Assessment of Retinal Side Effects of Fingolimod (Gilenya) Used in Treatment of Multiple Sclerosis Patients
Hala Kamal Hassan Elshahed, Abd El Rahman Gaber Salman, Thanaa Helmy Mohammed, Dina Abdelgawad Zamzam, Randa Hesham Ali Abdelgawad- General Medicine
Background
Multiple sclerosis is an inflammatory demyelinating disease that affects CNS. It is thought that multiple factors were implicated in the pathology of MS such as immunological factors, vitamin d deficiency, vitamin b12 deficiency or infection by EBV or HHV6. It has a lot of ocular manifestations as optic neuritis, diplopia, oscillopsia, nystagmus and ophthalmoplegia. Fingolimod is the first approved oral drug for RRMS. Macular edema was reported as a side effect of fingolimod after 4 months of use.
Aim of the Work
The objectives of the study are screening of retinal side effects of fingolimod used for treatment of relapsing remitting multiple sclerosis patients having no previous ophthalmic complains before starting the treatment. To assess structural changes within the retina using SD-OCT and to correlate these structural changes with the function affection (visual acuity assessment and electrophysiological studies).
Patients and Methods
Thirty eyes of fifteen patients were included in this prospective one arm clinical trial study. These thirty eyes belonged to multiple sclerosis patients who will be candidate for treatment with fingolimod (Gilenya). Patients were recruited from MS unit, neurology department, Ain Shams University.
Results
We found that the mean best corrected visual acuity change after treatment slightly decreased but this was non-significant. IOP measurements were not changed after treatment. Despite the changes in visual acuity; fingolimod associated macular edema did not develop. Among 15 patients (30 eyes), 14 eyes have slightly increased MT, 5 eyes have stable MT and 11 eyes have slightly decreased MT. Regarding electrophysiology follow up there were significant change in P1 amplitude in MfERG in ring 1, and it happened without development of macular edema (ME), as 50% of patients had MfERG changes in spite of the absence of ME. So we recommend doing electrophysiological test (MfERG) in follow up protocol of fingolimod treatment.
Conclusion
Finglimod is an immunomodulatory drug used for treatment of RRMS, it is the first oral drug approved by FDA for MS. Fingolimod associated macular edema is a known complication with a low incidence. Patients on fingolimod should have baseline and 3 to 4 months ophthalmic examination as a part of their protocol OCT is non-invasive technique used for detection of macular edema and follow up, but in our study we found that after 4 months of treatment by fingolimod, affection of retinal function in same patients may happen before macular edema development, which spots the light on the importance of performing the mfERG as well in the follow up of patients who were treated with fingolimod. Further studies are needed to support our results.