AIMS To investigate the clinical characteristics and compare the effects of several methods of treatment of Mooren's corneal ulcer.
METHODS 550 consecutive cases of Mooren's corneal ulcer were analysed in patients, including age, sex, laterality of eye, ulcer location, perforative rate, cure rate of surgeries, recurrent rate, the effects of conjunctiva excision, lamellar keratoplasty (LKP), and LKP plus 1% cyclosporin A eye drops.
RESULTS The average age of onset was 48.4 years of age. The ratio of males to females was 1:0.74. 165 (30%) cases had the disease bilaterally, of which 52 (31.5%) occurred in the young age group and 113 (68.5%) in the old age group. Ulcers of 501 eyes (70.1%) were located at the limbus of the palpebral fissure. The perforation rate was 13.3%, with perforation of 41 eyes (43.2%) occurring in the young age group and 54 (56.8%) in the old age group. Postoperative recurrence rate was 25.6%. The cure rate of the first procedure of LKP plus 1% cyclosporin A eye drops was 73.7%. The final cure rate was 95.6%, and the postoperative preservation rate of the eye globe was 99.7%.
CONCLUSION This primary study provided the clinical characteristics of patients with Mooren's corneal ulcer in China. LKP plus 1% cyclosporin A eye drops was an effective treatment.
- Mooren's corneal ulcer
- cyclosporin A
- lamellar keratoplasty
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Mooren's ulcer is a chronic, painful ulceration of the cornea with a steep, overhanging central and leading edge that starts in the periphery and may progress centrally or circumferentially to involve the entire cornea. It may be an autoimmune corneal disease1-3 that is hard to manage and can cause blindness. It was reported that the incidence of Mooren's ulcer in China was 0.03%.4 Between 1960 and 1996, 550 consecutive cases of Mooren's ulcer were seen in our hospital. The clinical characteristics of the disease and the effects of LKP surgery were retrospectively analysed as follows.
Patients and methods
Between 1960 and 1996, 550 consecutive cases (715 eyes) of Mooren's ulcer inpatients coming from different parts of China to our hospital were analysed. Of 550 patients, none of their relatives had Mooren's corneal ulcer. The geographic distributions of the patients are listed in Table 1 and their occupations in Table2.
Diagnosis of Mooren's ulcer
The diagnosis was established by the typical ulcer morphology (Fig1, Fig 2), detailed case history taking, physical examination, and comprehensive laboratory tests (erythrocyte suspension rate, antistreptolysin O, rheumatoid factor, and antinuclear antibody). Patients who had systemic diseases such as Wegener's granulomatosis, rheumatoid arthritis, and systemic lupus erythematosus, which could cause peripheral corneal ulcer, were excluded from the study. Patients who had a history of ocular trauma or surgeries were included (see Table 3). After samples of corneal lesions of 330 cases were pathologically examined, no infectious keratitis was found (Fig 3, Fig4).
Analysis of general condition of the patients—age, sex, and laterality of eye
The patients were divided into two groups according to age of onset; patients of 35 and younger were in the young age group, and those over 35 were in the old age group.
Analysis of the clinical characteristics and therapy effect of Mooren's ulcer
Analysis of the ulcer location, perforative rate, ocular complication, preoperative and postoperative vision, and recurrence of the ulcer was carried out. The effect of LKP was valued according to the three different stages of the surgery design. (1) From 1960 to 1975, the procedure was topical resection of the ulcer plus LKP. (2) From 1976 to 1989, the procedure was extensive excision of the ulcer and the corneal infiltrate, and episclera and conjunctiva adjacent to the ulcer plus LKP. In this stage, 2–3 mm sclera rim with the lamellar graft was used and fresh donor cornea was available for the patients. Crescent shape (Fig 5), doughnut shape (Fig 6), full lamellar graft (Fig 7), and double lamellar grafts (Fig 8) were adopted according to the shape of the corneal ulcer. Limbal sparing procedures were carried out for the crescent lamellar graft, but not for the doughnut and full lamellar grafts. (3) From 1990 to 1996, the procedure was LKP (same as that of (2)) plus topical 1% cyclosporin A eye drops, two to four times a day for 6 months to 1 year postoperatively. Cyclosporin A was provided by Sandoz Com, Switzerland. Cyclosporin A 1% eye drops were prepared by mixing cyclosporin A 30 ml (100 mg/ml) with olive oil solution, 270 ml, under sterile condition. The effect of conjunctival excision was analysed. Prednisolone 0.1% or dexamethasone 0.1% eye drops were given to all cases postoperatively for 3–6 months, two to four times a day. Antibiotic eye drops were given to all cases postoperatively for 2 weeks. Systemic immunosuppressants were not given to the patients for their Mooren's ulcer because they were expensive and also had some systemic side effects. We adopted topical immunosuppressants for the treatment of Mooren's ulcer.
The period of follow up was 1–7 years. When the patients were discharged they stayed in hotels near the hospital for 3–4 weeks so that they could conveniently come back to the hospital once a week for a check up. After that they went back to the central hospital (slit lamp microscope available) of their home town for eye examinations once a month during the first 6 months after the surgery. Six months later, they went to the central hospital every 3 months for eye examinations. Three monthly examinations lasted 1 year postoperatively.
The χ2 test was used to compare the treatments, while Mann–Whitney test to compare the effect on preoperative and postoperative vision.
The general conditions of the patients and clinical characteristics of the ulcer was summarised in Table 4. The symptoms, signs, and treatment of the patients in 10 year steps are summarised in Table 5.
AGE OF ONSET
Of 550 cases, the youngest patient was 14 years old while the oldest was 79 with the average age of the first onset being 48.4 years: 113 cases (20.6%) were in the young age group, 453 (79.4%) in the old age group.
Altogether 318 cases were male, and 232 cases female. The ratio of the male to the female was 1:0.74.
LATERALITY OF EYE
In all, 218 cases (39.6%) involved the right eye, 167 cases (30.4%) the left eye, and 165 cases (30%) both eyes. Fifty two cases (31.5%) of the bilateral disease occurred in the young age group, with 113 (68.5%) in the old age group.
LOCATION OF THE ULCER
Among the ulcerative eyes, in 332 eyes (45%) the corneal lesion covered half the limbus and in 150 ulcerative eyes (21%) it extended to the entire limbus. In 501 eyes the lesion (70.1%) involved either the medial or the lateral quadrant of the limbus. The degree of ulceration reached approximately from one third to one half of the corneal stroma.
Out of 715 eyes there were 95 eye perforations, of which 62 eyes (65.3%) were bilateral and 33 eyes (34.7%) unilateral; 41 perforated eyes (43.2%) occurred in the young age group, and 54 perforated eyes (56.8%) in the old age group.
LOCATION OF PERFORATION
Perforations occurred in the limbal cornea (48 eyes), in the peripheral cornea (32 eyes), and in the central cornea (15 eyes).
Of the 620 unperforated eyes, 42 eyes (6.8%) had mild anterior uveitis with fine dusty keratic precipitate and local posteria synechiae of the iris; 14 eyes (2.3%) had complicated cataract.
In all, 116 ulcerative eyes were treated with conjunctiva excision and corneal ulcer resection. Among the 116 eyes, 78 eyes were involved in one to two quadrants of the limbus, with cure rate of the first procedure being 51.3% (40 eyes); 38 eyes were involved in three to four quadrants of the limbus, with cure rate of the first procedure being 36.8 (14 eyes). Of the uncured 62 eyes, 23 eyes were given the second procedure, with four eyes being healed. The other 58 eyes were treated with LKP. The treatment effects of the three different stages are listed in Table 6.
Two eyes were enucleated because of endophthalmitis and secondary glaucoma due to the perforation (in the 1960s). The anatomical structure of 713 ulcerative eyes was preserved. The preservation rate was 99.7%. Nine cases did not undergo any surgery because of intestinal tract bleeding and other systemic diseases.
Visual acuity was, to some extent, improved postoperatively. The comparison of preoperative and postoperative visual acuity is listed in Table 7.
Of 550 cases, 141 cases had one or several postoperative ulcer recurrences and the postoperative recurrence rate was 25.6%; 99 cases (70.2%) had the first recurrence within 2–6 months after the surgery. The period of the multiple recurrence varied from 2 weeks to 15 years postoperatively. The location of the first recurrence was found to be the same as that before operation, and could also be found at the interface of the donor graft and the lamellar bed. The location of the multiple recurrence varied from the orginal ulcer location to that of normal cornea. From 1991 to 1996, one female patient experienced 10 recurrences, including two perforations. After 10 LKP surgeries, the anatomical structure of her eyes was preserved with visual acuity of the right eye being 0.05, and the left eye being 0.02. Of 141 cases of recurrence, 89 (63.1%) were bilateral and 52 (36.9%) unilateral; 46 (32.6%) of recurrence occurred in the young age group, and 95 (67.4%) in the old age group. Recurrence of the ulcer is summarised in Table 8.
CLINICAL CHARACTERISTICS OF MOOREN'S ULCER
Wood and Kaufman5 classified the disease into two groups according to the age of onset, clinical characteristics, and prognosis of nine cases. Type I was benign and usually unilateral with mild to moderate symptoms. This type was believed to occur in old people (over 35 years) and usually responded well to medical and surgical treatments. In contrast, the second type was more likely to be bilateral with relatively more pain and generally a poor response to the therapy. The second type was believed to occur in young patients (younger than 35), and became known as malignant Mooren's ulcer. Schanzlin6 reported that a bilaterality rate of 25% of cases of the benign type was found mostly in patients over the age of 35 and no difference of races was observed. The bilaterality rate of 75% of cases of the malignant type was discovered mostly in black patients younger than 35. Watson7 divided the disease into three types based on the clinical presentation and the low dose anterior segment fluorescein findings—that is, unilateral Mooren's ulcer, bilateral aggressive Mooren's ulcer, and bilateral indolent Mooren's ulcer. Lewallen and Courtright8 reviewed the literature on 287 cases of Mooren's ulcer and found that men were 1.6 times more likely to have Mooren's ulcer than women, and that 43% of older patients had bilateral disease, whereas bilateral disease was present in only one third of patients younger than 35. They pointed out that the data available did not support the clinical types of Mooren's ulcer classified by Wood and Kaufman. The clinical characteristics of Mooren's ulcer, the ratio of men to women patients, the liable age, laterality of eye, and the prognosis need to be further researched.
We retrospectively analysed 550 consecutive cases of Mooren's ulcer and found that the average age of the first attack was 48.4; 437 cases (79.5%) were over the age of 35, indicating that Mooren's ulcer was predominantly a disease of adults, and that the ratio of men to women was 1:0.74—that is, men were 1.35 times more likely to have the disease than women, which is similar to what was reported abroad—1.6 times.8 The right eye was involved in 39.6% of cases; the left eye was involved in 30.4% of cases, and the other 30% of cases had the disease bilaterally. Five hundred and one eyes (70.1%) had ulcers in the location of the limbus of palpebral fissure. The reason was not clear and probably related to the exposure of the limbus of palpebral fissure and fewer limbal stem cells in that position. Perforative rate of the disease was 13.3%, which was lower than the 36% reported by Keitzman.9 Ocular complications were mild anterior uveitis and complicated cataract. Taking initial recurrence as a standard, the postoperative recurrence rate was 25.6%. Initial recurrence occurred mostly within 6 months after the surgery. The ulcerative limbus of preoperation and the interface of the donor graft and the lamellar bed were the recurring positions. The period of multiple recurrence varied from 2 weeks to several years postoperatively. The location of the multiple recurrence was vastly different. The immunogical mechanisms of the initial and multiple recurrence may be different and need to be studied. The data, to some extent, reflect the clinical characteristics of Mooren's ulcer in China as they were collected from patients of different provinces of the country.
Mooren's ulcer has occurred after corneal trauma and eye surgery.10 Zegans et alreported that the patients who had a history of corneal trauma, surgery, or infection made up 68% (13/21) of patients with Mooren's ulcer.11 Lewallen and Courtright reported that the patients who had a history of corneal trauma or surgery accounted for 29.6% (85/287).8 Our results showed that 10.7% of the patients had ocular trauma or surgery before they got Mooren's ulcer. It is not clear yet why there is such a great difference in reported ratios of patients with Mooren's ulcer who had a history of corneal trauma or surgery. The difference in the effect of ocular trauma on Mooren's ulcer is not clear either. From the above, we consider that the relation between ocular trauma and Mooren's ulcer needs to be further studied.
Based on the facts of bilaterality, perforation, and recurrence, our results do not support the classification proposed by Woodet al 5—that is, the old age group was benign, and the young age group was malignant. Our results show that in both young and old age groups the perforation rate and recurrence rate of the bilateral cases are much higher than those of unilateral ones. We believe that the bilateral disease is the malignant type of Mooren's ulcer.
EVALUATION OF EFFECT OF LKP SURGERY OF MOOREN'S ULCER AND FACTORS INFLUENCING CURE RATE OF THE DISEASE
The main approaches to the management of Mooren's ulcer include conjunctival excision, keratoepithelioplasty,12 of which, fresh donor corneal lenticules are placed near the distal side of the ulcerated area and securely sutured on the bare sclera, LKP, and immunosuppressive treatment. Among them, LKP is widely used at present.
LKP surgery of Mooren's ulcer removes antigenic targets of the cornea, prevents immunogical reactions, reconstructs the anatomical structure, prevents it from perforating, and improves vision. The results indicate that the final healing rate of Mooren's ulcer treated with resection of the corneal lesion and adjacent conjunctiva combined with LKP surgery is 89.6%, and the final healing rate of LKP plus topical 1% cyclosporin A is 95.6%. The anatomical structure of cornea of 99.7% of the ulcerative eyes is preserved. We consider LKP surgery to be the most effective treatment of Mooren's ulcer at present.
The principle of LKP surgery of Mooren's ulcer is to remove necrotic ulcerative cornea thoroughly and to reconstruct anatomical structure of the cornea. The designs for surgery depend on the shape of the ulcer and infiltrate of the cornea. If the ulcer is smaller than a half circle of the limbus and the central area of the cornea, 7–8 mm in diameter, is not involved, crescent shaped lamellar graft is used so as to prevent the cornea from perforation. If the ulcer is larger than two thirds of a circle of the limbus, and the central 7–8 mm of the cornea is intact, then a doughnut shaped lamellar graft is used to maintain the refractive power of the central cornea. If the central cornea is involved, a full lamellar graft is used to maintain useful visual acuity. Double lamellar grafts are used for perforation of the peripheral cornea—that is, a fresh thin inner graft with corneal endothelial cells is used to repair the perforation, on the upper part of the inner graft is another lamellar graft whose shape depends on the shape of the ulcer. The anterior chamber is reformed for fresh perforation in the course of the operation. If the perforation lasts for 5–7 days, the herniated iris should be cut off to prevent implanted epithelial cyst. If the entire cornea is involved and with its central perforation, a full thickness graft and a penetrating keratoplasty are used to reconstruct the anterior segment of the eye. In all the four types of LKP surgery cornea lamellar graft with 2–3 mm sclera rim should be used and fresh donar graft should also be used for transplantation of allograft corneal limbal stem cells to the recipient to reconstruct the corneal surface and the “base” of the stem cells13 (which is beneficial to the reduction of ulcer recurrence due to inadequate epithelialisation). We used fresh donor cornea graft mostly for doughnut and full lamellar keratoplasties, and epithelial failure as a result of stem cell failure was hardly observed.
Since 1960 we have experienced three stages of design.14-17 The treatment effect, healing rate of the first procedure, and the final healing rate (more than one procedure) are significantly improved. The improvement in the treatment has something to do with the following: (1) thorough removal of corneal ulcer and infiltrate; (2) excision of conjunctiva and episclera adjacent to the corneal ulcer combined with LKP surgery; (3) application of fresh lamellar graft with sclera rim (having the limbal stem cells); (4) agood host-graft junction; and (5) topical use of steroids and 1% cyclosporin A postoperatively. LKP surgery plus 1% topical cyclosporin A is an effective treatment of Mooren's ulcer when these five principles are practised. Even if one procedure fails, regrafting can give patients the chance of ulcer healing and maintaining visual acuity.