Inducible Rbpms-CreERT2 Mouse Line for Studying Gene Function in Retinal Ganglion Cell Physiology and Disease.

Retinal ganglion cells (RGCs) are the sole output neurons conveying visual stimuli from the retina to the brain, and dysfunction or loss of RGCs is the primary determinant of visual loss in traumatic and degenerative ocular conditions. Currently, there is a lack of RGC-specific Cre mouse lines that serve as invaluable tools for manipulating genes in RGCs and studying the genetic basis of RGC diseases. The RNA-binding protein with multiple splicing (RBPMS) is identified as the specific marker of all RGCs. Here, we report the generation and characterization of a knock-in mouse line in which a P2A-CreERT2 coding sequence is fused in-frame to the C-terminus of endogenous RBPMS, allowing for the co-expression of RBPMS and CreERT2. The inducible Rbpms-CreERT2 mice exhibited a high recombination efficiency in activating the expression of the tdTomato reporter gene in nearly all adult RGCs as well as in differentiated RGCs starting at E13.5. Additionally, both heterozygous and homozygous Rbpms-CreERT2 knock-in mice showed no detectable defect in the retinal structure, visual function, and transcriptome. Together, these results demonstrated that the Rbpms-CreERT2 knock-in mouse can serve as a powerful and highly desired genetic tool for lineage tracing, genetic manipulation, retinal physiology study, and ocular disease modeling in RGCs.

Fixation disparity and refractive error among first-year optometry students / Disparidad de fijación y error de refracción entre estudiantes de primer año de optometría

Purpose: To determine the fixation disparity and refractive error of first-year optometry students to ascertain any relationship between them and also identify any association between fixation disparity and visual symptoms at near. Method: It was an analytical cross-sectional study involving 85 participants aged 17 to 27 years (18.60 ± 1.37), 41% of whom were males. Subjective refraction was done at 3 m and fixation disparity was measured with and without spectacle correction using the Wesson Fixation Disparity Card. All analysis was set within a 95% confidence interval with a p-value ≤ 0.05 considered statistically significant. Results: Refractive error ranged from 0.25 SEQ (spherical equivalent) to 5.50 SEQ. Mean fixation disparity ranged from 2.9 ± 2.6 to 3.9 ± 2.8 min arc. There was no statistically significant correlation between refractive error and fixation disparity without correction (r = −0.180, p = 0.098) and with correction (r = 0.155, p = 0.157). For fixation disparity in the ortho and exo direction, mean fixation disparity with correction of participants who experienced headaches during or after reading (5.1 ± 2.6 min arc) was significantly higher (p = 0.032) than participants who did not (2.0 ± 2.6 min arc). Conclusion: Myopia is common among first-year optometry students. Refractive error has no significant effect on fixation disparity. Headache is significantly associated with exo fixation disparity at near.(AU)

Fixation disparity and refractive error among first-year optometry students.

PURPOSE: To determine the fixation disparity and refractive error of first-year optometry students to ascertain any relationship between them and also identify any association between fixation disparity and visual symptoms at near. METHOD: It was an analytical cross-sectional study involving 85 participants aged 17 to 27 years (18.60 ± 1.37), 41% of whom were males. Subjective refraction was done at 3 m and fixation disparity was measured with and without spectacle correction using the Wesson Fixation Disparity Card. All analysis was set within a 95% confidence interval with a p-value ≤ 0.05 considered statistically significant. RESULTS: Refractive error ranged from 0.25 SEQ (spherical equivalent) to 5.50 SEQ. Mean fixation disparity ranged from 2.9 ± 2.6 to 3.9 ± 2.8 min arc. There was no statistically significant correlation between refractive error and fixation disparity without correction (r = -0.180, p = 0.098) and with correction (r = 0.155, p = 0.157). For fixation disparity in the ortho and exo direction, mean fixation disparity with correction of participants who experienced headaches during or after reading (5.1 ± 2.6 min arc) was significantly higher (p = 0.032) than participants who did not (2.0 ± 2.6 min arc). CONCLUSION: Myopia is common among first-year optometry students. Refractive error has no significant effect on fixation disparity. Headache is significantly associated with exo fixation disparity at near.