Abstract
Purpose :
Previous work exhibited robust postoperative inflammation and fibrosis after lensectomy with IOL insertion in juvenile rabbits. We sought to identify changes of the aqueous humor protein for the multiple steps of the procedure that underlies this postoperative response.
Methods :
All experiments were approved and in compliance with the Animal Care and Use Committee of MCW. 6-7 week old New Zealand White rabbits underwent one of the following unilateral surgical interventions including: anterior chamber paracentesis (n=8), corneal incision with wound suture (n=6), lensectomy without IOL (aphakia, n=5), and lensectomy with IOL (n=5). Aqueous humor was collected immediately prior (pre) and three days after the procedure. Samples were stored at -80 degrees C. Total protein concentrations were determined using a Pierce™ Bicinchoninic Acid Protein Assay (ThermoFisher). Results were analyzed using one-way ANOVA and Tukey’s Post Hoc test. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed using an Orbitrap Fusion™ Lumos™ Tribrid™ MS (ThermoFisher). MS data were analyzed using Proteome Discoverer™ and Skyline.
Results :
Protein levels increased compared to before surgery when lensectomy was performed. Average total protein concentration for each group were: pre, 2,807 ± 482.9µg/mL; paracentesis, 3,600 ± 1797µg/mL; corneal incision, 3,384 ± 903.9µg/mL; aphakia, 7,191 ± 1717µg/mL; lensectomy with IOL, 12,118 ± 4893µg/mL. There were significant increases for both the IOL and aphakia group compared to all other groups. Additionally, IOL insertion also had higher total proteins compared to aphakia (p < 0.05). Fibrinogen alpha, beta, and gamma chains were the largest contributor to the total protein increases. Despite the increase in total protein, several proteins identified by MS decreased in relative abundance including lysozyme, cystatin, and beta-2-microglobulin.
Conclusions :
The total protein concentration is greatest in eyes undergoing lensectomy with IOL insertion, which correlates with the most severe clinical postoperative response. Aphakic rabbits still exhibit robust increases in total protein concentration, while the paracentesis and corneal incision groups did not significantly differ compared to aqueous samples taken before surgery. Specific protein changes may play a role in the robust postoperative response following surgery.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.