Abstract
Purpose :
To investigate the impact of brain tumors on grating visual acuity in children.
Methods :
Grating visual acuity scores (GVA, in logMAR), GVA deficits (GVAD) and inter-ocular acuity differences (IAD) were determined by sweep-visual evoked potentials (SVEP) in children with brain tumors and compared to age-based norms. The GVAD was assigned as mild (from 0.11 to 0.39 logMAR), moderate (from 0.40 to 0.80 logMAR) or severe (>0.80 logMAR). The association of GVA, GVAD and IAD scores with optic pathway involvement (yes or no) adjusted to age at evaluation, tumor onset, gender, and surgical resection (yes or no) was explored by multivariate regression analysis.
Results :
A group of 40 children (22 boys) with ages from 3.1 to 130.2 months (mean±SD= 39.0± 27.0; median= 34.0) with brain tumors (31 gliomas; 5 supratentorial embryonal tumors, including 2 pinealoblastomas; 1 medulloblastoma; 1 hemangioma; 1 glioblastoma multiforme; 1 meningeoma) diagnosed from the intrauterine period and the 36th month of life (mean±SD= 11.2 ± 10.6 months; median= 6 months; 50% at the hypothalamic-chiasmatic transition) were evaluated. On ophthalmic evaluation, 24 (60.0%) children presented good fixation and pursuit in both eyes whereas 9 (20%) children in one eye only. Eye alignment was preserved in 19 (47.5%), exotropia was found in 18 (45%) and esotropia in 3 (7.5%) children. Nystagmus (n=15; 37.5%), ptosis (n= 1; 2.5%) and proptosis (n=1; 2.5%) were observed. Fundus was normal in 19 (47.5%) and optic nerve abnormalities were found in 18 (45%) patients. Optic pathway was affected in the majority (n=31; 77.5%). GVA scores were reduced in 36 (90%) children (mean±SD= 0.61±0.38 logMAR; median= 0.54 logMAR) with enlarged IAD (>0.1 logMAR) in 21 (52.5%). Overall, GVAD was 0.46±0.35 logMAR (median= 0.36 logMAR) assigned as mild in 17 (42.5%), moderate in 12 (30%) and severe in 7 (17.5%) children. Decrease in GVA scores (coefficient=.57 logMAR; 95% CI =.29 to .84; p<.001) and increase in GVAD (coefficient=.51 logMAR; 95% CI =.22 to .80; p=.001) were associated with optic pathway involvement by the brain tumor.
Conclusions :
Brain tumors had a negative impact on GVA measured by SVEP in children, with more severe visual impairment in those with lesions affecting the optic pathway. The current results support the usefulness of quantitative assessment of visual function in pediatric neuro-oncologic settings.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.