![]() Although SD-OCT (A) is useful in detecting myopic CNV in most cases, SS-OCT (B) can more clearly detect CNV and subtle subretinal fluid, and better image the choroid. 9 Early-phase ICGA provides information regarding choroidal circulation, and late-phase ICGA is useful for visualizing lacquer crack formation, which is responsible for the development of myopic CNV in many cases. A relatively thicker sclera and a thinner choroid are some biological indicators for myopic CNV on SS-OCT. SS-OCT uses longer wavelengths and can penetrate deeper into the posterior segment structures. When the activity of myopic CNV is uncertain, with minimal subretinal fluid on SD-OCT, SS-OCT may be helpful for the detection of very small CNV and subtle fluid (Figure 2). However, because FA is an invasive diagnostic exam with potential side effects, SD-OCT is commonly used during follow-ups (or even for initial diagnosis) since it is a non-invasive technique for assessing the activity of the myopic CNV.Īctive myopic CNV often reveals a dome-shaped hyperreflective elevation above the RPE, accompanied by subretinal fluid. FA reveals hyperfluorescence in the early phase and dye leakage in the later phases, based on the CNV activity. Among these, FA conventionally has been the gold standard, particularly for the initial diagnosis of CNV. The diagnosis can be confirmed using several imaging techniques, including fluorescein angiography, indocyanine green angiography, spectral-domain optical coherence tomography, swept-source OCT and OCT angiography. On examination, the CNV lesion often manifests as a light-colored lesion with a dark, hyperpigmented rim, with or without subretinal hemorrhage, and sometimes exudates (Figure 1). ![]() ![]() Asterisks indicate choroid (blue), sclera (red), and orbital fat (yellow). (E) Swept-source optical coherence tomography shows a dome-shaped hyper-reflective lesion with subretinal fluid (white arrow). (D) Late-phase indocyanine angiography revealing lacquer cracks, a known risk factor for myopic CNV (arrows). (C) Early-phase indocyanine green angiography revealing CNV (arrow). (B) Fluorescein angiography showing leakage (arrow). (A) Myopic choroidal neovascularization with hemorrhage (arrow). A 65-year-old female presented with a visual acuity of 20/30. 7 Incidence of myopic CNV is higher in eyes with lacquer cracks (29 percent) than in eyes with other types of myopic maculopathy. Ocular risk factors include lacquer cracks (fissures in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex), choroidal thinning, impaired choroidal circulation and patchy retinal atrophy in the posterior pole. 6 Patients with myopic CNV present with metamorphopsia (distortion of vision) and/or visual impairment similar to those with age-related macular degeneration. 5 It affects 5 to 11 percent of patients with pathologic myopia and is bilateral in approximately 15 percent. Myopic CNV is one of the most common vision-threatening complications in patients with pathologic myopia. In the following sections, we’ll delve into each of the vision-threatening conditions that are known to occur in eyes with pathologic myopia, including myopic choroidal neovascularization, myopic subretinal hemorrhage, myopic choroidal atrophy, dome-shaped macula, posterior staphyloma, myopic traction maculopathy and macular hole retinal detachment. 4 Although the cut-off values of the refractive error and axial length aren’t specified in the definition, pathologic myopia is usually associated with high myopia. ![]() Pathologic myopia (myopic degeneration) is defined as the presence of structural changes in the posterior segment owing to an increased axial elongation. In this article, we’ll detail the most effective way to diagnose and manage a patient with this condition. 1 (High myopia is generally defined as a refractive error of more than -6 D or an axial length longer than 26 or 26.5 mm, although some studies define high myopia as a refractive error of at least -5 D.) 2,3 In addition to the obvious vision difficulties posed by myopia, high myopia can also be associated with the vision-threatening ocular structural changes of pathologic myopia. Nearly half of the world’s population is predicted to suffer from myopia by 2050, with 10 percent of the population being high myopes.
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