Correlation between optical coherence tomography parameters and retinal sensitivity in idiopathic intracranial hypertension

Abstract

Purpose The aim of this study was to report the findings of optical coherence tomography measurement of retinal nerve fiber layer (RNFL) thickness and ganglion cell complex (GCC) in idiopathic intracranial hypertension (IIH) patients and to assess whether the RNFL and GCC correlate with retinal sensitivity determined by automated perimetry in the form of mean deviation (MD) and pattern standard deviation. Patients and methods A prospective observational study was carried out for 30 patients with confirmed IIH (age ≥18 years), BMI below 25, intracranial pressure (ICP) of at least 20 cmH 2 O, and normal neurological examination (except for papilloedema and horizontal diplopia). All patients received a complete neurological examination and most recent lumbar puncture opening pressure (latest ICP) was recorded. Complete ophthalmic evaluation including best-corrected visual acuity, perimetry, RNFL, and GCC thickness within 24 h of performing lumber puncture. Results In IIH patients the initial RNFL thickness was significantly higher, whereas GCC was significantly lower than controls ( P = 0.045 and 0.004, respectively). The value of ICP measured was found to be positively correlated with the stage of papilloedema ( r = 0.494, P = 0.000). The final recordings showed a significant decrease in GCC and RNFL values ( P = 0.000 and 0.002, respectively), and improvement in MD ( P = 0.003). Regression analysis showed that for every 10 μm increase in mean RNFL thickness, there was worsening in MD of 0.56 dB, whereas for every 10 μm decrease in mean GCC thickness, there was worsening in MD of 0.9 dB at the last follow-up. Conclusion GCC and RNFL thickness abnormalities assessed by optical coherence tomography in IIH patients were quantitatively correlated with visual field sensitivity losses and can be definitively useful to quantify optic nerve damage.