Facial Scanning With a Digital Camera: A Novel Way of Screening for Primary Angle Closure.

Primary angle closure (PAC) is common in Singapore. The prevalence of PAC in Asians is much higher than in the white population, with a prevalence rate of about 0.8% to 1.4% in Asians above the age of 40 years1–2 compared with a prevalence rate of about 0.1% in white populations.3–5 PAC is a condition that could lead to blindness. It causes a high rate of monocular blindness in Asia, with the rate of monocular blindness being >50%, and in some studies >30% of patients are blind in both eyes.1–2 The risk factors of PAC have been well documented. Patients are typically elderly and older than 40, and women are more predisposed to this disease.6–8 Ocular factors that increase the risk of developing PAC include decreased axial length, shallow anterior chamber, and an anteriorly positioned lens.9 To our knowledge, there has been no previous study regarding the facial characteristics of PAC. We hypothesized that patients with PAC have common significant facial characteristics that set them apart from an age-matched, sexmatched, and race-matched control population, on the basis of many years of experience observing these patients’ faces. We hypothesized that imaging modalities, including 3-dimensional (3D) photographic techniques, could differentiate the facial characteristics in these patients. Three-dimensional photographic technology has had rapid technological advances, and its use in medicine is increasing. It has been used in disciplines such as plastic surgery and dentistry to reconstruct hypothetical models in patients before and after surgery.10–12 It is fast, easy to perform, and safe for patients. It is minimally invasive, consistent, and does not emit any ionizing radiation. These properties make it attractive as a screening tool. There have been no previous reports on screening for PAC using such technologies for the analysis of facial parameters. We describe a novel method of applying 3D photographic technology to distinguish PAC from a control population.