Vol 33 No. 2 Original Article

Assessment of visual status of the Aeta, a hunter-gatherer population of the Philippines

Cecilia Santiago-Turla, MD, Mary Katherine Rivera-Francia, MD, Bernardita Navarro, MD, Jose Joel Eclarinal, MD, Benjamin Dizon, MD, Paul Francia, MD, Sandra Stinnett, MD, R. Rand Allingham, MD

Assessment of visual status of the Aeta, a hunter-gatherer population of the Philippines

Cecilia Santiago-Turla, MD1
Mary Katherine Rivera-Francia, MD2
Bernardita Navarro, MD3
Jose Joel Eclarinal, MD4
Benjamin Dizon, MD4
Paul Francia, MD4
Sandra Stinnett, MD1
R. Rand Allingham, MD1M
1Department of Ophthalmology
Duke University Medical Center
Durham, North Carolina
2Department of Ophthalmology
Iloilo Doctors College of Medicine
Iloilo, Philippines
3Department of Ophthalmology
Santo Tomas University Hospital
Manila, Philippines
4Department of Surgery
Iloilo Doctors College of Medicine
Iloilo, Philippines


A study was performed to assess levels of visual impairment and blindness among a representative sample of older members of the Aeta, an indigenous hunter-gatherer population living on the island of Luzon in the Philippines.

Unrelated older Aeta couples from 4 villages were randomly invited to participate in a visual-screening study. All participants had complete ophthalmic examination and their ocular and medical history, height, and weight were recorded.

A total of 225 individuals were screened from 4 villages. The mean height for the entire screened population was 54.6 inches (approximately 4.5 feet), 56.8 for men and 53.7 for women. Visual acuity, both uncorrected and pinholecorrected, was significantly worse among older vs. younger age groups for women, men, and when combined (p < 0.001). Visual impairment, defined as best-corrected VA > 20/40 and < 20/200, was present in 48% (100/208) of uncorrected eyes and 43% (90/208) of pinhole-corrected eyes in the older age group. Of all individuals screened, 6% (14/225) were bilaterally blind, defined as best-corrected VA ≥ 20/200. The major causes of blindness were readily treatable. The most common etiologies as a proportion of blind eyes were cataract 66% (39/59), refractive error 20% (12/59), and trauma 7% (4/59). No cases of primary open-angle (POAG), primary angle-closure (PACG), or pseudoexfoliation-associated glaucoma were observed.

Visual impairment and blindness were common in the Aeta population. Cataract was the most common cause of vision loss. Interestingly, POAG and PACG, both major causes of blindness in most population-based studies, were not observed in this population. The absence of these forms of glaucoma may reflect random-sampling error. However, the Australian Aborigines, a related indigenous population, also have a very low prevalence of these forms of glaucoma. These data suggest that these populations may share genetic and/or environmental factors that are protective against primary forms of glaucoma. Keywords: Aeta, Visual-status assessment, Visual impairment, Blindness