Glaucoma, a leading cause of irreversible blindness, poses a significant public health challenge worldwide. The disease, characterized by the gradual loss of retinal ganglion cells, is primarily associated with elevated intraocular pressure (IOP). While controlling IOP is crucial in managing glaucoma, many patients still experience progression despite optimal IOP control. This has led to a need for alternative treatments that can effectively halt the advancement of the disease.
Citicoline, also known as CDP-choline, has garnered attention for its potential neuroprotective properties. Initially studied for its efficacy in central neurodegenerative diseases like Alzheimer’s and Parkinson’s, citicoline has shown promise in enhancing brain function and protecting neurons. More recently, researchers have explored its potential benefits in ophthalmology, including conditions like amblyopia, non-arteritic ischemic optic neuropathy, corneal oxidative damage, and glaucoma.
Experimental studies on retinal cell cultures and animal models have indicated a protective effect of citicoline on glaucomatous retinal ganglion cell damage. Some clinical studies and online news coverage have even suggested using citicoline as a supplement to IOP-lowering medications in glaucoma patients. However, these studies have often been small in scale, leading to inconclusive results. To address this knowledge gap, a systematic review was conducted to comprehensively evaluate the therapeutic potential of citicoline in glaucoma patients.
The systematic review adhered to the PRISMA 2020 guidelines and involved a meticulous search of various databases to identify clinical studies investigating citicoline’s efficacy in glaucoma management. Key outcomes of interest included IOP, visual field testing, retinal nerve fiber layer, and the pattern electroretinogram in glaucoma patients. Ten studies, encompassing a total of 424 patients, met the eligibility criteria and were included in the review. The average follow-up duration was approximately 12.1 months, and the patients had a mean age of 56.7 years. The majority of patients had open-angle glaucoma, with a smaller percentage having secondary glaucoma or normal tension glaucoma. Importantly, all patients continued their IOP-lowering medications throughout the study period.
The overall risk of bias in the included studies was assessed as low to moderate. The key findings revealed no significant differences in IOP, visual field testing, retinal nerve fiber layer, or the pattern electroretinogram between the group receiving citicoline and the control group. Additionally, there was no improvement observed in these parameters from baseline to the last follow-up for either group.
Based on the findings of this systematic review, citicoline supplementation did not lead to a significant reduction in IOP or notable improvements in retinal ganglion cell preservation, visual field function, or retinal function in glaucoma patients. These results do not provide strong support for the use of citicoline as an adjunctive therapy in glaucoma management.
One limitation of the study was the relatively small number of clinical studies available for analysis. Additionally, half of the included studies were retrospective, which may affect the overall quality of evidence. The heterogeneity in citicoline dosage, administration route, treatment duration, and control groups across studies further complicates the interpretation of results. The absence of a standardized follow-up scheme for monitoring visual field progression is also a limitation.
In conclusion, the available evidence does not strongly support the use of citicoline as a therapeutic agent for slowing the progression of glaucoma. While earlier studies hinted at its potential benefits, this systematic review does not demonstrate significant improvements in key glaucoma-related parameters. Future research, consisting of larger randomized, prospective studies, is needed to determine the ideal treatment regimen for citicoline in specific subtypes of glaucoma. Until more robust evidence emerges, caution should be exercised when considering citicoline as an adjunctive neuroprotective therapy for glaucoma patients. The search for effective treatments to halt the progression of glaucoma continues.