Hyperreflective Ganglion Cell Layer Bands Reveal Retinitis Pigementosa Function

A hyperreflective ganglion cell layer band (HGB) is associated with  poor visual outcomes  in patients with retinitis pigmentosa (RP), according to a retrospective study published in Retina. This spectral domain optical coherence tomography (OCT) finding is detectable in approximately 25% of eyes with RP, according to the report. 

Retinitis pigmentosa is a rare ocular disease that causes progressive degenerative changes to the retina. These microstructural changes are not well understood. Therefore, the study authors sought to characterize HGB as a feature of RP. The researchers used OCT to evaluate 144 eyes from 77 patients (54.5% were women) with RP and 74 eyes from 37 matched healthy controls. The study defined HGBs as continuous hyperreflective bands within the thickness of the ganglion cell layer (GCL).

The estimated prevalence of HGB in patients with retinitis pigmentosa was 25.3% (95% CI, 18.7-33.0; P <.001) with bilateral presentation in 23.4% of patients and unilateral presentation in 3.9% of patients. Hyperreflective ganglion cell layer bands were not detected at all in the study’s healthy control participants. Patients with HGB tended to have worse best-corrected visual acuity (BCVA) compared with patients without HGB (20/50 Snellen equivalent vs 20/32 Snellen equivalent; P <.001). No correlation was identified between HGB and pathogenetic mutations.

These findings support the identification of hyperreflective ganglion cell layer bands as a new feature sign of RP. There are several morphogenetic hypotheses that may explain this relationship. The study authors suggest that neurite sprouting from the inner retina, astrocyte gliosis, or microvascular changes of the superficial capillary plexus as possible pathogenic mechanisms. They  also emphasize the role genetics may play in pathogenesis.

“Reactive gliosis of the aforementioned perivascular astrocytes of the GCL seems the most reasonable hypothesis to explain the morphological aspect of HGB,” the researchers explain. “We hypothesize that the changes resulting in the manifestation of HGB on OCT may be attributed to specific genetic influences. Patients carrying more severe genetic alterations may experience deeper cell degeneration and transformation.”

Study limitations include its retrospective and cross-sectional design and limited sample size.