APBA Kısa Özet

This cross-sectional study examined 158 Yanomami individuals in the Brazilian Amazon to characterize the glaucoma spectrum in this Indigenous population. The research represents the first systematic investigation of intraocular pressure, optic disc morphology, and fundoscopic findings among the Yanomami, one of the largest and most geographically isolated Indigenous peoples of the Amazon. Key findings include generally normal mean intraocular pressure (approximately 13.6-13.9 mmHg), rare ocular hypertension (0.66%), and mostly normal cup-to-disc ratios, with 2.03% of participants having C/D ratio >0.5. One confirmed case of secondary angle-closure glaucoma and two possible primary glaucoma cases were identified. No diabetic retinopathy was detected. The study suggests that primary open-angle glaucoma may not be a major burden in this population, though limited case numbers and methodological constraints require cautious interpretation of the results.

# Çalışma neyi araştırdı?

This research aimed to systematically characterize intraocular pressure (IOP), optic disc cup-to-disc (C/D) ratio, and fundoscopic findings in the Yanomami Indigenous population of the Brazilian Amazon. The study sought to determine the prevalence of glaucoma-indicative findings and establish a baseline for glaucoma spectrum indicators in this geographically isolated community. By examining a population with limited prior ophthalmic data, the research provides crucial baseline information for understanding eye health in Indigenous Amazonian communities.

# Yöntem

  • Study Design: Cross-sectional observational study
  • Timeframe: June-August 2024
  • Location: Yanomami Indigenous Health House (CASAI-Y), Boa Vista, Brazil
  • Participants: 158 self-identified Yanomami individuals aged ≥5 years, enrolled voluntarily
  • Assessment Tools:
  • Non-contact tonometry (Huvitz HNT-7000) for IOP measurement
  • Portable non-mydriatic fundus photography (Eyer) for optic disc imaging
  • Portable slit-lamp biomicroscopy and direct ophthalmoscopy
  • Data Analysis: Descriptive statistics (mean, standard deviation), ratios; associations assessed using odds ratios (OR) with 95% confidence intervals (CI), Student t-test, one-way ANOVA, Fisher exact test, and Spearman and Pearson correlations. P-values were adjusted for multiple comparisons using the Benjamini-Hochberg procedure.
  • Ethics: Study received approval from the local ethics committee; informed consent was obtained from participants or their guardians.

# Temel bulgular

  • Intraocular Pressure: Among 151 participants with assessable IOP (secondary glaucoma case excluded from descriptive analysis), mean IOP was 13.64 mmHg (SD 1.59) in the right eye and 13.93 mmHg (SD 1.75) in the left eye.
  • Ocular Hypertension: Ocular hypertension was identified in 1 of 151 participants (0.66%).
  • Cup-to-Disc Ratio: Among 148 participants, mean C/D ratio was 0.261 (SD 0.129) OD and 0.267 (SD 0.138) OS. Three participants (2.03%) had C/D >0.5 in at least one eye.
  • Glaucoma Cases:
  • One participant had confirmed secondary angle-closure glaucoma with IOP 35/55 mmHg, 360° synechiae, and no light perception.
  • Two further participants had findings suggestive of primary glaucoma (elevated C/D ratio, potential nerve fiber layer loss), though definitive diagnosis required additional diagnostic workup not performed in this study.
  • Diabetic Retinopathy: No diabetic retinopathy was identified in any participant.

# Bulgular ne anlama geliyor?

The findings indicate that mean intraocular pressure in the Yanomami population falls within the normal range globally (10-21 mmHg). The low prevalence of ocular hypertension (0.66%) and elevated C/D ratio (2.03%) suggests that the burden of primary open-angle glaucoma is limited in this population. However, the identification of one secondary angle-closure glaucoma case and two possible primary glaucoma cases demonstrates that glaucoma spectrum indicators are not absent from this community. The absence of diabetic retinopathy may indicate low diabetes prevalence, though screening scope and methodology were not fully detailed in the report. These results provide important baseline data for future glaucoma screening programs in Indigenous Amazonian populations, though the limited number of glaucoma-related events limits precision in prevalence estimates.

# Klinik önem

APBA emphasizes that while these findings suggest a relatively low glaucoma burden in the Yanomami population, they do not eliminate the need for eye health monitoring. Particularly, the rare but identified case of secondary angle-closure glaucoma highlights that glaucoma subtypes requiring different management strategies do exist in this population. The use of portable, field-friendly equipment (non-contact tonometry and portable fundus photography) demonstrates the feasibility of ocular assessment in remote Indigenous communities. However, APBA does not recommend changing glaucoma screening policies based on these data alone; larger-scale studies with reference-standard measurements are needed to establish definitive prevalence rates and risk factors specific to Indigenous Amazonian populations.

# Sınırlılıklar

  • Cross-sectional Design: The study design precludes assessment of causality or temporal changes in ocular parameters.
  • Limited Sample Size for Glaucoma Events: With only one confirmed secondary angle-closure glaucoma case and two possible primary glaucoma cases, prevalence estimates have wide confidence intervals and limited precision.
  • Single-Center Study: Conducted at only one Yanomami health facility (CASAI-Y), limiting generalizability to other Yanomami communities or Indigenous groups in different regions.
  • Methodological Differences: Non-contact tonometry and portable fundus photography may introduce measurement variability compared to reference-standard methods (Goldmann applanation tonometry, stereoscopic fundus examination).
  • Angle-Closure Glaucoma Characterization: With only a single case, epidemiological data on angle-closure glaucoma in this population remain insufficient.
  • Conflict of Interest Uncertainty: The reported conflict of interest status is unclear, which may introduce some uncertainty in result interpretation.
  • Diabetes Screening Scope: The methodology for diabetic retinopathy screening and its comprehensiveness were not fully detailed in the report, limiting interpretation of the negative findings.

APBA Interpretation: This study provides the first systematic characterization of the glaucoma spectrum among the Yanomami Indigenous people of the Brazilian Amazon. While findings suggest a low burden of primary open-angle glaucoma, the limited number of glaucoma-related events and methodological constraints prevent definitive conclusions. Larger-scale studies with reference-standard measurements and longitudinal follow-up are needed to inform glaucoma screening and intervention strategies for Indigenous Amazonian populations.