Comparison of Fellow Eyes of Acute Primary Angle Closure and Phacomorphic Angle Closure:

[Angle-closure glaucoma]

Angle-closure glaucoma is a rare form of glaucoma characterized by a narrow or an occlusion of the anterior chamber angle and subsequently an obstruction of the outflow of aqueous humor resulting in an increase in intraocular pressure. Symptoms can include severe eye pain and/or headache, blurred vision, a medium-sized and rigid pupil, conjunctival hyperemia, and nausea. Treatment options include pressure-lowering topical and systemic medications as well as surgical interventions, especially cataract surgery and laser iridotomy. Besides parasympathomimetics (pilocarpine), all topical antiglaucoma medications can principally be used (beta-receptor antagonists, carbonic anhydrase inhibitors, alpha‑2 selective adrenergic antagonists, prostaglandins and prostaglandin analogues). Carbonic anhydrase inhibitors and osmotic agents (e.g., mannitol) can be systemically used.

A-Scan Parameters and the Risk of Phacomorphic Glaucoma in the Kazakh Population

Background and Objectives: The aim of our study was to identify risk factors associated with phacomorphic glaucoma (PG) by comparing the biometric parameters of contralateral eyes of patients with PG with the eyes of patients with a mature cataract. Methods: This retrospective case−control study included 71 eyes affected with PG, 311 eyes of control participants, and 71 contralateral eyes of patients with PG. All participants were ethnically Kazakh. Axial lengths (AL), anterior chamber depths (ACD), and lens thicknesses (LT) were measured using A-scan ultrasound biometry. To determine the threshold value of the A-scan parameters associated with PG, we performed ROC analysis. Results: The eyes with PG had smaller AL and ACD values and larger LT values, followed by the fellow eyes with PG and the control eyes. There were no differences in age and sex between patients with PG and mature cataracts. After adjustment for age and other A-scan parameters, continuous measures of ACD and LT were associated with PG (OR 0.57, 95% CI 0.38−0.73, p < 0.001; OR 3.36, 95% CI 1.64−6.912, p = 0.001). When A-scan parameters were dichotomized according to the identified threshold, an ACD of less than 2.5 mm (OR 3.113, 95% CI 1.562−6.204, p = 0.001) and an LT thicker than 4.75 mm (OR 26.368, 95% CI 9.130−76.158, p < 0.001) were found to be related to PG. Conclusions: We found that a thicker lens and, possibly, a shallow ACD are risk factors for PG.

Classifications of Qualitative Characteristics on Angle Configurations via Ultrasound Biomicroscopy in Acute Primary Angle Closure

Purpose

To study the classifications of qualitative characteristics on the angle configurations in the acute primary angle closure (APAC) and fellow eyes by ultrasound biomicroscopy (UBM).

Methods

A total of 131 patients (262 eyes) were researched retrospectively. The qualitative parameters from UBM images were classified into iris form (IF), ciliary body configuration (CBC), basal iris thickness (BIT), iris convexity (IC), iris insert (II), iris angulation (IA), ciliary body size (CBS) and ciliary body position (CBP). Comparative analyses between the APAC (case group) and fellow (control group) eyes were performed.

Results

There were significant differences in IF, CBC, IC, II, CBS, CBP between the case group and control group in all quadrants (P<0.001). The IA of the case group and control group presented significant difference in all quadrants (P=0.001). However, there was not a significant difference in BIT between the case group and control group in all quadrants (P=0.495). The case group had fewer parallelogram-like and mushroom-like and more cone-like and hook-like CBCs than the control group (P<0.001).

Conclusion

Multiple ciliary body configurations can influence the stability of the lens and the anatomic configuration of the anterior chamber angle indirectly. New qualitative classification system of UBM may be more intuitionistic and refined to reflect the angle configurations to help clinical practice.

Diagnostic Performance of Optical Coherence Tomography and Nonspecialist Gonioscopy to Detect Angle Closure

Aim

To compare the usefulness of gonioscopy performed by general ophthalmologists (GO) and anterior segment optical coherence tomography (AS-OCT) in detecting angle closure in patients with a shallow anterior chamber.

Methods

Forty-four patients with a shallow anterior chamber (defined by a ratio of peripheral anterior chamber depth to peripheral corneal thickness lower than 1/2) were included in this cross-sectional study. Gonioscopy was performed in all subjects by two glaucoma experts (GE1 and GE2) and one GO. Anterior segment imaging was performed using Visante® OCT (Carl Zeiss Meditec Inc.). Agreement between examiners was assessed with first-order agreement coefficients (AC1). Diagnostic accuracies of GO gonioscopy and AS-OCT were evaluated using sensitivity, specificity, and area under the receiver operating characteristic (AROC) curves.

Results

For static gonioscopy, the agreement between GE1 and GE2 was substantial (AC1 = 0.65), and that between GE1 and GO was moderate (AC1 = 0.50). For indentation gonioscopy, the agreement between GE1 and GE2 was slightly lower (AC1 = 0.55); however, the agreement between GE1 and GO showed a larger reduction (AC1 = 0.12). GO's gonioscopy presented a low specificity (25%) and the AROC to angle closure detection was lower than AS-OCT (0.56–0.73). Combined information of GO gonioscopy and AS-OCT improved specificity (85.7%) and AROC (0.77) of angle closure evaluation.

Conclusion

Agreement between GO and glaucoma experts was moderate for static gonioscopy and slight for indentation gonioscopy. AS-OCT performed better than GO gonioscopy in detecting angle closure in patients with a shallow anterior chamber. The addition of AS-OCT to clinical information in patients with GO positive gonioscopy improved the specificity and AROC of gonioscopy test.

How to cite this article

Esporcatte BLB, Vessani RM, Melo Jr LAS, et al. Diagnostic Performance of Optical Coherence Tomography and Nonspecialist Gonioscopy to Detect Angle Closure. J Curr Glaucoma Pract 2022;16(1):53–58.

Accuracy of different lens power calculation formulas in patients with phacomorphic glaucoma

PURPOSE:

The purpose of the study was to determine the most accurate formula for intraocular lens (IOL) power calculation among five currently used formulas in eyes with phacomorphic glaucoma (PG) undergoing cataract extraction surgery.

MATERIALS AND METHODS:

In this prospective interventional case series Patients diagnosed with PG were undergone uneventful phacoemulsification and IOL implantation. After 3 months, the refractive outcome for each formula was evaluated with mean prediction error (PE), mean absolute error (MAE), and the percentages of eyes within 0.25 D and 0.5 D of predicted error.

RESULTS:

Twenty-three patients completed the study. PEs were significantly different among the 5 formulas (P = 0.019), and Holladay I had the least error (−0.02 ± 1.11). Haigis formula had the highest hyperopic shift (0.37 ± 1.22), highest MAE (0.99 ± 0.78) and the lowest percentages of desired PEs, while the SRK II produced the greatest percentages. The overall differences in MAE between the 5 formulas were statistically insignificant (P = 0.547).

CONCLUSION:

In some extreme situations like patients with PG, lower generation of IOL power calculation formulas may still produce more acceptable refractive outcomes.

Lens-vault analysis and its correlation with other biometric parameters using swept-source OCT

PURPOSE

To measure lens vault (LV) and to assess its correlation with various ocular parameters in healthy eyes, using for all measurements the same high-resolution swept-source optical coherence tomographer (SS-OCT).

METHODS

We prospectively recruited 67 Caucasian healthy patients whose mean age was 41.9 ± 12.4 years; only their right eye was included in the study. Data were all recorded with the ANTERION SS-OCT and comprised, for each patient, 5 consecutive measurements of LV, anterior chamber depth (ACD), lens thickness (LT), axial length (AL), white-to-white (WTW) distance, central corneal thickness (CCT), anterior chamber volume (ACV) and spur-to-spur (STS) distance.

RESULTS

Mean LV was 0.26 ± 0.23 mm (ranging from -0.24 to 0.78 mm). Data analysis revealed a statistically significant negative correlation between LV and ACD (R=-0.80, p < 0.001), AL (R = -0.36, p = 0.002), and ACV (R = -0.68, p < 0.001), and a positive correlation between LV and LT (R = 0.67, p < 0.001), and age (R = 0.53, p < 0.001). In contrast, no statistically significant correlation was found between LV and WTW (R=-0.17, p = 0.15), CCT (R = 0.11, p = 0.36) or STS (R=-0.10, p = 0.41).

CONCLUSIONS

Taking into account our findings about intra-parameter correlation levels, we believe that LV should be measured and analyzed together with other ocular parameters in clinical routine practice both for diagnosis and for some refractive surgeries.

Aphakic Pupillary Block by an Intact Anterior Vitreous Membrane after Total Lens Extraction by Phacoemulsification

An 85-year-old Japanese woman with acute primary angle closure in her right eye underwent cataract extraction. Because of the weakness of the Zinn's zonules, all of the lens tissue including the lens capsule was removed by phacoemulsification. Because of the absence of vitreous prolapse into the anterior chamber, vitrectomy was not performed. Nine days postoperatively, acute angle closure due to pupillary block by an anterior vitreous membrane developed. To resolve the pupillary block, anterior vitrectomy was performed on the same day. Postoperatively, her symptoms resolved, the anterior chamber deepened, and the intraocular pressure normalized. Although rare, acute angle closure due to pupillary block by an anterior vitreous membrane can occur after total lens extraction with phacoemulsification. If no vitreous prolapse occurs with total lens extraction, an intentional hyaloidotomy using an anterior vitreous cutter or iridectomy should be considered to avoid secondary angle closure.

Automated measurement of iris surface smoothness using anterior segment optical coherence tomography

Fuchs uveitis (FU) is a chronic and often unilateral ocular inflammation and characteristic iris atrophic changes, other than heterochromia, are common in FU and are key to the correct diagnosis in many cases. With the advent of anterior segment optical coherence tomography (AS-OCT), some investigators attempted to quantitatively study these atrophic changes; mostly by introducing various methods to measure iris thickness in AS-OCT images. We aimed to present an automated method in an observational case series to measure the smoothness index (SI) of the iris surface in AS-OCT images. The ratio of the length of the straight line connecting the most peripheral and central points of the anterior iris border (in nasal and temporal sides) to the actual length of this border on AS-OCT images, was defined as SI. In a uveitis referral center, twenty-two eyes of 11 patients with unilateral Fuchs uveitis (FU) (7 female) and 22 eyes of 11 healthy control subjects underwent AS-OCT imaging. Image J and a newly developed MATLAB algorithm were used for manual and automated SI measurements, respectively. Agreement between manual and automated measurements was evaluated with Bland–Altman analysis and interclass correlation coefficient. The inter-eye difference of SI was compared between the FU group and the control group. Automated mean overall SI was 0.868 ± 0.037 and 0.840 ± 0.039 in FU and healthy fellow eyes, respectively (estimated mean difference =  − 0.028, 95% CI [− 0.038, − 0.018], p < 0.001). Bland- Altman plots showed good agreement between two methods in both healthy and FU eyes. The interclass correlation coefficient between the manual and automated measurements in the FU and healthy fellow eyes was 0.958 and 0.964, respectively. The inter-eye difference of overall SI was 0.029 ± 0.015 and 0.012 ± 0.008 in FU group and control group, respectively (p = 0.01). We concluded that the automated algorithm can rapidly and conveniently measure SI with results comparable to the manual method.

Evaluation of biometric parameters in phacomorphic glaucoma and mature cataracts

PURPOSE

The aims of this study were to compare the biometric parameters and axial lengths of eyes with phacomorphic glaucoma and mature cataract and to identify differences that might predispose to development of phacomorphic glaucoma.

METHODS

Three hundred forty-two patients were enrolled in this retrospective study. The eyes were divided into four groups-Group (G)1: phacomorphic glaucoma (n = 29), G2: mature cataract (n = 313), G3: contralateral phacomorphic glaucoma (n = 29), and G4: contralateral mature cataract (n = 313). Central corneal thickness and anterior chamber depth were assessed by optical low-coherence reflectometry (Lenstar LS 900®; Haag-Streit AG, Switzerland), while axial length was determined by A-scan ultrasound biometry.

RESULTS

The mean central corneal thickness of G1 was significantly higher than in other groups (p < 0.001) and the mean anterior chamber depth of G1 was the lowest among the groups (p < 0.001). Also, G2 had lower mean anterior chamber depth than G4 (p < 0.001) and G3 had lower mean anterior chamber depth than G4 (p = 0.007). Anterior chamber depth less than 3.27 mm had the higher odds ratio for distinguishing G3 versus G4 (odds ratio = 10.79, p < 0.001). Furthermore, patients aged ⩾68.9 years had the higher odds ratio for distinguishing G1 versus G2 (odds ratio = 2.82, p = 0.019). There was no significant difference in the presence of pseudoexfoliation material between G1 and G2 (p = 0.057). There were no significant differences in axial length values among the four groups (p = 0.097).

CONCLUSION

Advanced age and shallow anterior chamber depth were found to be risk factors for developing phacomorphic glaucoma, but the presence of pseudoexfoliation material was not found to play a role as a risk factor in phacomorphic glaucoma development.

Pathophysiology and management of glaucoma and ocular hypertension related to trauma

Ocular trauma is a significant cause of blindness worldwide, particularly if associated with glaucoma. Direct damage from blunt or penetrating trauma, bleeding, inflammation, lens-related problems, orbital and brain vascular pathologies related to trauma, and chemical injuries may increase intraocular pressure and lead to traumatic glaucoma. Treatment may be as simple as eliminating the underlying cause in some conditions or management can be challenging, depending on the mechanism of damage. If proper management is not undertaken, visual outcomes can be poor. We discuss a broad spectrum of trauma-related mechanisms of intraocular pressure elevation, as well as their management.