Blood-brain-barrier therapy for CNS tumors may have lasting effect on vision

Reuters Health - 10/12/2020 - Osmotic blood-brain-barrier disruption (BBBD) therapy, which increases the penetration of chemotherapeutics into malignant tumors of the central nervous system (CNS), may also affect sight, researchers say.

"Osmotic blood-brain-barrier disruption for CNS tumors causes a dose-dependent maculopathy that can affect vision and progress over years even after cessation of therapy," Dr. Phoebe Lin of Oregon Health and Science University, in Portland, told Reuters Health by email. "Thus, patients undergoing treatment with this modality should be counseled and screened at baseline and at yearly intervals."

Pigmentary maculopathy was first described in the 1980s in patients with primary CNS lymphoma treated with BBBD and chemotherapy, Dr. Lin and her colleagues note in JAMA Ophthalmology.

Subsequent work showed that this particular maculopathy was seen only in such patients, they add. There have been no reports of such findings beyond those associated with primary CNS lymphoma.

To investigate whether pigmentary maculopathy was also seen in patients with other malignant CNS tumors, the researchers retrospectively reviewed data on 283 patients with a mean age of 46 years who were treated with BBBD and chemotherapy. As well as primary CNS lymphoma, studied patients included those with glioma, pineal tumor and other morbidities including primitive neuroectodermal tumors.

Of the 68 who had a documented ophthalmoscopic examination and/or retinal imaging after the start of BBBD therapy, 65 met inclusion criteria. Thirty-two of these patients had pigmentary maculopathy, a proportion similar to that reported in patients with primary CNS lymphoma.

Maculopathy development was not associated with age, cancer type, or the systemic-chemotherapy agent. However, the number of BBBD sessions had a significant association (odds ratio, 1.30), suggesting a dose-dependent effect.

A post-therapy progression analysis involving eight patients who had two or more visits with retinal imaging after their last BBBD therapy date showed that macular changes were common. Progressive enlargement of geographic atrophy was seen in five eyes of three patients, and choroidal neovascularization developed in one eye of another patient.

The researchers caution that "the lack of uniform follow-up makes it difficult to draw definite conclusions about the timeline of structural changes. The relatively high mortality rate of the conditions treated with BBBD therapy also limits follow-up."

However, they propose that "patients undergo a baseline ophthalmic examination before the start of BBBD therapy, as well as yearly ophthalmic examinations during and after systemic treatment with retinal imaging if a pigmentary maculopathy or retinal pigment epithelium atrophy is detected."

SOURCE: https://bit.ly/33YTu4u JAMA Ophthalmology, online December 3, 2020.

By David Douglas



Posted on 10 December, 202015 December, 2020