It has been recognized that HLA-B27-associated uveitis is the most common cause of hypopyon uveitis in the United States. 1 The aim of our study was to determine common causes of hypopyon uveitis in Japan and to clarify the incidence of hypopyon in each disease entity. In addition, we present the clinical features of hypopyon uveitis in Japan.
Patients and Methods
We retrospectively reviewed the clinical records pertaining to 114 eyes in 93 patients with hypopyon uveitis who visited the Hokkaido University Hospital, Sapporo, Japan, from 1991 to 1998. The total number of patients with uveitis who visited our clinic during this period was 1,243. Of the 93 patients with hypopyon uveitis, 56 were men and 37 were women, and their ages ranged from 10 to 69 years. The mean age of the patients was 39.9 years.
We examined the etiology of uveitis, the incidence of hypopyon in each disease entity, visual acuity at the onset of hypopyon uveitis, accompanying ocular findings, treatment, and final visual acuity. Although hypopyon formation was observed several times in one patient, we selected only the visual acuity at the first episode of hypopyon formation.
Laterality of Uveitis with Hypopyon
Bilateral uveitis was observed in 67 patients (72%), and unilateral uveitis was seen in 26 patients (28%). Among the bilateral uveitis patients, bilateral hypopyon was seen in 21 patients (31%) and unilateral hypopyon in 46 patients (69%).
Locations of Principal Uveitic Lesions
There were 33 cases of anterior uveitis (35%) and 60 cases of panuveitis (65%).
Behçet's disease was found in 72 eyes in 55 patients (59%), HLA-B27-associated uveitis was present in 17 eyes in 15 patients (16%), and fungal endophthalmitis was seen in 3 eyes of 3 patients (3%) (Table 1). These diseases were followed, in frequency of occurrence, by ulcerative colitis–associated uveitis, diabetic iritis, and psoriasis-associated uveitis. We could not determine the etiology of anterior uveitis in 8 patients (9%) or that of panuveitis in 7 patients (8%).
Frequency of Hypopyon Formation in Each Disease Entity
The incidence of hypopyon formation was 8% among all patients with uveitis. Twenty-three percent of Behçet's disease patients had hypopyon uveitis, and as many as 50% of the patients with HLA-B27-associated uveitis and 38% of those with fungal endophthalmitis had hypopyon.
Frequency of Recurrent Hypopyon Formation
It is apparent that the frequency of recurrent hypopyon formation was much higher in Behçet's disease than in other diseases (Table 2). Sixty-three percent of Behçet's disease eyes showed recurrent hypopyon, whereas only 12% of patients with HLA-B27-associated uveitis suffered from recurrent hypopyon.
Visual Acuity at First Episode of Hypopyon Formation
The visual acuity of 74 eyes (65%) was worse than 0.1, whereas the visual acuity in 23 eyes (20%) was better than 0.6 (Table 3).
Accompanying Ocular Findings in Hypopyon Uveitis
The formation of posterior synechiae was quite common, occurring in 49% of the eyes with hypopyon uveits (Table 4). Fibrin was seen in the anterior chamber in 29% of the eyes with hypopyon uveitis. Folds in Descemet's membrane were observed in 14% of the eyes, and 4% of the eyes experienced increased intraocular pressure. Anterior chamber fibrin and the folds of Descemet's membrane were more likely to be observed in HLA-B27-associated uveitis than in Behçet's disease.
All patients were treated with corticosteroids and mydriatic eye drops. Periocular injection of corticosteroids was performed in 65 patients (70%). Systemic prednisone was given to 12 patients (13%). The dosage of the corticosteroids was from 20 to 40 mg/day.
Final Visual Acuity
The final visual acuity of 65 eyes (57%) was worse than 0.1. Of those 65 eyes, 58 had Behçet's disease (89%). Also of those 65 eyes, 2 with fungal endophthalmitis (3%) and 5 with panuveitis of unknown etiology (8%) showed poor final visual acuity.
The visual prognosis for patients with hypopyon uveitis is generally good. However, the final visual acuity is poor in patients with Behçet's disease. Therefore, it is important to discriminate between Behçet's disease and other diseases. Behçet's disease is the most common cause of hypopyon uveitis in Japan, and the recurrence of hypopyon is most frequent among patients with this disease. However, the rate of hypopyon formation in HLA-B27-associated uveitis is higher than that in Behçet's disease. Characteristically, hypopyon forms horizontally in Behçet's disease, whereas it swells in the middle in HLA-B27-associated uveitis. In addition, anterior chamber fibrin and folds in Descemet's membrane are more likely to be observed in HLA-B27-associated uveitis than in Behçet's disease.
Because the formation of posterior synechiae is common in eyes with hypopyon uveitis, first-stage treatment to prevent posterior synechiae is important. Therefore, we have frequently given mydriatic eye drops and topical corticosteroids to hypopyon uveitis patients. Systemic corticosteroids have not been commonly used.
Although hypopyon uveitis has been reported in patients with masquerade syndrome 2 or juvenile rheumatoid arthritis, 3 we have not seen such cases during the study period reported in this chapter. Nonetheless, ophthalmologists must keep these diseases in mind when making an etiological diagnosis of hypopyon uveitis.
1. D'Alessandro LP, Forster DJ, Rao NA. Anterior uveitis and hypopyon. Am J Ophthalmol 1991; 112: 317–321
2. Kuwayama W, Hanamura A, Maeda H. Case of hypopyon associated with malignant lymphoma. Ganka 1992; 34: 567–570
3. Akai Y, Haruta Y, Nakagawa Y, Yuasa T. Cases of chronic recurrent uveitis with hypopyon. Folia Ophthalmol Japonica 1986; 37: 201–206