Corneal Opacity Induced by Light in a Mouse Model of Gelatinous Drop-Like Corneal Dystrophy.

Gelatinous drop-like corneal dystrophy (GDLD) is a severe inherited corneal dystrophy characterized by subepithelial corneal amyloid deposition. We had previously succeeded in identifying the responsible gene, TACSTD2, and subsequently found that the epithelial barrier function is significantly decreased. As with GDLD patients, the knockout mice showed severe loss of tight junction, progressive opacity, and neovascularization in the cornea. We devised an easy method to confirm the loss of the corneal barrier function even before corneal opacity is observed. Furthermore, by using knockout mice, we were able to verify clinical findings, such as the wound healing delay and light-induced acceleration of the disease. This mouse model should prove to be a highly useful tool for investigating the pathology of GDLD and for developing new therapies.

A novel mutation in gelatinous drop-like corneal dystrophy and functional analysis.

We identified a novel mutation of the tumor-associated calcium signal transducer 2 (TACSTD2) gene in a Japanese patient with gelatinous drop-like corneal dystrophy (GDLD). Genetic analysis revealed a novel homozygous mutation (c.798delG, which may result in frameshift mutation p.Lys267SerfsTer4) in the TACSTD2 gene. This mutated gene was devoid of its original function in helping the claudin (CLDN) 1 and 7 proteins transfer from the cytoplasm to the plasma membrane.

Diquafosol Ophthalmic Solution Increases Pre- and Postlens Tear Film During Contact Lens Wear in Rabbit Eyes.

OBJECTIVES: To investigate the behavior of prelens tear film (PLTF) and postlens tear film (PoLTF) after the instillation of diquafosol using an experimental rabbit model of eyes with contact lens. METHODS: Cross-sectional, anterior segment optical coherence tomographic images of the inferior midperipheral cornea were obtained at baseline and at 5, 15, 30, 60, 90, and 120 min after the instillation of 3% diquafosol ophthalmic solution in 10 Japanese white rabbits wearing contact lenses. From the obtained images, the areas of the PLTF and PoLTF were calculated. Both artificial tear solution and 0.1% sodium hyaluronate ophthalmic solution were used for comparison. RESULTS: Significant fluid accumulation in both the PLTF and PoLTF was observed after diquafosol instillation, whereas no fluid accumulation was visible after the instillation of artificial tear or sodium hyaluronate. The increase in PLTF area after diquafosol instillation was significantly higher (P<0.01) at 15 and 30 min than that after the instillation of artificial tear or sodium hyaluronate. The increase in PoLTF area up to 60 min after the instillation of diquafosol was significantly higher (P<0.01) than that after the instillation of either of the other two drugs. CONCLUSIONS: Instillation of 3% diquafosol ophthalmic solution increases PLTF and PoLTF in rabbit eyes with contact lenses. Diquafosol has potential as a treatment option for contact lens-related dry eye.

Prolonged increase in tear meniscus height by 3% diquafosol ophthalmic solution in eyes with contact lenses.

PURPOSE: This study aimed to evaluate the increase in tear meniscus height (TMH) induced by 3% diquafosol ophthalmic solution in eyes with contact lens (CL). METHODS: Ten healthy subjects wearing high-water-content CLs received topical instillation of two ophthalmic solutions - 3% diquafosol ophthalmic solution in one eye and artificial tears in the other eye. Lower TMH was measured at 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 60 minutes after instillation by anterior segment optical coherence tomography. RESULTS: TMH increased significantly (P<0.001) at 5 minutes and 15 minutes after instillation of saline compared with the baseline values. After instillation of 3% diquafosol ophthalmic solution, TMH significantly increased (P<0.05) at 5 minutes, 15 minutes, 30 minutes, and 60 minutes compared with the baseline values. Increases in TMH after diquafosol instillation were significantly greater (P<0.05) at 15 minutes, 30 minutes, and 60 minutes than increases in TMH after saline instillation. CONCLUSION: Topical instillation of 3% diquafosol ophthalmic solution increases TMH for up to 60 minutes in eyes with high-water-content CLs.

Prominent Decrease of Tear Meniscus Height With Contact Lens Wear and Efficacy of Eye Drop Instillation.

OBJECTIVE: To investigate the change in tear meniscus height (TMH) before and after wearing soft contact lenses (CLs) of different water contents (WCs) and the influence of eye drop instillation on TMH during CL wear. METHODS: Tear meniscus heights were measured using anterior segment optical coherence tomography in 20 normal subjects wearing a high-WC CL (WC, 69%) in 1 eye and a low-WC CL (WC, 24%) in the other. Tear meniscus height change after eye drop instillation with 3% diquafosol ophthalmic solution or saline with CL wear was evaluated at 5, 15, 30, and 60 min after instillation. RESULTS: A significant decrease in TMH was observed after lens insertions of both CLs. Tear meniscus height was significantly decreased with high-WC CL wear compared with that with low-WC CL wear. With high-WC CL wear, TMH increased significantly (P<0.001) at 5 min after the instillation of 3% diquafosol ophthalmic solution compared with the baseline values and then returned to the pre-instillation level. No significant TMH changes were found with the instillation of either eye drop (diquafosol or saline) with low-WC CL wear. CONCLUSIONS: Tear meniscus height decreased with CL wear, especially with high-WC CL wear. Significant increases in TMH were observed at 5 min after the instillation of diquafosol ophthalmic solution with high-WC CL wear. The increases in TMH after diquafosol instillation tended to be greater than those after saline instillation at least for 30 min with both high-WC and low-WC CLs.