Early Detection of Functional Changes in an Intraocular Hypertension Rabbit Model Treated with Human Wharton Jelly Mesenchymal Stem Cells (hWJ-MSCs) Using Chromatic Pupillometry

The present study was designed to evaluate the use of a chromatic pupillometry test for the early detection of functional impairment in intrinsically photosensitive retinal ganglion cells (ipRGCs) in an experimental glucocorticoid model of ocular hypertension (OH) treated with intravitreal injection of human Wharton’s jelly derived mesenchymal stromal cells (hWJ-MSCs). For this purpose, fifteen New Zealand rabbits were randomly assigned to three groups: OH (G1), hWJ-MSCs (G2), and OH + hWJ-MSCs (G3). The chromatic pupillary light reflex (cPLR) was assessed after dark adaptation to high-illuminance red and blue light stimuli. Response to blue light was used as a marker of ipRGC activity. Amplitude and latency were evaluated using flash-visual evoked potentials (VEP). Intraocular pressure (IOP) (mmHg) was monitored over time. The results indicated a significant increase (P<0.001) in the IOP by third week. Pupil diameter (mm) for blue light significantly increased (P<0.05) in all groups compared to the control eyes. However, the pupillary diameter in G3 tended to remain constant. Red light elicited significant differences in the responses in G1 (P=0.025) and G2 (P=0.007). Moreover, we found no correlation between the parameters of blue light intensity and flash-VEP (P>0.05). A non-significant increase in the latency of G2 (P=0.437) and G3 (P=0.779), and a slight increase in the amplitude of G3 were observed (P=0.268). The changes generated by the OH can be recognized early through quantitative measurements of the pupillary function. We found that intravitreal injection of human hWJ-MSCs appears to influence ipRGC activity, detectable early through cPLR in eyes with OH. In summary, our study indicates that intravitreal injection of human hWJ-MSCs appears to influence ipRGC activity facilitating the early detection capabilities for ocular hypertension-related changes through cPLR in eyes with OH.