Seattle, Wa. (May 6, 2013) — Meaningful pharmacological dilation of pupils is possible after death, a new study shows. The findings were presented today at the 2013 Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting.
About the Study
Fourteen eyes were obtained by the Lions Eye Institute for Transplant & Research (LEITR) in Tampa, FL, between December 2012 and April 2013. LEITR inspected the eyes for iris color and signs of abnormalities. A review of pre-death records also was conducted to include demographics, medical history, ocular history, and medications, when available. None of the eyes were excluded due to a prior history of iris surgery, iris trauma, iris melanoma, iritis, or iridoschisis.
At study onset, images of the pupils were recorded on a digital camera, and then two drops of a solution of 10 percent phenylephrine and 1 percent tropicamide were placed on the surface of the corneas. Seven of the eyes received drops pre-procurement and seven post-procurement. The set of drops was repeated twice, every three minutes. Pupils were then measured at 20 minutes and at 60 minutes with a millimeter ruler and recorded on a digital camera for future analysis.
The findings show that effective pupillary dilation was achieved up to 24 hours after death. Pupil dilation from 0.7mm to 2.6mm was measured and seen across a range of iris colors both pre- and post- tissue procurement.
“Our group has developed a very simple protocol, which resulted in some degree of postmortem pupillary dilation in all 14 of the heterogeneous eyes studied,” says Jeffrey R. Golen, M.D, Department of Ophthalmology, University of South Florida. “Knowledge of this phenomenon is an exciting finding, which may be useful in many areas of ophthalmic research where ocular human tissue plays an essential role.”
“Future studies on imaging of the dilated eyes by photography and coherence tomography would be important next steps,” adds Patrick Gore, RN, CEBT, Director, Business Development, Lions Eye Institute for Transplant & Research. “Looking ahead, our goal is to be able to better evaluate eyes for which we may have a limited clinical history and to continue to provide researchers with disease-specific ocular tissue that is best suited to their research efforts.”
Source: Golen JR, Saunder T, Sprehe N, Gore P, Malavade SS, Pavan PR, Margo CE, Can Meaningful Pharmacological Dilation of Pupils Occur After Death? 2013 Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting.