BACKGROUND:Bulous keratopathy has an increasing annual incidence, but its treatment is restricted by few sources of materials for corneal transplantation and high cost of operation. Additionaly, some patients who present with serious symptoms have little chance of recovery and low success in corneal transplantation. Amniotic membrane from the corneal stroma has a rich source with low cost, which can effectively relieve the symptoms and improve the quality of life in patients.
OBJECTIVE:To observe the therapeutic efficacy of amniotic membrane implantation into the corneal stroma in the treatment of bulous keratopathy.
METHODS: Forty healthy adult New Zealand rabbits (half male and female) were randomly divided into four groups (A, B, C, D groups), with 10 rats in each group. Rabbit models of bulous keratopathy were made in the groups A, B, C. At 2 weeks after modeling, amniotic membrane implantation into the corneal stroma and corneal surface was performed in groups A and B, respectively, and in group C, corneal lamelar dissection was done but with no amniotic membrane transplantation. In group D, there was no surgical treatment (blank control). A slit lamp microscope with constant crack width and angle of light projection was used to observe the central corneal thickness, and corneal opacification degree, corneal epithelial bula of rabbits were observed at different time in each group. Under microscope, the rabbit corneal endothelial cels and healing were observed at different time.
RESULTS AND CONCLUSION: At 1 day and 2 weeks after transplantation, the central corneal thickness of rabbits had significant differences in the four groups (P< 0.05). At 4, 8, 12 weeks after transplantation, the central corneal thickness of rabbits showed no difference between groups A and B as wel as between groups C and D (both P > 0.05), but there was a significant difference between groups A, B and group C (P < 0.05). At 4 and 8 weeks after transplantation, the degree of corneal opacity was significantly better in group A than the other three groups (P < 0.05). There were obvious scars forming at the incision of rabbits in the group C. Compared with the other three groups, the bula was improved better in the group A (P < 0.05). At 2 weeks after transplantation, bulous keratopathy relapsed in the group B, and symptoms of edema with bula were stil seen in groups C and D at 12 weeks after transplantation. These findings indicate that amniotic membrane implantation into the corneal stroma can effectively repair rabbit corneal endothelial cels and aleviate the symptoms of edema, but its specific mechanism need to be further studies.

IgG4⁃related sialadenitis (IgG4⁃RS) is a type of autoimmune disease that has been recognized in recent years, and the pathogenesis remains unclear. IgG4⁃RS mainly affects the submandibular gland and parotid gland and is characterized by diffuse painless swelling of the bilateral salivary glands and/or lacrimal glands, usually lasting more than 3 months. Some patients have accompanying hearing loss or hearing impairment, sinusitis, lymphadenopathy and other symptoms; nearly half of patients have different degrees of salivary gland secretion disorders. Most patients have elevated serum IgG4 levels, but they cannot be used as the only marker for diagnosis. Histopathology remains the“gold standard”for diagnosis. Presently, submandibular gland biopsy is often used for diagnosis. Histopathology showed lym⁃phoplasmacytic infiltration, occlusive phlebitis, striated fibrosis; immunohistochemistry showed IgG4 + /IgG + plasma cells >40%, and IgG4 + plasma cell/high⁃power field vision > 10. Glucocorticoids are regarded as first⁃line drugs for the treat⁃ment of this disease. Clinically, glucocorticoids are often combined with immunosuppressive agents such as cyclophos⁃phamide, but no standard drug regimen exists. Most patients have a significant short⁃term treatment effect, and the long⁃term prognosis requires further study. Patients with a recurrence tendency should adjust the hormone dose over time. In the future, further research is needed regarding the pathogenesis and treatment of the disease to improve the clinical di⁃agnosis rate and therapeutic effect.