Background: Severe myopia (SM) is commonly defined as a refractive error that exceeds -10.0 diopters (D). To date, however, studies focusing on visual field changes in eyes affected by SM remain scarce. The present study aims to characterize changes to central visual fields in the presence of SM among Chinese individuals and to provide evidence for enabling early diagnosis of primary open-angle glaucoma (POAG) in cases of SM.
Methods: The data of 26 cases (44 eyes) involving Chinese individuals with SM were collected using a Humphrey Visual Field Analyzer 750i. The following aspects were identified: types of visual field defects in the probability map of pattern standard deviation, the features of patterns in visual field defects in four quadrants, the frequencies of scotomas, and the proportions of relative scotomas.
Results: (I) Among all visual field defects, 95.45% were found to be relevant to selected ocular fundus changes; (II) the proportion of relative scotomas was 65.02%. The two major types of visual field scotomas were the enlargement of the physiologic blind spot (43.20%) and central scotoma (38.64%), while additional types included nasal step defects (18.18%), paracentral scotomas (13.64%), and temporal sector-shaped defects (9.09%). The proportions for scotomas in the four quadrants were: 38.74% (superior temporal quadrant), 25.87% (inferior temporal quadrant), 19.32% (superior nasal quadrant), and 16.07% (inferior nasal quadrant).
Conclusions: (I) Visual field analysis should be conducted alongside consideration of fundus changes. The bulk of visual field defects were found to be relative scotomas. (II) Scotomas in SM patients were mainly due to the enlargement of a physiological blind spot and central scotomas, and nasal arch-shaped scotomas presented as arc-shaped damage. (III) Abnormal scotomas were detected most frequently in the inferior temporal quadrant.
Keywords: Chinese population; Severe myopia (SM); central; visual field.