Photodynamic therapy and chronic CSC

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Photodynamic therapy has been found to reduce subretinal fluid and increase visual acuity for patients with central serous chorioretinopathy.

Dr. Lim

By Michelle Dalton, ELS; Reviewed by Jennifer I. Lim, MD

CHICAGO-A retrospective study conducted by the Macula Society has found that photodynamic therapy (PDT) for patients with central serous chorioretinopathy (CSC) significantly reduced subretinal fluid while improving visual acuity in about half, according to Jennifer I. Lim, MD.

Untreated CSC can cause visual impairment with symptoms of metamorphopsia and micropsia. Most cases resolve spontaneously, but some last for well over 6 months, said Dr. Lim, professor of ophthalmology and the Marion H. Schenk, Esq., Chair in Ophthalmology for Research of the Aging Eye, director of the retina service at Illinois Eye and Ear Infirmary, University of Illinois, Chicago, and spearhead of the Macula Society study.

CSC is usually unilateral, but recurrence rates can run as high as 50%, research has shown.

Debate is ongoing about which treatment regimen is optimal, but close observation seems to be preferred in cases of acute CSC (which is likely to resolve spontaneously), and focal photocoagulation if the lesion is focal and extrafoveal, Dr. Lim explained.

PDT has shown promising results in cases where the leak is foveal or the pattern is more diffuse.

Dr. Lim’s group sought to assess the clinical utility of PDT and surveyed all Macula Society members.

About the study

The 37 Macula Society respondents represented 11 countries and 237 patients (265 eyes) with CSC: 176 (74%) of the patients were male; mean age of all patients was 52 years. The majority of patients (69%) were Caucasian, with Asians representing 18%, and Hispanics 12%. Thirty patients (13%) had a history of systemic steroid use.

PDT-fluence was normal in 49%, half in 46%, other in 3%, Dr. Lim said, with 94% having treatment duration of 83 seconds (with 5% at 40 seconds).

The majority of patients (89%) underwent one PDT session, and 86% had one treatment spot. Indocyanine green angiography guidance was followed in 51% of the cases, Dr. Lim reported.

Follow-up ranged from 1 month to more than 1 year, but the mean follow up was 15 weeks (98%). At baseline, mean visual acuity (logMAR) was 0.39 (or about 20/50).

“Post-PDT VA was strongly correlated to the patient’s baseline VA,” Dr. Lim said. “At the last post-PDT visit, VA improved more than 2 lines in 26% of those with baseline VA of 20/32 or better, in 55% of those with baseline VA of 20/40 to 20/80, and in 59% of eyes with baseline VA of 20/100 or worse.”

Vision improved more than 3 lines in less than 1%, 29%, and 48% of eyes with baseline VA 20/32 or better, 20/40 to 20/80 and 20/100 or worse, respectively, she said.

“These were eyes with chronic disease,” Dr. Lim said. “There may have been some irreversible photoreceptor damage,” she said. “There is also a ceiling effect. Eyes with better vision do not have as much room for gaining lines of vision as those that are, for example, 20/200.”

Overall, only 18 eyes (7%) lost 3 or more lines of vision, but none from geographic atrophy.

Subretinal fluid resolved in 75% of patients after the first visit, and in 81% by the last post-PDT visit, Dr. Lim said.

“The subretinal fluid resolution was maintained over time,” she said.

Overall, OCT changes were more than 25 μm in 68% to 86% of eyes.

A multivariate analysis showed no differences in response for age, race, fluence, fluorescein angiography leakage type, steroid use, ICG guidance, or fluid location.

Lastly, complications were uncommon, Dr. Lim said, with only 4% having retinal pigment epithelium atrophy and only 2% having an acute visual decrease.

In eyes with CSC, Dr. Lim explained that VA is more important than anatomy when considering re-treating, but she added that “if the VA is still down and there is leakage, I would re-treat, but I’d wait 3 months between PDT treatments.”

Jennifer I. Lim, MD

The Macula Soceity received an unrestricted grant from QLT for this study. Dr. Lim does not have any financial interests to report (and was not a recipient of the grant funding).

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