The lamina cribrosa (LC), acutely vulnerable in glaucoma, is also impacted by central nervous system diseases affecting the optic nerve like Parkinson’s and multiple sclerosis (MS).
A recent study used OCT to evaluate thickness of the LC in patients with MS and the effect of optic neuritis (ON) attacks on these measurements in the remission period. The team found that LC measurements may be important for early detection of optic nerve damage in MS patients.
The study included 20 patients diagnosed with relapsing-remitting MS with a history of ON attacks affecting one eye and in remission of MS and ON attacks for at least three months. It also included 28 randomly selected healthy control eyes, matched for age and sex.
Eyes in the MS group that were affected by ON attacks were assigned to group 1 (MS+ON) and fellow eyes unaffected by ON were assigned to group 2 (MS-ON). Healthy control eyes comprised group 3. All patients underwent OCT.
The researchers found that mean LC thickness in the MS+ON and MS-ON groups was significantly lower than in the control group. There was no significant difference in mean LC thickness between the MS+ON and MS-ON groups. The two MS groups also had statistically significantly lower mean peripapillary RNFL thickness than the control group.
“It’s noteworthy that LC is significantly affected in eyes with MS who haven’t had a history of ON attack,” the researchers wrote in their paper. “This region is essential to provide the integrity of the retinal nerve fibers. Increased IOP is thought to disrupt LC hemodynamics due to its mechanical effect on microcirculation in LC.”
“We investigated the ON attack’s effect on these measurements and revealed that LC [and peripapillary RNFL were] significantly thinner in the MS eyes affected and unaffected by ON attacks than the healthy controls,” they wrote. They concluded that more studies need to be conducted on larger populations with longer follow-up periods to measure LC and peripapillary RNFL thickness before and after ON attacks. “More homogeneous groups in terms of MS subtypes may help to reach a better understanding of the role of LC structure in ON attacks in cases of MS,” they added.
Balci S, Beyza Yildiz M, Özçelik Köse A, et al. Optic nerve head changes in patients with optic neuritis secondary to multiple sclerosis: a comparison of the affected and fellow healthy eyes. Medeni Med J. 2020;35:330-7.