Understanding the Pathology and Current Treatment Strategy of Highly Myopic Complications.

The population of high myopia in Japan is large and increasing. It is a high risk factor not only for its specific macular complications but also as a precursor for cataracts and glaucoma. Myopic foveoschisis and the consequent macular hole with retinal detachment (MHRD) are caused by inner retinal traction which may include the vitreous cortex, epiretinal membrane, internal limiting membrane and posterior staphyloma formation. Vitrectomy is the 1st choice of treatment, and releasing the retina from traction is the goal. MHRD has poor anatomical success rates, and, therefore, inverted internal limiting membrane is a common treatment procedure to enhance MH closure. Myopic choroidal neovascularization occurs predominantly in highly myopic eyes, and anti-vascular endothelial growth factor therapy is the 1st line treatment. Normally the patient's eyes respond well, however, recurrence is an important issue. Conventional optical coherence tomography (OCT) and fluorescein angiography are the major diagnostic tools. At the same time, advanced technologies such as OCT-angiography and Polarization-sensitive OCT may enable an early and more accurate diagnosis. High myopia is a high risk factor for glaucoma and its mechanism is still uncertain. Studies using OCT thus far have shown variety of abnormalities occurring in highly myopic eyes inside and around the optic nerve head. High myopia has uncommon progression patterns such as preceding the papillo-macular bundle damage, especially in younger patients. Future studies are needed.