Abnormal Retinal Vessel Architecture in Albinism and Idiopathic Infantile Nystagmus

Papillary and peripapillary vascular densities and corresponding correlation with peripapillary retinal thicknesses using optical coherence tomography angiography in healthy children and adolescents

To evaluate the peripapillary retinal thickness (PPRT), vascular density (PPVD), and disc vascular density (PVD) and their correlations in normal healthy children using optical coherence tomography angiography (OCTA). This was a cross-sectional study of 70 eyes from 36 normal healthy children aged 6-18 years who performed optic nerve head scans using OCTA. The PPRT included the peripapillary nerve fiber layer (PP-RNFLT), inner retina (PP-IRT), middle retinal thickness, and outer retinal thicknesses. The PP-RNFLT and PP-IRT were not significantly different between males and females. Superior nasal peripapillary RNFLT and IRT were significantly affected by age (ANOVA, P > 0.05). The PP-IRT and PP-RNFLT were lower in the 7-11 years old group in comparison with the other 3 groups (Post hoc Tukey test, P value < 0.05). Age and sex-matched PVD were not correlated with PPVD (partial correlation, P > 0.05). PPRT was not correlated with PVD, PPVD, superficial and deep retinal vascular densities, and choroidal vascular density. This study demonstrated that PPRT appears to change during growth in childhood. Superior nasal PPRT was affected more in the groups, decreasing from less than 7 years old to 7-11 years old and then back to pre-reduction values after 11 years old.

Visual Field Deficits in Albinism in Comparison to Idiopathic Infantile Nystagmus

Purpose

This is the first systematic comparison of visual field (VF) deficits in people with albinism (PwA) and idiopathic infantile nystagmus (PwIIN) using static perimetry. We also compare best-corrected visual acuity (BCVA) and optical coherence tomography measures of the fovea, parafovea, and circumpapillary retinal nerve fiber layer in PwA.

Methods

VF testing was performed on 62 PwA and 36 PwIIN using a Humphrey Field Analyzer (SITA FAST 24-2). Mean detection thresholds for each eye were calculated, along with quadrants and central measures. Retinal layers were manually segmented in the macular region.

Results

Mean detection thresholds were significantly lower than normative values for PwA (-3.10 ± 1.67 dB, P << 0.0001) and PwIIN (-1.70 ± 1.54 dB, P < 0.0001). Mean detection thresholds were significantly lower in PwA compared to PwIIN (P < 0.0001) and significantly worse for left compared to right eyes in PwA (P = 0.0002) but not in PwIIN (P = 0.37). In PwA, the superior nasal VF was significantly worse than other quadrants (P < 0.05). PwIIN appeared to show a mild relative arcuate scotoma. In PwA, central detection thresholds were correlated with foveal changes in the inner and outer retina. VF was strongly correlated to BCVA in both groups.

Conclusions

Clear peripheral and central VF deficits exist in PwA and PwIIN, and static VF results need to be interpreted with caution clinically. Since PwA exhibit considerably lower detection thresholds compared to PwIIN, VF defects are unlikely to be due to nystagmus in PwA. In addition to horizontal VF asymmetry, PwA exhibit both vertical and interocular asymmetries, which needs further exploration.

Visual Function and Neuropsychological Profiling of Idiopathic Infantile Nystagmus

Though considered a benign condition, idiopathic infantile nystagmus (IIN) may be associated with decreased visual acuity and oculo-motor abnormalities, resulting in developmental delays and poor academic performance. Nevertheless, the specific visual function profile of IIN and its possible impact on neuropsychological development have been poorly investigated. To fill this gap, we retrospectively collected the clinical data of 60 children presenting with IIN over a 10-year period (43 male; mean age of 7 years, range of 2 months-17 years, 9 months). The majority of the subjects in our cohort presented with reduced visual acuity for far distances and normal visual acuity for near distances, associated with oculo-motor abnormalities. The overall scores of cognitive and visual-cognitive tests were in the normal range, but revealed peculiar cognitive and visual-cognitive profiles, defined by specific frailties in processing speed and visual-motor integration. The same neuropsychological profiles characterize many neurodevelopmental disorders and may express a transnosographic vulnerability of the dorsal stream. As the first study to explore the neuropsychologic competencies in children with IIN, our study unveils the presence of subclinical frailties that need to be addressed to sustain academic and social inclusion.