In Vivo Confocal Microscopic Study of Hard Contact Lens-Induced Lipid Keratopathy Secondary to Corneal Neovascularization in a Rabbit Hypercholesterolemic Model

Corneal structural alterations in autism spectrum disorder: An in vivo confocal microscopy study

Individuals with autism spectrum disorder (ASD) often exhibit joint hypermobility and connective tissue disorders. However, it remains unclear if ASD individuals also have structural alterations in the connective tissue of the cornea. This study aims to determine whether the Kobayashi structure (K-structure) characteristics differ between adults with ASD and typically developing controls (TDC) and explore the clinical correlates of the K-structure abnormality. We recruited 30 ASD adults and 35 TDC. Corneal structures, particularly the K-structure in the Bowman's layer, of the participants were examined using in vivo confocal microscopy (IVCM), and a K-grading ranging from 1 to 4 was given to each eye based on the level of morphological mosaicism. The ASD participants' eyes received a significantly higher single-eye K-grading than that of the TDC eyes (p < 0.001), and the medians [25th, 75th percentile] of bilateral-eye summed K-grading were 8 [7, 8] and 5 [4, 6] in ASD and TDC, respectively (p < 0.001). A significantly higher K-grading in the ASD participants' eyes was still observed after adjusting for the within-subject inter-eye correlation (p < 0.001). Youden Index showed the optimal cutoffs to differentiate ASD from TDC by bilateral-eye summed K-grading and single-eye K-grading was >6 and >3, respectively. Additionally, a higher K-grading was associated with fewer visual sensation seeking in ASD (Spearman's correlation coefficient ρ = -0.518, p = 0.008) and low visual registration (i.e., higher sensory threshold) in TDC (ρ = 0.446, p = 0.023). This study provided novel evidence of corneal structural alterations in ASD by IVCM. Our findings may not only support the prior hypothesis of the association between ASD and connective tissue abnormalities but also shed light on the relationship between connective tissue disorder and neurodevelopmental disorders.

Lipid Keratopathy: A Review of Pathophysiology, Differential Diagnosis, and Management

Lipid keratopathy is a disease in which fat deposits accumulate in the cornea, leading to opacification and decrease of visual acuity. This condition can be idiopathic without signs of previous corneal disease or secondary to ocular or systemic diseases. Lipid keratopathy is usually associated with abnormal vascularization of the cornea, and the lipid classically deposits adjacent to these vessels. Treatment of this condition usually aims to eliminate or prevent abnormal vessel formation, and several modalities have been described. In this review we summarize the etiology, pathophysiology, and clinical presentation of lipid keratopathy and describe current and emerging treatment regimens.