Associations between corneal curvature and other anterior segment biometrics in young myopic adults.

To investigate the associations between corneal curvature (CC) and other anterior segment biometrics in young myopic adults. In this retrospective multi-center study, 7893 young myopic adults were included. CC and other anterior segment biometrics were measured by Scheimpflug imaging (Pentacam). CC was defined as SimK at central 3 mm area, and other anterior segment biometrics included white-to-white corneal diameter (WTW), central corneal thickness (CCT), corneal volume (CV) at 3 mm, 5 mm, and 7 mm area, anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), anterior corneal eccentricity (ACE) and asphericity (ACAP), posterior corneal eccentricity (PCE) and asphericity (PCAP), anterior chamber depth (ACD), and anterior chamber volume (ACV). Univariate regression analyses were used to assess the associations between CC and other anterior segment biometrics, and multivariate regression analyses were further performed to adjusted for age, gender and spherical equivalent. CC was higher in patients of female gender and higher myopia (all P < 0.05). Eyes in higher CC quartiles had lower WTW, thinner CCT, lower CV at 3 mm and 5 mm, lower ACD, and lower ACV (all P < 0.001), but had larger ACA, larger PCA, less PCE and less PCAP (all P < 0.001), compared to eyes in lower CC quartiles. The trends of CV at 7 mm, ACE and ACAP were inconsistent in different CC quartiles. After adjusting for age, gender and spherical equivalent with multivariate linear regression, CC was positively correlated to CV at 7 mm (ßs = 0.069), ACA (ßs = 0.194), PCA (ßs = 0.187), ACE (ßs = 0.072), PCAP (ßs = 0.087), and ACD (ßs = 0.027) (all P < 0.05), but was negatively correlated to WTW (ßs = - 0.432), CCT (ßs = - 0.087), CV-3 mm (ßs = - 0.066), ACAP (ßs = - 0.043), PCE (ßs = - 0.062), and ACV (ßs = - 0.188) (all P < 0.05). CC was associated with most of the other anterior segment biometrics in young myopic adults. These associations are important for better understanding of the interactions between different anterior segment structures in young myopic patients, and are also useful for the exploration of the pathogenesis of myopia.

Anterior Segment Biometry During Accommodation After Posterior Chamber Phakic Implantable Collamer Lens Implantation.

PURPOSE: To evaluate the dynamic changes in anterior segment parameters during accommodation following Implantable Collamer Lens (ICL) implantation with swept-source optical coherence tomography (SS-OCT). METHODS: Under the accommodation of 0.00 diopters (D), 3.00 D, and maximum amplitude, SS-OCT was used to examine the anterior segment parameters, including ICL vault, ICL depth (the distance between the corneal endothelium and the posterior surface of ICL), crystalline lens thickness, anterior chamber depth, and various parameters of the anterior chamber angle, comprising angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle. RESULTS: During accommodation, the ICL vault showed a significant decrease from baseline (536 ± 278 µm) to 3.00 D (522 ± 281 µm), followed by an increase from 3.00 D to maximum amplitude (548 ± 306 µm) (analysis of variance [ANOVA], P < .001). Four eyes (2.61%) exhibited a decrease in ICL vault to less than 100 µm (47 ± 32 µm) at maximum accommodation. The ICL depth decreased significantly as accommodation increased (ANOVA, P < .001). Crystalline lens thickness increased, whereas anterior chamber depth decreased during accommodation (ANOVA, P < .001). The anterior chamber angle widened during 3.00 D of accommodation but narrowed at maximum accommodation, leading to significant changes in the angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle during accommodation (ANOVA, P < .001 for all). CONCLUSIONS: The anterior segment, including ICL vault and anterior chamber angle, undergo significant dynamic changes during accommodation. These accommodative changes may require careful monitoring for the surgery design of ICL implantation. [J Refract Surg. 2024;40(3):e164-e172.].

Repeatability of biometric measures from the IOLMaster 700 in a cataractous population.

PURPOSE: The purpose of this study was to investigate the repeatability of biometric measures and also to assess the interactions between the uncertainties in these measures for use in an error propagation model, using data from a large patient cohort. METHODS: In this cross-sectional non-randomised study we evaluated a dataset containing 3379 IOLMaster 700 biometric measurements taken prior to cataract surgery. Only complete scans with at least 3 successful measurements for each eye performed on the same day were considered. The mean (Mean) and standard deviations (SD) for each sequence of measurements were derived and analysed. Correlations between the uncertainties were assessed using Spearman rank correlations. RESULTS: In the dataset with 677 eyes matching the inclusion criteria, the within subject standard deviation and repeatability for all parameters match previously published data. The SD of the axial length (AL) increased with the Mean AL, but there was no noticeable dependency of the SD of any of the other parameters on their corresponding Mean value. The SDs of the parameters are not independent of one another, and in particular we observe correlations between those for AL, anterior chamber depth, aqueous depth, lens thickness and corneal thickness. CONCLUSIONS: The SD change over Mean for AL measurement and the correlations between the uncertainties of several biometric parameters mean that a simple Gaussian error propagation model cannot be used to derive the effect of biometric uncertainties on the predicted intraocular lens power and refraction after cataract surgery.

Association of refractive outcome with postoperative anterior chamber depth measured with 3 optical biometers.

PURPOSE: This study evaluated the relationship between refractive outcomes and postoperative anterior chamber depth (ACD, measured from corneal epithelium to lens) measured by swept-source optical coherence tomography (SS-OCT), optical low-coherence reflectometry (OLCR), and Scheimpflug devices under the undilated pupil. METHODS: Patients undergoing cataract phacoemulsification with intraocular lens (IOL) implantation in a hospital setting were enrolled. Postoperative ACD (postACD) was performed with an SS-OCT device, an OLCR device, and a Scheimpflug device at least 1 month after cataract surgery. After adjusting the mean predicted error to 0, differences in refractive outcomes were calculated with the Olsen formula using actual postACD measured from 3 devices and predicted value. RESULTS: Overall, this comparative case study included 69 eyes of 69 patients, and postACD measurements were successfully taken using all 3 devices. The postACD measured with the SS-OCT, OLCR, and Scheimpflug devices was 4.59 ± 0.30, 4.50 ± 0.30, and 4.54 ± 0.32 mm, respectively. Statistically significant differences in postACD were found among 3 devices (P < 0.001), with intraclass correlation coefficients (ICCs) and Bland-Altman showing good agreement. No significant difference in median absolute error was found with the Olsen formula using actual postACD obtained with 3 devices. Percentage prediction errors were within ± 0.50 D in 65% (OLCR), 70% (Scheimpflug), and 67% (SS-OCT) calculated by actual postACD versus 64% by predicted value. CONCLUSION: Substantial agreement was found in postACD measurements obtained from the SS-OCT, OLCR, and Scheimpflug devices, with a trend toward comparable refractive outcomes in the Olsen formula. Meanwhile, postACD measurements may be potentially superior for the additional enhancement of refractive outcomes.

Aqueous misdirection syndrome post silicone oil removal in a vitrectomized eye - a case report.

PUROPSE: Aqueous misdirection syndrome (AMS) is an aggressive post-operative glaucoma unresponsive to conventional measures with grave outcomes. In this report, we describe a rare case of AMS following silicon oil removal in a vitrectomized eye. METHODS: A diabetic patient with tractional retinal detachment underwent pars plana vitrectomy with silicon oil injection. Following retinal reattachment, silicon oil removal was performed at three months. Post oil removal she developed increased intraocular pressure with shallowing of both the peripheral and central anterior chamber suggestive of AMS. RESULTS: Initial medical management with anti-glaucoma medications and cycloplegics was not beneficial. A pars plana lensectomy with complete anterior hyaloidectomy along with a surgical peripheral iridectomy helped relieve the aqueous misdirection. CONCLUSION: AMS can rarely occur following vitrectomy and is likely secondary to intact anterior hyaloid. Lensectomy along with zonulo-hyaloido-iridectomy is essential. This report highlights the occurrence of this rare complication and its effective management.

Changes in Intraocular Pressure and Anterior Chamber Parameters Following Cataract Surgery, Vitrectomy, and Combined Surgery.

PURPOSE: The aim of this study is to investigate changes in intraocular pressure (IOP) and anterior-segment parameters before and after cataract surgery, vitrectomy, and combined surgery. METHODS: The records of patients who had undergone cataract surgery (cataract group), vitrectomy (vitrectomy group), or combined cataract surgery and vitrectomy (combined group) at our hospital were retrospectively examined. The vitrectomy group consisted of pseudophakic eyes. IOP and anterior-segment measurements, including anterior chamber depth (ACD), angle opening distance (AOD), trabecular-iris angle (TIA), and trabecular-iris space area (TISA), were measured using swept-source anterior-segment optical coherence tomography before and 6 months after surgery in 41, 15, and 40 eyes, respectively. RESULTS: In the cataract and combined groups, there was a decrease in IOP (cataract group: from 15.8 to 13.4 mmHg, p <0.001; combined group: from 15.8 to 14.2 mmHg, p = 0.002) and an increase in the central corneal thickness after surgery (p <0.001). The ACD increased in all groups, with a smaller increase in the vitrectomy group (p <0.03). Postoperative AOD, TIA, and TISA were significantly increased in the cataract and combined groups (p <0.02). Higher preoperative IOP and larger IOP reduction after surgery were correlated with smaller preoperative AOD, TISA, and TIA in cataract and combined groups (p <0.034). A small preoperative ACD was related to smaller preoperative AOD, TISA, TIA (r > 0.649, p <0.001), and postoperative IOP reduction in the cataract and combined groups (r = 0.377, p = 0.018 and r = 0.559, p = 0.001, respectively). CONCLUSIONS: Compared to the vitrectomy group, the cataract and combined groups showed reduced postoperative IOP and increased AOD, TISA, and TIA. In these two groups, patients with shallower preoperative ACDs showed greater changes in IOP after surgery. Changes in IOP after surgery are thought to be related to changes in the anterior segment caused by the removal of the crystalline lens.

Evaluation of a New All-in-One Optical Biometer and Comparison With a Validated Swept-source OCT Biometer.

PURPOSE: To assess agreement between a new all-in-one non-contact optical biometer based on optical low coherence reflectometry (SW-9000 µm Plus; Suoer) and a swept-source optical coherence tomography biometer (OA-2000; Tomey). METHODS: Each eye was scanned three times in a row by each device at random. The measured ocular parameters included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), flat keratometry (Kf), steep keratometry (Ks), mean keratometry (Km), astigmatism, corneal diameter (CD), and pupil diameter (PD). The paired t test was used to show the differences between the SW-9000 and OA-2000. Bland-Altman plots and the 95% limits of agreement (LoA) were applied to assess the consistency of the measurements. RESULTS: Sixty eyes from 60 healthy participants were examined, with a mean spherical equivalent refraction of -5.58 ± 2.31 diopters and a mean age of 30.40 ± 6.07 years. The Bland-Altman plots showed high agreement for AL, ACD, LT, Kf, Ks, Km, astigmatism, and CD measurements (95% LoA: -0.06 to 0.04 mm, -0.10 to 0.06 mm, -0.12 to 0.11 mm, -0.30 to 0.29 D, -0.35 to 0.38 D, -0.29 to 0.30 D, -0.30 to 0.34 D, and -0.50 to 0.06 mm, respectively), whereas the agreement for CCT and PD were moderate (95% LoA: 7.12 to 20.43 µm, -0.75 to 1.19 mm, respectively). CONCLUSIONS: The new all-in-one non-contact biometer had high agreement with the OA-2000 biometer on the AL, ACD, LT, Kf, Ks, Km, astigmatism, and CD measurements. For most of the ocular parameters assessed, they were clinically interchangeable. [J Refract Surg. 2023;39(12):825-830.].

Imaging analysis of the biological parameters of the lens in patients with cortical age-related cataracts using ultrasound biomicroscopy.

BACKGROUND: The spatial position of the lens in patients with cortical age-related cataract (CARC) is unclear. We investigated a basis for the assessment of visual quality after cataract surgery by analysing the ultrasound biomicroscopic characteristics of the biological parameters of the lens in patients with CARC. METHODS: In this retrospective study, 119 patients (50 males and 69 females, totalling 238 eyes) with CARC who underwent simple cataract surgery were selected. The lens thickness (LT), axial length (AL), anterior chamber depth (ACD), lens vault (LV), trabecular-iris angle (TIA), iris-lens angle (ILA), iris-lens contact distance (ILCD) were measured by A-scan ultrasound and ultrasound biomicroscopy. The corresponding lens position (LP) and relative lens position (RLP) were calculated. RESULTS: LP was greater in men than in women (P < 0.05), LV was smaller in men than in women (P = 0.002), ILA and ILCD were not statistically significant (P = 0.072 and P = 0.854, respectively). There were significant differences in TIA, ILA, and ILCD in the four quadrants (all P < 0.05), with a trend in the distribution of TIA: superior < inferior < nasal < temporal, ILA: nasal < inferior < temporal < superior, and ILCD: superior < temporal < inferior < nasal. CONCLUSIONS: The lens protrudes more obviously in females than in males and the lens tilts to a certain extent with the increase of age and tends to be more upward and temporal in the supine position. Therefore, trends in lens-related parameters in patients with CARC should be taken seriously.

Comparison of the ocular ultrasonic and optical biometry devices in the different quality measurements.

PURPOSE: To compare the reliability and agreement of axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) measurements obtained with optical biometry based on swept-source optical coherence tomography (IOLMaster 700; Carl Zeiss, Germany) and an ultrasound biometry device (Nidek; US-4000 Echoscan, Japan) in different qualities of AL measurement. METHODS: A total of 239 consecutive eyes of 239 cataract surgery candidates with a mean age of 56 ± 14 years were included. The quality measurements were grouped according to the quartiles of SD of the measured AL by IOLMaster 700. The first and fourth quartile's SD are defined as high and low-quality measurement, respectively, and the second and third quartiles' SD is defined as moderate-quality. RESULTS: The reliability of AL and ACD between the two devices in all patients and in different quality measurement groups was excellent with highly statistically significant (AL: all ICC=0.999 and P<0.001, ACD: all ICC>0.920 and P<0.001). AL and ACD in all quality measurements showed a very strong correlation between devices with highly statistically significant. However, there was poor (ICC=0.305), moderate (ICC=0.742), and good (ICC=0.843) reliability in measuring LT in low-, moderate-, and high-quality measurements, respectively. LT showed a very strong correlation (r = 0.854) with highly statistically significant (P<0.001) between devices only in patients with high-quality measurements. CONCLUSIONS: AL and ACD of the IOLMaster700 had outstanding agreements with the US-4000 ultrasound in different quality measurements of AL and can be used interchangeably. But LT should be used interchangeably cautiously only in the high-quality measurements group.

Comparative study of the effects of laser peripheral iridotomy and cataract surgery on anterior chamber angle parameters in primary angle closure suspect patients.

INTRODUCTION: Prophylactic laser peripheral iridotomy (LPI) and cataract surgery are considered the primary treatments for primary angle closure suspect (PACS) as they have proven effectiveness in widening the iridocorneal angle and addressing the underlying anatomical issues associated with this condition. The objective of this study is to compare the impact of LPI and cataract surgery on anterior chamber angle parameters, aiming to fill the existing research gap. METHODOLOGY: A prospective comparative study was conducted, involving 76 eyes of 61 patients. The study focused on patients diagnosed with PACSs and early cataract. The patients received treatment either through LPI or cataract surgery. Comprehensive eye examination was performed, including gonioscopy and anterior segment parameters were measured using anterior segment ocular coherence tomography (ASOCT). Follow-up examinations were conducted at 1 week and 1 month after the procedures, which included ASOCT and gonioscopy performed during the 1-month follow-up. RESULTS: All anterior chamber angle parameters increased significantly after treatment in both groups, including trabecular iris angle (TIA), angle opening distance at 250, 500 and 750 µm (AOD 250, AOD500, AOD750), trabecular iris surface area at 500 and 750 µm (TISA500, TISA750) and angle recess area at 500 and 750 µm from scleral spur (ARA500, ARA750) (p<0.05 for all). Moreover, all these parameters were greater after cataract surgery than after LPI (p<0.05 for all). CONCLUSION: Compared with LPI, cataract extraction resulted in a wider anterior chamber angle. Moreover, no residual angle closure was observed after cataract extraction, which could morphologically prevent the progress of angle closure. Thus, cataract extraction is superior to LPI in PACSs with early cataract in widening the anterior chamber angle.

Correlation Between Corneal Keratometry, Central Corneal Thickness and Anterior Chamber Depth as Measured by Wavelight OB 820 Biometer and Wavelight Oculyzer II in Preoperative Cataract Surgery Patients.

OBJECTIVE: To compare and correlate corneal keratometry (K), central corneal thickness (CCT), and anterior chamber depth (ACD) using a partial coherence interferometry device and a Scheimpflug camera system device in patients planned for cataract surgery. STUDY DESIGN: Comparative cross-sectional study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology, from December 2021 to June 2022. METHODOLOGY: Patients planned for cataract surgery underwent measurement of central corneal thickness (CCT), anterior chamber depth (ACD), and keratometric values (K) by Wavelight OB 820 biometer and Allergo Oculyzer II, preoperatively. Correlation and inter-device agreement were assessed between two devices. RESULTS: There were 115 patients with a mean age of 64.23 ± 9.26 years. All anterior segment parameters showed excellent agreement and high degree of correlation between the two optical devices. Correlation coefficient (r) for central corneal thickness was r = 0.958 (p<0.001) while correlation coefficient for anterior chamber depth was r = 0.965 (p<0.001), r = 0.966 (p<0.001) for flat K, and r = .0969 (p<0.001) for steep keratometry, respectively. CONCLUSION: Ophthalmic parameters assessed by both devices were comparable and are recommended to be used in the clinical practice of keratorefractive and cataract surgeries interchangeably. KEY WORDS: ACD, CCT, Keratometry, Cataract, OB 820 biometer, Oculyzer II.

Association between anterior chamber biometry and posterior capsular defects.

PURPOSE: To analyze the association between anterior chamber biometric factors and posterior capsular defects (PCDs) that occur during extracapsular cataract extraction. SETTING: University Eye Hospital, Goethe University Frankfurt, Germany. DESIGN: Population-based study. PATIENTS AND METHODS: Extracapsular cataract extractions for inpatient cases within 4 years were retrospectively analyzed. The data on the occurrence of PCDs, age, sex, surgeon, and biometry were obtained. For cases with PCDs, the secondary ocular diseases, number of procedures, lens implant, visual acuity, and course were also recorded. Swept-source optical coherence tomography measurements allowed the measurement of lens thickness (LT) in addition to the usual biometry values. RESULTS: A total of 1967 cataract surgeries (patients age: 70.56 ± 8.42, 1005 women; 962 men) were included, and PCDs were documented for 59 (2.54%; 31 women, 28 men) cases (patient age: 70.95 ± 8.52 years). There were no differences ( P = .76) related to the surgeons (n = 9) with minimal effect sizes. The mean LT, axial length, corneal curvature, and anterior chamber depth were 4950.36 ± 466.63 µm, 23.73 ± 1.77 mm, 43.89 ± 1.36 diopters, and 3.02 ± 0.71 mm, respectively. The Wilcoxon-Mann-Whitney test showed significant associations between LT ( P = .01) and PCDs with moderate relevance for the Rosenthal effect size (LT R = 0.34; ACD R = 0.29). CONCLUSIONS: In addition to ACD, a tendency for the occurrence of PCD could be proven, especially for LT. Therefore, special attention should be paid to LT preoperatively for comprehensive risk stratification.

A vault-prediction formula for implantable collamer lens based on preoperative parameters: a retrospective clinical study.

OBJECTIVES: The aim of the present study was to predict the vault of implantable collamer lens (ICL) using a formula established based on the preoperative parameters. METHODS: This retrospective study included data on 226 eyes from 114 patients(the median age and range was 27.5 ± 5.7; 18-46 years) who underwent EVO-ICL surgery between May 2021 and April 2022. Preoperative parameters, such as anterior chamber depth (ACD) horizontal angle-to-angle diameter (ATA), Crystalline lens rise (CLR), and vault (1 week after surgery) were measured by anterior segment optical coherence tomography. The axial length of eyes (AL) and white-to-white (WTW) values were measured using an IOLmaster and calipers under a slit lamp separately. RESULT: The mean WTW, ACD, horizontal ATA diameter, CLR, AL, and vault 1 week after surgery were 11.42 ± 0.37 mm, 3.25 ± 0.25 mm, 11.72 ± 0.44 mm, 45.78 ± 175.42 µm, 27.61 ± 1.93 mm, and 586.51 ± 254.54 µm respectively. Multivariate regression analysis showed that the ICL-width, ACD (ß = 0.293), ATA (ß =-0.657), CLR (ß =-0.157), and the anterior chamber angle in temporal side (T:ACA) (ß=-0.277) were predictors of the vault size (adjusted-R2 = 0.39, P < 0.001). CONCLUSION: The formula built based on these preoperative parameters could be used to predict the vault before surgery. The predictors indicated that the pre-operative parameters of eye such as ACD, ATA, CLR and T:ACA play an important role in choosing optimal ICL size.

Anterior Segment Biometry in a Caucasian Population with Cataracts.

PURPOSE: To investigate biometric factors of the anterior segment of phakic eyes with cataracts. METHODS: This population-based study included Caucasian patients with cataracts in the University Eye Hospital, Goethe University Frankfurt, Germany. Biometric parameters were measured using the swept-source optical coherence tomography method. Patients were grouped into intermediate stages based on decades of life. RESULTS: In total, 6289 eyes of 3615 patients (age: 70.67 ± 8.42 years) were included. Age-related reductions in the anterior chamber depth (mean ± standard deviation) decreased from 3.26 ± 0.42 mm (group A: 55-59 years) to 2.94 ± 0.4 mm (group G: 85-89 years), and those in the axial length decreased from 24.37 ± 1.87 mm (group A) to 23.39 ± 1.07 mm (group G). Likewise, the white-to-white distance decreased from 12.12 ± 0.48 mm (group A) to 11.96 ± 0.47 mm (group G). Lens thickness tended to increase accordingly from 4.39 ± 0.36 µm (group A) to 4.9 ± 0.40 µm (group G). A comparison of the eyes showed no detectable lateral difference regarding the biometric parameters between the groups (axial length: p = 0.26, Rosenthal effect size = 0.03; lens thickness: p = 0.12, R = 0.03; anterior chamber depth: p = 0.63, Rosenthal effect size = 0.01). The axial length and anterior chamber depth differed significantly between sexes (r = 0.22, p < 0.0001 and r = 0.16, p < 0.0001, respectively). Multiple regression analysis of the anterior chamber depth as a function of biometry parameters as well as age and sex additionally indicated a positive correlation of anterior chamber depth with white-to-white distance (b = 0.32, p = 10-5), axial length (b = 0.10, p = 10-5), keratometry (b = 0.07, p = 10-5), and lens thickness (b=-0.05, p = 10-5) with a high effect size (Cohen f2=1.866, p = 10-5) and strong multiple correlation coefficient (Rosenthal effect size = 0.80, p = 10-5). CONCLUSIONS: In the anterior segment, there are age- and sex-dependent changes in biometric parameters. In addition, changes in anterior chamber depth were noted in relation to white-to-white distance, axial length, keratometry, and lens thickness. These data should be considered in lens calculation formulas.

The Non-uniform Distribution of Horizontal and Vertical Crystalline Lens Rise Using Optical Coherence Tomography.

PURPOSE: To observe the crystalline lens rise (CLR) in horizontal and vertical orientations using anterior segment optical coherence tomography (AS-OCT). METHODS: Non-invasive swept-source AS-OCT was used to measure the lens thickness, CLR, and angle-to-angle distance (ATA) in both the horizontal and vertical orientations. Anterior chamber depth (ACD) and horizontal white-to-white corneal diameter were obtained using the Pentacam HR (Oculus Optikgeräte GmbH). Axial length was obtained using the IOLMaster 700 (Carl Zeiss Meditec AG). The paired t test was used to analyze the difference in CLR between the two orientations. Pearson correlation analysis was performed to investigate the correlations between CLR and other ocular variables. RESULTS: This prospective observational study comprised 99 eyes (99 patients) that underwent Visian Implantable Collamer Lens (STAAR Surgical) implantation for myopic correction. The mean CLR was 64.29 ± 168.04 and 208.09 ± 173.12 µm in the horizontal and vertical orientations, respectively. The vertical CLR (VCLR) was significantly greater than the horizontal CLR (HCLR) (P < .05). Both the HCLR and VCLR were positively correlated with lens thickness and negatively correlated with ACD (all P < .05). The difference in CLR (VCLR-HCLR) was positively correlated with the axial length and the difference in ATA between the two orientations (P < .05). CONCLUSIONS: VCLR was greater than HCLR in most patients with myopia, especially in the longer eyes. This nonuniform distribution in CLR implied different placements of the iridocorneal angles in the horizontal and vertical orientations and should be considered for the selection of ICL size and placement position. [J Refract Surg. 2023;39(5):354-359.].

Changes in Anterior Segment Morphology and Intraocular Pressure after Cataract Surgery in Non-glaucomatous Eyes.

BACKGROUND: It is known that cataract extraction is associated with a significant reduction in intraocular pressure, especially in narrow angled eyes; however, the modifications of anterior segment parameters associated with this phenomenon have still not been completely defined. The purpose of this study was to evaluate changes in anterior segment anatomy and intraocular pressure after cataract surgery in non-glaucomatous eyes. METHODS AND MATERIAL: This retrospective case series study included 64 eyes of 64 consecutive patients who underwent phacoemulsification with intraocular lens implantation. Anterior segment parameters and intraocular pressure were assessed and compared before and 6 months after surgery. Anterior segment imaging was performed using Casia SS-1000 anterior segment optical coherence tomography (Tomey, Nagoya, Japan). Anterior segment measurements included anterior chamber depth, anterior chamber width, anterior chamber volume, angle opening distance at 500 µm anterior to the scleral spur, angle recess area 750 µm from the scleral spur, lens vault, trabecular iris space area at 500 µm from the scleral spur, and trabecular iris angle at 500 µm from the scleral spur. Intraocular pressure was measured using the Goldmann applanation tonometer (Model AT 900 C/M, Haag-Streit, Bern, Switzerland). Anterior segment parameters and the relationship of changes in intraocular pressure were also evaluated. RESULTS: All anterior segment parameters increased significantly after surgery (p < 0.05). Both angle opening distance at 500 µm anterior to the scleral spur and anterior chamber depth changes were positively correlated with the preoperative lens vault. The mean intraocular pressure significantly decreased from 14.91 mmHg (± 2.8 SD) to 12.91 mmHg (± 3.13 SD) (p < 0.001). Changes in intraocular pressure correlated negatively with values for the width of the preoperative anterior chamber (r = - 0.533; p = 0.001). CONCLUSION: Cataract surgery led to significant widening of the anterior chamber angle and lowering of intraocular pressure. Further investigations are needed to better understand whether anterior chamber width may be a new independent predictive factor for reduction in postoperative intraocular pressure.

Effect of the Presence of Silicone Oil in the Anterior Chamber After Complicated Retinal Detachment Surgery on Corneal Morphology by In Vivo Confocal Microscopy.

PURPOSE: This study evaluated the corneal endothelium, stromal keratocytes, subbasal nerve number and density in patients with silicone oil transferred to the anterior camera after pseudophakic complicated retinal detachment surgery by in vivo laser scanning confocal microscopy (IVLSCM). METHODS: Sequential measurements were made by IVLSCM between 3-6 months after surgery in two groups of patients: a) with silicon oil migration (Group 1) and without silicone oil migration (Group 2). RESULTS: A total of 63 cases (Group 1: 32 and Group 2: 31) were examined. The mean ages of patients were 65 ± 12 and 61 ± 11 and M/F ratio was 18/14 and 17/14, respectively. Mean intraocular pressures were 16.60 ± 4.60 and 15.75 ± 5.70 mm Hg, respectively. Changes were detected by IVLSCM mostly on the superior part of the cornea. A significant decrease in endothelial cell density and the number was detected in group 1 (2072 ± 116.2 cells/mm2 vs 2752 ± 512.3 cells/mm2; p < 0.001). Significant increases in posterior keratocyte density and stromal hyperreflective deposits were observed in group 1 (887 ± 45.8 cells/mm2 vs 725 ± 65.8 cells/mm2; p < 0.001). A significant negative correlation was observed between the size of stromal deposits and endothelial cell density (r=-0.758; p < 0.001). The number and density of corneal subbasal nerves were significantly lower in group 1 (1.8 ± 0.8 and 4.8 ± 1.2 vs 420 ± 101 and 701 ± 112 µm/square; p < 0.001). CONCLUSION: IVLSCM is a useful tool for the early detection of corneal abnormalities caused by silicone oil injection. This study verified silicone oil's detrimental effect on the corneal endothelium and revealed stromal changes in the anterior chamber, which we believe can be also been associated with the presence of silicone oil.