Intraocular Pressure While Using Gonioscopy, SLT, and Laser Iridotomy Lenses: An Ex Vivo Study.

Purpose: The purpose of this study was to measure intraocular pressure (IOP) elevation while applying standard gonioscopy, selective laser trabeculoplasty (SLT), and laser iridotomy procedural lenses. Methods: Twelve cadaver eyes were mounted to a custom apparatus and cannulated with a pressure transducer which measured IOP. The apparatus was mounted to a load cell which measured the force on the eye. Six ophthalmologists performed simulated gonioscopy (Sussman 4 mirror lens), SLT (Latina lens), and laser iridotomy (Abraham lens) while a computer recorded IOP (mm Hg) and force (grams). The main outcome measures were IOP and force applied to the eye globe during ophthalmic diagnostics and procedures. Results: The average IOP's during gonioscopy, SLT, and laser iridotomy were 43.2 ± 16.9 mm Hg, 39.8 ± 9.9 mm Hg, and 42.7 ± 12.6 mm Hg, respectively. The mean force on the eye for the Sussman, Latina, and Abraham lens was 40.3 ± 26.4 grams, 66.7 ± 29.8 grams, and 65.5 ± 35.9 grams, respectively. The average force applied to the eye by the Sussman lens was significantly lower than both the Latina lens (P = 0.0008) and the Abraham lens (P = 0.001). During gonioscopy indentation, IOP elevated on average to 80.5 ± 22.6 mm Hg. During simulated laser iridotomy tamponade, IOP elevated on average to 82.3 ± 27.2 mm Hg. Conclusions: In cadaver eyes, the use of standard ophthalmic procedural lenses elevated IOP by approximately 20 mm Hg above baseline.

Bent ab interno needle goniotomy versus gonioscopy-assisted transluminal trabeculotomy in primary open-angle glaucoma: study protocol of a randomized clinical trial.

BACKGROUND: Minimally invasive glaucoma surgery (MIGS) is a new class of surgeries, which combines moderate to high success rates and a high safety profile. Bent Ab interno Needle Goniotomy (BANG) and Gonioscopy-Assisted Transluminal Trabeculotomy (GATT) are two low-cost MIGS procedures that communicate the anterior chamber to Schlemm's canal. Most of the available publications on MIGS are either case series or retrospective studies, with different study protocols. The aim of this manuscript is to describe a randomized clinical trial (RCT) protocol to compare the long-term intraocular pressure (IOP) control and the safety of both procedures in eyes with primary open-angle glaucoma. METHODS: This is a parallel, double-arm, single-masked RCT that includes pseudophakic primary open-angle glaucoma (POAG) eyes. After inclusion criteria, medications will be washed out to verify baseline IOP before surgery. Patients will be randomized to BANG or GATT using a sealed envelope. Follow-up visits will be 1, 7, 15, 30, 60, 90, 180, 330 and 360 days after surgery. On PO330, a new medication washout will be done. The main outcome is the IOP reduction following the procedures. Complimentary evaluation of functional and structural parameters, safety, and quality of life will be done after 30, 90, 180, and 360 days. DISCUSSION: Our study was designed to compare the long-term efficacy and safety of two low-cost MIGS. Most of the published studies on this subject are case series or retrospective cohorts, with different study protocols, which included different types and severities of glaucomas, combined with cataract extraction. Our study only included mild to moderate POAG eyes, with previous successful cataract extraction. Moreover, it provides a standardized protocol that could be replicated in future studies investigating various types of MIGS. This would allow comparison between different techniques in terms of efficacy, safety, and patients' quality of life. TRIAL REGISTRATION: Retrospectively registered at the Registro Brasileiro de Ensaios Clínicos (ReBEC) platform RBR-268ms5y . Registered on July 29, 2023. The study was approved by the Ethics Committee of the University of Campinas, Brazil.

Outcome of illuminated microcatheter-assisted circumferential trabeculotomy following failed angle surgery in PAX6 aniridic glaucoma: a case report and literature review.

BACKGROUND: Aniridia is a rare eye disorder with a high incidence of glaucoma, and surgical intervention is often needed to control the intraocular pressure (IOP). Here, we reported a case of illuminated microcatheter-assisted circumferential trabeculotomy (MAT) performed on an aniridic glaucoma patient following a previous failed angle surgery. The surgical procedures for aniridic glaucoma were also reviewed. CASE PRESENTATION: A 21-year-old man, diagnosed with aniridic glaucoma, came to our hospital consulting for the poor control of left eye's IOP despite receiving goniotomy surgery 3 years ago. The IOP was 26 mmHg with maximum topical antiglaucoma eyedrops. The central cornea was opaque and the majority of iris was absent. The gonioscopy and ultrasound biomicroscopy (UBM) demonstrated that 360° anterior chamber angle was closed. The whole exome sequencing of peripheral blood confirmed a 13.39 Mb copy number loss at chromosome 11p15.1p13, containing PAX6 and WT1 gene. The 360° MAT surgery was performed on his left eye. At 1-year follow-up, the IOP was 19mmHg with 2 kinds of topical antiglaucoma medications, and the postoperative UBM demonstrated the successful incision of the anterior chamber angle. CONCLUSIONS: The case presented here exhibited a case of aniridic glaucoma treated by MAT surgery. The MAT surgery may be an effective option for IOP control in aniridic glaucoma patients following a previous failed angle surgery.

Estimation of angle parameters by ASOCT and biometric parameters by optical biometer in eyes with occludable angles and open angles.

PURPOSE: To compare anterior chamber angle (ACA) parameters measured by Anterior Segment Optical Coherence Tomography (ASOCT) and biometric parameters measured by Swept-Source (SS) OCT-based biometry among patients with suspected occludable angles and open angles. METHODS: An analytical, cross-sectional study was performed on subjects attending our ophthalmology outpatient department with suspected occludable angles (van Herick grades 0, 1, and 2) in group 1, and with open angles (van Herick grades 3 and 4) in group 2. Each subject underwent a complete ophthalmic examination to exclude any intraocular pathology like cataract. We recruited 128 eyes of 64 subjects, 34 in group 1 and 30 in group 2. Each eye was henceforth subjected to ASOCT (Spectralis, Heidelberg Engineering, Heidelberg) and SS-OCT-based optical biometry (IOL Master 700, Carl Zeiss Meditec AG). Anatomical parameters were recorded and compared between the two groups. RESULTS: The main outcome measures of the study included nine ASOCT parameters (central corneal thickness [CCT], lens vault, AOD750, ACA, TISA750 [nasal and temporal], and ACW) and five optical biometric parameters (CCT, ACD, WTW, LT, and axial length). We found a significant difference (p < 0.05) among all the anatomical parameters between the two groups, except CCT which was not significantly different (p = 0.297). CONCLUSIONS: ASOCT and SSOCT biometry overcome the challenges of gonioscopy and allow screening for angle closure disease in otherwise normal subjects. ASOCT may serve as an alternative to gonioscopy as it clearly separates occludable angles from open angles in a non-invasive and objective manner.

Phacoemulsification combined with goniosynechialysis versus phacoemulsification alone for patients with primary angle­closure disease: A meta-analysis.

This meta-analysis aims to systematically compare the efficacy between phacoemulsification (PE) combined with goniosynechialysis (GSL) and PE alone for primary angle-closure disease (PACD) patients. All the data were searched from the PubMed, EMBASE and the Cochrane Library. The Cochrane Handbook was used to evaluate the quality of the included studies. Additionally, this meta-analysis was performed by using the Revman 5.4 software. Nine randomized controlled trials (RCTs) were included in this study. Compared with PE alone group, PE+GSL could result significant reduction in the IOP (MD, 1.81; p = 0.002). In the instrumental subgroup, also more reduction of IOP was shown in the PE+GSL group (MD, 2.11; p = 0.02). In the viscogonioplasty (VGP) subgroup, there was not no statistical difference between PE alone group and PE+GSL group (MD, 1.53; p = 0.11). Also, more reduction of peripheral anterior synechiae (PAS) was shown in the PE+GSL group (MD,59.15; p<0.00001). For the change in angle open distance (AOD)500, AOD 750, trabecular-iris space (TISA)500, number of glaucoma medications and best corrected visual acuity (BCVA), there was no difference between two groups (p = 0.25, 0.35, 0.17, 0.56, 0.08). For TISA 750, more improvement was shown in the PE+GSL group (p<0.00001). Instrumental separation had better effect on lowering IOP when it combined with PE. Both instrumental separation and VGP could reduce postoperative PAS. The operation of GSL has no obvious effect on postoperative vision.

Outcomes of gonioscopy-assisted transluminal trabeculotomy in primary congenital glaucoma treatment: a retrospective study.

BACKGROUND: This retrospective study aimed to evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in Chinese patients with primary congenital glaucoma (PCG) and identify factors influencing surgical success. METHODS: Fourteen patients (24 eyes) diagnosed with PCG who underwent gonioscopy-assisted transluminal trabeculotomy were recruited, and data on intraocular pressure (IOP), antiglaucoma medication, surgery-related complications, and additional treatments were collected during preoperative and postoperative visits. Surgical success was defined as IOP ≤ 21 mmHg and a reduction of > 30% from baseline, with (partial success) or without (complete success) antiglaucoma medication. RESULTS: Mean preoperative IOP was 30.41 ± 6.09 mmHg. At the final visit, mean IOP reduction was 16.1 ± 9.1 mmHg (52%), and 19 of 24 eyes were topical medication-free. IOP was significantly decreased at each postoperative visit compared with baseline (P < 0.05 for all time points). Cumulative proportions of complete and partial success were 79.2% and 95.8%, respectively, at three years postsurgery. Patients without prior antiglaucoma procedures, without postoperative IOP spikes, and those undergoing complete trabeculotomy exhibited improved surgical prognosis. No permanent vision-threatening complications occurred in the 24 eyes by the end of the respective follow-ups. CONCLUSION: Gonioscopy-assisted transluminal trabeculotomy emerged as a safe and effective procedure for PCG treatment, characterized by outstanding IOP reduction efficacy and high surgical success rates.

Quantitative analysis of dynamic iris changes in primary angle-closure disease with long axial lengths: the Handan Eye Study.

OBJECTIVE: To investigate dynamic iris changes in patients with primary angle-closure disease (PACD) with long axial length (AL) compared to those with short and medium AL. METHODS: This observational cross-sectional study enrolled participants aged 35 years or older from the Handan Eye Study follow-up examination who were diagnosed with PACD and underwent Visante anterior segment optical coherence tomography (ASOCT) imaging under light and dark conditions. The right eye of each participant was included in the analysis. AL was categorized as short (<22.0 mm), medium (≥22.0 to ≤23.5 mm), or long (>23.5 mm). Anterior segment parameters, including iris dynamic changes, were compared among the three groups with different ALs. RESULTS: Data from 448 patients with PACD were analyzed. We found that 10.9% of included eyes had a long AL with a flatter cornea; larger central anterior chamber depth, angle opening distance, anterior chamber width, anterior chamber area, and volume; and smaller lens thickness and lens vault (LV) (P < 0.05) than those with short AL. No significant difference existed between the three groups in iris thickness, iris cross-sectional area (IA), iris curvature, or pupil diameter (PD) change between light and dark (P > 0.05). The significant associated factors for IA changes were area recess area (ARA) in the dark, LV in the dark, and PD change from light to dark (P < 0.05). CONCLUSIONS: Dynamic and static iris parameters were consistent across patients with PACD with short, medium, or long AL and may contribute to the pathogenesis of angle closure in atypical PACD.

Comparison of clinical outcomes between gonioscopy-assisted transluminal trabeculotomy and trabeculectomy in advanced-stage pseudoexfoliation glaucoma.

PURPOSE: To compare clinical outcomes between gonioscopy-assisted transluminal trabeculotomy (GATT) and trabeculectomy (TRAB) in patients with advanced-stage pseudoexfoliation glaucoma (PEXG). METHODS: This comparative study comprised 62 patients who underwent GATT (N = 31) or TRAB (N = 31) for advanced-stage PEXG. Primary outcome was cumulative probability of surgical success at the end of 12-month follow-up. Success was determined as intraocular pressure (IOP) reduction ≥ 30% from baseline, IOP between 6 and 18 mmHg and IOP upper limits for IOP < 15 mmHg and < 12 mmHg, separately. Secondary outcomes were IOP reduction, antiglaucoma medication (AGM) use, and complications in the study. RESULTS: Age, sex, cup/disc ratio, mean deviation, pattern standard deviation, and retinal nerve fiber layer thickness did not significantly differ between the groups (p > 0.05 for all). The probability of cumulative surgical success at the end of 12 months was similar between the two groups for IOP < 15 mmHg and < 18 mmHg but significantly higher after TRAB (92.0%) than GATT (82.5%) for IOP < 12 mmHg (log-rank test p = 0.035). Percentage of IOP reduction from baseline was similar between the groups (53.1 ± 18.6% in GATT group and 53.0 ± 16.6% in TRAB group, p = 0.98) at the end of 12 months. No significant difference in the mean number of AGM was present at the 12-month visit (1.3 ± 1.4 in GATT and 1.1 ± 1.4 in TRAB, p = 0.65). CONCLUSION: At the end of 12 months, IOP reduction rate was similar between GATT and TRAB. Cumulative surgical success was higher after TRAB than GATT for IOP < 12 mmHg.

Iris volume change with physiologic mydriasis to identify development of angle closure: the Zhongshan Angle Closure Prevention Trial.

AIMS: To assess dynamic change of iris area (Iarea) and volume (VOL) with physiologic pupil dilation for progression of primary angle closure suspects. METHODS: Participants underwent baseline examinations including gonioscopy and anterior segment OCT (AS-OCT) as part of the Zhongshan Angle Closure Prevention Trial. The AS-OCT images were obtained both in the dark and light. Progression was defined as development of primary angle closure or an acute angle closure attack. Static ocular biometrics and dynamic changes were compared between progressors and non-progressors and multivariable logistic regression was developed to assess risk factors for progression. RESULTS: A mean 16.8% decrease in Iarea and a mean 6.26% decrease in VOL occurred with pupil dilation, while 22.96% non-progressors and 40% progressors presented VOL increases with pupil dilation. Iarea in light and dark and VOL in light were significantly smaller in progressors. In a multivariable logistic model, older age (p=0.008), narrower horizontal angle opening distance (AOD) 250 µm from the scleral spur (AOD250, p=0.001), flatter iris curvature (IC, p=0.006) and lower loss of iris volume (ΔVOL, p=0.04) were significantly associated with progression. With receiver operating characteristic analysis, the area under the curve for ΔVOL alone was 0.621, while that for the combined index (age, AOD250, IC and ΔVOL) was 0.824. Eyes with elevated intraocular pressure had less VOL loss compared with progressors developing peripheral anterior synechiae alone (p=0.055 for ΔVOL adjusted for pupil enlargement). CONCLUSION: A smaller change in ΔVOL is an additive risk factor to identify eyes more likely to develop angle closure disease. TRIAL REGISTRATION NUMBER: ISRCTN45213099.

Persistent Mydriasis Following Gonioscopy-Assisted Transluminal Trabeculotomy.

Herein we describe 2 cases of persistent mydriasis after gonioscopy-assisted transluminal trabeculotomy for open angle glaucoma. Both surgeries were uneventful, but the patients experienced postoperative hyphema and intraocular pressure elevation. They then developed persistent fixed and dilated pupils resistant to pilocarpine that led to intolerable photosensitivity and glare. An iris cerclage pupilloplasty was performed with adequate relief of symptoms in one case.

Phacoemulsification with gonioscopy-assisted transluminal trabeculotomy versus phacoemulsification alone in primary angle closure glaucoma: A randomized controlled study.

PURPOSE: To assess the safety and efficacy of combining phacoemulsification with gonioscopy-assisted transluminal trabeculotomy (GATT) compared to phacoemulsification alone in the management of primary angle closure glaucoma (PACG). METHODS: Prospective, institutional study in which eyes requiring surgery for PACG were randomized to undergo phacoemulsification followed by GATT (phaco-GATT group) or phacoemulsification alone. Success was defined as having a final IOP of 6-20 mmHg with no subsequent glaucoma surgery or vision-threatening complications. RESULTS: Thirty-six eyes underwent phaco-GATT with 360° angle incision and 38 eyes underwent phacoemulsification alone. IOP and glaucoma medications were significantly lower in the phaco-GATT group at 1, 3, 6, 9 and 12 months. The success rate in the phaco-GATT group was 94.4% after 12.16 ± 2.03 months, with 75% of eyes being off medications compared to 86.8% after 12.47 ± 4.27 months in the phaco group, with 42.1% off medications. (p = 0.008). Hyphema and fibrinous anterior chamber reaction were the most common complications in the phaco-GATT group and resolved with conservative treatment or required YAG capsulotomy. Although this delayed visual rehabilitation in the phaco-GATT group, it did not affect the final visual outcome with no significant difference in the final best-corrected visual acuity between both groups (p = 0.25). CONCLUSION: Combining phacoemulsification with GATT in PACG yielded more favourable outcomes in terms of IOP, glaucoma medications and surgical success. Although the postoperative hyphema and fibrinous reaction may delay visual rehabilitation, GATT further lowers the IOP by breaking residual peripheral anterior synechiae and removing the dysfunctional trabeculum circumferentially, while avoiding the risks inherent in more invasive filtering procedures.

Outcomes of newly referred patients with suspected angle closure: do we need to redefine the clinical pathways?

BACKGROUND/OBJECTIVES: To investigate outcomes of referrals for suspected angle closure and explore whether anterior segment optical coherence tomography (AS-OCT) can be used to tighten triaging criteria in a glaucoma virtual clinic. SUBJECTS/METHODS: Retrospectively collected data. The first audit (04/2018-03/2019) identified referrals for suspected angle closure without other glaucoma-related findings (primary angle closure suspect (PACS) referrals). All patients underwent gonioscopy. The second audit (04-08/2019) identified patients with suspected angle closure in a virtual clinic. Management outcomes were assessed, using gonioscopy as reference standard. The outcomes of the second audit were re-audited after changing the triaging criterion from angle width <10° to iridotrabecular contact (ITC) in ≥1 quadrants on AS-OCT. RESULTS: Out of 1754 glaucoma referrals (first audit), 24.6% (431/1754) were PACS referrals. Of these, only 10.7% (42/393) had an occludable angle on gonioscopy, with 97.6% (41/42) being PACS. Of these, 78% (32/41) underwent laser peripheral iridotomy. Out of 137 referrals in the virtual clinic (second audit), 66.4% (91/137) were triaged to the face-to-face clinic. Of these, 31.9% (29/91) were discharged. AS-OCT had positive and negative predictive value of 74.3% (95% confidence intervals (CI) 57.8-86.0) and 82.1% (95% CI 70.0-90.2%), respectively, in detecting ITC in ≥1 quadrants. In the re-audit 45.9% (45/98) of those with suspected angle closure were triaged for gonioscopy, with 24.4% (11/45) of them being discharged. CONCLUSION: PACS referrals represent a substantial burden to hospital-based services and their accuracy is low. ITC in ≥1 quadrants on AS-OCT can be useful in triaging those who need further evaluation with gonioscopy.

Intraocular pressure spikes after gonioscopy-assisted transluminal trabeculotomy (GATT).

PURPOSE: Intraocular pressure (IOP) spikes (IOP > 30 mmHg or > 10 mmHg above baseline IOP) are a common and worrisome complication of gonioscopy-assisted transluminal trabeculotomy (GATT). The purpose of this study is to identify risk factors for IOP spikes and to describe their characteristics, management, and clinical course in a large cohort of patients. METHODS: A retrospective, single-center study which included 217 consecutive eyes of patients that underwent GATT between December 2019 and April 2022 with follow-up of at least 90 days. RESULTS: IOP spikes occurred in 52 of 217 (24%) eyes. Spikes occurred in 15.5% of patients in whom pre-operative IOP-lowering medications were continued after surgery (90 eyes), and in 29.9% in whom IOP-lowering medications were stopped after surgery (127 eyes). Spikes were diagnosed at a mean of 7.7 ± 6.5 days after surgery. All IOP spikes occurred within the first month of surgery. The mean duration of a spike was 4.9 ± 5.4 days. Management of IOP spikes included adding a mean of 3.13 ± 1.7 groups of glaucoma medications. Thirty-seven (72.5%) eyes were treated with oral carbonic anhydrase inhibitor, 11 (21.6%) were treated with IV mannitol, and anterior chamber paracentesis was performed in 16 (31.4%). Six (11.8%) eyes underwent additional glaucoma surgery to control IOP. Patients that continued their pre-operative IOP-lowering medications after surgery were 2.3 times less likely to develop a spike as compared to patients who discontinued their medications (P = 0.016). Spikes were found to be a risk factor for failure of GATT. CONCLUSIONS: IOP spikes are a common occurrence after GATT. They most commonly appear during the first two post-operative weeks and usually resolve with topical and systemic IOP-lowering treatment. The continuation of IOP-lowering medications after GATT is recommended to lower the risk of IOP spikes.

Atypical presentation of bilateral iridoschisis with abnormal visibility of iris vessels: Role of anterior segment optical coherence tomography.

PURPOSE: To describe clinical and anterior segment optical coherence tomography (AS-OCT) findings in a patient with bilateral iridoschisis and unilateral angle closure glaucoma (ACG) associated with abnormal visibility of iris vessels. CASE PRESENTATION: A 67-year-old male patient with a history of red and painful left eye (LE) one year earlier, presented to our ophthalmology department for a routine examination.Ophthalmic examination of the right eye revealed narrow anterior chamber with sectorial iris atrophy associated to abnormal visibility of an iris vessel. Intraocular pressure (IOP) was 12 mmHg with normal optic disc appearance. LE anterior chamber was narrow with diffuse iris atrophy and abnormal vessels visibility. IOP was 28 mmHg with an important optic disc excavation. On gonioscopy, angle was narrow without neovessels nor synechiae. AS-OCT of both eyes revealed shallow angles, iris splitting with material release in the anterior chamber, while pigmented epithelium was preservedAnti-glaucoma eye drops were prescribed and peripheral laser iridotomy was performed in both eyes with decreased IOP at 14 mmHg in the LE. CONCLUSION: Iridoschisis is a rare ocular condition characterized by a separation between the anterior and posterior layers of iris stroma with several clinical presentations, and may be associated with abnormal visibility of iris vessels in some cases. The diagnosis of iridoschisis may be challenging and AS-OCT can be a very useful tool to confirm the diagnosis in atypical presentations and to detect associated angle closure.

Alterações oculares decorrentes de picada de abelha na córnea / Ocular changes due to corneal bee sting

RESUMO O propósito deste estudo foi reportar as alterações oculares observadas após picada de abelha com ferrão retido na córnea. Destacamos o tratamento e o desfecho de uma lesão de córnea incomum e sua patogênese. Trata-se de relato de caso e revisão da literatura de lesões oculares por picada de abelha. Paciente do sexo feminino, 63 anos, procurou atendimento oftalmológico de urgência devido à picada de abelha na córnea do olho direito há 6 dias. Queixava-se de embaçamento visual, dor e hiperemia ocular. Apresentou acuidade visual de vultos no olho afetado. Ao exame, notaram-se hiperemia moderada de conjuntiva bulbar, edema corneano com dobras de Descemet e presença do ferrão alojado na região temporal, no estroma profundo da córnea. A paciente foi internada para ser abordada no centro cirúrgico sob anestesia geral. Durante a cirurgia, o ferrão teve que ser retirado via câmara anterior, mediante a realização de uma paracentese e uma lavagem da câmara anterior, com dupla via e solução salina balanceada. Ainda não existe na literatura um tratamento padrão na abordagem de pacientes com lesões oculares por picada de abelha, sendo importantes a identificação e o reconhecimento precoce de possíveis complicações que ameacem a visão.

ABSTRACT The purpose of this study was to report the ocular changes observed after a bee sting with a stinger retained in the cornea. We show the treatment and outcome of an unusual corneal injury and its pathogenesis. This is a case report and literature review of ocular injuries caused by bee stings. A 63-year-old female patient sought emergency ophthalmic care because of a bee sting on the cornea of her right eye six days before. She complained of blurred vision, pain, and ocular hyperemia. She had glare sensitivity on visual acuity in the affected eye. Examination revealed moderate hyperemia of the bulbar conjunctiva, corneal edema with Descemet's folds and a stinger lodged in the temporal region, in the deep stroma of the cornea. The patient was admitted to the operating room under general anesthesia. During surgery, the stinger had to be removed via the anterior chamber, by performing a paracentesis and washing the anterior chamber with a double flushing and balanced saline solution. There is still no standard treatment in the literature for patients with eye injuries caused by bee stings, and early identification and recognition of possible sight-threatening complications is important.

Primary congenital glaucoma: An iridotrabeculodysgenesis?

PURPOSE: To analyze primary congenital glaucoma (PCG) anterior chamber and angle anomalies over 360° as possible biomarkers of severity and prognosis. METHODS: A cross-sectional observational study was conducted analyzing anterior segment anomalies of PCG patients over 4 years of age who underwent trabeculectomy combined with trabeculotomy and age-matched controls using anterior segment optical coherence tomography (ASOCT), CASIA-2. Anterior iridotrabecular adhesions or anterior iris insertion was identified and quantified from the scleral spur using the iridotrabecular contact (ITC) index parameter as a surrogate. RESULTS: There was a variable but significantly increased anterior iridotrabecular adhesion on ITC index, ITC area, corneal volume, anterior chamber volume, iris volume, anterior chamber depth, and small/absent trabecular meshwork in PCG eyes compared to control eyes. In PCG eyes, anterior iridotrabecular adhesion had a positive correlation with pre-operative central corneal thickness (CCT) (r = 0.53, P = 0.02), review iris thickness (r = 0.4, P = 0.04), and ITC area (r = 0.85, P < 0.001). Review iris thickness had a negative correlation with pre-operative vertical cup-disc ratio (r = -0.51, P = 0.008). Iris hypoplasia with fewer or absent folds, collarette, pupillary ruff, and pupillary ruff to collarette distance was significantly different from controls. CONCLUSION: ASOCT in PCG eyes has shown that they have variable anterior iridotrabecular tissue adhesions, anomalous tissue/membranes in the angle, and iris hypoplasia correlating with pre-operative cup-disc ratio. These features could be used as gonioscopic and clinical biomarkers to assess the severity and prognosis of the disease. The presence of abnormal iris morphology and iridotrabecular tissue anomalies in PCG suggests that it is more than just isolated trabeculodysgenesis and is probably best considered as part of the anterior segment dysgenesis spectrum.

Progressive Changes in the Anterior Segment and Their Impact on the Anterior Chamber Angle in Primary Angle Closure Disease.

PURPOSE: To investigate longitudinal changes in the anterior segment (AS) using serial optical coherence tomography (OCT) images and determine the impact of these changes on the anterior chamber angle (ACA) in eyes with primary angle closure disease (PACD) treated with laser peripheral iridotomy (LPI). DESIGN: Retrospective clinical cohort study. METHODS: This study included 103 patients with PACD who underwent LPI and were followed up by a mean 6.7 ± 1.7 AS-OCT examinations for a mean 6.5 ± 2.9 years. Temporal changes in AS-OCT parameters, including anterior chamber depth (ACD), angle opening distance (AOD750), angle recess area (ARA750), iris thickness (IT750), lens vault (LV), and pupil diameter (PD), were analyzed by multivariate linear mixed effects models (LMEMs). RESULTS: Multivariate LMEMs showed that decrease in AOD750 was not significant (-1.59 µm/y, P = .222); however, ARA750 decreased over time (-2.3 × 103 µm2/y, P = .033) and SSA showed marginal significance (-0.20°/y, P = .098), and LV increased significantly (11.6 µm/y, P < .001) after LPI. Mean LV change was negatively associated with AOD750, ARA750, and SSA, whereas PD was negatively associated with ARA750 (P < .001 each). PD decreased with aging (-13.7 µm/y, P = .036), accompanied by thinning of IT750 (-1.7 µm/y, P = .063). CONCLUSIONS: LV tends to increase with aging, which contributes to the shallowing of the anterior chamber and narrowing of ACA in PACD eyes treated with LPI. In the meantime, pupillary constriction and subsequent peripheral iris thinning associated with aging could possibly offset the effect of ACA narrowing.

Anterior Segment Changes and Refractive Outcomes after Cataract Surgery Combined with Gonioscopy-Assisted Transluminal Trabeculotomy in Open-Angle Glaucoma

Objectives: To compare the accuracy of intraocular lens (IOL) calculation formulas in patients undergoing phacoemulsification combined with gonioscopy-assisted transluminal trabeculotomy (phaco-GATT) and to determine the predictive factors for refractive errors. Materials and Methods: Fifty-three eyes of 53 patients undergoing phaco-GATT were retrospectively reviewed. The preoperative and postoperative 3-month anterior segment (AS) parameters were measured by Scheimpflug camera. The mean prediction error (PE), mean absolute error (MAE) in the Sanders-Retzlaff-Kraft/theoretical (SRK/T), Barrett- Universal II, Hill-radial basis function (Hill-RBF) and Kane formulas were compared. The influence of biometric parameters on PE were analyzed by correlation analysis. Results: Postoperatively, there was a statistically significant decrease in axial length (AL) and significant enlargement in anterior chamber depth (ACD), anterior chamber angle (ACA), and anterior chamber volume (p<0.001). The mean PE using SRK/T (-0.08 diopters [D]) was more myopic than in the Barret (0.01 D) and Hill-RBF (0.01 D). The PE closest to zero was in the Kane formula (0.001 D). The Kane formula provided a lower MAE (0.30±0.28 D) than the SRK/T (0.38±0.32 D) and Barrett (0.36±0.30 D) (p<0.001). The MAE in Hill-RBF (0.32±0.28) was comparable with that in Kane (p=0.02). Preoperative AL was significantly associated with PE in all formulas except Kane. Barrett was the only formula that did not have a significant correlation between PE and postoperative ACD and ACA. Conclusion: The Kane formula may provide higher predictability of the IOL power calculation than the SRK/T and Barrett-Universal II formulas in phaco-GATT surgery, which can cause significant changes in the AS and AL.

'Intraoperative predictors for clinical outcomes after microinvasive glaucoma surgery".

PURPOSE: To evaluate the clinical applicability of intraoperative predictors for surgical outcomes after gonioscopy-assisted transluminal trabeculotomy (GATT) and microincisional trabeculectomy (MIT). METHODS: Consecutive patients with primary, or secondary glaucoma (trauma, aphakic, or status post-retinal surgeries) with uncontrolled IOP>21mm Hg, who were scheduled to undergo GATT or MIT with or without significant cataract surgery, at a tertiary eye centre in East India between September 2021 to March 2023, were included. All surgeries were done by a single surgeon. Blanching and Trypan blue (0.4%) staining after intracameral injection using a 25 canula, were analysed in each video. The extent/pattern of blanching and blue staining in each eye was analysed objectively using an overlay of a circle with 12 sectors and a protractor tool to quantify the degrees or quadrants of blanching/staining. Multivariate regression was used to identify predictors for surgical success or the need for medications after surgery. RESULT: Of 167 eyes that were included (male: female- 134: 33), 49 eyes and 118 eyes underwent GATT and MIT, respectively, with 81 of 167 eyes undergoing concurrent cataract surgery. All eyes had a significant reduction in the number of medications after surgery. Blanching was seen in 154 of 167 eyes in a mean of 2±1.8 quadrants with 41% of eyes showing a blanching effect in >3 quadrants. Of 99 of 167 eyes where Trypan blue staining was assessed, staining in a venular, diffuse haze, or reticular pattern of staining was seen in 73 eyes, 26 eyes showed blue staining in >2 quadrants, with 16% staining in >3 quadrants. Surgical success was not predicted by the quadrants of blanching, blue staining, or other clinical variables (age, visual field, baseline intraocular pressure, type of surgery). The variables significantly predicting the need for medications included blanch (r = -0.1, p = 0.03), and blue staining (r = -0.1, p = 0.04) in <2 quadrants. CONCLUSIONS: Blanching and Trypan blue staining in >2 quadrants after GATT or MIT can serve as surrogate predictors for the need for medications. However more studies are mandated to find predictors for surgical success after GATT or MIT.