Intrachoroidal cavitation in myopic eyes.

PURPOSE

To determine the incidence and characteristics of intrachoroidal cavitation (ICC) in the eyes with high myopia.

METHODS

In this retrospective, non-interventional, comparative study, we analysed the case records of 108 eyes with and without pathological myopia (PM). PM was defined as having a refractive error (spherical equivalent) of ≥ - 6.0 D or axial length ≥ 26 mm. The presence of other features like posterior vitreous detachment, myopic traction maculopathy, posterior staphyloma, focal/patchy chorioretinal atrophy (CRA), choroidal neovascularisation and retinoschisis was looked for on OCT. The association of these features with ICC was analysed using statistical tests.

RESULTS

In this study, 38 out of 68 eyes with PM and 4 out of 40 eyes with non-PM showed the bowing of the posterior sclera and the presence of ICC. On statistical analysis with Chi-square test and multiple variable linear regression analysis tests, it was identified that the presence of focal/patchy CRA (p = 0.005) and intrascleral vessels (p = 0.018) in and around the cavitation was important features noted in eyes with ICC. The OCT features of macular and peripapillary ICC were similar. The transudation of fluid from the dilated intrascleral vessels in and around the ICC could be one other mechanism responsible for the development of ICC.

CONCLUSION

ICC is seen in 55.8% of highly myopic eyes with the presence of focal CRA or myopic conus and/or presence of intrascleral vessels near the cavitation. These findings suggest that patchy atrophy affects the scleral contour within posterior staphyloma beyond the funduscopically identified patchy atrophy by ICC. The presence of intrascleral vessels could also contribute to the ICC development. Eyes with patchy CRA or myopic conus needs to be checked on further follow-up visits for the development of macular or peripapillary ICC.