High myopia is frequently associated with retinal degenerative changes (such as myopic foveoschisis, macular hole and its related retinal detachment, and choroidal neovascularization) which are the major causes of visual loss in high myopic eyes. Optical coherence tomography may help us to understand the macular lesions in high myopia. Peeling of internal limiting membrane and removal of posterior vitreous cortex at an appropriate time, are believed to facilitate restoring the retinal flexibility and resolution of myopic foveoschisis, and promote the macular hole closure and retinal reattachment. Antiangiogenesis treatment combined with photodynamic therapy and (or) corticosteroid therapy are the future options to treat myopic choroidal neovascularization. Correctly understanding and mastering the methods and timing of diagnosis and treatment of high myopiarelated macular degeneration, and taking targeted interventions to enable patients to be rational and effective treated, are the keys to further reduce the damage of visual function in patients with high myopia.
Myopic choroidal neovascularization (MCNV) is one of the main reasons of vision loss in working population in Asia, which has brought economical and social-psychological burdens with high incidence in China, The precise pathogenesis of MCNV is unclear. Metamorphosia is the main reported symptom in these patients. The lesions were usually with smaller area, less leakage and relatively slow progression. Currently, intravitreal anti-vascular endothelial growth factor agents are now the established standard of care for MCNV, which was a major breakthrough in the treatment of MCNV achieving visual acuity improvement. Since the natural history, clinical features and therapy response of this disease is significant different from that in choroidal neovascularization secondary to age-related macular degeneration, the treatment dosing, frequency, retreatment criteria and the follow-up interval should been considerately. Facing the myopia boom in China, there is a need for the development of a precise definition and a more detailed classification for pathogenic myopia, optimize the outcome assessment and follow-up strategy, which should benefit to the further basically and clinical studies.
Optical coherence tomography angiography (OCTA) is an noninvasive, rapid and reproducible technology which can provide high resolution view of the vascular structures and quantifies the vessel densities in retina and choroid. Myopia can be divided into simple myopia and pathologic myopia. The mechanism of myopia is not clear while it is closely related to the vessel density. For simple myopia, OCTA can monitor the course and deepen the understanding of myopia by quantifying the vessel densities in each layers and sectors and the foveal avascular zone. For pathologic myopia, OCTA has an advantage of observing the choroidal neovascularization, chorioretinal atrophy and Zinn-Haller arterial circle which can contribute to the early diagnosis and management and follow-up to estimate the prognosis. However, there are several limitations of OCTA which need to be improved, including in the process of acquiring high-quality images, accurate layering and dynamic observation.
ObjectiveTo analyze the diagnostic value of multicolor scanning laser imaging (confocal scanning laser ophthalmoscopy, cSLO) combined with swept-source optical coherence tomography (SS-OCT) for lacquer cracks (LC) and myopia stretch lines (MSL) of pathological myopia.MethodsA observational study. A total of 83 eyes of 58 patients with pathological myopia were recruited from May 2017 to January 2018 in Department of Ophthalmology of The First People’s Hospital Affiliated to Shanghai Jiao Tong University. Among 58 patients, 20 were males (30 eyes) and 38 were females (53 eyes). The mean age was 50.65±12.02 (range from 24 to 70) years old; the average BCVA was 0.37±0.32; the average diopter was −11.38±4.96 D; and the average axial length was 28.91±2.15 mm. All participants underwent FFA and ICGA examination to obtain FFA, ICGA, infrared light reflection (IR) and autofluorescence (AF) images. SS-OCT was applied for scanning macular and optic disc at 9 mm × 9 mm range. cSLO was performed with macular as the center. All images were inspected carefully by three independent observers and the consistency test was detect. LC were diagnosed as hyperreflective line in FFA and hypofluorescent linear lesions in late ICGA. MSL were defined as both hypofluorescent linear lesions in FFA and late ICGA. The accuracy of each inspection item in the diagnosis of LC was detected. The optimal technique was applied with SS-OCT to further explore the detection rate of LC.ResultsThe intra-observer reproducibility was good to excellent for all measurements (Kappa=0.938, P＜0.01). The positive detection rate of LC and MSL was highest in the standard images of cSLO (77.1%), followed by SS-OCT red free (73.1%), fundus photography (72.3%), IR (72.3%) and AF (49.4%). The cSLO was optimal in the test consistency (Kappa=0.520, P＜0.01) and accuracy (the area under the receiver operating characteristic was 0.750). SS-OCT and cSLO were jointly applied to diagnosis of LC and MSL in high myopia. The positive detection rate of LC, MSL and LC+MSL were 91.7%, 91.2% and 93.3% respectively. The characteristics of LC in SS-OCT were irregularities and discontinuous of the RPE-Bruch membrane line, discontinuous inner ellipsoid zone, thinner choroid, an increased light penetrance into deeper tissues, and RPE fracture in severe cases. MSL was mainly manifested as RPE clumps, visible large choroidal vessels protruding and pushing the overlying RPE toward the vitreous.ConclusionsThe diagnosis rate of LC in pathological myopia by cSLO is 77.1%. The standard images of cSLO combined with SS-OCT can diagnose LC, MSL and LC+MSL at rates of 91.7%, 91.2% and 93.3% respectively.