A Single-centre, Randomised, Double-blind Study to Assess the Efficacy of Citicoline Compared With Placebo on Visual Function in Glaucoma Patients Undergoing Subconjunctival Filtering Surgery for Glaucoma

Glaucoma is a group of conditions characterised by a progressive loss of retinal ganglion cells (RGCs) and their axons, leading to characteristic changes in the optic nerve head and the retinal nerve fibre layer. If left untreated, the disease has a natural course that can lead to progressive and significant impairment of visual function. Intraocular pressure (IOP) is the main modifiable risk factor for the onset and progression of the disease. The positive effect of surgery on the progression of glaucoma is certainly due to the reduction in IOP levels achieved in the post-operative period, with probable secondary effects on ocular haemodynamics as well. Although IOP reduction is now considered the most potent neuroprotective treatment for glaucoma, it has been shown that good tonometric control may, in some cases, not be sufficient to preserve visual function. There are, in fact, pressure-independent mechanisms involved in the pathogenesis of glaucomatous damage, in which the progressive deterioration and apoptosis of RGCs are linked to mechanisms such as oxidative stress, glutamate neurotoxicity, the inhibition of anterograde transport of neurotrophic factors, and mitochondrial dysfunction. In recent years, various molecules, including cytidine-5'-diphosphocholine (citicoline), have been proposed in combination with hypotensive therapy due to their neuroprotective and neuroenhancing effects. In addition to its structural action, it possesses a functional action (neuroenhancer) as it increases the synthesis of neurotransmitters such as noradrenaline, acetylcholine, serotonin and dopamine, which are involved in visual signal transmission at both the retinal and post-retinal levels. To date, there is no scientific evidence regarding the effect of citicoline on visual function in glaucoma patients who have undergone filtration surgery. Therefore, the hypothesis of this study is that if surgery increases the likelihood of an improvement in the function of residual RGCs, citicoline could help achieve this objective either by increasing the proportion of patients showing improvement or by increasing the extent of the improvement. The use of a placebo is ethically justified because all patients involved in the study, having signed an informed consent form, will undergo surgical treatment - which is considered the treatment of choice for progressive glaucoma - and the efficacy of citicoline treatment needs to be validated in terms of its ability to alter the course of the disease.