Changes of the Peripapillary Retinal Nerve Fiber Layer After Filtration Surgery in Glaucoma Patients

Effect of Trabeculectomy on Peripapillary Retinal Nerve Fiber Layer Thickness Using Spectral Domain Optical Coherence Tomography

At present, trabeculectomy is the most common performed and effective surgical method of filtration surgery for patients with medically uncontrolled glaucoma.

The aim of this prospective observational case study is to determine changes of the peripapillary retinal nerve fiber layer thickness using spectral domain optical coherence tomography in patients with glaucoma after surgical reduction of intraocular pressure.

Baseline and postoperative measurement of the peripapillary retinal nerve fiber layer (RNFL) thickness will be performed using the following spectral domain optical coherence tomography (OCT): Cirrus™ HD-OCT (Carl Zeiss Meditec) and Spectralis® Heidelberg-Engineering.

The main outcome measures will be changes in overall and quadrant RNFL thickness with respect to reduction in intraocular pressure (IOP), correlation between RNFL thickness and alteration in visual field and predictive factors of postoperative IOP-reduction and changes of RNFL thickness.

Inclusion Criteria:

• primary or secondary open angle glaucoma
• target intraocular pressure under medical treatment was not reached
• progression of visual loss
• best corrected visual acuity of 20/100 or more
• spherical equivalent refraction of -8.0 to +4.0 D
• perimetry: less than 20% false positive answers

Exclusion Criteria:

• primary or secondary angle closure glaucoma
• congenital glaucoma
• normal tension glaucoma
• neovascular glaucoma