Efficacy of Citicolline in Treatment of
Amblyopia as an Adjunct to Patching
Anurag Narula1, Rajiv Kumar2, Shilpa Singh3* and Manish Yadav1
1,2VMMC and Safdarjung Hospital, India
2Visitech Eye Centre, India
Submission: July 30, 2018; Published: September 21, 2018
*Corresponding author: Shilpa Singh, D-II/368 Pandara Road New Delhi-3.
How to cite this article: Anurag N, Rajiv K, Shilpa S, Manish Y. Efficacy of Citicolline in Treatment of Amblyopia as an Adjunct to Patching. JOJ Ophthal.
2018; 7(2): 555706. DOI: 10.19080/JOJO.2018.07.555706
Aim: To study the effectiveness of the addition of citicoline to patching in the treatment of amblyopia in the age group of 4-12 years.
Materials and Methods: A randomized controlled trial, which included 30 patients who were randomly divided into two groups. Both the groups received patching therapy for 6 months or till plateau was reached. Then in phase 2, group I received citicoline plus patching and group II continued to receive only patching.
Outcome measures:Outcome was measured by the visual acuity using snellens chart every month till 6 months when citicolline was added to one group and the visual acuity was recorded 2 monthly.
Results: No significant difference was found in the mean visual acuities in these two groups in first 6 months or till plateau was reached. After starting citicolline in one group for the initial two months, there was no significant difference in the visual acuities in these two groups, at the respective intervals. However, four months onward, up to 12 months, there was a significant difference in the visual acuities in these groups. The result was the same in younger patients (< eight years of age) as well as in older patients (> eight years of age). After starting citicolline the improvement in group I was significantly more than that in group II, at two months and onward, at the respective intervals.
Conclusion: The improvement in visual acuity with citicoline plus patching was significantly more than that with patching alone.
Amblyopia is the most common cause of monocular visual impairment in children, young, and middle-aged adults . There is a consensus that amblyopia can be effectively treated in young children [2-4]. Although there has been, in the past, a general belief that treatment beyond a certain age is ineffective, it has been conclusively proved that ‘age’ is no bar, for the success of the treatment of anisometropic amblyopia . Some believe that a treatment response is unlikely after the age of six or seven years, while others consider the age of nine or ten years to be the upper age limit for successful treatment [6-10]. However, there are many studies involving older children and adults with amblyopia, responding to treatment with patching [11-24].
Occlusion therapy with patching of the sound eye has been the conventional treatment. However, there are many studies stating the effectiveness of some pharmacological agents in the treatment of amblyopia - citicoline is one of them [25,26].
Citicoline (cytidine-5-diphosphocholine) activates the biosynthesis of structural phospholipids in the neuronal cell membranes, which results in increased levels of neurotransmitters, and thus, has neuroprotective effects . It has also been shown to improve the learning and memory
performance. There are few animal studies that have reported the enhancement of dopaminergic neurotransmission in the brain with citicoline (exogenous cytidine-5′-diphosphocholine). A study aimed at determining whether citicoline (50 mg/kg., twice daily) could influence retinal catecholamine levels in adult male Albino rabbits, has reported that, compared to vehicle-treated controls, citicoline-treated animals displayed a significantly higher retinal dopamine concentration and a tendency toward an increase in adrenaline concentration, while the noradrenaline concentration remained unchanged .
B. Cover test/uncover test for the amount of squint and type of squint, added vertical or oblique deviation
C. Alternate cover test
D. Extraocular movements
E. Prism cover test
F. Forced duction test as per the case, local or general
G. Direct ophthalmocopy for eccentric fixation in
H. Observation of result on initial patching therapy in
I. Color vision testing.
Following this, the patching therapy was started in both
groups. The patients were followed at one month intervals and
visual acuity was recorded. If there was no improvement in the
visual acuity for three consecutive followups, then a plateau
was considered. It was approximately corresponding to the
maximum correction that could be achieved with patching. Once
a plateau was achieved, second part of study was started.
Group I received citicoline in addition to continued patching.
The doses of citicoline were 250 mg BD (for patients below five
years) and 500 mg BD (for patients above five years). Group II
continued to receive only patching. Dosage was continued for 45
days then gap of 15 days and then 2 more such cycles. Visual
acuity was calculated at 2 monthly interval.
No significant difference was found in the mean visual
acuities in these two groups in first 6 months or till plateau was
reached. After starting citicolline in one group for the initial two
months, there was no significant difference in the visual acuities
in these two groups, at the respective intervals. However,
four months onward, up to 12 months, there was a significant
difference in the visual acuities in these groups. The result was
the same in younger patients (< eight years of age) as well as
in older patients (> eight years of age). After starting citicolline
the improvement in group I was significantly more than that in
group II, at two months and onward, at the respective intervals.
Drawbacks of study include not being a double blind trial
and having just 30 patients. The present multicentric study
was carried out to find out the effectiveness of the addition of
citicoline to the conventional patching therapy for the treatment
of amblyopia. This study has suggested that addition of citicoline,
even after maximum improvement with conventional patching
was achieved, can further improve the visual acuity.
Citicoline primarily acts by increasing the synthesis
of phosphatidylcholine, the primary neuronal membrane
phospholipid, thus enhancing the production of acetylcholine.
Oral citicoline administration increases the plasma levels
of choline and cytidine, the building blocks used to restore
neuronal membrane integrity . It is also postulated that
citicoline facilitates the preservation of sphingomyelin, which
promotes signal transduction in nerve cells .
Citicoline may significantly impact the brain-remodeling
activity. A study in rats has shown that citicoline treatment
significantly increases the length and branch points of the
dendrites, increasing the overall surface area occupied by
neurons, which leads to an increased efficiency of sensory
information processing. This mechanism of activity may
potentially account for a significant portion of citicoline’s
neurorestorative functions .