Contrast Sensitivity, Color Discrimination and Visual Acuity as Risk Factors for Visual Dysfunction in Non-Proliferative Diabetic Retinopathy
Visual Functions as Predictors for NPDR
Abstract
Diabetic retinopathy (DR) diagnosis relies on clinical signs visible during dilated fundus examinations. However, pre-clinical DR may have neurodegenerative alterations that are only apparent through visual function assessments. This study compared visual functions in type 2 diabetes mellitus (DM) patients at various non-proliferative diabetic retinopathy (NPDR) stages and determined the risks of reduced visual functions. A total of 56 adult DM participants (mean age: 40.41 + 7.281 years) were classified into DM without DR, mild NPDR, and moderate-to-severe NPDR. Visual acuity (VA), colour vision discrimination (CV) and contrast sensitivity (CS) were assessed using logMAR chart, FM100 Hue test, and Pelli-Robson chart, respectively. The moderate-to-severe NPDR group exhibited poorest VA than other groups, with reduced CV discrimination (all parameters p<0.05) and reduced CS [F(2,107)=22.898, p<0.001]. An adjusted multinomial logistic regression model revealed a 24.4% higher risk of reduced CS in the moderate-to-severe NPDR group compared to DM without DR group (OR:0.756, 95% CI: 0.627-0.913, p=0.004). In conclusion, moderate-to-severe NPDR had reduced CS and CV, with higher risks of reduced CS compared to those without DR. Incorporating these parameters into current DR optometric screening programs can mitigate NPDR progression and enhance long-term visual function outcomes of the patients.
Keywords :
Colour discrimination,
contrast sensitivity,
diabetic retinopathy,
diabetes mellitus,
visual acuity,
Abstrak
Diagnosis retinopati diabetik (DR) biasanya bergantung pada tanda-tanda klinikal yang ditemui semasa pemeriksaan fundus. Walau bagaimanapun, DR pra-klinikal mungkin mengalami perubahan neurodegeneratif yang berpotensi dikesan melalui penilaian fungsi penglihatan. Kajian ini bertujuan untuk membandingkan fungsi visual pada pesakit diabetes mellitus (DM) jenis 2 pada pelbagai tahap retinopati diabetes bukan proliferatif (NPDR) dan menentukan jika tahap NPDR yang lebih teruk mempunyai risiko kemerosotan fungsi visual yang lebih tinggi. Sejumlah 56 subjek DM dewasa (purata usia: 40.41 +±7.281 tahun) dikelaskan kepada DM tanpa DR, NPDR ringan dan NPDR sederhana-teruk. Akuiti visual (VA), diskriminasi warna (CV) dan sensitiviti kontras (CS) dinilai menggunakan carta logMAR, ujian FM100, dan carta Pelli-Robson. Kumpulan NPDR sederhana-teruk menunjukkan VA paling teruk berbanding kumpulan lain dengan kemerosotan signifikan CV (p<0.05) dan CS yang berkurang [F(2,107)=22.898, p<0.001]. Analisis regresi logistik multinomial menunjukkan kumpulan NPDR sederhana-teruk berisiko 24.4% lebih tinggi untuk kemerosotan CS berbanding DM tanpa DR (OR:0.756, 95% CI: 0.627-0.913, p=0.004). Kesimpulannya, NPDR sederhana-teruk mempunyai CS dan CV yang merosot, dengan risiko yang lebih tinggi untuk kemerosotan CS berbanding pesakit dengan DM tanpa DR. Inklusi parameter-parameter ini ke dalam program saringan optometri DR yang sedia ada boleh mengurangkan perkembangan NPDR dan meningkatkan hasil penglihatan jangka panjang pesakit.
Kata Kunci :
Akuiti visual,
diabetis melitus,
diskriminasi warna,
retinopati diabetis,
sensitiviti kontras,
Correspondance Address
Mohd Izzuddin Hairol. Centre for Community Health Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia. Tel: +603-9289 7499 Email: izzuddin.hairol@ukm.edu.my
