Surgical Treatment of 32 Cases of Long-term Atopic Keratoconjunctivitis Using the Amniotic Membrane

J Yang; F-h Yang; C-H Peng; D Erol; S H Tsang; X-r Li

Disclosures

Eye. 2013;27(11):1254-1262. 

In This Article

Discussion

This study showed that even in eyes with refractory AKC, in which long-term immunological injuries had led to corneal damage because of misdiagnosis and mismanagement, appropriate surgical treatment could still result in significant, visible improvements of the corneal surface. Among all subjects treated with surgical intervention, only two recurrences were observed, both cases in which patients stopped the medication on their own. In addition, corneal epithelial erosions, ulcers, and perforations healed sooner after the surgery compared with the control group.

Chronic inflammation caused by AKC can be easily mistaken for other conditions and misdiagnosed (Figure 1). Disease mismanagement can allow the disease to worsen, making it subsequently harder to treat. Most cases in this study involved refractory corneal complications even after multiple medicinal treatments.

The surgical option was considered to avoid sight-threatening corneal sequelae. Surgical treatments with amniotic membrane tissue were tailored to the patients' symptoms. From our results, it is clear that although recovery is possible, once corneal deep ulcer and perforation have formed, the recovery time generally lengthens (Table 3). A correct AKC diagnosis and a suitable surgery involvement should be given as early as possible.

The lessons learned from these cases provide several key points to making a diagnosis. First, most patients have a history of atopic conditions, such as allergic rhinitis, eczema, and asthma dermatitis. Disease course is usually chronic, with most patients reporting more than half a year of history. Testing for serum IgE levels may help confirm the diagnosis. Vernal keratoconjunctivitis is another form of allergic keratoconjunctivitis involving high serum IgE, but is distinguished by its pattern of seasonally exacerbation.

It is well established that amniotic membrane has many properties that make it favorable for transplant surgeries: an avascular stromal matrix, anti-inflammatory, and anti-scarring properties, and the ability to enhance epithelialization, and so on.[10] Persistent and complicated corneal lesions are common in AKC patients. The treatment of AKC by AM transplantation has been discussed in a few case reports. Two case reports described successful corneal epithelialization after long-term corneal epithelial defects were treated with single AMT.[11,12] After AM transplantation, long-term corneal epithelial defects can heal dramatically. Some reports showed that for the smaller-sized (<1.5 mm) corneal ulcer and perforations, multiple layers of AM transplant surgeries have been used to treat the cornea with the stromal side facing the anterior chambers.[13,14] Multiple layers of AM not only rapidly epithelialized these small defects but also reduced ocular inflammation and resulted in recovery of corneal stromal thickness. As all of the surgical treatments of our 32 patients involved AM, and all featured different degrees of corneal ulcers or perforations, we have combined these features in a single report.

AMF and inlay filling are variations on a single approach: using multilayer AM to treat AKC in cases without any perforated ulcers or with smaller-sized perforations. Nonetheless, we would argue that a more exact placement of AM across corneal lesions would have improved outcomes in the cornea in this study. The differences between the AM fillings and multilayer AM transplants are that the former can allow the AM to completely fill the inside of the ulcer, bringing the AM and ulcer into direct contact and raising the surface area on which AM can have a direct effect. All the six patients who were treated by AMF and AMC healed relatively quickly, within 1 month, with no evidence of recurrence at 2-year follow-up.

For AKC cases featuring corneal perforations >1.5 mm, corneal path grafting may be considered. Rodriguez-Ares et al[13] have reported that the success rate of multilayer AM transplant surgery depends on perforation size: when corneal perforations are >1.5 mm, there is only a 40% chance that surgery will succeed. In addition, earlier surgeries have shown that corneal path grafts are suitable for cases with corneal perforations and severe corneal ulcers,[15] effectively restoring the integrity of the eye.

Such findings suggest that for larger perforations, corneal path grafts should be the first choice for treatment. However, patients with AKC and high serum IgE levels are thought to pose increased risks of graft rejection.[16] For this reason, we used glycerol-preserved corneal patches to treat AKC patients. Glycerol-preserved corneal tissue, in contrast to fresh tissue, is thought to lack antigen-presenting cells, and thus to be unable to directly sensitize the recipient T cells or lead to activation of an indirect immune transplant rejection pathway. This method could prevent allograft rejection and promote graft survival rate in high-risk corneas.[9] Applying 0.2% cyclosporine A eye drops after surgery may also maintain graft health,[17] as well as decrease the recurrence rate of AKC.

Recently, a novel AMIF technique was used to treat necrotic scleral calcification.[6] Inlay fillings were found to aid graft survival. We used the same methods combined with graft corneal transplant on 11 patients, testing whether AMIFs and coverings would stabilize the graft and promote healing. All patients showed efficient healing and no recurrences.

On the whole, surgical treatments using the tailored amniotic membrane may be highly effective for patients suffering from AKC. The disease is the most severe of all forms of ocular atrophy and may result in poor vision for many patients. Although clearly earlier correct diagnosis is needed, and therapy requires a multidisciplinary approach, for a subset of chronic AKC patients, surgical treatment may become an ultimate necessity. AM tissue, a source of nutrients with anti-inflammatory proprieties, not only can be used as an effective graft tissue but also may promote postsurgical recovery. Finally, AMCs, AM inlay fillings, and GCTs surgeries can be combined with highly effective results.

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