Identification and Quantitative Assessment of Schlemm's Canal in the Eyes with 360° Angle Recession Glaucoma

Iridocorneal angle imaging of a human donor eye by spectral-domain optical coherence tomography

Iridocorneal angle (ICA) details particularly the trabecular meshwork (TM), Schlemm's canal (SC), and collector channels (CCs) play crucial roles in the regulation of the aqueous outflow in the eyes and are closely associated with glaucoma. Current clinical gonioscopy imaging provides no depth information, and studies of 3D high-resolution optical coherence tomography (OCT) imaging of these structures are limited. We developed a custom-built spectral-domain (SD-) OCT imaging system to fully characterize the angle details. Imaging of a human cadaver eye reveals the visibility of details in the TM/SC/CC region via a 'crossline' scanning and a series of image processing. This shows that ICA imaging can be used for preoperative glaucoma inspections in the clinical setting with the proposed prototype.

Comparison of Both Eyes Anterior Segment Structures of Patients with Unilateral Blunt Trauma

BACKGROUND

To evaluate anterior segment optical coherence tomography (AS-OCT) data in patients with unilateral blunt ocular trauma (BOT), to determine the relationship of results with hyphema development METHODS: 21 patients who received unilateral BOT were included in the study. Healthy eyes of patients were included in the control group. Iris stromal thickness (IST), schlemm canal area (SCA) and pupil diameter were measured by AS-OCT of the participants. In addition, eyes with ocular trauma were divided into those with and without hyphema and compared in terms of these parameters.

RESULTS

The mean nasal and temporal (n-t) IST was measured as 373± 40 µm and 369 ± 35 µm in BOT in comparison with 344 ± 35 µm and 335 ± 36 µm in control eyes, respectively (p = 0.000 and p = 0.001, respectively). The mean nasal and temporal (n-t) SCA was measured as 12,571 ± 880 µm² and 12,162 ± 1,181 µm² in developed hyphema in comparison with 10,455 ± 1,506 µm² and 10,188 ± 939 µm² in did not develop hyphema, respectively (p = 0.016 and p = 0.002 respectively).

CONCLUSION

The ISTs of the traumatized eyes in the nasal and temporal quadrants were statistically thicker than the other healthy eyes. SCA in both nasal and temporal quadrants of eyes with hyphema was statistically significantly larger than the group without hyphema.

Clinical outcomes of penetrating canaloplasty in patients with traumatic angle recession glaucoma: a prospective interventional case series

BACKGROUND/AIM

To evaluate the clinical outcomes of penetrating canaloplasty in traumatic angle recession glaucoma at 1 year.

METHODS

Patients with angle recession glaucoma underwent penetrating canaloplasty, a new Schlemm's canal-based internal drainage procedure, which creates a direct canal for flow of aqueous humour from the anterior chamber to the ostia of Schlemm's canal via a window created at the corneal scleral bed without use of antimetabolites. Postoperative intraocular pressure (IOP), number of glaucoma medications, and procedure-related complications were evaluated. Success was defined as an IOP ≤21 mm Hg without (complete) or with (qualified) use of glaucoma medication.

RESULTS

Forty eyes in 40 patients with angle recession glaucoma underwent successful circumferential catheterisation. The mean patient age was 42±13 years. In patients with penetrating canaloplasty that was deemed to be completely successful, the mean IOP decreased from a preoperative value of 37.8±12.3 mm Hg on 3.3±1.2 anti-glaucoma medications to 18.5±6.4 mm Hg on 1.2±1.4 medications, 14.9±4.6 mm Hg on 0.1±0.5 medications, 15.7±5.4 mm Hg on 0.1±0.4 medications and 14.8±3.6 mm Hg on 0.1±0.5 medications at 1, 3, 6 and 12 months postoperatively (p<0.05). Complete success was achieved in 35/40 eyes (87.5%) at 6 months and in 34/38 (89.5%) at 12 months. Hyphema (18/40, 45.0%) and transient IOP elevation (≥30 mm Hg, 9/40, 22.5%) were the most common postoperative complications.

CONCLUSION

Penetrating canaloplasty significantly reduces IOP and has a high success rate in angle recession glaucoma.

TRIAL REGISTRATION NUMBER

ChiCTR1900020511.