms of predicted refractive error (obtained by subtracting preoperative predicted refractive error from actual postoperative refractive error) 1wk (P=0.47), 1mo (P=0.30), and 3mo (P=0.06) after the PE surgery. Regarding the CTR group, the changes of ACD was statistically significant 1 and 3mo after the PE surgery, compared to those obtained 1wk post-surgery (P=0.005). The CTR implantation in PEX cataractous patients without zonulysis has no statistically significant effect on the predicted refraction and ACD changes after PE. The predicted refraction error has a hyperopic shift in both groups. The results reveal the unnecessary of calculating modified IOL in CTR implantation.