Measurement Of Trabecular-Iris Space Area Using Spectral-Domain Anterior Segment Module : A Pilot Study

Published 2022 - 40th Congress of the ESCRS

Reference: FPT08.12 | Type: Free paper | DOI: 10.82333/majw-vj36

Authors: Guilherme Almeida* ¹ , Miguel Leitão ² , Francisco Alves ² , Júlio Brissos ² , João Segurado ²

¹Ophthalmology,Instituto de Oftalmologia Dr. Gama Pinto,Lisboa,Portugal;Ophthalmology,Instituto de Oftalmologia Dr. Gama Pinto,Lisboa,Portugal, ²Ophthalmology,Instituto de Oftalmologia Dr. Gama Pinto,Lisboa,Portugal

Purpose

Anterior segment OCT (ASOCT) is a useful adjuvant for evaluating the anterior chamber angle. The
relationship between ASOCT and clinical gonioscopy has not been yet fully elucidated. Objective anatomic anterior
chamber angle parameters can provide good way of examining and monitoring angle closure existence and risk of development of high IOP and Glaucoma.

Setting

Prospective, comparative pilot study enrolled at Instituto de Oftalmologia Dr. Gama Pinto, Lisbon, Portugal.

Methods

Eyes undergoing both ASOCT and gonioscopy were identified by retrospective review of clinical registries.
Gonioscopy grading was assessed and compared by two observers: one glaucoma specialist and one resident. Grading of the ASOCT was made by two independent observers. ASOCT imaging was taken using Spectralis® Anterior Segment Module (Heidelberg®, Germany). Anatomic parameters included: the angle-opening distance (AOD), at 500 and 750 μm distant from the scleral spur (AOD500 and AOD750). Trabecular-iris space areas (TISA) were manually drawn on the software provided and measured at a distance of 500 and 750 μm from the scleral spur (TISA500 and TISA750). The ASOCT findings were compared to Shaffer gonioscopy grades

Results

In the initial cohort, 24 eyes were reviewed by the clinician and masked anterior segment imaging evaluators. By gonioscopy, 18 of 24 (75%) of eyes were found to have narrow angles. The average AOD500 of the 12 right eyes was 197.5 μm (+/-127.30), of the left eyes 185.22 μm (+/-93.94). The average AOD750 was 249.2 μm (+/-155.05) in right and 262.67 μm (+/-128.66) in left eyes. The average TISA500 in right and left eyes was 0.064 mm² (+/-0.054) and 0.057 mm² (+/-0.047). The average TISA750 in right and left eyes was 0.117 mm² (+/-0.073) and 0.114 mm² (+/-0.073), respectively

Conclusions

Gonioscopy can be subjective based on observer and technique. The use of ASOCT can provide a more
objective and reproducible way to evaluate the angle. To our knowledge, this is the first study that propose a way of measure TISA using Spectralis® Anterior Segment Module. Precise parameters such as AOD and TISA are reliable and can help us guide future decision on primary angle closure suspects, primary angle closure with or without Glaucoma.