Purchase this article with an account.
H. V. Danesh-Meyer, T. Papenchenko, A. Law, G. D. Gamble; Pre-Operative Retinal Nerve Fiber Layer Thickness Correlates With Degree of Visual Recovery Following Surgery in Patients With Compressive Optic Neuropathy. Invest. Ophthalmol. Vis. Sci. 2007;48(13):2478.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the spatial relationship between pre-operative retinal nerve fiber layer thickness (RNFL) measured with Optical Coherence Tomography (OCT) in patients with compressive optic neuropathy and visual field recovery following decompressive surgery.
Twenty-four eyes of 12 patients with perichiasmal compression were prospectively recruited prior to neurosurgery. All patients underwent complete neuroophthalmic assessment and magnetic resonance imaging (MRI) of the brain. Patients also had OCT and HFA2 automated visual field testing (VF) pre-operatively (visit 1), within four weeks following surgery (visit 2), and between two and six months post-operatively (visit 3). Patients were classified as having a ‘Thin’ RNFL if the value was in the lowest 2.5%( one SD from the mean) of the normative data base and otherwise was classified as ‘Normal’ RNFL. The relationship was also studied parametrically. The spatial relationship between RNFL thickness pre-operatively (average, clock hours, and sectors) and VF zones pre- and post-operatively were evaluated by linear regression. Coefficients of determination (R2) were calculated by using a multivariate model.
Mean age was 39.8 years (SD 12.44). Ten patients had pituitary adenomas, 1 meningioma and 1 neurosarcoid. No significant difference existed in pre-operative mean deviation (MD) between eyes classified as ‘Thin’ or "Normal’ based on pre-operative RNFL thickness (MD= 8.8 vs MD 13.2, respectively, P=0.37). Among all patients, mean RNFL thickness did not change significantly between visits (Visit 1=90.9 um, Visit 2 =93.1um, Visit 3=98.9um; P=0.3). However, MD improved significantly overall (Visit 1= 10.3 dB, Visit 2= 7.7dB, Visit 3= 2.8 dB; P< 0.01). MD improved significantly more in eyes with Normal RNFL thickness pre-operatively compared to the Thin eyes between visit 1 and 2 (6.2 dB (SD 7.65) vs 0.75 dB (SD 1.39); P<0.01) and between visit 1 and 3 (11.5 dB (SD 9.0) vs 4.0 dB (SD 4.6), P= 0.03). Between visit 1 and 3, MD improved 86.3% in the Normal group compared to 32.2% in the Thin group (P=0.001).
This is the first study to demonstrate that pre-operative RNFL thickness provides predictive information regarding visual field recovery in patients with compressive optic neuropathy. Normal pre-operative RNFL thickness is suggestive of greater postoperative improvement in visual field sensitivity (MD).
This PDF is available to Subscribers Only