Short-term changes in the optic nerve head and visual field after trabeculectomy

Abstract

Aims or Purpose To evaluate short-term changes in optic nerve head topography and visual field induced by surgical reduction of intraocular pressure. Methods A prospective study was performed on 56 eyes of 56 patients with uncontrolled primary open-angle glaucoma despite maximum medical therapy, which underwent trabeculectomy. Optic nerve head evaluations by means of Heidelberg Retina Tomograph, and visual field tests were performed pre-operatively, and at 3 and 6 months after surgery. Differences in intraocular pressure, visual field indices, and Heidelberg Retina Tomograph parameters were evaluated with the t-test for paired data. A linear regression model was calculated to analyze the relationship between intraocular pressure reduction and visual field changes, and optic nerve head changes. Results Mean intraocular pressure decreased from 24.4 ± 5.0 mm Hg to 12.1 ± 3.1 mm Hg (month 3, Po0.001), and 10.6±2.8 mm Hg (month 6, Po0.001) after trabeculectomy. Mean retinal nerve fiber layer thickness (baseline, 0.19±0.034; month 3, 0.24 ± 0.039, P ¼ 0.05; month 6, 0.21 ± 0.037, P ¼ 0.05) showed a statistical significant change compared with baseline values. Conclusions In this 6-months study, a significant increase in retinal nerve fiber layer thickness was detected after glaucoma filtration surgery.

Laminar Displacement and Prelaminar Tissue Thickness Change after Glaucoma Surgery Imaged with Optical Coherence Tomography

“…Anterior displacement of the ONH surface resulting from acute reduction in IOP has been observed in adult glaucoma patients undergoing trabeculectomy [12][13][14][15][16][17] and in a subset of patients with a large IOP reduction after medical treatment. 18,19 Because these studies used CSLT in which the ALS cannot be visualized, the source of ONH surface changes cannot be precisely elucidated.…”

“…10,11 Several studies have examined ONH surface changes with confocal scanning laser tomography (CSLT) after surgical [12][13][14][15][16][17] or medical 18,19 reduction of IOP. However, because CSLT is able to image only ONH surface changes, none of these earlier studies were able to evaluate the contribution of deep ONH structures resulting in the increase of neuroretinal rim area and decrease of optic disc cupping after IOP reduction.…”

Short- and Long-Term Phasing of Intraocular Pressure in Stable and Progressive Glaucoma

“…We tried to overcome method limitations by using largely validated operating procedures to record the 24-hour IOP curves which have been reported in previous publications [6,17,18,19,20,21,22,23]. The operators at each site were well trained and had shown a high degree of concordance at the beginning of the study.…”

“…IOP reduction also reduces the effects of the disease on the visual field and optic nerve head [6,7], and as a consequence also the effects of IOP-lowering treatments need to be monitored over time.…”

Bimatoprost 0.01% vs bimatoprost 0.03%: a 12-month prospective trial of clinical and in vivo confocal microscopy in glaucoma patients

“…3,4 Several risk factors for progression of visual field loss have been identified, including abnormal baseline anticardiolipin antibody levels, older age, raised intraocular pressure (IOP), and female sex. 5 Nevertheless, the only modifiable risk factor for the glaucoma progression is currently IOP.…”