Abstract
Purpose :
Preterm infants have low serum Vitamin D (Vit-D, 25 hydroxy Vitamin-D3) levels, which are reported to correlate with retinal immaturity. The association of Vit-D and vascular endothelial growth factor (VEGF) levels is currently unknown.
Methods :
Tears were collected from ROP Stage-I (SI=12 eyes), Stage-II (SII=22 eyes), Stage-III (SIII=8 eyes) infants along with age-matched controls (22 eyes). Samples were obtained using Schimer’s strips and stored at -80C. Levels of Vit D and secreted VEGF were measured using competitive ELISA and cytometric bead array analysis respectively.
Results :
The tear levels showed ROP SI (median-203 pg/ml; range-133.4 to 698pg/ml) had significantly lower VEGF levels when compared with SII (294.4pg/ml range 134.1-852.7pg/ml; P<0.001) and SIII (260.7pg/ml, range 195.5-793.8; P<0.05) infants. In SII zone-2, 68.4% of infants had VEGF levels <300pg/ml of which 15% underwent laser treatment. Interestingly, all patients in SII zone-3 group had >300pg/ml of VEGF levels and remained untreated until last follow-up. In SIII zone-2, all patients were treated though 62.5% samples had <300pg/ml. The mean post-menstrual age (PMA) was higher (38.3±0.5 weeks) in patients belonging to SII zone-3 compared to SII zone-2 (35.8±1.5) and SIII zone 2 (36.7±0.6). Moreover the PMA of zone-3 infants was similar to the controls (mean 38.7±0.4). Further, the Vit-D levels were lower in SI and SIII infants (median-17.6 ng/ml, range 11.3-24.6ng/ml; median 17.3ng/ml, range 10.90-31.60ng/ml) when compared with SII (median-21.6 ng/ml, range 12.0-31.0 ng/ml). There was a positive correlation between the levels Vit-D and VEGF in tears of SI infants (r=0.6260, P<0.005).
Conclusions :
Eyes with low levels of VEGF and lower PMA with ROP in zone-2 required treatment in a higher proportion compared to eyes with ROP SI and SII in zone 3 with a higher PMA. Eyes with <300pg/ml VEGF and lower PMA had a higher probability for undergoing treatment. The study establishes an association between VEGF and Vit-D levels in tears of infants with ROP.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.