Prevalence of Visual Impairment and Refractive Errors in an Urban Area of Mexico

  • The study aims at determining the distribution of refractive errors in a school-age population in Quintana Roo (Mexico) in the framework of an international cooperation campaign for the prevention of blindness.

  • A sample of 2647 school-age children (ranging from 5 to 14 years old) with a mean age of 9.1±1.9 years old were tested by trained volunteers for distance visual acuity (VA) and refractive errors.

  • A total of 633 (23.9%) children underwent the second complete eye examination.

  • Bilateral amblyopia was found in 17 children (2.7% of refracted eyes; 0.64% of the total).

  • The main reason for visual impairment (VI) in the sample analyzed was found to be refractive errors.

  • In 12 children (1.9% of refracted eyes; 0.45% of the total) the VI was bilateral and 9 (1.4% of refracted eyes; 0.34% of the total) achieved a corrected distance visual acuity of 20/25 or better in both eyes.

  • Mean magnitude of sphere and refractive cylinder was +0.20±0.96 D and -0.43±0.85 D in right eyes, and +0.24±1.08 and -0.43±0.83 D in left eyes.

  • The proportion of myopic eyes [standard equivalent (SE) ≤-0.50 D] was 4.6% of the whole sample (5290 eyes). The mean magnitude of myopia was -0.84±3.44 D for the right eyes and -0.82±5.21 D for the left eyes.

  • The proportion of hyperopic patients (SE≥+2.00 D) was 2.4% (15/633), which corresponded to 0.60% of the whole sample (32/5290 eyes).

  • No statistically significant correlation of age to manifest sphere or cylinder was found.

  • VI due to uncorrected refractive errors can be easily corrected with glasses but it is still a burden to be treated.

  • Myopia is prevalent in this sample.

  • More efforts towards correcting uncorrected refractive errors are needed.

Publication date

February 21, 2020


International Journal of Ophthalmology


Isabel Signes-Soler, David P Piñero, Milagro Inés Murillo, and Silvia Tablada
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