Clinical Study On The Application Of Biological Amniotic Membrane And Conjunctival Flap In Refractory Corneal Ulcers

Objectives:To evaluate the clinical efficacy of biological amniotic membrane covering,conjunctival flap coverage,staged conjunctival flap and biological amniotic membrane coverage in the treatment of refractory corneal ulcers.Methods:The clinical records of 49 eyes of 45 patients with refractory corneal ulcers from 2016 to 2019 were analyzed retrospectively.These patients were treated with one kind of those operative methods:biological amniotic membrane covering,conjunctival flap coverage,staged conjunctival flap and biological amniotic membrane coverage.The main outcome measure of the patients treated with biological amniotic membrane is corneal epithelial healing rate.The outcome index of the ulcerative patients treated by conjunctival flap coverage is the healing rate of conjunctival flap in the first operation.Visual acuity,conjunctival congestion and corneal opacity scores were the main effectiveness indexes of the patients treated with staged conjunctival flap coverage and biological amniotic membrane coverage.Results:23 of 45 patients were treated with biological amniotic membrane covering,including 14 males and 9 females,with the average age of 52.17±13.49 years.There were 27 eyes in this part,15 eyes in the right eye and 12 eyes in left.The ulcer site of 13 eyes was located in the center of cornea and the others were in the periphery.The average area of corneal ulcers was 0.32.The number of chemical injuries was the largest,followed by the patients with virus.One time of amniotic membrane covering was sufficient to heal ulcers in 65.22%of patients,34.78%of the patients had not healed the epithelial of corneal ulcer and they received multiple times of amniotic membrane coverage or tarsorrhaphy.The highest healing rate of corneal epithelium was found in viral ulcers(83.33%),followed by chemical injured(66.67%)and thermal burned ulcers(50%),and the lowest healing rate was immunological and neurotrophic ulcers(33.33%).15 patients were treated with conjunctival flap,including 10 males and 5 females.Their mean age was 55.27±14.47 years.There were 9 eyes in the right eye and 6 eyes in the left eye.Among the 15 cases,80%of them were infectious corneal ulcers,mainly caused by fungi and Acanthamoeba.The ulcerative site of 14 eyes was located in the center of cornea and one eye was in the periphery.The average size of corneal ulcer was 0.28,the largest one was 0.79.After one time of operation,the conjunctival flap healed well in 13 patients,dissolved in 2 patients and who received the second time of conjunctival flap coverage.The success rate of conjunctival flap operation was 86.67%There were 7 patients including 6 males and 1 female in the part of staged conjunctival flap and biological amniotic membrane coverage,whose average age was 50.86 ± 14.46 years.There were 4 eyes in the right eye and 3 eyes in left.For the pathogeny of 7 cases,three of them was fungi,two of them was fungi and acanthamoeba,one of them was HSK,and the another one was thermal burn.The ulcer sites of 5 eyes were located in the central cornea,2 eyes were located in the periphery.At the initial time,the largest amount of hypopyon in all eyes was 3 mm,and the average size of ulcers was 0.34.There was no difference in corneal ulcers size through the treatment of medication.The conjunctival congestion scores of all patients were significantly differential before and after two-staged operation,while there were no difference in visual acuity and corneal opacity scores.At last,one eye of all eyes was corneal nebula,4 eyes of them were corneal macula and corneal leukoma in 2 eyes.Conclusions:1.Biological amniotic membrane covering is an effective method for the treatment of the refractory corneal ulcers,such as chemical injured,viral,immunological and neurotrophic ulcers2.Conjunctival flap coverage is an available method for the treatment of severe infectious refractory corneal ulcers when there is no conditions for keratoplasty or amniotic membrane transplantation.3.In the absence of corneal donors or patients unwilling to accept keratoplasty and other situations,staged surgery can be used as an alternative surgical treatment for the patients with refractory corneal ulcers and the grassroots hospitals without qualification for keratoplasty.