Peripapillary Intrachoroidal Cavitation Is A Type of Suprachoroidal Detachment

Study sheds new light on peripapillary complications of high myopia, establishing a link between tilted disc and peripapillary staphyloma as critical factors for PICC emergence.

Researchers observed constant alignment of peripapillary intrachoroidal cavitation (PICC) with the subarachnoid space (SAS), suggesting PICC is a suprachoroidal detachment (SCD), in high myopia, according to a study published in Clinical Ophthalmology.

Ehongo and colleagues conducted a prospective non-interventional, cross-sectional study comparing the peripapillary polar characteristics in eyes combining peripapillary staphyloma and gamma peripapillary atrophy according to the presence or absence (combination group) of PICC.

The study included 667 eyes of 334 patients with high myopia. Using optical coherence tomography (OCT) sections from the polar peripapillary regions to the opening of Bruch’s membrane, the researchers analyzed the configuration of the posterior curvature of the choroid, visibility of the SAS, and SCD as well their topographic relationships. 

We suggest that the tensile forces of the optic nerve sheaths during adduction promote the collapse of the scleral flange onto the SAS, leading to PICC.

The team found protrusion of the posterior choroidal wall, with anterior elevation on either side, in both groups that progressed and transformed into a wedge-shaped deformity on the side of gamma peripapillary atrophy. They found that this wedge-shaped deformity was significantly more frequent in the PICC group than in the combination group for both the upper and lower poles (P =.004 and P <.001; respectively). 

The team also observed the SAS more frequently in the PICC group than in the combination group for both the upper and lower poles (P =.002 and P <.001, respectively) and detected SCD only in the PICC group (P <.001, for both poles). In these patients, the wedge-shaped deformity and SCD were aligned antero-posteriorly with the SAS.

“This study shed new light on 3 peripapillary complications of high myopia, allowing us to establish a link between [tilted disc] and [peripapillary staphyloma] as critical factors for the PICC emergence, to define the PICC and to suggest a hypothesis of mechanical development of PICC,” the researchers concluded. “We suggest that the tensile forces of the optic nerve sheaths during adduction promote the collapse of the scleral flange onto the SAS, leading to PICC. Further studies are warranted to confirm this hypothesis.”

Limitations of the study included limited sharpness in OCT images due to artifacts observed in elongated myopic eyes, inability to assess the impact of meningeal traction intensity and scleral resistance, and inability to limit papillary rotation to the vertical axis, as the optic nerve is directed forwards, outward and downward during adduction.

References:

Ehongo A, Bacq N, Kisma N, et al. Analysis of peripapillary intrachoroidal cavitation and myopic peripapillary distortions in polar regions by optical coherence tomography. Clin Ophthalmol. 2022;16(8):2617-2629. doi:10.2147/OPTH.S376597