Changes in axial length and choroidal thickness after intraocular pressure reduction resulting from trabeculectomy

Abstract

Shinichi Usui,1,2 Yasushi Ikuno,2 Sato Uematsu,1 Yuko Morimoto,1 Yoshiaki Yasuno,3 Yasumasa Otori11National Hospital Organization, Osaka National Hospital, Osaka, Japan; 2Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan; 3Computational Optics Group, University of Tsukuba, Tsukuba, JapanPurpose: To evaluate changes in axial length and choroidal thickness after trabeculectomy.Patients and methods: Fourteen patients under 80 years of age with glaucoma, were enrolled. The choroid was imaged using prototypical high-penetration optic coherence tomography (OCT) and the thickness was measured. Axial length, choroidal thickness, and intraocular pressure (IOP) were measured bilaterally at 3 pm 1 day before and 6 days after trabeculectomy. The choroidal thickness was measured at the fovea and four other locations (2 mm superior, temporal, inferior, and nasal to the center of the optic nerve head).Results: The IOP and axial length significantly decreased in eyes that underwent trabeculectomy (P < 0.0001 for the IOP; P < 0.001 for axial length comparisons). The mean choroidal thicknesses significantly increased in eyes that underwent trabeculectomy compared to preoperatively (P < 0.0001 for the fovea; P < 0.01 for four locations around the optic disc). The mean magnitude of change in IOP was correlated positively with the mean magnitude of change in axial length, but not correlated with the mean magnitude of change in choroidal thickness at the fovea that underwent trabeculectomy. The sum of the axial length and subfoveal choroidal thickness in eyes decreased significantly postoperatively (P <0.05).Conclusion: The axial length shortened, the choroid thickened, and the sum of the axial length and subfoveal choroidal thickness decreased with IOP reduction early after trabeculectomy.Keywords: choroidal thickness, trabeculectomy, optical coherence tomography, IOP reduction