Background: Conjunctival microangiopathy has been described among diabetics similar to retinal vessel angiopathy. Correlation of these conjunctival microangiopathy changes with retinopathy may form the basis of screening by external examination without expert fundus evaluation.
Methods: Conjunctival vessels widths and tortuous segment length of conjunctival vessels of 96 patients with type 2 diabetes mellitus were photographed and measured by the Zeiss Fundus camera Visupac software. The measurements were correlated with retinopathy grade in those eyes.
Results: The mean conjunctival vessel width was 40.61 μ (SD 17.25) with a uniform increase from 34.4 μ (SD 8.70) in mild NPDR to 53.50 μ (SD 33.45) in the PDR group which was statistically significant (p < 0.01). The tortuous conjunctival vessel segment length increased from 711.51 μ (SD 83.90) in the mild NPDR group to 921.94 μ (SD 129.26) in those with PDR (p < 0.01). Vessel width greater than 80 μ was seen only in PDR and tortuosity values greater than 900 μ were seen in severe grades (severe NPDR and PDR). Both conjunctival vessel width and tortuosity showed a positive statistical correlation with increasing severity of retinopathy (r = 0.386, r2 = 0.149 and r = 0.645, r2 = 0.415).
Conclusion: A positive correlation was seen between conjunctival vessel width and tortuosity with severity of retinopathy. Widths over 80 μ and tortuous segment length over 900 μ are suggestive of severe grades of retinopathy.
Keywords: Conjunctival microangiopathy; Diabetes; Retinopathy.
Conjunctival impression cytology in non-proliferative and proliferative diabetic retinopathy.Int J Ophthalmol. 2014 Apr 18;7(2):321-5. doi: 10.3980/j.issn.2222-3959.2014.02.23. eCollection 2014. Int J Ophthalmol. 2014. PMID: 24790878 Free PMC article.
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Retinal vascular tortuosity in persons with diabetes and diabetic retinopathy.Diabetologia. 2011 Sep;54(9):2409-16. doi: 10.1007/s00125-011-2200-y. Epub 2011 May 29. Diabetologia. 2011. PMID: 21625945
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Proliferative retinopathy during hyperbaric oxygen treatment.Diving Hyperb Med. 2017 Sep;47(3):203. Diving Hyperb Med. 2017. PMID: 28868603 Review.