Changes In Anterior Chamber Depth Research Articles

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.

Changes of anterior segment parameters after horizontal rectus muscles recession versus resection

Background: To record the corneal, and anterior chamber depth changes after performing recession versus resection of horizontal recti muscles. Methods: Consecutive patients who underwent isolated lateral rectus muscle recession or resection February 2014 to January 2015 were prospectively studied. Refractive error (spherical equivalent); K1, K2, and mean k reading, anterior and posterior corneal elevation; and anterior chamber depth were measured (Pentacam) before, 1 month, and 3 months after surgery. Patients who could not maintain reliable fixation and those with a history of eye surgery were excluded. Pre- and postoperative measurements were compared by analysis of variance. Results: A total of 36 eyes of 23 patients (average age, 16 years) were included. Rectus muscle recession was performed in 24 eyes; and resection was performed in 12 eyes. Statistically significant changes in mean keratometry of recession group only. Central anterior elevation, and central anterior chamber depth were significant when both groups are compared at first month after surgery. Changes became regressive at the end of the third month. Although a significant change of central anterior elevation persisted. Conclusions: In recession group, the mean K was the only statistically significant variable by the first postoperative month. Comparing the both groups, the anterior corneal elevation, and central anterior chamber depth revealed a significant difference by the end of the first postoperative month. After 3 months, all parameters showed a statistical insignificant difference between the recession and resection groups except the anterior corneal elevation.

Weighted Comparison of the Corneal Topographic Data in Intracapsular versus Ciliary Sulcus Intraocular Lens Implantation during Phacoemulsification Surgery.

Objectives:This study aimed to evaluate the preoperative and postoperative changes in corneal topography, intraocular pressure (IOP), and visual acuity in patients who developed posterior capsule rupture during phacoemulsification surgery and simultaneously underwent ciliary sulcus intraocular lens (IOL) implantation and in those with intact capsular integrity who simultaneously underwent intracapsular IOL implantation and to compare these changes within and between the two groups.Methods:Among the 855 patients, 92 eyes of 69 patients whose corneal topography, IOP, and best-corrected visual acuity (BCVA) were successfully measured were included in the study. Preliminary chamber parameters [horizontal visible iris diameter (HVID), iridocorneal angle, anterior chamber volume (ACV), and anterior chamber depth (ACD)] were measured before and after surgery using a Sirius corneal topography device.Results:The IOL was implanted in the capsular bag in 58 patients and in the ciliary sulcus between the posterior iris and the capsule in 34 patients. In the sulcus IOL group, both BCVA and IOP measurements statistically significantly increased in the postoperative period compared with the preoperative values (p<0.001). As regards postoperative changes between the intracapsular and sulcus IOL groups, no significant difference was found in the changes in HVID (p=0.584), iridocorneal angle (p=0.282), and ACD (p=0.382), whereas the changes in ACV, IOP, and BCVA were statistically significantly different (p=0.020, p<0.001, and p<0.001, respectively).Conclusion:While the IOP of the sulcus IOL group significantly increased, that of the intracapsular group significantly decreased. Visual acuity increased in both lens implants, but patients with intracapsular lenses had greater improvement in visual acuity; thus, intracapsular IOL implantation was more advantageous than sulcus IOL implantation.

Evaluation of Anterior Chamber Depth and Anterior Chamber Angle Changing After Phacoemulsification in the Primary Angle Close Suspect Eyes.

BACKGROUND:Phacoemulsification surgery has the ability to deeply alter the segment anterior morphology, especially in eye with shallow anterior chamber (AC), narrow anterior chamber angle (ACA). However, the changes of anterior chamber depth (ACD) and ACA on the close angle suspect eyes after phacoemulsification have not been mentioned in many studies. So, we conduct this research.AIM:To evaluate the alteration in the ACA and ACD after phacoemulsification in the close angle suspect eyes.METHODS:Interventional study with no control group. Subjects were the primary angle closure suspect (PACS) eyes, that were operated by phacoemulsification with intraocular lens (IOL) at Glaucoma Department of VNIO from December 2017 to October 2018.RESULTS:29 PACS eyes with cataract were operated by phacoemulsification with intraocular lens. After 3 months of monitoring, the average ACD augmented from 2.082 ± 0.244 to 3.673 ± 0.222 mm. AOD500 increase from 0.183 ± 0.088 to 0.388 ± 0.132 μm, AOD750 increased from 0.278 ± 0.105 to 0.576 ± 0.149 μm. The TISA500 enlarged from 0.068 ± 0.033 to 0.140 ± 0.052 mm2, TISA750 enlarged from 0.125 ± 0.052 to 0.256 ± 0.089 mm2 at the third month (p < 0.01).CONCLUSION:Phacoemulsification surgery increases the ACD and enlarged the angle in the PACS eyes.

Systematic Review and Meta-Analysis of Comparing Phacoemulsification Combined with goniosynechialysis to other mainstream procedures in treating patients with angle-closure glaucoma.

Background:The aim of this meta-analysis is to compare the efficacy and safety of combined phacoemulsification (Phaco) with goniosynechialysis (GSL) to either Phaco or to Phaco combined with trabeculectomy or trabeculectomy alone in patients with angle closure glaucoma (ACG).Methods:Five main electronic databases were searched for the eligible studies. Intraocular pressure (IOP) decrease was set as the primary outcome, while anti-glaucomatous medication decrease, changes of anterior chamber depth (ACD), range of peripheral anterior synechia (PAS), and complication occurrence were the secondary outcomes. Standard mean difference (SMD) and relative risk (RR) were the size effects for continuous and binomial data, respectively. Either fixed-effects model or random-effects model was chosen to pool the data based on the heterogeneities.Results:A total of 7 eligible studies were included. The combined data showed the IOP decreased more significantly after Phaco-GSL than that after Phaco alone (SMD = –0.42,95%CI: –0.70 – 0.14, I2 = 17.6%, Z = 2.90, P = .004). However, there were no distinct differences regarding medication decrease (SMD = –0.25,95%CI: –0.70 – 0.21, I2 = 0%, Z = 1.06, P = 0.29), ACD, the range of PAS and complication occurrence rate when compared Phaco-GSL to Phaco. Moreover, Phaco-GSL was comparable to Phaco-trabeculectomy/trabeculectomy in decreasing IOP (SMD = –0.08, 95%CI = –0.32 – 0.15, I2 = 0%, Z = 0.70, P = .49).Conclusions:Phaco-GSL might be an optimal procedure to treat ACG with concomitant cataract due to its bleb-less nature, and its capacity for lowering IOP seems superior to Phaco alone and comparable to Phaco-trabeculectomy/trabeculectomy.

Changes in Anterior Chamber Depth and Angle Before and After Phacoemulsification of Intumescent Cataract

Changes in Anterior Chamber Depth and Angle Before and After Phacoemulsification of Intumescent Cataract

Short term effects of intravitreal anti-vascular endothelial growth factor agents on cornea, anterior chamber, and intraocular pressure

Objective: To evaluate short term changes in anterior chamber depth (ACD), central corneal thickness (CCT), intraocular pressure (IOP), and corneal endothelial cell density (ECD) after intravitreal anti-vascular endothelial growth factor (VEGF) injections.Materials and methods: A total of 100 eyes from 100 patients, who were naive for intravitreal injection treatment, were included in this retrospective study. Patients who received only a single type of intravitreal anti-VEGF injections (bevacizumab, ranibizumab, or aflibercept) for two consecutive months were examined. ACD, CCT, IOP, and ECD measurements were taken at pre-injection and one month after the first and second injections and were compared.Results: The mean corneal ECD for all eyes and phakic eyes was significantly lower one month after the first (p = 0.041 and p = 0.047, respectively) and second injections (p = 0.013 and p = 0.034, respectively) compared to the values at pre-injection levels. Similarly, the mean ACD of all eyes and phakic eyes was significantly lower one month after the first (p < 0.001 and p < 0.001, respectively) and second injections (p < 0.001 and p < 0.001, respectively) compared to the values at pre-injection levels. However, there was no significant difference in pseudophakic eyes one month after the first and second injections (ECD, p = 0.28 and p = 0.23; ACD, p = 0.75 and p = 0.71, respectively). There was no significant change in IOP and CCT values at pre-injection and one month after the first and second injections for all eyes and for both the phakic and pseudophakic eyes.Discussion: After the anti-VEGF injections, IOP and CCT values were not significantly changed and were similar in all eyes and phakic eyes; however, in these groups, there was a small but statistically significant decrease in ACD and ECD. On the contrary, there was no significant difference in pseudophakic eyes. Clinicians performing intravitreal injections must be aware of these associations for a better understanding of ACD and ECD changes in phakic eyes.

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

IntroductionTo evaluate the effects of cycloplegia on the biometric components and anterior segment parameters of the eye.MethodsIn 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.ResultsSignificant 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).ConclusionCycloplegia 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.

Effect of topical application of adrenaline on Schlemm canal, trabecular meshwork and intraocular pressure.

Aim:To measure changes in the sizes of Schlemm canal (SC) and trabecular meshwork (TM) in healthy individuals before and after topical application of 1% adrenaline at 15, 45, and 90 minutes using anterior segment optical coherence tomography (ASOCT).Methods:Anterior chamber angle imaging of the nasal and temporal regions of the right eyes was performed with anterior segment optical coherence tomography (ASOCT) before and after topical application of 1% adrenaline at 15, 45, and 90 minutes. The diameter and area of SC, width and thickness of TM, anterior chamber depth (ACD) and pupil diameter (PD) were measured with ASOCT images. Intraocular pressure (IOP) was also recorded simultaneously.Results:A total of 15 healthy individuals were enrolled and included 7 male subjects and 8 female subjects; Compared with the parameters before intervention, both the SC diameter and area in the 2 quadrants increased after the application of adrenaline at the 3 time points (P < .05). The TM width increased after medication (P < .05). IOP decreased significantly after application (P < .05). There were no statistically significant changes in TM thickness, ACD, and PD at any point of time (P > .05).Conclusion:Topical application of 1% adrenaline in eye led to decrease in IOP with the SC diameter and area as well as the TM width increased after medication. While the TM thickness, ACD, PD seemed to remain constant.

Short-term refractive and ocular parameter changes after topical atropine.

PURPOSE:The purpose of this study is to explore short-term refractive and ocular parameter changes and their correlations after cycloplegia with atropine.METERIALS AND METHODS:This is a prospective clinical trial that enrolled 96 eyes of 96 participants (mean age, 8.5 ± 2.1 years). Spherical equivalent refractive error (SER), axial length (AL), mean keratometric value (mean-K), anterior chamber depth (ACD), and intraocular pressure (IOP) were measured at baseline and 1 week after topical use of 0.125% atropine. Postcycloplegic changes of refractive error and ocular parameters were evaluated, and their correlations were analyzed with multiple linear regression models.RESULTS:After topical atropine use, the mean AL decreased by 0.016 mm (P = 0.008), and the mean ACD increased by 0.58 mm (P < 0.0001). There was no significant change in the Mean-K or IOP. Eighty-two eyes (85%) had an emmetropic or hyperopic shift, and 14 (15%) had a myopic shift. Those with an emmetropic or hyperopic shift had their mean AL shortened by 0.023 mm, whereas the eyes with myopic shifts had their mean AL lengthened by 0.026 mm (P = 0.003). Change in SER was negatively correlated with change in AL (−2.57 D for an increase of 1 mm in AL, P < 0.001) and positively correlated with change in ACD (+0.96 D for an increase of 1 mm in ACD, P = 0.013).CONCLUSION:Most eyes had emmetropic or hyperopic changes after short-term topical atropine use, and AL shortening and anterior chamber deepening both contributed to the hyperopic changes. Meanwhile, myopic change may be observed in some eyes (15%), which were related to transient AL elongation but not invalid myopic control. This encouraged clinicians to sustain the atropine treatment for a longer period before switching to other modalities for myopic control in clinical practice.The clinical trial registration number NCT03839888 (clinicaltrials.gov).

Comparison of anterior chamber depth between normal and keratoconic eyes: A systematic review and meta-analysis

PurposeTo review the published data about changes in the anterior chamber depth (ACD) in keratoconus patients. MethodsIn this systematic review and meta-analysis of observational studies, we reviewed the available and relevant literature on anterior segment changes in keratoconic eyes, with a special focus on the ACD, an effective factor in many surgical methods. Articles published up to December 2017 were identified in the following data sources: PubMed, Scopus, Ovid, ISI, ScienceDirect, and Google Scholar. Databases were comprehensively searched using the key words “Anterior Chamber Depth AND Anterior segment AND Keratoconus”. ResultsA total of 496 studies including these key words were detected. 453 studies were excluded, and overall 16 studies which precisely described the change in ACD were included in the literature review. The results show that with respect to the applied device, there was a statistically significant difference in ACD between keratoconic eyes and normal eyes except for Galilei analyzer. ConclusionSummarizing the results of studies, this review revealed that ACD is significantly deeper in keratoconic eyes as compared with normal eyes, which could be explained by the steeper corneal curvature.

Ocular biometric changes after trabeculectomy

Introduction/Objective. Trabeculectomy is a conventional filtration procedure in surgical glaucoma treatment. Even after successful trabeculectomy, the patient?s visual acuity can be reduced. Studies (1991) showed that changes in visual acuity occur due to changes of corneal curvature and anterior chamber depth. Anterior chamber depth change for 1 mm results in about 2 diopters change in refractive sphere. Simultaneous with anterior segment changes, anti-glaucoma surgery effect can also be manifested in posterior segment of the eye: choroidal thickness, axial length and the ocular perfusion. Axial length reduction after trabeculectomy was supposed according to biometry, more pronounced if intraocular pressure is higher preoperatively, or in the first postoperative week with spontaneous recovery to preoperative values one year after surgery. A study was conducted at the Clinic for Eye Diseases in Nis to determine the difference in pre/post-operative values of biometry on 60 patients with glaucoma. Methods. In this study we used retrospective-prospective biometric analysis in patients with open-angle glaucoma. Results. Anterior chamber depth was significantly different during the observed period, for 1.1 mm in first week (p &lt; 0.0001) in the whole group and glaucoma type. The mean axial length varies considerably during the observed period, shorter for 0.39 mm in first week (p &lt; 0.05). Conclusion. By analyzing biometric parameters, a postoperative difference of biometry with spontaneous recovery was determined. There is a difference in postoperative visual acuity of patients compared to preoperative, with spontaneous recovery at the end of the follow-up.

Anterior Chamber Angle and Volume Do Not Change after Myopic Laser-Assisted In Situ Keratomileusis in Young Patients.

Purpose We aimed to investigate whether anterior chamber angle, depth, and volume change after myopic laser-assisted in situ keratomileusis (LASIK) in young patients. Methods This retrospective study included 29 eyes of 29 patients (15 females and 14 males) between the ages of 18 and 39 years who underwent LASIK for the treatment of myopia. In addition to complete ophthalmic examination, anterior chamber angle (ACA), central anterior chamber depth (ACD), and anterior chamber volume (ACV) were measured by using a Sirius rotating Scheimpflug camera combined with Placido disc corneal topography (CSO, Florence, Italy). Preoperative and postoperative values were compared using paired t-tests. Linear regression was used to evaluate the relationship between changes in refraction and changes in ACA, ACD, and ACV as well as between attempted maximum ablation depth and changes in ACA, ACD, and ACV. Results The mean age of the study population was 25.5 ± 6.2 years. The mean preoperative and postoperative spherical equivalent values were −3.30 ± 1.92 D and −0.18 ± 0.29 D, respectively. ACV and ACA were not significantly changed after surgery; however, central ACD was significantly decreased (preoperatively = 3.366 ± 0.316 mm vs postoperatively = 3.3 ± 0.298 mm) with a mean difference of 0.066 ± 1.121 mm. There were no significant relationships between changes in refraction and anterior segment dimensions or between attempted maximum ablation depth and anterior segment dimensions. Conclusion Measurements with Sirius showed that ACA and ACV did not change; however, central ACD significantly decreased after myopic LASIK in young patients, indicating that the preoperative central ACD value should not be used interchangeably with the postoperative central ACD value.

Subjective and objective accommodation of the Crystalens Advanced Optics (AO) in patients 6 months after bilateral implantation

Background: The aim of this study was to analyze and compare objective and subjective accommodation in patients after bilateral implantation of the FDA-approved accommodating Crystalens Advanced Optics (AO). Material and methods: This study was performed on 8 eyes of 4 patients. The subjective accommodation was measured by monocular and binocular defocus curves under photopic and mesopic conditions. The objective accommodation was analyzed using partial coherence interferometry (PCI) and wavefront aberration. Pupil diameter at different set-ups and refraction were derived from wavefront data. Results: Uncorrected and corrected distance and uncorrected near visual acuity improved significantly following implantation of the Crystalens AO in all eyes. Only one patient needed spectacles to correct distance visual acuity. Mean distance uncorrected visual acuity was 0.05 ± 0.06 logMAR. All patients were able to read newspapers without spectacles. Mean near uncorrected visual acuity was 0.17 ± 0.12 logMAR. Subjective accommodative amplitude under photopic conditions was significantly better binocularly than monocularly (p = 0.03) and was significant worse monocularly under mesopic conditions than photopic conditions (p = 0.016). No significant changes in anterior chamber depth were observed by PCI, with a fixation on optical stimuli at different distances. There were also no significant changes in the wavefront aberrations between the different set-ups. Pupil diameter increased significantly in the near set-up under mesopic conditions. Conclusions: No objective change in lens configuration was observed under different set-ups. Due to a variety of factors involved in pseudoaccommodation (e.g. pupil diameter, astigmatism, and multifocality), the subjective accommodative amplitude tends to be overestimated relative to objective measurements. No real accommodative action was observed.

Influence of pupil dilation on predicted postoperative refraction and recommended IOL to obtain target postoperative refraction calculated by using third- and fourth-generation calculation formulas.

PurposeTo evaluate the influence of pupil dilation on predicted postoperative refraction (PPR) and recommended intraocular lens (IOL) power to obtain target postoperative refraction calculated by using the third- and fourth-generation IOL power calculation formulas with a new optical biometer.MethodsThis retrospective study included 162 eyes with cataract that underwent uneventful phacoemulsification with IOL implantation. PPR, recommended IOL power, anterior chamber depth (ACD), and lens thickness (LT) were measured pre- and post-pupil dilation. The change in PPR detected by using third-generation (Hoffer Q and SRK/T) and fourth-generation formulas (Haigis and Holladay 2) and the changes in ACD and LT were evaluated pre- and postdilation. The influence of dilation on the recommended IOL power calculated by each formula was analyzed.ResultACD and LT significantly changed from pre- to postdilation. The mean absolute change in PPR between pre- and postdilation was significantly higher for fourth-generation formulas compared with third-generation formulas. The change in PPR between pre- and postdilation showed a significantly positive correlation with change in ACD and a significantly negative correlation with change in LT with fourth-generation formulas, but not with third-generation formulas. The discrepancy rate of recommended IOL power between pre- and postdilation calculated by fourth-generation formulas was significantly higher than that calculated by third-generation formulas.ConclusionACD and LT significantly changed by dilation. PPR and recommended IOL power significantly changed more by dilation when using fourth-generation formulas compared with third-generation formulas. Given the significant correlations of the change in PPR (between the pre- and postdilation) in the fourth-generation formulas and the changes in ACD and LT, the latter changes may be key in influencing dilation in the fourth-generation power calculation. Knowledge of the influence of dilation on fourth-generation formulas could help improve IOL calculation.

Quantitative assessment of changes in anterior segment morphology after argon laser peripheral iridoplasty: findings from the EARL study group.

Argon laser peripheral iridoplasty (ALPI) could be effective in widening residual angle closure following laser peripheral iridotomy (LPI). We investigated changes in angle parameters following ALPI and its safety profile in this study. Retrospective, observational case series. The records from a single centre, of 36 patients (60 eyes) who underwent ALPI, for residual angle closure following LPI, were reviewed. We analysed anterior chamber parameters in anterior segment optical coherence tomography (ASOCT) images using customized software pre- and post-ALPI. Paired t-test was used to compare changes. ASOCT parameters analysed included angle opening distance (AOD 500 and 750), trabecular iris surface area (TISA 500 and 750), anterior chamber width (ACW), anterior chamber volume (ACV), angle recess area (ARA), anterior chamber area (ACA), anterior chamber depth (ACD) and lens vault (LV). There was a mean increase in AOD 500 (0.05 vs. 0.16 mm, P < 0.001), AOD 750 (0.15 vs. 0.27 mm, P < 0.001), TISA 500 (0.010 vs. 0.038 mm2 , P < 0.001), TISA 750 (0.039 vs. 0.102 mm2 , P < 0.001), ACV (89.76 vs. 102.25 mm3 , P = 0.01), ARA 500 (0.015 vs. 0.033 mm2 , P < 0.001) and ARA 750 (0.044 vs. 0.088 mm2 , P < 0.001). There was no significant change in ACW, ACD, ACA and LV. Mean intraocular pressure (IOP) decreased post-ALPI (17.2 vs. 15.7 mmHg, P = 0.002). The mean follow-up duration was 2.1 years (range 0.5-5 years). ALPI results in changes to the angle morphology and lowered IOP in eyes with residual angle closure. Our findings suggest a possible role for ALPI in eyes with residual angle closure following peripheral iridotomy.

The impact of Nd: YAG laser posterior capsulotomy by the use of "the circular pattern with vitreous strand cut" technique on anterior chamber parameters.

The purpose of this study is to identify the effect of Nd: YAG laser posterior capsulotomy using an anterior chamber morphology. This study included 42 eyes of 33 pseudophakic patients with visually significant PCO after uncomplicated cataract surgery. Exclusion criteria were complications related to cataract surgery, corneal pathology, pseudoexfoliation, glaucoma, uveitis, previous ocular surgery or trauma, and posterior segment pathology. All patients underwent routine ophthalmic examinations. The AS-OCT measurements were performed using NIDEK RS-3000 Lite retinal scan with anterior segment module. The anterior chamber depth (ACD) was measured by Monitor A&B Scan biometer. Nd: YAG laser posterior capsulotomy was done in a single session by the circular pattern with rupture of vitreous strands. Anterior chamber depth (ACD), central corneal thickness (CCT), and intraocular pressure (IOP) were measured. Anterior chamber angle (ACA), angle opening distances (AOD) at 500mm (AOD500), AOD at 750mm (AOD750), trabecular-iris space area at 500 (TISA 500), and TISA at 750 (TISA 750) were measured both nasally and temporally. The mean patient age was 55.56 ± 6.33years. There were non-significant changes in IOP, ACD, and CCT with P values 0.395, 0.153, and 0.541, respectively. ACA, AOD500, AOD750, TISA 500, and TISA 750 highly significantly increased with P value < 0.001 for all. Nd: YAG laser posterior capsulotomy with the circular pattern with vitreous strand cut technique is a safe technique for laser posterior capsulotomy.