Prevalence of Cataract changes in a Guatemala population evaluated by direct ophthalmoscopy
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Purpose: To grade cataract changes in a Guatemala population with direct ophthalmoscopy and a grading system based on the grading system used by V. Mehra and D. C. Minassian in 1988.
Methods: A population from Guatemala who attended field clinics conducted by Vision For All were included in this study. The sample consisted of 352 participants, 219 women and 133 men, from 9-90 years old. Mean age of the participants was 47.9 ± 17.8 years old. Binocular VA and subjective refraction was obtained with trial lenses and a Snellen E-chart at 5 meters. A 2 mm pinhole was used monocularly with the subjective refraction and whether participants felt any improvement in VA was documented. The opacities in the red reflex in the crystalline lens were graded using a handheld direct ophthalmoscope. The grading was made in an angle of 25o nasal and at approximately 33 cm from the participant’s undilated eye.
Results: The prevalence of cataract was 28.6% and 68% had some form of opacity in the red reflex. There was no statistically significant difference (p > 0.05) between the grade of lens opacities in right and left eye. Mean grade of lens opacities in right eye was 1.64 ± 1.46 and 1.63 ± 1.43 in left eye. The analysis showed a highly significant correlation between age and grade of lens opacities in right eye (y = 0.0657x -1.5106; r = 0.8; p < 0.001) and left eye (r = 0.78; p < 0.001). Lens opacities start to develop at an average age of 38.5 years in this population. There was a significant correlation between aided VA and grade of lens opacities for right eye (r = 0.52; p < 0.05) and left eye (r = 0.49; p < 0.05). 72 participants (20.5%) who had grading 3-5 in one or both eyes felt an improvement in their vision with the pinhole.
Conclusions: The prevalence of cataract was 28.6% and this population had an earlier development of cataract compared to previous studies. This could be due to the UV-radiation, the temperature and nutrition and antioxidant insufficiency. Also this study showed a highly significant correlation between age and grade of lens opacities and a low, but significant, correlation between aided VA and grade of lens opacities.
Place, publisher, year, edition, pages
2013. , 32 p.
cataract, Guatemala, direct ophthalmoscopy
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:lnu:diva-26786OAI: oai:DiVA.org:lnu-26786DiVA: diva2:630490
Subject / course
Optometry Programme, 180 credits
Theagarayan, Baskar, PhD, Lecturer in Optometry
Baskaran, Karthikeyan, PhD, Lecturer