Evaluation and Comparison of Indentation Ultrasound Biomicroscopy Gonioscopy in Relative Pupillary Block, Peripheral Anterior Synechia, and Plateau Iris Configuration

Efficacy and safety of primary customized phacoemulsification combined with goniosynechialysis for refractory acute primary angle closure

PURPOSE

To assess the safety, efficacy, and long-term clinical outcomes of primary customized phacoemulsification (phaco) combined with goniosynechialysis (GSL; phaco-GSL) in refractory acute primary angle closure (APAC) eyes with uncontrolled high intraocular pressure (IOP).

METHODS

This retrospective case series comprised 51 eyes of 42 consecutive patients with refractory APAC and high IOP who were treated using primary customized phaco-GSL at 3 hospitals in China, from 2014 to 2021. Preoperative and postoperative IOP, corrected distant visual acuity (CDVA), corneal endothelial cell density (CECD), intraoperative and postoperative complications were recorded. The safety, efficacy and subsequent long-term clinical outcomes were analyzed.

RESULTS

The mean CDVA (LogMAR) was improved from 1.67 ± 0.94 preoperatively to 0.23 ± 0.26 postoperatively (P < 0.001). Preoperative CECD was 2309.39 ± 541.03 cells/mm2 in 33 eyes and inaccessible in 18 eyes due to severe corneal edema; at the final follow-up, the mean CECD of all patients was 1823.50 ± 533.40 cells/mm2 (P < 0.001). The mean IOP decreased from 48.51 ± 6.25 mmHg preoperatively to 15.66 ± 2.27 mmHg at the final follow-up (P < 0.001). Among 51 eyes, additional customized procedures performed were corneal indentation in 42 eyes, epithelial debridement in 9 eyes, giant epithelial bullae view in 4 eyes, pars-plana fluid aspiration in 3 eyes, and secondary intraocular lens implantation in 7 eyes. The IOP of all eyes was well controlled eventually and 47 eyes (92.16%) were successfully treated by phaco-GSL alone. No significant intraoperative or postoperative complications were observed.

CONCLUSIONS

Primary customized phaco-GSL is a safe and effective surgical management strategy for patients with refractory APAC and high IOP.

Anterior segment optical coherence tomography findings in the Infant Aphakia Treatment Study (IATS): a secondary analysis of a randomized clinical trial

PURPOSE

To correlate the diagnosis of glaucoma among children in the Infant Aphakia Treatment Study (IATS) by age 10 years with anterior segment optical coherence tomography (AS-OCT) findings.

METHODS

A multicenter randomized controlled trial of 114 infants with unilateral congenital cataract who were 1-6 months of age at surgery. Data on long-term glaucoma-related status and outcomes were collected when children were 10.5 years old. Participants were randomized at cataract surgery to either primary intraocular lens (IOL) or no IOL implantation (contact lens [CL]). AS-OCT findings in eyes with glaucoma were compared to eyes which did not have glaucoma and to the fellow eyes, between fellow and treated eyes, and between the IOL and CL groups.

RESULTS

There were no significant differences in the mean nasal and temporal anterior chamber angle (ACA) or mean nasal and temporal angle opening distance (AOD) for nonglaucomatous, glaucomatous, and fellow eyes (P = 0.31, 0.16, 0.43, 0.08 resp.). There were also no significant differences in mean nasal and temporal ACA and AOD between fellow and treated eyes (P = 0.44, 0.67, 0.57, 0.38 resp.), or between IOL and CL groups (P = 0.36, 0.35, 0.49, 0.44, resp.).

CONCLUSIONS

AS-OCT confirmed that eyes with glaucoma in IATS had predominantly open angles with similar ACA and AOD to eyes without glaucoma and to fellow eyes. Furthermore, congenital cataract surgery with or without an IOL did not result in a significant difference in ACA or AOD compared to fellow eyes in IATS.

Anterior-segment imaging for assessment of glaucoma

This article summarizes the physics, technology and clinical application of ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT) for assessment of the anterior segment in glaucoma. UBM systems use frequencies ranging from approximately 35 to 80 MHz, as compared with typical 10-MHz systems used for general-purpose ophthalmic imaging. OCT systems use low-coherence, near-infrared light to provide detailed images of anterior segment structures at resolutions exceeding that of UBM. Both technologies allow visualization of the iridocorneal angle and, thus, can contribute to the diagnosis and management of glaucoma. OCT systems are advantageous, being noncontact proceedures and providing finer resolution than UBM, but UBM systems are superior for the visualization of retroiridal structures, including the ciliary body, posterior chamber and zonules, which can provide crucial diagnostic information for the assessment of glaucoma.

Anterior segment imaging in glaucoma

Anterior segment imaging allows objective assessment of the anterior segment of the eye, particularly the anterior chamber angle. Both qualitative and quantitative analyses are possible and aid in detecting and managing closed-angle and open-angle mechanisms in various forms of glaucoma. This review focuses primarily on anterior segment optical coherence tomography and ultrasound biomicroscopy, with emphasis on principles of technology, commercially available devices, and clinical applications in glaucoma with potential advantages and disadvantages of each technology.

Prevalence of plateau iris configuration in primary angle closure glaucoma using ultrasound biomicroscopy in the Indian population

Purpose:

To report the prevalence of plateau iris in patients with primary angle closure glaucoma (PACG), in North India.

Materials and Methods:

The patients with PACG, attending the glaucoma services at a tertiary care center in North India were included in the study. All patients had undergone Nd-YAG laser peripheral iridotomy at least four weeks prior to inclusion in the study. Four weeks prior to inclusion in the study, none of the patients had used pilocarpine. Ultrasound Biomicroscopy (UBM) images were qualitatively evaluated and plateau iris configuration was defined in an eye if the following criteria were fulfilled in two or more quadrants: anteriorly directed ciliary process supporting the peripheral iris, steep rise of iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, absent ciliary sulcus, and iridotrabecular contact in the same quadrant.

Results:

One hundred and one eyes were included in the study. There were 63 (62.4%) females and 38 (37.6%) males. The mean age of the patients was 57.8 ± 9.5 years (range: 42 to 78 years). The mean axial length in the study population was 22.2 ± 1.1 mm. The mean spherical equivalent refraction was 0.06 ± 1.12 D. The mean intraocular pressure was 18.5 ± 4.7 mmHg (range: 12 – 24 mmHg). Twenty-nine (28.7%) subjects were diagnosed with plateau iris on the basis of above-defined criteria. Of the 29 eyes, 18 (62.1%) subjects had plateau iris in two quadrants, nine (31.03%) in three quadrants, and two (6.8%) had this configuration in all the four quadrants.

Conclusions:

Approximately 30% of the eyes with PACG had plateau iris on UBM. Plateau iris was very often the cause for residual angle closure following laser peripheral iridotomy in Indian eyes with PACG.

Characteristics and reproducibility of anterior chamber angle assessment by anterior-segment optical coherence tomography

PURPOSE

To evaluate the basic characteristics and reproducibility of anterior chamber angle (ACA) measurements determined by anterior-segment optical coherence tomography (AS-OCT) in open-angle and primary angle closure suspect (PACS) patients.

METHODS

Thirty-nine open-angle and 18 PACS patients were imaged for ACA by AS-OCT. Subjects underwent imaging of the nasal, temporal and inferior ACA under conditions of constant light, and darkness. For analysis, we used three ACA parameters handled by the Visante OCT software: angle opening distance at 500 μm (AOD(500)), trabecular-iris space area at 500 μm (TISA(500)) and angle recess area at 500 μm (ARA(500)). For determination of inter-session reproducibility, a single well-trained operator (D.Y.K.) scanned all patients at two different visits. For determination of inter-operator variability, a second operator (S.B.P.) acquired another set of images independently. Three sets of images were acquired at least 24 hour apart.

RESULTS

All parameters were significantly different when measured both in light and darkness, and in the nasal and temporal quadrants. There were no significant differences between the left and right eyes in the three ACA parameters in all quadrants. The temporal angle was wider than the nasal and inferior angles. All parameters of the nasal, temporal angles had excellent inter-session and inter-operator reproducibility [intra-class correlation coefficient (ICC) 0.796-0.981], but these values were slightly lower for inferior angle measurements (ICC 0.662-0.892) in both open-angle and PACS groups.

CONCLUSION

AS-OCT provides quantitative and reproducible assessment of ACA. Reproducibility was lower in the inferior angle compared with the nasal and temporal angles, perhaps because of variable placement of the scleral spur.

Corneal indentation in the early management of acute angle closure

PURPOSE

To describe in detail corneal indentation (CI) in the management of a series of patients treated for acute angle closure (AAC).

DESIGN

Retrospective, consecutive, noncomparative case series.

PARTICIPANTS

Seven consecutive patients (8 eyes) referred to the authors with the diagnosis of AAC. Patients presented to the Prince of Wales Hospital, Randwick, or to the private practices of the authors.

INTERVENTION

Seven patients (8 eyes) underwent CI as part of their early management for AAC.

MAIN OUTCOME MEASURES

Reduction in intraocular pressure (IOP), symptoms of AAC and pain relief.

RESULTS

Of the 7 patients, complete data were available for 6. The IOP was significantly reduced (P<0.05) and 3 of 4 patients with severe acute pain reported early resolution of pain after CI. The average reduction in IOP was 20.9 mmHg (range +1 to -45). All patients subsequently underwent definitive management with laser peripheral iridotomies or lensectomy using phacoemulsification. Three patients treated acutely with CI without any medical agents had a mean IOP reduction of 21 mmHg (range, 20-23) after indentation.

CONCLUSIONS

Corneal indentation is a rapid, portable, and effective method of reducing elevated IOP in the setting of AAC. It can be performed with instrumentation that is readily at hand and allows for rapid pain relief. This reduction in IOP improves corneal clarity and permits further definitive management of the patient with AAC.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Anterior chamber configuration in patients with glaucoma: MR gonioscopy evaluation with half-Fourier single-shot RARE sequence and microscopy coil

The purpose of the study was to determine the accuracy of half-Fourier single-shot rapid acquisition with relaxation enhancement high-spatial-resolution magnetic resonance (MR) imaging performed with a microscopy coil in the diagnosis of narrow anterior chamber angle in patients with glaucoma. Slit-lamp biomicroscopy served as the reference standard. The institutional review board approved this study, and written informed consent was obtained from the 20 recruited patients. There was excellent agreement between MR gonioscopy and slit-lamp biomicroscopy in the classification of anterior chamber angles as narrow or open (kappa = 0.89 [95% confidence interval: 0.69, 1.10]). MR gonioscopy has substantial potential as a technique used to evaluate glaucoma.

Prevalence of Plateau Iris in Primary Angle Closure Suspects

PURPOSE

To determine the prevalence of plateau iris in a cohort of primary angle closure suspects (PACSs) using ultrasound biomicroscopy (UBM).

DESIGN

Cross-sectional observational study.

PARTICIPANTS

Subjects over the age of 50 years diagnosed as PACSs.

INTERVENTION

Subjects were randomized to undergo laser peripheral iridotomy (LPI) in one eye. Ultrasound biomicroscopy was performed before and a week after LPI.

MAIN OUTCOME MEASURES

Ultrasound biomicroscopy images were qualitatively assessed using standardized criteria. Plateau iris was defined in a quadrant by the presence of an anteriorly directed ciliary body, an absent ciliary sulcus, a steep iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, presence of a central flat iris plane, and irido-angle contact. At least 2 quadrants had to fulfil the above criteria for an eye to be defined as plateau iris.

RESULTS

Two hundred five subjects were enrolled; UBM images of 167 subjects were available for analysis. Plateau iris was found in 54 of 167 (32.3%) PACS eyes after LPI. Quadrantwise analysis showed that 44 of 167 (26.3%) eyes had plateau iris in 1 quadrant, 36 (21.5%) in 2 quadrants, 16 (9.5%) in 3 quadrants, and 2 (1.2%) in all 4 quadrants. Plateau iris was most commonly observed in the superior and inferior quadrants.

CONCLUSIONS

Using standardized UBM criteria, plateau iris was found in about a third of PACS eyes after LPI. Prospective longitudinal studies are required to determine the clinical significance of this finding for the management of PACSs.