Is it Myopia or Glaucoma? Clinical Tools to Identify the Disease

青光眼是一种慢性进行性眼病，以视网膜神经节细胞损伤为特征，表现为视盘的典型外观和视野丧失。它是世界上造成不可逆转失明的第二大常见原因。2013年，青光眼患者总数估计为6400万，预计到2020年将增加到8000万。近视是指远处的物体看起来模糊。当光线聚焦在视网膜前，通常与眼轴长度超过标准有关时，就会发生近视。全球近视患病率正在迅速增加，从2010年的约14亿人增加到2050年的约50亿人。患有近视的人患青光眼的可能性是没有近视的人的2.5倍。然而，临床面临的挑战是近视视神经头类似于视盘青光眼损伤，这使得近视青光眼的诊断变得困难。同时视盘近视可能被误诊为青光眼，甚至造成健康近视患者青光眼的过度诊断和过度治疗。本研究的目的是准确区分近视伴青光眼和不伴青光眼。我们假设，通过光学相干断层扫描（OCT）和OCT血管造影（OCTA）识别的近视视盘的独特特征可以用来区分患有和不患有青光眼的近视。OCT和OCTA是常规眼科检查中广泛使用的两种视网膜成像方式，被认为是青光眼和其他视网膜疾病治疗的标准。OCT用于可视化和测量视网膜的不同层，而OCTA显示脉络膜和视网膜血管。乳头旁萎缩区是视盘周围的绒毛膜视网膜萎缩区，OCT可将其分为-α区、-β区和-γ区等亚型，但临床检查未将其区分。最近的研究表明，瞳孔旁萎缩带-β与近视和青光眼的相关性更强，而瞳孔旁萎缩带-γ与近视而非青光眼的相关性更强。我们假设，视盘倾斜、卵形指数、中央凹到视盘的角度和距离、视神经头脉络膜厚度和OCTA测量等OCT参数可以用来区分近视合并青光眼和近视无青光眼。如果我们的假设是正确的，这些OCT和OCTA参数可以用于开发临床决策支持算法，以提高近视患者青光眼的检测。最后，这些新的临床决策支持工具将有助于预防近视患者青光眼引起的功能损害和失明，另一方面有助于预防健康近视患者的过度诊断和过度治疗，提高生活质量，降低过度治疗导致的医疗费用。

Glaucoma is a chronic, progressive eye disease, characterized by retinal ganglion cell damage, which presents with a pathognomonic appearance of the optic disc and visual field loss. It is the second most common cause of irreversible blindness worldwide. The total number of people with glaucoma was estimated to be 64 million in 2013 and is expected to increase to 80 million by 2020.Myopia or nearsightedness is a condition where distant objects appear blurry. Myopia occurs when light is focused anterior to the retina and is usually associated with axial length above the norm. The prevalence of myopia is rapidly increasing from ~1.4 billion worldwide in 2010, to an estimated 5 billion by 2050.Individuals with myopia are 2.5 times more likely to have glaucoma than those without myopia. However, the clinical challenge is that the myopic optic nerve head mimics glaucomatous damage to the optic disc, which makes it difficult to diagnose glaucoma in myopes. At the same time a myopic optic disc may mistakenly be interpreted as glaucoma and even result in overdiagnosis and overtreatment of glaucoma in healthy myopes.The objective of this study is to differentiate accurately between myopia with and without glaucoma. We hypothesize that unique features of the myopic optic disc, identified by optical coherence tomography (OCT) and OCT-Angiography (OCTA) could be used to differentiate between myopic eyes with and without glaucoma.OCT and OCTA are two retinal imaging modalities that are used extensively in routine ophthalmic examinations and considered the standard of care for management of glaucoma and other retinal diseases. OCT is used to visualize and measure different layers of the retina, while OCTA visualizes choroidal and retinal vasculature. The parapapillary atrophy zone is a chorioretinal atrophy zone around the optic disc, which can be categorized into subtypes parapapillary atrophy zone-α, zone-β and zone-γ by OCT but not by clinical examination. Recent studies suggest that parapapillary atrophy zone-β is more strongly associated with myopia and glaucoma and parapapillary atrophy zone-γ with myopia and no glaucoma. We hypothesize that parapapillary atrophy along with other OCT parameters such as optic disc tilt, ovality index, fovea to disc angle and distance, optic nerve head choroidal thickness and OCTA measurements could be used to differentiate between myopic eyes with glaucoma and myopic eyes without glaucoma. If our hypothesis is correct, these OCT and OCTA parameters can then be used to develop clinical decision support algorithms to improve detection of glaucoma in individuals with myopia. Finally, these new clinical decision support tools will help to prevent functional impairment and blindness caused by glaucoma in patients with myopia and on the other hand will help to prevent overdiagnosis and overtreatment in healthy myopes, improve quality of life and reduce health care costs due to overtreatment.