Citicoline and Filtration Surgery

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.

Study Overview

• Status: Completed
• Conditions: Glaucoma Therapy
• Intervention / Treatment: Device: Citicoline; Other: Placebo

• Study Type: Interventional
• Enrollment (Actual): 6
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Italy
  • Lombardy
    • Pavia, Lombardy, Italy, 27100
      • Fondazione IRCCS Policlinico San Matteo di Pavia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• age > 18 years
• Ability to understand the protocol and provide informed consent to participate in the study
• Diagnosis of primary or secondary open-angle glaucoma (PEX - PIG) and the need to undergo subconjunctival filtration surgery due to signs of morphological/functional progression of the condition or failure to achieve target pressure with medical or pre-surgical therapy.

The diagnosis of glaucoma is defined by the presence of typical ophthalmoscopic damage to the optic nerve head and the consequent visual field defect. In particular, a glaucomatous visual field defect will be considered as such if there is a cluster of 3 or more contiguous points in the pattern deviation plot with a probability of occurrence in the normal population of less than 5%, one of which has a probability of less than 1%, a pattern standard deviation with a probability of less than 5%, or a GHT result outside the normal limits.

• Early to moderate visual field defect, according to the Hodapp-Parrish-Anderson classification, i.e. with MD up to -12 dB, as determined by the Humphrey 24-2 SITA Standard computerised test.
• Rate of visual field defect progression > 0.5 dB/year, in the 2 years prior to surgery.
• At least 3 visual field examinations performed using standard perimetry in the 2 years prior to surgery.

Exclusion Criteria:

• Diagnosis of angle-closure glaucoma
• Previous glaucoma surgery (trabeculectomy, valve implantation or placement of other devices, cyclophotocoagulation)
• Previous vitreoretinal or corneal eye surgery
• Visual, neurological or general medical conditions that may affect the visual field, electrophysiological tests, OCT or A-OCT scans
• Systemic administration (oral or parenteral) of cerebral vasoactive drugs, neurotrophic agents, lutein, zeaxanthin, docosahexaenoic acid, ubiquinone and/or its derivatives, citicoline and/or its derivatives within 6 months prior to enrolment in the study
• Topical therapy with citicoline and/or its derivatives within 6 months prior to enrolment in the study
• Known or suspected allergy or sensitisation to the study product
• Pregnancy or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: citicolina; The experimental group will be treated with citicoline in oral solution (Neurotidine, Omikron, Italy) at a dose of 10 ml per day, starting two weeks before surgery and continuing for the following 24 months.	Device: Citicoline; Citicoline is a mononucleotide composed of ribose, pyrophosphate, cytosine and choline. It is the natural intracellular precursor of phosphatidylcholine. As an intermediate in the synthesis of phosphatidylcholine, citicoline acts at a structural level, promoting the synthesis of membrane phospholipids and inhibiting their degradation. In addition to its structural action, it has a functional effect (as a neuroenhancer) in that 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. In addition to its structural effects, it also has a functional effect (as a neuroenhancer) in that it increases the synthesis of neurotransmitters such as noradrenaline, acetylcholine, serotonin and dopamine, which are involved in the transmission of visual signals at both the retinal and post-retinal levels.
Placebo Comparator: Placebo; The placebo arm will receive a solution consisting of the Neurotidine vehicle (placebo) according to the same dosing regimen and schedule.	Other: Placebo; solution consisting of the Neurotidine vehicle (placebo)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in the mean deviation (MD) index	The Mean Deviation (MD) perimetric index is a measure of the average differential light sensitivity of the visual field. It is calculated as the sum of the defects found in the individual tested loci divided by the number of such loci. A higher MD indicates greater damage to the visual field. The MD index is used in conjunction with other perimetric indices to assess light sensitivity and the progression of glaucomatous damage	24 months after the operation

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in the implicit P100 latency measured via PEV (visual evoked potentials)	24 months after surgery
Change in p50 amplitude measured using PERG (retinal evoked potentials)	24 months after surgery
Incidence of progression as determined by the Glaucoma Progression Analysis (GPA) programme	24 months after surgery
Changes in the thickness of the retinal nerve fibre layer (RNFL) and ganglion cell layer (GCC) as measured by SD-OCT (Spectral Domain Optical Coherence Tomography)	24 months after surgery
Change in choroidal hypoperfusion areas (dropouts) measured using A-OCT (Optical coherence tomography)	24 months after surgery
Changes in the total score and sub-item scores on the NEI-VFQ-25 questionnaire (National Eye Institute Visual Function Questionnaire)	24 months after surgery

Collaborators and Investigators

• Sponsor: Fondazione IRCCS Policlinico San Matteo di Pavia

Study record dates

Study Major Dates

• Study Start (Actual): August 10, 2021
• Primary Completion (Actual): December 31, 2025
• Study Completion (Actual): December 31, 2025

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: April 30, 2026
• First Posted (Actual): May 5, 2026

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 30, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: CHIRCIT

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No