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Abstract #70348 Published in IGR 18-2
Changes in Anterior Segment Morphology and Predictors of Angle Widening after Laser Iridotomy in South Indian Eyes
Zebardast N; Kavitha S; Krishnamurthy P; Friedman DS; Nongpiur ME; Aung T; Quigley HA; Ramulu PY; Venkatesh ROphthalmology 2016; 123: 2519-2526
PURPOSE: To compare anterior segment optical coherence tomography (ASOCT) angle morphology before and after laser peripheral iridotomy (LPI) in a cohort of South Indian subjects with primary angle-closure suspect (PACS) or primary angle-closure/primary angle-closure glaucoma (PAC/PACG) and to examine baseline parameters associated with angle widening. DESIGN: Prospective observational study. PARTICIPANTS: A total of 244 subjects aged ≥30 years with PACS or PAC/PACG in at least 1 eye. METHODS: The ASOCT images and angle gonioscopic grades were analyzed for all subjects at baseline and 2 weeks after LPI. Multivariable linear and logistic regression models were used to determine predictors of angle widening (change in mean angle opening distance [AOD750]) and angle opening (all 4 quadrants with trabecular meshwork [TM] visible on gonioscopy after LPI). MAIN OUTCOME MEASURES: Change in ASOCT parameters with LPI and baseline predictors of angle widening. RESULTS: Laser peripheral iridotomy resulted in angle widening on ASOCT with significant increases in AOD750, angle recess area, and trabecular iris surface area (P < 0.05 for all). Gonioscopically, 44.7% of all subjects had open angles in all 4 quadrants after LPI, with a greater percentage of angles open in the PACS group compared with the PAC/PACG group (52.4% vs. 36.4%; P = 0.01). In multivariable regression analyses, greater postoperative angle widening as defined by change in AOD750 was associated with shorter baseline AOD750 and axial length, and greater baseline anterior chamber depth, iris curvature, and lens vault (P ≤ 0.002 for all). Gonioscopic angle opening after LPI was more common with wider baseline angle width (modified Shaffer grade) and lower cup-to-disc ratio (P < 0.001 for both). CONCLUSIONS: In a South Indian population with PACS or PAC/PACG, LPI results in significant anterior chamber angle widening seen on both ASOCT and gonioscopy, although some degree of persistent iridotrabecular contact was present in approximately half of PACS eyes and approximately two thirds of PAC/PACG eyes on gonioscopy. The greatest widening by ASOCT was observed in eyes with features most consistent with greater baseline pupillary block.
Wilmer Eye Institute, John Hopkins University, Baltimore, Maryland; Dana Center for Preventive Ophthalmology, Johns Hopkins University, Baltimore, Maryland.
Full articleClassification:
12.2 Laser iridotomy (Part of: 12 Surgical treatment)
9.3.5 Primary angle closure (Part of: 9 Clinical forms of glaucomas > 9.3 Primary angle closure glaucomas)
9.3.4 Primary angle closure suspect (Part of: 9 Clinical forms of glaucomas > 9.3 Primary angle closure glaucomas)
9.3.2 Chronic primary angle closure glaucoma (pupillary block) (Part of: 9 Clinical forms of glaucomas > 9.3 Primary angle closure glaucomas)
