library_construction_protocol: After imaging the corneas, eyes had 15µl of 4% formalin (ThermoFisher) dropped onto them and were left to fix at room temperature for 15 minutes. Eyes were then carefully resected and placed in 1ml of iced 4% formalin (ThermoFisher) and were fixed at 4°C for 48-72hrs. After fixation, formalin was removed, and tissue was washed twice with sterile 1x PBS. Samples were then placed in 2ml of 70% ethanol and were kept at 4°C until shipment to UMass Histopathology was complete. Tissue embedding was done by UMass Histopathology.  All tissues were processed using UMass Chan Medical School Morphology Core services following standard protocols. Illumina i5 and i7 dual-indexing primers (Nanostring Technologies) were added to the collected barcodes during polymerase chain reaction (8 µl collected oligonucleotides/ROI) to uniquely index each ROI. Briefly, collected barcodes were re-suspended in 10 mL of nuclease-free water and incubated for 10min at room temperature. In a 96-well PCR plate, 2 mL of master mix (Nanostring Technologies), 4 mL of seq-code indexes (Nanostring Technologies) and 4 mL of re-suspended barcodes were mixed and placed in a thermocycler for PCR amplification using the following program. 1x UDG incubation for 30min at 37° C, 1x UDG deactivation for 10min at 50° C, 1x Initial denaturation for 3min at 95° C, 18x Denaturation for 15sec at 95° C > Anneal for 60sec at 65° C > Extend for 30sec at 68° C, Final extension for 5min at 68° C, Hold at 4° C.