**8. Participants**

This was a cross-sectional study in an institutional setting [24]. Subjects older than 30 years were recruited at an annual community health checkup project held in the city of Akita (with a population of 325,537), the capital of Akita Prefecture, Japan. A total of 1,173 subjects participated in the comprehensive examinations from September 10, 2007 to October 26, 2007. Of these, 710 individuals underwent glaucoma screening. All of the participants were ethnically Japanese.

present or suspected, glaucoma was categorized based upon the criteria of previous popula‐ tion studies (Table 2). In the definitive diagnosis, anomalous discs, including tilted discs, were carefully excluded. The final diagnosis of glaucoma was determined by 4 glaucoma specialists.

Screening for Narrow Angles in the Japanese Population Using Scanning Peripheral Anterior Chamber Depth Analyzer

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2) Presence of abnormalities in the stereoscopic fundus photographs, including one or more of the following

2. Rim width at the superior portion (11-1 h), or inferior portion (5-7 h) was less than or equal to 0.2 of disc

The vertical cup-to-disc ratio of the optic nerve head is 0.7 or more, or the rim width at the superior portion (11-1 h) or the inferior portion (5-7 h) is 0.1 or less of the disc diameter, or the difference of the vertical cup-to-disc ratio is 0.2 or more between both eyes, or a nerve fiber layer defect is found, and the hemifield based visual field abnormality is

When the visual field test is not reliable or available, the cup-to-disc ratio of the optic nerve head is 0.9 or more, or the rim width at the superior portion (11-1 h) or the inferior portion (5-7 h) is 0.05 or less of the disc diameter, or the

When the cup-to-disc ratio of the optic nerve head is 0.7 or more portion (5-7 h) is 0.1 or less but more than 0.05 of the disc diameter but less than 0.9, or the rim width at the superior portion (11-1h) or the inferior, or the difference of the vertical cup-to-disc ratio is 0.2 or more but less than 0.3 between both eyes, or the nerve fiber layer defect is found, and the visual field test is not reliable or available or does not show hemi-field based compatible defect, the

The vertical cup-to-disc ratio of the optic nerve head is 0.7 or more, or the rim width at the superior portion (11-1 h) or the inferior portion (5-7 h) is 0.1 or less of the disc diameter, or the difference of the vertical cup-to-disc ratio is 0.2 or more between both eyes, or a nerve fiber layer defect is found, and the hemifield based visual field abnormality is compatible with optic

1. Vertical cup/disc ratio of the optic nerve head was more than or equal to 0.6

3. Difference in the vertical cup/disc more than or equal to 0.2 between both eyes

4. Nerve fiber layer defect or splinter disc hemorrhage was found

1) Intraocular pressure of 21mm Hg or higher in either eye

3) Failure to take stereoscopic fundus photographs

**Table 1.** Criteria for Definitive Examination Eligibility.

compatible with optic disc appearance or nerve fiber layer defect.

difference of the vertical cup-to-disc ratio is 0.3 or more between both eyes

glaucomatous changes:

**Category 1**

**Category 2**

**Glaucoma suspect**

**10.1. Category 1**

eye is diagnosed with suspected glaucoma

**Table 2.** Criteria for Glaucoma Diagnosis.

disc appearance or nerve fiber layer defect.

diameter ratio was

This study was performed after the approval by the Ethical Committee of Akita Prefecture Health Care Foundation. All study procedures adhered to the principles outlined in the Declaration of Helsinki for research involving human subjects, and all participants gave written informed consent for this research prior to their participation.

Exclusion criteria were (1) eyes with previous ocular surgery, trauma, or significant ocular disease; (2) eyes with any inborn aberrations, which might affect the morphology of the optic disc (eg, superior segmental optic disc hypoplasia).
