Anterior Chamber Volume Research Articles

The impact of celiac disease and duration of gluten free diet on anterior and posterior ocular structures: Ocular imaging based study.

To evaluate the eyes of adult celiac disease (CD) patients and investigate the association between these ocular parameters with celiac specific antibodies and duration of gluten free diet (GFD). This cross-sectional study included 72 eyes of 36 CD patients (18-51 years of age) and 70 eyes of 35 age- and sex-matched healthy controls. In addition to a complete ophthalmologic examination, all patients were scanned by a Scheimpflug camera, specular microscopy and spectral domain optical coherence tomography. Endothelial cell density (ECD), anterior chamber angle (ACA) degrees, anterior chamber depth (ACD), anterior chamber volume (ACV) and central macular thickness (CMT) values were lower in CD patients as compared with control group (p values = 0.038, 0.024, 0.002, 0.038 and 0.046 respectively). ECD and CMT were lower in celiac patients whom endomysial antibodies (EMA) IgA were positive (p = 0.001, p = 0.042 respectively). Tissue transglutaminase IgA antibody (anti tTG IgA) was weakly positively correlated (p > 0.05) with ACD, and positively (r = 0.319; p < 0.05) correlated with ACV. As the duration of compliance to the diet increased in the celiac group the mean and inferior retinal nerve fiber layer (RNFL) thickness decreased (p = 0.035, p = 0.008 respectively). Mean, inferior and temporal RNFL thicknesses were lower in celiac patients whose duration of GFD was longer than 5 years (p < 0.05). Decreases in ECD, ACA degree, ACD, ACV and CMT can occur in CD patients. In adult celiac patients; ECD, CMT might be effected in the presence of positive EMA, and ACD, ACV might be effected in the presence of higher anti tTG IgA titer. Adult celiac patients who had longer duration of GFD may have thinner RNFL. RNFL may be thinner in celiac patients who comply with GFD for more than 5 years.

Potential of the Pentacam in Screening for Narrow Angles in Patients with Chronic Angle-Closure Glaucoma

Background: Chronic angle-closure glaucoma (CACG) is a visually destructive disease. Effective management of CACG requires identifying eyes with narrow angle.&#x0D; Objective: To compare pentacam with gonioscopy in detecting narrow angles in eyes with CACG.&#x0D; Method: We enrolled 101 eyes with glaucoma. Gonioscopy was performed on all eyes. Using Shaffer’s grading, subjects were classified into angle closure and open angle. Anterior chamber volume (ACV) and anterior chamber depth (ACD) were measured with the pentacam. Receiver operating curve was constructed for each parameter and the area under the curve (AUC) was calculated.&#x0D; Results: Ten eyes (9.9%) were classified as angle closure on gonioscopy. To detect narrow angles, ACV (AUC 0.956; 95% confidence interval (CI) 0.894–0.987) performed similar to ACD (AUC=0.930, p=0.33). Using a cutoff of 102 mm3 , ACV had 100% sensitivity and 88.5% specificity for detecting narrow angles in CACG patients. With an ACV cutoff of 102 mm3 , the PPV for detecting angle closure was 48.9% (95% CI, 34.8–68.2), while the NPV was 100% (94.1– 100%), using 9.9% prevalence of angle closure from this study.&#x0D; Conclusion: ACV and ACD measured by the pentacam have the potential to determine narrow angles in eyes with CACG.&#x0D; Keywords: Chronic angle-closure glaucoma, Pentacam HR, Anterior chamber volume, Gonioscopy

Endophthalmitis Prophylaxis Failures in Patients Injected With Intracameral Antibiotic During Cataract Surgery

To estimate the association of cefuroxime and moxifloxacin in relation to the occurrence of endophthalmitis following phacoemulsification cataract surgery. Retrospective clinical cohort study. We studied patients with noncomplex phacoemulsification cataract surgery in Kaiser Permanente Northern California during 2014-2019. Data were obtained for acute, postoperative endophthalmitis within 90 days of phacoemulsification, including culture and antibiogram results, intracameral and topical antibiotic agent, and dose. In a post hoc analysis, we also examined preoperative anterior chamber depth (ACD) and postoperative anterior chamber volume (ACV). Of 216,141 surgeries, endophthalmitis occurred in 0.020% of moxifloxacin-injected eyes and 0.013% of cefuroxime eyes (relative risk 1.62 with 95% CI 0.82-3.20, P=.16). Of the 34 (0.016%) cases of endophthalmitis, cefuroxime 1 mg was injected into 13 eyes and moxifloxacin 0.1% into 21 eyes. Organisms with antibiograms were identified in 12 (35%) cases. Of these, bacteria recovered from cefuroxime-injected eyes were resistant to cefuroxime in all cases (4/4), with Enterococcus comprising half of these. In eyes injected with moxifloxacin 0.1%, 6 out of 7 organisms were sensitive to moxifloxacin injected with 0.1 mL and in 1 eye injected with 1 mL. Streptococcus was the most common organism recovered (6/9) in moxifloxacin-injected eyes. Preoperative ACD and postoperative calculated ACV were higher in eyes injected with moxifloxacin. Endophthalmitis cases with positive cultures were generally related to organism resistance in cefuroxime eyes but to sensitive organisms in moxifloxacin eyes. Moxifloxacin doses may have been insufficient in eyes with larger ACV.

Evaluation of anterior segment parameters with Pentacam in children with poorly-controlled type 1 Diabetes Mellitus without diabetic retinopathy.

To determine the effect of abnormal glucose metabolism on the cornea, lens, anterior chamber volume (ACV), and anterior chamber depth (ACD) in children with poorly-controlled type 1 diabetes mellitus (DM) without diabetic retinopathy (DR). After the complete ophthalmologic examination of children with poorly-controlled (glycosylated hemoglobin [HbA1c] >7.0 %) type 1 DM without DR and age-matched healthy subjects (control group), the central corneal thickness (CCT), keratometry (K) values (Kmean front and back, and Kmax), radius (R) values (Rmin front and back), corneal volume (CV), ACD, ACV, pupil diameter, mean lens density (MLD), lens density standard deviation (LD SD), and maximum lens density (LD max) were measured using Pentacam High Resolution. Endothelial cell density was measured using a specular microscope. The results were assessed and compared between the two groups. There were 60 patients (38 boys and 22 girls) in the DM group and 30 (14 boys, 16 girls) in the control group. There were considerable differences between the groups in terms of CCT, CV, ACD, MLD, LD SD and LD max, and Kmean back. Further, there was a positive correlation between HbA1c and MLD, LD SD, CV, and CCT in patients with DM. The results of our study demonstrate that poorly-controlled type 1 DM without DR affects the cornea, ACD, and LD based on anterior segment measurements taken with a Scheimpflug camera. CCT, CV, LD SD, and MLD values may be parameters that can be used to follow-up patients with type 1 DM.

Evaluation of changes in corneal volume, volume and angle of anterior chamber in keratoconus patients using Pentacam after CXL.

Introduction and Objective:Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A (UVA) is a new technique of mechanical stability of the cornea and prevention of keratoconus progression. The present study aimed at the evaluation of the changes in the corneal volume (CV), volume, and the angle of anterior chamber in keratoconus patients using the Pentacam after CXL.Methods:This prospective study was performed on 48 eyes of 24 patients (including 12 men, 17–33 years old) with progressive keratoconus undergoing CXL treatment at collagen cross-linking Imam Khomeini Hospital in Ahvaz in 2019. The CV (CV) and anterior chamber parameters such as anterior chamber volume (ACV) and anterior chamber angle (ACA) were measured using the Pentacam before CXL and at 6 and 12 months after CXL. Also, all of the patients were evaluated in terms of best-corrected visual acuity (BCVA), during the follow-up.Results:The pre-CXL values of BCVA was significantly lower than the post-CXL values in 6 and 12 months (0.18 ± 0.11, 0.15 ± 0.10, and 0.11 ± 0.10, respectively, P < 0.0001). In general, there was a significant improvement in the BCVA (P < 0.0001), a significant decrease in the CV (P = 0.001), and a significant increase in the ACV (P < 0.0001), and angle (P < 0.0001) 6 and 12 months after CXL.Conclusion:It seems that CXL has a positive effect on the anterior chamber parameters (ACV and ACA) and CV after 6 months and 1 year in the treatment of keratoconus patients. In addition, the visual acuity improves after CXL. Finally, further studies with a higher sample size and longer follow-up periods are recommended.

Does graves ophthalmopathy affect anterior segment parameters?

Aim: To evaluate whether anterior segment parameters (ASPs) differ between patients with Graves’s ophthalmopathy (GO) and healthy individuals. Materials and Methods: In a case-control study, 62 patients with GO and 45 healthy sex- and age-matched individuals were compared for ASPs obtained from Scheimpflug camera imaging (Sirius, Florence, Italy). The ASPs were anterior chamber depth (ACD), anterior chamber volume (ACV), iridocorneal angle (ICA), corneal volume, corneal curvatures (K1, K2, and Kmean), and white-to-white, apical, and thinnest corneal thickness. Results: Mean white-to-white corneal distance, corneal volume, ACD, ACV, ICA, K1, K2, and Kmean were similar between patients and controls (p = 0.815, p = 0.285, p = 0.522, p = 0.102, p = 0.275, p = 0.114, p = 0.566, p = 0.137, p = 0.405, and p = 0.447, respectively). There was a negative correlation between mean Hertel measurement and mean ACD (r = - 0.284, p = 0.003), ACV (r = - 0.283, p = 0.003), and ICA (r = - 0.295, p = 0.002). Conclusion: The ASPs were not associated with significant alterations between patients with GO and controls.

Evaluation of intraocular pressure change and anterior segment parameters after intravitreal bevacizumab injection - Cannula size matters.

PURPOSE:To determine the changes in intraocular pressure (IOP) and anterior chamber parameters following intravitreal bevacizumab injection with different sizes of cannulas.METHODS:This clinical trial was conducted with 70 eyes of 70 patients who received an intravitreal injection of bevacizumab with 26 G (Group 1) or 30 G (Group 2) needle. Preinjection and postinjection 30th-min IOP and pentacam measurements were obtained. Anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), corneal volume (CV), and iridocorneal angle (ICA) measurements were evaluated in pentacam.RESULTS:Preinjection mean IOP values in Group 1 and 2 were 14.7 ± 3.29 mm Hg and 15.1 ± 2.87 mm Hg, respectively. Postinjection mean IOP in Group 1 was 16.8 ± 6.24 mm Hg and in Group 2 was 20.3 ± 3.66 mm Hg. Postinjection mean IOP values were significantly higher than preinjection values in both groups (Group 1 P < 0.005 and Group 2 P < 0.001). IOP change was significantly higher in Group 2 after injection (P < 0.05). In both groups, the change in IOP found to be more significant in phakic eyes than pseudophakic eyes (Group 1 P < 0.001, Group 2 P < 0.001). CCT and CV were significantly higher in both groups 30 min after the injection than preinjection (Group 1 and Group 2; P < 0.01). In Group 2 ACD, ACV and ICA values were significantly lower than preinjection values (P < 0.05).CONCLUSION:Needle bore size is an important parameter that influences anterior segment parameters and IOP change in the intravitreal injection. IOP rise and anterior segment changes are more prominent with a thinner cannula.

Anterior Segment Parameters and Intraocular Pressure Changes after Phacoemulsification in Pseudoexfoliation Syndrome

Aim: The aim of this study was to compare anterior segment and intraocular pressure changes in eyes with and without pseudoexfoliation after cataract surgery.Materials and Methods: This prospective study included 35 eyes of 35 patients (Group 1) without pseudoexfoliation and 40 eyes of 37 patients with pseudoexfoliation (Group 2) undergoing elective phacoemulsification surgery. The anterior segment was evaluated preoperatively and one week, and one and three months postoperatively using a Sirius-Scheimflug device. Intraocular pressures were measured using Goldman applanation tonometry. Central corneal thickness, anterior chamber volume, anterior chamber depth, anterior chamber angle, and corneal volume parameters were evaluated among the anterior segment parameters.Results: A statistically significant difference was observed between Group 1 and Group 2 in terms of pre- and postoperative anterior chamber volume, anterior chamber depth, anterior chamber angle and intraocular pressure values (p <0.001). Central corneal thickness was higher in the group with pseudoexfoliation at first week and first month measurements (p <0.05). Corneal volume was significantly higher in Group 2 at all pre-and post-operative measurements.Conclusion: According to the findings of this study, phacoemulsification surgery causes changes in intraocular pressure and anterior segment parameters. Additionally, these changes occur more dramatically in pseudoexfoliative cataracts.

The anterior and posterior biometric characteristics in primary angle-closure disease: Data based on anterior segment optical coherence tomography and swept-source optical coherence tomography.

Purpose:Obtaining a better understanding of the pathogenesis of primary angle-closure disease (PACD) still requires studies that provide measurements of anterior and posterior biometric characteristics together and that assess the relationship between them.Methods:In total, 201 eyes were enrolled in this cross-sectional study: 50 normal controls, 49 primary angle-closure suspect (PACS), 38 primary angle closure (PAC), and 64 primary angle-closure glaucoma (PACG) eyes. The anterior and posterior structural features were measured by anterior segment optical coherence tomography and swept-source optical coherence tomography.Results:All PACD groups had smaller anterior chamber depth (ACD), anterior chamber area (ACA), anterior chamber volume (ACV), angle opening distance at 750 μm from the scleral spur (AOD750), trabecular–iris space area at 750 μm from the scleral spur (TISA750), and angle recess area (ARA), as well as a larger lens vault (LV), than controls (all P < 0.001). The PACS and PAC groups had thicker iris thickness at 750 μm from the scleral spur (IT750) than controls (P = 0.017 and P = 0.002, respectively). Choroidal thickness (CT) was not statistically different among normal, PACS, PAC, and PACG eyes. Univariate and multivariate linear regression analysis revealed a significant association between thinner IT750 and increased CT in PACD eyes (P = 0.031, univariate analysis; P = 0.008, multivariate analysis).Conclusion:Thinner iris thickness was associated with increased CT in PACD eyes; however, the underlying mechanism needs further investigation.

Corneal and anterior chamber morphology in patients with nonınfectious ıntraocular ınflammation.

To evaluate the corneal and anterior chamber morphology in phakic eyes with noninfectious intraocular inflammation. This study included 59 eyes with active uveitis, 62 with inactive uveitis, and 95 healthy eyes. Corneal endothelial cell density, hexagonal cell ratio, coefficient of variation (CV), corneal thickness and volume, maximum keratometry, and anterior chamber volume and depth (ACD) measurements were performed using a specular microscope and Pentacam HR. The mean duration of uveitis was 24.6 ± 40.5 (0-180) months. The mean number of uveitis attacks was 2.8 ± 3.0 (1-20). Coefficient of variation was significantly higher in the active uveitis group compared with inactive uveitis group (p=0.017, Post Hoc Tukey). Anterior segment parameters other than coefficient of variation were not significantly different between active/inactive uveitis and control groups (p>0.05). Multiple linear regression analysis showed that coefficient of variation was greater in active uveitis compared with inactive uveitis after adjusting for the duration of uveitis, type of uveitis, having a rheumatologic disease, and having immunosuppressive treatment (p=0.003). The duration of uveitis and number of attacks were not significantly correlated with ocular parameters (p>0.05, Spearman's correlation). The difference in parameters was not significant based on uveitis type (p>0.05). Coefficient of variation was higher in eyes with active uveitis than that in eyes with inactive uveitis, whereas corneal endothelial cell density and anterior chamber morphology did not significantly differ between active/inactive uveitis and control groups.

Anterior chamber parameters in simple myopia and hypermetropia using Pentacam

Background Measurement of the anterior chamber parameters of the eye is an essential test and must be done in ophthalmic practice. Many studies were focused on the differences between the values of anterior segment parameters of myopic and hypermetropic eyes from that of emmetropic eyes. A significant correlation has been found between the RE and anterior chamber parameters. However, the strength of the correlation varied according to the race and the age of individuals. Objective To measure anterior chamber parameters (central corneal thickness, thinnest corneal thickness, apex corneal thickness, corneal volume, anterior chamber depth, anterior chamber volume, and anterior chamber angle) in simple myopia and hypermetropia and emmetropia to evaluate their effect on the anterior chamber. Patients and methods Patients presented with errors of refraction. Their SE ranged between −5 and +5.37 D. Their mean age was 29.70±5.55 years, ranging from 20 to 39 years old. The study included 63 (52.5%) right eyes and 57 (47.5%) left eyes. We examined 120 eyes divided into three groups according to their SE. Group I (control group) included 40 eyes with normal refraction, group II included 40 eyes with simple myopia less than −6 D, and group III included 40 eyes with hypermetropia less than 6 D. Results The main central corneal thickness in emmetrope, myope, and hypermetrope was 518.45±50.99, 531.95±43.04, and 552.90±34.44 μm, respectively; corneal volume was 58.10±4.35, 60.17±3.94, and 61.03m3±3.99 m3, respectively; mean anterior chamber depth was 2.98±0.29, 3.34±0.29, and 2.63 ±0.28 m2, respectively; mean anterior chamber volume was 178.98±30.63, 202.25±28.50, and 133.68±25.76 m3m3, respectively; and mean anterior chamber angle was 37.61±6.00, 42.87±3.62, and 31.10±3.76°, respectively. Our results add to the evidence that errors of refraction have an effect on anterior chamber parameters. Conclusion This study provided valuable measurements of anterior chamber parameters of the Egyptian adults with error of refraction.

Is There a Relationship between Statin Use and Corneal Specular Microscopy and Topography Findings?

Objectives:Information about the possible effect of statins on the human corneal endothelium is still not clear. This study was the first known investigation of the influence of statins on corneal specular microscopy (SM) and topography parameters.Methods:Thirty-four patients using a statin (atorvastatin) as hyperlipidemia treatment (Group 1) and 34 age- and sex-matched healthy subjects (Group 2) were prospectively included in the study. Demographic data and ophthalmic findings of participants were reported and analyzed. Cellular morphology was evaluated using the noncontact SM and corneal endothelial cell density (CECD) (cells/mm2), polymegathism (coefficient of variation in cell size [CV], %), and pleomorphism (% hexagonal cells [Hex]) data. Anterior chamber depth and volume, iridocorneal angle degree, average keratometry diopters were also measured with corneal topography.Results:The mean age was 53.03±7.23 years (range: 38–73 years) for Group 1 and 53.15±10.7 years (range: 34–80 years) for Group 2 (p=0.958). Group 1 consisted of 11 female and 23 male patients and Group 2 included 13 female and 21 male participants (p=0.798). The mean CECD density was significantly higher in Group 1 when compared with that of Group 2 (2544.34±244.76 cells/mm2 [range: 2126.60–3107.00 cells/mm2] vs 2404.53±285.46 cells/mm2 [range: 1839.80–2892.30 cells/mm2], p=0.034). There were no significant statistical differences in the CV and Hex values between the groups (p=0.450 and p=0.717, respectively). The corneal topographic measurements were also not significantly different.Conclusion:The findings of this study revealed higher CECD values in statin users. Statins may have beneficial effects on cornea morphology.

Corneal Properties in Primary Open-angle Glaucoma Assessed Through Scheimpflug Corneal Topography and Densitometry.

The purpose of this study was to compare corneal topography and densitometry measurements in patients with primary open-angle glaucoma (POAG) and healthy subjects. A total of 200 eyes of 75 patients with POAG and 125 healthy controls underwent corneal topography and densitometry (Oculus Pentacam HR). The data compared in the 2 groups were: anterior chamber angle, anterior chamber depth, and anterior chamber volume, keratometry (Kminimum, Kmaximum, and Kmean), central corneal thickness, central anterior elevation, anterior elevation apex, maximum anterior elevation, and posterior elevation apex. Densitometry measurements were made at 3 depths on a 12-mm-diameter circle divided into 4 concentric rings (0 to 2, 2 to 6, 6 to 10, and 10 to 12 mm). The diagnostic capacity of the corneal variables was assessed through the areas under the receiver operating characteristics curve. The corneal density of practically all depth layers and total corneal density were significantly higher in the POAG than the control group (P<0.05). Total corneal density was positively correlated with age (r=0.623; P<0.001) and also showed a good diagnostic capacity for glaucoma [area under the curve=0.617; 95% confidence interval (CI): 0.541-0.697; P<0.001]. In a multiple linear regression designed to assess its relationship with age, sex, central corneal thickness, and Kmean, age emerged as a significant confounder both in controls (coefficient=0.315; P<0.001; 95% CI: 0.246-0.384) and patients (coefficient=0.370; P<0.001; 95% CI: 0.255-0.486). Corneal densitometry measurements showed a good diagnostic capacity for POAG suggesting this type of examination could have clinical applications in the diagnosis and management of glaucoma.

Pupillary and Anterior Chamber Changes Following Upper Eyelid Blepharoplasty.

This study investigated the preoperative and postoperative pupillary and anterior chamber (AC) characteristics of patients undergoing upper eyelid blepharoplasty. This prospective, cross-sectional study examined 32 eyes from 20 dermatochalasis patients. Following a detailed ophthalmological examination, quantitative pupillometry and Scheimpflug corneal topography were used to evaluate the pupil and AC characteristics of eyes on the day of operation and postoperative days 1 and 7. Static and dynamic pupillometry characteristics, including scotopic, mesopic, low photopic, and high photopic pupil diameter (PD), resting diameter, amplitude, latency, duration, and velocity of pupil contraction, and latency, duration, and velocity of pupil dilation, were measured. Additionally, AC volume, depth, and angle parameters were analyzed. There were significant differences between scotopic, mesopic, and resting PD and the amplitude of pupil contraction. Pairwise comparisons showed that postoperative day 1 scotopic, mesopic, and resting PD and amplitude of pupil contraction measurements were significantly higher than preoperative measurements (p = 0.008, p < 0.001, p = 0.006, and p = 0.033, respectively). Additionally, scotopic and resting PD were significantly lower on postoperative day 7 compared with postoperative day 1 (p = 0.001 and p = 0.041, respectively). However, there were no significant differences in AC parameters. This study revealed that static and dynamic pupil measurements changed following blepharoplasty, with postoperative increased PD occurring particularly under low-light conditions. Therefore, low-light environments should be avoided following blepharoplasty, and patients with angle-closure risk factors should be closely monitored in the early postoperative period.

Visian® ICLV4c™ and Artiflex®: Comparative Analysis with the HD AnalyserTM and Integration with Subjective Performance and Anatomical Parameters.

PurposeTo analyze and compare the mid-term objective and subjective performance of two phakic intraocular lenses (PIOLs) – Visian® ICL™ V4c and Artiflex® and to correlate those results with anatomical parameters.Patients and MethodsObservational retrospective study including thirty patients (15 for each PIOL) randomly selected from those who underwent bilateral implantation of one of the PIOLs (60 eyes were analysed). Uncorrected and corrected distance visual acuities (UDVA and CDVA), anterior chamber structural parameters, and corneal endothelial cells density and morphology were evaluated. Quality of vision was assessed both subjectively with a questionnaire, and objectively using a double-pass technology optical quality analysis system.ResultsAt the end of follow-up the Artiflex® group showed better UDVA (0.95±0.11 vs 0.99±0.05, p=0.027) and higher proportion of eyes reaching at least 20/20 (28/30 vs 18/30, p=0.005). Excellent and similar objective scatter index (1.79±0.9 vs 2.14±1.6, p=0.306) and modular transfer function cutoff frequency (26.91±9.2 vs 26.51±11.9, p=0.784) results were achieved in the HD Analyzer® and the questionnaire showed comparable high Satisfaction (55.7±3.5 vs 54.3±5.4, p=0.386) and low Dysphotopsia Scores (3.1±1.8 vs 2.1±2.2, p=0.213). The ICL group showed inferior anterior chamber volume (p<0.001), and angle (p<0.001) and superior pupillary diameter (p=0.007). Minimum follow-up was 24 months.ConclusionBoth the Visian® ICLV4c™ and the Artiflex® showed excellent optical performance through the HD AnalyzerTM technology, translated in high patient satisfaction. Overall, both PIOLs showed similar safety, predictability, stability and effectiveness of for the reduction of high sphero-cylindrical refractive errors, despite better UDVA results with the Artiflex®.

Comparison of postoperative anterior segment changes associated with pars plana vitrectomy with and without vitreous base shaving.

To compare changes in anterior segment topography and axial length (AL) evaluated with Pentacam and IOL Master after pars plana vitrectomy (PPV) performed with and without vitreous base shaving. This prospective study included patients who underwent PPV or phacoemulsification+PPV (Phaco+PPV) for various indications. Patients who underwent total posterior hyaloid detachment and excessive vitreous base shaving with scleral indentation were referred to as complete PPV (c-PPV). The patients whom posterior hyaloid was separated as far as the posterior arcades and vitreous base shaving with scleral depression was not performed were classified as the partial PPV (p-PPV) group. All patients underwent detailed ophthalmologic examinations preoperatively and 1wk, 1, and 3mo postoperatively. Changes in the anterior chamber depth (ACD), anterior chamber volume (ACV), iridocorneal angle (ICA), central corneal thickness (CCT), and keratometric measurements (K1 and K2) were evaluated with Pentacam HR. Changes in the AL measurements were analyzed with IOL Master. A significant increase in ACD was observed in c-PPV cases (P=0.02), but this increase was not significant in the p-PPV group (P=0.053). In contrast, ICA increased significantly in the c-PPV group (P=0.02) but decreased in the p-PPV group (P=0.09). BCVA was significantly improved in the c-PPV group from week 1 (P<0.001) while the increase in the p-PPV group reached significance at 3mo (P=0.035). CCT increased in the first week and later returned to baseline in both groups. No significant differences in the other parameters were observed between the groups, and there were no significant changes in intraocular pressure, ACV, AL, K1 or K2 values (P>0.05 for all). Incomplete posterior hyaloid excision and not removing the vitreous base in PPV surgeries may create a more stable anterior chamber, thus preventing the downward movement of the lens-iris diaphragm, and may cause ciliary body retraction, thereby reducing ICA. Awareness of these effects can provide some amount of guidance to physicians in selecting the appropriate PPV procedure and preempting surgical complications.

Prediction of anterior chamber volume after implantation of posterior chamber phakic intraocular lens.

PurposeTo predict the anterior chamber volume (ACV) after implantable collamer lens (ICL) implantation based on ICL size and parameters of anterior segment optical coherence tomography (AS-OCT).DesignRetrospective study.MethodsThis study included 222 eyes of 222 patients who underwent ICL implantation at Nagoya Eye Clinic. The patients were divided into two groups: prediction group, for creating the prediction equation (148 eyes, mean age: 32.11 ± 8.04 years), and verification group, for verifying the equation (74 eyes, mean age: 33.03 ± 6.74 years). The angle opening distance (AOD), anterior chamber width (ACW), ACV, anterior chamber depth, lens vault, angle-to-angle distance, angle recess area, and trabecular iris space area were calculated using AS-OCT. A stepwise multiple regression analysis was performed. After the creation of the prediction equation, its accuracy was verified in the verification group.ResultsThe ACV, AOD750, ACW, and ICL size were selected as explanatory variables to predict postoperative ACV. Mean predicted (114.2 ± 21.83 mm3) and actual postoperative ACVs (116.1 ± 25.41 mm3) were not significantly different (P = 0.269); absolute error was 10.59 ± 9.13 mm3. In addition, there was high correlation between actual and predictive ACV (adjusted R2 = 0.6996, p < 0.0001). Bland-Altman plot revealed that there was no addition or proportional error between predicted and actual postoperative ACV.ConclusionPostoperative ACV was accurately predicted using AS-OCT parameters and ICL size. This prediction equation may be useful for making decisions regarding ICL size.

Evaluating the Relationship of Intraocular Pressure and Anterior Chamber Volume With Use of Prostaglandin Analogues.

In this prospective study, naive prostaglandin use in primary open-angle glaucoma was associated with scleral biomechanical alteration and intraocular pressure (IOP) measuring errors. The purpose of this study is to determine the effects of naïve use of prostaglandin analogues (PGA) on IOP and anterior chamber volume (ACV), as well as investigate how PGAs might affect corneal and scleral stiffness and their impact on ocular rigidity. This study was a prospective study of 21 recently diagnosed open-angle glaucoma patients (33 eyes) initiating medical therapy with a topical prostaglandin eye drop. Corneal morphologic and biomechanical parameters as well as IOP were measured at 3 visits over a 4-month period with the following equipment: Pentacam, Corvis ST, Ocular Response Analyzer, Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry. The study demonstrated a significant decrease in mean IOP with initiation of PGA in all 4 tonometers (P<0.0001). The greatest change in IOP occurred in the first 4 weeks of treatment (P<0.0001). The mean ACV showed a significant decrease at visit 2 (P<0.02) and visit 3 (P<0.04) compared with baseline visit 1. However, there was a paradoxical increase in ACV in 37% of eyes at visit 2, despite a significant mean reduction in IOP by GAT and dynamic contour tonometry.The IOP/ACV ratio at visit 1 significantly predicted the reduction in respective measures of IOP, as well as scleral stiffness measured by stiffness parameter-highest concavity. In clinical practice, GAT may not be the most appropriate tonometer for measuring IOP in PGA treated eyes due the measurement errors from ocular biomechanical alteration. The IOP/ACV ratio could potentially serve as a new diagnostic parameter to determine the likelihood of PGA treatment success.

Age distribution and associated factors of cornea biomechanical parameter stress-strain index in Chinese healthy population

BackgroundTo investigate the new cornea biomechanical parameter stress-strain index (SSI) in Chinese healthy people and the factors associated with SSI.MethodsA total of 175 eyes from 175 participants were included in this study. Axial length was measured with the Lenstar LS-900. Pentacam measured curvature of the cornea and anterior chamber volume (ACV). Cornea biomechanical properties assessments were performed by corneal visualization Scheimpflug technology (Corvis ST). Student’s t-test, one-way ANOVA, partial least square linear regression (PLSLR) and linear mixed effects (LME) model were used in the statistical analysis.ResultsThe mean (±SD) SSI was 1.14 ± 0.22 (range, 0.66–1.78) in all subjects and affected by age significantly after age of 35 (P < 0.05). In LME models, SSI was significantly associated with age (β = 0.526, P < 0.001), axial length (AL) (β = − 0.541, P < 0.001), intraocular pressure (IOP) (β = 0.326, P < 0.001) and steepest radius of anterior corneal curvature (RsF) (β = 0.229, P < 0.001) but not with ACV, biomechanical corrected intraocular pressure (bIOP), flattest radius of anterior corneal curvature (RfF) or central corneal thickness (CCT) (P > 0.05 for each).ConclusionsSSI increased with age after the age of 35. In addition to age, SSI was positively correlated with RsF and IOP, while negatively correlated with AL.

Changes of Anterior Chamber Biometry and Relationship to Intraocular Pressure Changes after Phacoemulsification Emulsification Surgery in Non-Glaucomatous Eyes

Fifty percent of blindness worldwide is attributed to cataract, and cataract surgery is the most commonsurgery performed by ophthalmologist. Cataract surgery has its effects on the structures of the anteriorsegment, and hence the aqueous humor outflow, these may include more space in anterior chamber, widerangles, as the thick aging lens would be replaced by the thinner intraocular lens. So this study to investigatethe changes in anterior segment parameters and its correlation to IOP changes after phacoemulsification.A prospective Cohert study that was done at Ibn Al-Haitham Teaching Eye Hospital for patients plannedto have phacoemulsification, for 55 patients during 8 months, from the 1st of July/2018 until the 28th ofFebruary/2019. The data included full preoperative and postoperative assessment, key parameters were:axial length measurement, intraocular lens, anterior chamber depth, anterior chamber volume, anteriorchamber angle for the four quadrants and their mean value was calculated. It was done before the operationsand after two months from the operation. Findings were the mean age of the study group was 56.9years,with 30 (54.5%) males and 29 (52.7%) right eyes,. The mean axial length was 23.12±1.11 mm. There werestatistically significant differences in preoperative compared to postoperative values of IOP (decreased by4.55 mmHg), anterior chamber depth (increased by 0.74 mm), volume (increased by 32.75 µl), and meanangle (increased by11.78 degree) maximum inferiorly (12.31 degree) and minimum superiorly. There wereno statistically significant correlation between IOP changes with anterior chamber depth, volume, or angles,but there was a statistically significant correlation with preoperative IOP .Conclusions cataract surgerysignificantly decreases the IOP, and increase anterior chamber depth, volume, and angle. The decrease in IOPdoes not correlate with anterior chamber depth, volume, and angle. The decrease in IOP was significantlyhigher in patients with higher preoperative values of IOP.