Effect of 532 nm argon laser pan retinal photocoagulation on corneal thickness and corneal endothelial cell parameters among proliferative diabetic retinopathy patients



Laser photocoagulation has been the mainstay treatment for diabetic retinopathy (DR). However, the applied laser light must pass through multiple ocular structures such as the cornea to reach the retina, potentially causing thermal injury to non-target tissues. The purpose of this study was to examine the effects of 532 nm Argon laser pan-retinal photocoagulation (PRP) on corneal thickness and corneal endothelial cell parameters by comparing central corneal thickness (CCT), endothelial cell density (ECD), and endothelial cell area coefficient of variation (CoV) before and after PRP for proliferative diabetic retinopathy (PDR). The effect of laser PRP on these corneal parameters may help in adapting treatment protocols to reduce corneal damage and thereby improve patient outcome.


This was a prospective cohort study involving newly diagnosed PDR patients. All patients underwent specular microscopy examination (CCT, ECD and endothelial cell area CoV) both pre-PRP and at 1-week and 6-weeks after the final PRP session (post-PRP). A Carl Zeiss Visulas Argon laser (532 nm) was used to perform PRP.


A total of 33 newly diagnosed PDR patients were included in this study. There were no significant differences in mean CCT, ECD, and endothelial cell area CoV at 1-week and 6-weeks following PRP compared to pre-treatment baseline (p > 0.05). Further, there were no significant correlations between laser energy delivered and CCT, ECD and endothelial cell area CoV at either post-PRP examination time.


Argon laser (523 nm) energy delivered within recommended ranges for PRP had no adverse effects on corneal structure.

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All the data and materials are contained within the manuscript.

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We would like to thank all the members of Department of Ophthalmology and Visual Science, Univerisiti Sains Malaysia for extending their help and support in my data collection.

Author information




SIG carried out the study, interpreted and analysed the data, and prepared the manuscript. ZE design the study, monitor the progress of the research and revised the manuscript.

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Correspondence to Embong Zunaina.

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Ghani, S.I., Zunaina, E. Effect of 532 nm argon laser pan retinal photocoagulation on corneal thickness and corneal endothelial cell parameters among proliferative diabetic retinopathy patients. J Diabetes Metab Disord (2021). https://doi.org/10.1007/s40200-021-00780-9

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  • Proliferative diabetic retinopathy
  • Central corneal thickness
  • Corneal endothelial density
  • Coefficient of variation
  • Argon laser
  • Pan-retinal photocoagulation