A recent study has directly visualized the structural changes caused by radiation therapy in two groups of patients according to the location of their ocular lymphoma. The researchers noted that higher radiation energy and dose are required in deeply placed and large tumors. They found dry eye symptoms were most severe right after radiation therapy in both groups, but the researchers noted a gradual resolution in most patients with conjunctival lymphoma, whereas symptoms persisted in orbital-type lymphoma patients (i.e., orbit, lacrimal gland and lacrimal sac).

The study examined 64 eyes with ocular adnexal mucosa-associated lymphoid tissue lymphoma affecting the conjunctiva, orbit, lacrimal gland or lacrimal sac and separated them into the two groups based on the location. The team found a statistically significant increase in meiboscore in both groups, although the increase in the score was significantly greater in the orbital-type lymphoma group than in the conjunctival lymphoma group.

The researchers also noted that changes in ocular surface disease index (OSDI) score, tear film break-up time (TBUT), corneal fluorescein staining score and lid margin abnormality score after treatment were significantly different across the two groups.

After radiation therapy, the study found more morphological damage in the meibomian glands in orbital-type lymphoma, inducing more severe dry eye. The researchers suggested that practitioners should inform patients of post-treatment persistent dry eye that may not be easily curable, as many orbital-type lymphoma patients will have some degree of injury to the meibomian glands. Doctors should strongly consider an examination of the meibomian glands in these patients.