**13. Results**

#### **13.1. Results of primary screening and definitive examination**

A glaucoma specialist judged that 26 eyes of 19 subjects required the definitive examination, and all 19 subjects were enrolled in the definitive examination. The definitive examination revealed that 1 subject had PACG (0.08%), 1 subject had PAC (0.08%), and 1 had ciliary cyst (0.08%). None of all these eyes showed IOP elevation of more than 21mm Hg. Laser iridotomy was performed on PACG and PAC subjects. None of these subjects presented with subjective symptoms that are thought to demonstrate a strong association with angle closure.

#### **13.2. Association of gender and age with SPAC parameters**

Association of gender and age with SPAC parameters are summarized in Table 4.

In male subjects of 30 to 60 years of ages, the central and the peripheral anterior chamber depths were gradually decreased with ages. There were significant differences in these depths among 30, 40, and 50 age groups (p<0.0001). However, there was no significant difference in depths between 60 years and 70 years age group (Fig. 5). In female subjects, the ACD tended to be shallower in women than in men in each generation. The central and the peripheral anterior chamber depths were gradually decreased with ages. There were significant differences among



were reported using SPAC [25] (Table 6). Kamo et al. [25] also reported that the frequen‐ cy of eyes at risk for angle closure increased in women 50 years of age or older, and it is corresponding to our present results.

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It has been reported that the prognosis of eyes with PACG especially acute angle clo‐ sure is poor compared with that of eyes with PAC undergoing suitable treatment [6, 7]. Therefore, detecting eyes at risk of PACG or PAC is very important. The van Her‐ ick technique was employed for primary screening in previous epidemiologic studies of ACG eyes [21]. It has been reported that the results of peripheral ACD measure‐ ment by SPAC were well correlated with those by the van Herick technique as well as Shaffer's grading system and the ultrasound biomicroscope [22]. As the sequential testing using both SPAC and van Herick demonstrates high specificity and sensitivity [23], we considered that the SPAC examination in conjunction with the van Herick method is considered as a choice of the first-line screening tests for angle closure fol‐ lowing precise examination by OCT, UBM, or gonioscopy. Further, almost all of the previous studies were conducted under the guidance of an ophthalmologist, and there are few reports of angle closure screening conducted as part of a public health exami‐ nation that does not involve an ophthalmologist. Primary screening using SPAC meas‐ urements of ACD by nonphysicians seems to have possibility to induce cost-effective angle closure screening.

It seems that screening for PACG at least with SPAC and van Herick method should be performed in all the patients over 50 every 6 months and in those with shallow (periph‐ eral) anterior chamber or high IOP, the angle should be further evaluated. LI should be performed in all PAC and PACG patients and those who do not respond to LI should undergo cataract surgery.


**Table 6.** Comparison of frequencies of eyes at risk (judged as S or P by SPAC) between Akita (the present result) and Yamanashi in Japan.
