For paraffin sections, eyes were fixed as above before embedding in paraffin using a Leica TP1020 tissue processor (Wetzlar, Germany). Then, 5-µm sections were prepared and subjected to antigen retrieval (10-mM Tris, 1-mM ethylenediaminetetraacetic acid containing 0.05% Tween 20 [Sigma-Aldrich], pH 9.0, autoclaved on liquid cycle, 30-minute sterilization time). Blocking and staining were as above. For cryosections, eye cups were fixed, cryoprotected in 30% sucrose solution overnight, embedded in OCT medium (Sakura Finetek, Torrance, CA, USA), and sectioned by cryostat at 12 to 16 µm. Retina sections were blocked and stained as above. Primary antibodies used included rat anti-CD31 (#553370, 1:100; BD Biosciences, Franklin Lakes, NJ, USA), rabbit anti-calbindin (Chemicon, #AB2724, 1:1000; Sigma-Aldrich), rabbit anti-choline acetyltransferase (#PA5-29653, 1:500; ThermoFisher Scientific), goat anti-PROX1 (#AF2727, 1:500; R&D Systems, Minneapolis, MN, USA), rabbit anti-calretinin (Chemicon, #AB5054; 1:1000; Sigma-Aldrich), and mouse anti-PKCα (NB600-201, 1:500; Novus Biologicals, Centennial, CO, USA). After several washes, secondary antibodies were applied for 2 hours at room temperature. These included donkey anti-mouse immunoglobulin G (IgG) conjugated to Alexa Fluor 488 dye (green fluorescence) and donkey anti-rabbit IgG and donkey anti-rat IgG either conjugated to Alexa Fluor 594 dye (red fluorescence) (ThermoFisher Scientific), all diluted 1:1000. Three-dimensional Z stacks were captured on a Carl Zeiss LSM 800 microscope (Oberkochen, Germany) and subsequently projected to a two-dimensional plane.