Abstract
Purpose: :
Gonioscopy is the current reference standard for diagnosing angle closure. Anterior segment optical coherence tomography (AS-OCT) is an imaging device that can be used to evaluate the angle. In a community-based screening study carried out in 2006, AS-OCT detected angle closure in 10% of the cohort, in whom gonioscopy revealed open angles. The aim of this study was to re-examine these subjects with open angles on gonioscopy but had angle closure on AS-OCT four years previously.
Methods: :
Phakic subjects with previously closed angles in at least one quadrant on AS-OCT but had open angles on gonioscopy 4 years ago were re-examined, as was a sample of patients with previously open angles on both AS-OCT and gonioscopy. The examination included gonioscopy, repeat AS-OCT, and slit lamp evaluation. We compared the incidence of angle closure based on gonioscopy (defined as Shaffer grade 1 or less in at least two quadrants) between the two groups. Subjects who underwent cataract surgery in both eyes were excluded.
Results: :
178 patients with previously found angle closure on AS-OCT (for at least one quadrant) but open angles on gonioscopy, and 37 patients with previously found open angles on both AS-OCT and gonioscopy were examined. In 2010, 21.9% (39/178, 95% CI 16.4-28.6%) of those with AS-OCT angle closure in 2006 now had gonioscopic angle closure while none (0/37, 97.5% CI 0 - 1.1%) developed angle closure among those with open angles on AS-OCT in 2006 (p =0.004).
Conclusions: :
Of patients with open angles on gonioscopy in 2006, those who were closed on AS-OCT four years ago were more likely to have developed gonioscopic angle closure compared with those who had open angles on AS-OCT four years ago. AS-OCT angle findings were predictive of future gonioscopic status and incident angle closure 4 years later.
Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • anterior segment