Changes In Anterior Chamber Parameters Research Articles

Commentary: Reliability, repeatability, and accuracy of Sirius topographer in assessing anterior segment morphology following laser peripheral iridotomy in primary angle-closure disease.

Commentary: Reliability, repeatability, and accuracy of Sirius topographer in assessing anterior segment morphology following laser peripheral iridotomy in primary angle-closure disease.

TO ASSESS THE ANTERIOR CHAMBER PARAMETERS USING PENTACAM IN PRIMARY ANGLE CLOSURE SUSPECTS FOLLOWING PERIPHERAL LASER IRIDOTOMY

Objective: The aim of the present study was to study the changes in anterior chamber parameters before and after laser peripheral iridotomy (LPI) in primary angle closure suspects (PACS) using pentacam. Methods: This was a prospective, non-randomized, and interventional study which was conducted on 40 patients of PACS attending the Outpatient Department of Ophthalmology, Government Medical College, Patiala. Evaluation of the anterior segment of the eye was done by Pentacam (Oculus) using rotating Scheimpflug imaging technology, before and after LPI. Results: Following LPI, anterior chamber volume (ACV) increased from 90.13±9.82 mm3 to 105.8±11.5 mm3; anterior chamber angle (ACA) increased from 27.01±3.23 degree to 28.13±2.29 degree. Peripheral anterior chamber depth (PACD) at 4 mm increased significantly in superior, inferior, nasal, and temporal quadrant in all cases. Conclusion: LPI serves both prophylactic and therapeutic benefit in PACS by increasing the ACV, ACA, and PACD, and thus preventing glaucoma. Pentacam is a useful tool to assess the efficacy of LPI and can guide further course of treatment.

Changes in Anterior Chamber Volume, Depth and Angle After Prophylactic Laser Peripheral Iridotomy in Patients With Primary Angle-closure Suspect

Background and Objectives This study aims to assess changes in anterior chamber parameters after prophylactic laser peripheral iridotomy (LPI) in patients with primary angle-closure suspect (PACS). Subjects and Methods In this study, 43 patients (86 eyes) with PACS (Mean age: 55.16±9.14 years) participated. The anterior chamber parameters including anterior chamber volume (ACV), anterior chamber angle (ACA) and central anterior chamber depth (CACD) were extracted from the Pentacam map at 0-180° meridian before and one month after prophylactic LPI. Results The only parameter that had a significant increase after LPI was ACV, which increased from 99.26±19.57 mm3 to 113.09±19.712 mm3 after LPI (P<0.001). The relationship between age and ACV changes after LPI was statistically significant (P=0.014), indicating that the increase of age is associated with the increased of ACV after LPI. The relationship of ACV and ACD with their initial values was statistically significant, such that with the increase of the initial values of ACV and ACD, their changes decrease. Due to the lack of significant increase in CACD after LPI, the relationship between its changes after LPI and its initial value cannot be relied upon. Conclusion ACV is the only anterior chamber parameter that changes significantly after prophylactic LPI. This parameter can be used as a measurable scale to evaluate and monitor the eyes of patients with PACS. Among the PACS cases, older patients and patients with lower initial ACV have greater increase of ACV after LPI

Changes in Anterior Chamber Parameters Measured by Pentacam in Coronavirus Disease 2019 Infection: A Longitudinal Study.

Purpose To evaluate changes in anterior segment parameters measured by imaging in coronavirus disease 2019 (COVID-19) infection. Methods This longitudinal observational study included patients who recovered from COVID-19. All subjects exhibited a confirmed diagnosis of COVID-19 with a positive result of nasopharyngeal reverse transcription-polymerase chain reaction evaluation. Corneal Pentacam (Oculus, Dutenhofen, Germany) imaging was performed at least two weeks after recovery from systemic COVID-19. Measurements were repeated one and three months later. Results A total of 20 patients, 11 (55%) of whom were females, with a mean age of 35.5 ± 7.1 years (age range: 25–51 years) recovered from nonhospitalized COVID-19 infection, were enrolled in this study. An increase in the keratometry mean front, keratometry mean back, cornea volume, and anterior chamber depth was observed in the longitudinal evaluation; however, they showed no statistical significance. The anterior chamber volume was statistically increased at three-month follow-up, compared to baseline (baseline: 177.8 ± 36.68 mm3; three months: 182.25 ± 39.58 mm3, P=0.048). Conclusion COVID-19 infection may affect the cornea and anterior segment.

The short-term effects of intravitreal bevacizumab injection on intraocular pressure, cornea, iridocorneal angle, and anterior chamber.

Transient increase in intraocular pressure (IOP), changes in anterior chamber parameters, and changes in aqueous humor dynamics may occur after intravitreal injections because of intravitreal volume changes. In this observational study, we investigated the early effects of intravitreal bevacizumab (IVB) injection on IOP, central corneal thickness (CCT), corneal volume (CV), anterior chamber depth (ACD), and iridocorneal angle (ICA). The patients who had one single-dose IVB (2.5 mg/0.1 mL) injection were included in the study. The patients underwent IOP, CCT, CV, ACD, and ICA measurements before and 1 h and 1 day after the injection. Pre-injection and post-injection values were compared. Forty-two eyes of 42 patients were included in the study, and the mean age of patients was 60.1 ± 7.4 years. The mean IOP measurements before and after injection at 1 h and day 1 were 15 ± 2.4, 17.4 ± 2.4, and 14.7 ± 2.3, respectively. The mean IOP, CCT, and CV values 1 h after injection were significantly higher than pre-injection values (p < 0.05, p < 0.05, and p = 0.02, respectively). Conversely, mean ACD and ICA values 1 h after injection were significantly lower than pre-injection values (p = 0.01 for both). There were no statistically significant differences on the first day after injection for all parameters. IVB (2.5 mg/0.1 mL) injection causes transient increases in IOP and transient decreases in ACD and ICA at the first hour after injection. Related to elevation in IOP, CCT and CV may increase transiently. These changes return to baseline values on the first day after injection.

Factors affecting changes in the intraocular pressure after phacoemulsification surgery

AIM: To assess the changes in anterior chamber parameters and examine the factors associated with changes in the intraocular pressure (IOP) in individuals who have undergone phacoemulsification surgery. METHODS: It is a longitudinal analysis of secondary clinical data collected from 105 non-glaucomatous eyes (82 patients) undergoing a cataract surgery. We studied the association between anterior chamber parameters, grade of cataract, demographics, and changes in the IOP over a period of three weeks. We also evaluated the association between the pressure-depth (PD) ratio and changes in the IOP during this time. RESULTS: The mean age (SD) of the 82 patients was 60.1±7.8y. The mean±standard deviation (SD) IOP was 15.06±3.36 mm Hg pre-operatively; it increased to 15.75±4.21 mm Hg on day one (P=0.20). In the multifactorial models, the mean IOP was -1.715 (95%CI: -2.795, -0.636) mm Hg on day 21±5 compared with the pre-operative values. The anterior chamber depth (ACD), axial length, age, sex, and grade of cataract were not significantly associated with changes in the IOP. Each unit increase in the PD ratio was associated with an increase in the mean IOP by 1.289 mm Hg (95%CI: 0.906, 1.671). After adjusting for pre-operative PD ratio, none of the other variables (ACD, axial length, temporal angle) were significantly associated with changes in mean IOP. CONCLUSION: The PD ratio was the single most important factor associated with the changes in post-operative IOP over three weeks post-surgery.

Changes in anterior segment parameters following insertion of ExPRESS mini glaucoma implant vs. trabeculectomy.

To compare changes in anterior segment parameters following ExPRESS Mini Glaucoma Shunt surgery vs. trabeculectomy using the Pentacam rotating Scheimpflug camera. In this prospective, comparative study, 27 patients with glaucoma treated at the Rabin Medical Center from 2009 to 2013 were enrolled in this prospective comparative study: 19 participants (19 eyes) underwent ExPRESS shunt implantation and 12 (13 eyes) underwent trabeculectomy. Changes in anterior chamber parameters at postoperative day 1 and postoperative month 3 were evaluated on Scheimpflug images. Intraocular pressure decreased significantly from baseline in both groups. The decrease in both groups was similar at postoperative month 3 (p=0.82). ExPRESS surgery caused a transient increase in posterior corneal astigmatism (p=0.008) and a transient decrease in anterior chamber depth (p=0.016) and volume (p=0.006) on postoperative day 1. At postoperative month 3, these parameters were no longer statistically significant (p=0.65, p=0.51, and p=0.57 respectively). Trabeculectomy caused a transient increase in anterior and posterior corneal astigmatism on postoperative day 1 (p=0.003 and p=0.005, respectively), which were not evident at postoperative month 3 (p=1.0 and p=1.0, respectively). At postoperative month 3, both ExPRESS and trabeculectomy showed similar changes in anterior chamber parameters. Both ExPRESS mini glaucoma implant and trabeculectomy significantly decreased intraocular pressure and had transient effects on anterior segment parameters, with minor differences between the methods.

Evaluating relaxed ciliary muscle tone in presbyopic eyes.

Studies of age-related changes in ciliary muscle (CM) morphology and contractility have variously reported that CM weakens or strengthens with age. In response, the aim of this study was to evaluate relaxed CM tone in vivo in pre-presbyopic and presbyopic patients using a predictor value (PCM). Two groups of eyes-40 eyes of 40 healthy volunteers with a mean age of 28.1 ± 5.8years and 40 eyes of 40 healthy volunteers with a mean age of 56.6 ± 7.3years-formed the sample for this prospective, observational cross-sectional study. Used to evaluate relaxed CM tone, PCM was calculated as the difference between the change in mean anterior chamber depth (ACD) and lens thickness (LT) before and after cycloplegia, as measured with swept-source optical biometry. The PCM for relaxed CM tone was 0.04 ± 0.04mm in pre-presbyopic participants, 0.06 ± 0.03mm in presbyopic ones, and significantly greater in presbyopic patients (p = .018). The statistical significance of PCM between pre-presbyopic and presbyopic eyes might not signify clinical significance, since the difference was close to the repeatability limits for swept-source optical biometry. When relaxed, CM tone does not diminish with presbyopia according to changes in anterior chamber parameters due to cycloplegia.

The Course of the Changes in Anterior Chamber Parameters After Laser Peripheral Iridotomy: Follow-up for 6 Months With a Scheimpflug-Placido Disc Topographer.

To evaluate the course of the changes in anterior chamber (AC) parameters using a Scheimpflug-Placido disc topographer before and through 6 months after laser peripheral iridotomy (LPI). A total of 109 eyes of 56 consecutive patients classified as primary angle closure suspect (PACS), primary angle closure (PAC), and primary angle closure glaucoma (PACG) were included in this prospective, interventional, observational case series. Anterior chamber volume (ACV), central anterior chamber depth (CACD), and anterior chamber angle (ACA) were measured by Scheimpflug photography preoperatively and at 1, 3, and 6 months after LPI. With respect to the parameters above, alterations in the measurements were assessed to determine whether the effects induced by LPI on AC morphology persisted with time. At 1 month after LPI, mean ACV, CACD, and ACA increased significantly in all groups (P<0.05). However, in eyes with PACG, significant reductions at 3 months in ACA [0.00 (-1.00 to 0.00) degrees, median (Md) [quartile 1 (Q1) to quartile 3 (Q3)], P=0.032] and at 6 months in ACV [-1.00 (-2.25 to 1.00) μL, P=0.043) and CACD (-0.01 (-0.02 to 0.00) mm, P=0.006) were shown. On analysis of all eyes together, a weak correlation was found between axial length and the change in CACD (r=0.266, P=0.007). Eyes with ACA≤25 degrees widened by 6.6±2.8 degrees versus 4.9±2.4 degrees in eyes with ACA>25 degrees at 1 month after the procedure (P=0.002). Scheimpflug-Placido disc topographer detected significant changes in the AC parameters after LPI in all groups. However, compared with PACS and PAC, the PACG showed significant alterations in the AC parameters through 6 months.

Changes in Anterior Segment Morphology after Intravitreal Injection of Bevacizumab and Bevacizumab–triamcinolone Acetate Combination

To evaluate the effects of 2 different amounts of commonly used intravitreal agents on anterior segment morphology in conjunction with intraocular pressure (IOP) changes. Two groups of 46 patients who received intravitreal injection of bevacizumab (group 1, 0.05 mL) or bevacizumab-triamcinolone acetate (TA) combination (group 2, 0.1 mL) were included in this prospective study. All patients underwent anterior segment optical coherence tomography (AS-OCT) imaging with Visante OCT and IOP measurement before and at 5 minutes, 1 hour, and 3 hours after injection. Anterior chamber depth (ACD), angle-opening distance (AOD 500-750), trabecular-iris space area (TISA 500-750), and anterior chamber angle (ACA) were measured. Results were compared between groups and measurement time points. The mean change in IOP showed significant difference between baseline and first measurements after the injection in group 1 and group 2 (p = 0.012, p = 0.008, respectively). There was a statistically significant difference from baseline in ACD at the first and second measurements in group 2 (p = 0.005, p = 0.018, respectively). All angle parameters showed insignificant decrease from baseline at all measurement time points in both groups (p>0.05 for each). The difference of angle parameters after injection was not statistically significant between the groups (p>0.05 for each). Intravitreal injection of bevacizumab (0.05 mL) or bevacizumab-TA combination (0.1 mL) caused a change in anterior segment configuration determined by AS-OCT. The changes in anterior chamber parameters returned to baseline values with the normalization of IOP values after the first few minutes of injection.

Changes in Anterior Chamber Parameters with the Pentacam Rotating Scheimpflug and Axial Length Measurements by Ultrasound in Patients Who Use Isotretinoin

Purpose: Evaluation of changes in anterior chamber parameters with the Pentacam rotating Scheimpflug and axial length measurements (Alx) by ultrasound in patients who use isotretinoin for the treatment of acne vulgaris.Methods: Twenty-nine eyes of 29 patients (15 men, 14 women) were evaluated with the Pentacam before the treatment, and at the 3rd and 6th months of treatment. The axial length was evaluated by ultrasound biometry. The non-parametric paired t-test was used to compare pretreatment and 3rd and 6th month anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) width, central corneal thickness (CCT), lens thickness (LT), pupil size, axial length measurement (Alx) and mean keratometry values (K).Results: The mean age of the patients was 21.82 ± 4.14 years. The differences between the pretreatment and 3rd and 6th month ACD, ACV, CCT, Alx, LT and mean K values were statistically significant (p < 0.05). The differences between the pretreatment and 3rd and 6th month pupil size measurements were not statistically significant (p > 0.05). The differences between the pretreatment and 3rd month ACA measurements were statistically significant (p > 0.05), but there was no statistically significant difference with 6th month values (p < 0.05).Conclusions: Isotretinoin treatment causes statistically significant changes in most anterior segment parameters during treatment.

Does lens status affect the course of early intraocular pressure and anterior chamber changes after intravitreal injection?

This study aimed to observe changes in anterior chamber parameters and the course of intraocular pressure (IOP) after injection of 0.1 ml intravitreal triamcinolone acetonide (TA) and to determine differences between phakic and pseudophakic eyes without vitreous reflux. A prospective observational clinical trial was conducted with 89 patients who received an intravitreal injection of TA and did not display vitreous reflux. Intraocular pressure measurements were made before injection and at 3, 10, 20, 30 and 40 mins after injection. Pentacam measurements were made before injection and at 5, 15, 30 and 45 mins after injection. Anterior chamber depth (ACD) and anterior chamber volume (ACV) were significantly greater in pseudophakic eyes than in phakic eyes at all measurement time-points (p < 0.001). There was a decrease in both ACD and ACV at 5 mins after injection, and a gradual increase to normal values was observed at 15, 30 and 45 mins after injection in all study eyes. Compared with pre-injection measurements, changes in ACD and ACV were statistically significant at each time-point in both phakic and pseudophakic eyes (p < 0.001). A significant increase in IOP within 3 mins of injection was observed in both groups and a more rapid decrease 10 mins after injection was observed in pseudophakic eyes. The differences in IOP between phakic and pseudophakic eyes at all measurement time-points, except baseline and 3 mins after injection, were statistically significant (p < 0.001). Intraocular pressure < 30 mmHg and < 24 mmHg was recorded in all pseudophakic eyes at 10 and 20 mins after intravitreal injection, respectively. Following intravitreal injection of 0.1 ml TA, without vitreous reflux, IOP decreased to safe levels more quickly in pseudophakic eyes than in phakic eyes. Although there were more pronounced changes in anterior chamber parameters in pseudophakic eyes, these changes were reversible without any residual clinical significance.

Comparison of Preoperative and Postoperative Anterior Segment Measurements with Pentacam in Horizontal Muscle Surgery

To evaluate the effect of horizontal muscle surgery (recession or recession plus resection) on the anterior chamber parameters in patients after strabismus surgery. The Scheimpflug of 18 eyes of 12 patients with horizontal deviations were recorded just before surgery and 1 month after surgery. The power of anterior surface of cornea in horizontal and vertical axis, thinnest corneal thickness, anterior chamber depth, anterior chamber volume, and cornea volume were analyzed. The clinical characteristics of patients, the size of the deviations, the surgical doses, and observed responses to surgery were reviewed. There were six male and six female patients with an average age of 11.4 years (range, 4 to 22 years). Mean preoperative deviation was 47.91 PD (range, 20 to 75 PD), eight patients had esotropia with 57.5 PD average deviation (range, 40 to 75 PD), and four patients had exotropia with 28.75 PD average deviation (range, 20 to 35 PD). Of these 18 eyes, 12 eyes had horizontal muscle recession and 6 eyes had recession plus resection surgery. At the end of 1 month, three patients were orthophoric and eight patients had residual deviations varying between 16 and 35 PD. Preoperative and postoperative comparison of the whole study group documented insignificant changes in anterior chamber parameters and in keratometer readings. However, after dividing patients into two groups-recession or recession plus resection group-only one parameter, anterior chamber volume, was significantly reduced in recession plus resection group. Patients with strabismus who undergo recession plus resection procedure are prone to change in anterior chamber volume. Study with larger groups and long follow-up is necessary for clearer documentation of alterations at anterior chamber parameters.