Hyperreflective Dots Signal Outer Retinal Degeneration in RRD

Hyperreflective dots in the outer retina found on baseline optical coherence tomography (OCT) imaging in patients with rhegmatogenous retinal detachment (RRD) may be evidence of outer retinal degeneration, according to data published in Ophthalmology Retina. The research shows long-standing and extensive RRDs are more likely to develop in patients after hyperreflective dots were identified.

A number of reports have suggested that inflammation is an inherent element in rhegmatogenous retinal detachment (RRD). Investigators of this study say, after evaluating patients with fovea-involving detachments, that the hyperreflective dot findings are particularly correlated with specific preoperative factors such as morphologic stage and extent of detachment, as well as postoperative cystoid macular edema (CME), affirming inflammatory aspects of RRD.

The investigation analyzed records for 351 consecutive patients with RRD and gradable OCT foveal images at baseline, treated at a tertiary retina center in Canada from January 2012 to September 2022. Morphologic stages were separated into 5 levels — a majority presented stage 3b RRD; appearance of high-amplitude outer retinal corrugations.

Outer retinal hyperreflective dots showed significant associations with higher baseline stage, increased height of detachment, longer duration of central vision loss, larger clock-hour extent of RRD, and reduced condition of foveal photoreceptors (all P <.001). Preoperative dots did not have a connection to post-surgery re-detachments during a 1-year period.

Postoperatively — excluding those with vision-interfering cataracts — individuals with hyperreflective dots exhibited worse best corrected visual acuity (BCVA) at 3, 6, and 12 months compared to those without this sign (all P <.001). Hyperreflective dots did not express a relationship with postoperative epiretinal membrane incidence or severity, but they were significantly linked to CME at 3 and 6 months.

“Given that this is a non-infectious state, the inflammatory component of RRD has been hypothesized to be a result of the photoreceptors being in an anoxic and dysregulated state, which starts immediately after the detachment,” the researchers explain.

Previous studies have shown subretinal microglia accumulation as soon as 24 hours after a detachment. Also, prior research has found off-white spots on outer retinal layers may involve combinations of macrophages and degenerated photoreceptors.

Study limitations comprise lack of detailed information on specific number or severity of hyperreflective dots which are not typically recorded at this center, and no data for later stubborn vs resolving dots — potentially difficult to image with OCT postoperatively. Conversely, this analysis offers new statistics toward using hyperreflective dots to cue treatment urgency.