“Sunset Glow” Fundus in Vogt–Koyanagi–Harada Disease
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Quantitative Evaluation of “Sunset Glow” Fundus in Vogt–Koyanagi–Harada Disease Saburosuke Suzuki Department of Ophthalmology, Keio University, School of Medicine, Shinjuku, Tokyo, Japan Purpose: To evaluate the color of the fundus quantitatively, especially the “sunset glow” fundus, in patients with Vogt–Koyanagi–Harada (VKH) disease. Methods: The fundus of 39 patients (13 men and 26 women) who were diagnosed with VKH disease were photographed. The photographs were scanned by a film scanner and the amount of red, green, and blue pixels making up the image was determined by image analyz- ing software. A “sunset glow” index, the ratio of the number of red pixels to the total number of pixels, was determined for all patients as well as 31 normal controls. Results: In comparison to the controls, the “sunset glow” indices at 3 months after onset of the “sunset glow” fundus showed significant increases in VKH patients. Six months after on- set, the “sunset glow” indices showed further significant increases and continued to increase during the course of the disease. Conclusions: The depigmentary changes can be found earlier by using our method rather than ophthalmoscopy. Because our method is more sensitive for slight depigmentary changes, the pigmentary changes in the fundus could be found in all the VKH patients. This quantitative evaluation of the fundus makes a correct diagnosis possible even in patients who do not demonstrate the “sunset glow” fundus by normal ophthalmoscopic examinations. Jpn J Ophthalmol 1999;43:327–333 © 1999 Japanese Ophthalmological Society Key Words: Quantitative evaluation, sunset glow fundus, uveitis, Vogt–Koyanagi–Harada disease. Introduction ever, patients exhibiting the characteristic ocular findings, but who lack the systemic findings are re- Vogt–Koyanagi–Harada (VKH) disease is a sys- 1–3 temic disorder that involves tissues in many organs ported as suffering from VKH disease. In the ocular aspects of VKH disease, the “sunset (eg, eye, ear, skin, meninges, and hair). VKH disease glow” fundus has been thought to be the most im- is thought to be an autoimmune disease directed portant finding.4 Because the Vogt–Koyanagi type against the melanocytes in systemic organs, espe- (iridocyclitis type) of VKH disease often shows gran- cially the eyes. The most common ocular finding in ulomatous iridocyclitis but not exudative retinal de- VKH disease is bilateral granulomatous iridocyclitis tachment, its diagnosis can be done in the convales- with exudative retinal detachment. For diagnosis, cent stage. These patients are diagnosed as having the important symptoms are not only the character- VKH disease by the presence of the “sunset glow” istic ocular findings but also the systemic findings of fundus that appears 2–6 months after the onset. poliosis, dysacousia, alopecia, vitiligo, cerebrospinal In the last two decades, widespread use of high- fluid pleocytosis, and meningeal symptoms. How- dose, systemic steroid therapy has changed the clini- cal features of VKH disease.3,5 Many VKH disease Received: December 17, 1997 patients can be cured and have no severe complica- Correspondence and reprint requests to: Saburosuke SUZUKI, tions or severe atrophic changes of the fundus and MD, Department of Ophthalmology, Keio University, School of 3,6 Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-0016, Japan skin. In recent reports, some VKH disease patients did not show the “sunset glow” fundus after high- Jpn J Ophthalmol 43, 327–333 (1999) © 1999 Japanese Ophthalmological Society 0021-5155/99/$–see front matter Published by Elsevier Science Inc. PII S0021-5155(99)00016-7 328 Jpn J Ophthalmol Vol 43: 327–333, 1999 dose systemic steroid therapy. Because the color of index (I). This index is the ratio of the number of red the fundus depends on race and the individual, the pixels to the total number of pixels (red, green, and 5 1 1 “sunset glow” fundus is a subjective and not an ob- blue) in a fundus image (Ptotal Pred Pgreen 5 jective diagnostic criterion. Therefore, we have not Pblue): I Pred/Ptotal. been able to diagnose patients as having VKH dis- We compared the “sunset glow” indices of VKH ease if they have no systemic findings at the onset disease patients with the indices we had recorded in and also do not show the “sunset glow” fundus after normal controls (31 eyes of 31 subjects, 15 men and high-dose, systemic steroid therapy. 16 women, aged 10–77 years, average age 5 32.9 In this report, we make a new attempt to eval- years), who had no eye diseases except refractive uate the color of the fundus quantitatively, especially disorders. We evaluated the “sunset glow” indices the “sunset glow” fundus, in patients with VKH for the patients throughout the course of their disease. disease. In normal controls, the “sunset glow” indices ranged from 0.48 to 0.60, with an average of 0.55. Materials and Methods Neither refractive disorders (Figure 3) nor age (Fig- We analyzed the records of 39 patients (13 men ure 4) significantly affected the “sunset glow” indices and 26 women) who were diagnosed with VKH dis- of the controls. ease at the uveitis clinic of the Keio University Hos- Because the distribution of the “sunset glow” indi- pital. All patients had the typical bilateral ocular ces was not normal, nonparametric methods were findings of VKH disease as well as cerebrospinal used in analysis. Statistical analysis for two indepen- fluid pleocytosis in the acute stage or marked “sun- dent samples was performed using the Mann-Whit- set glow” fundus in the convalescent stage. They met ney U test. The means and standard errors were cal- the criteria for Vogt–Koyanagi–Harada disease es- culated to help visualize the data, but were not used tablished in 1977 by the Third Japanese Uveitis in the statistical analysis. Meeting,4,7 and also met the criteria established in 1978 by the American Uveitis Society.8 Case Reports Fundus photographs were taken several times with a fundus camera (Kowa RC-W, TRC-50X; Top- The following two case reports show two typical con, Tokyo) on slide film (35 mm reversal color film courses of change in the “sunset glow” indices of the RD ISO 100; Fuji, Tokyo) during the clinical course VKH patients. of their disease. The age at disease onset ranged from 16 to 77 years, the average age was 40.9 years. Case 1 All patients were treated with high-dose systemic The first case was a 17-year-old woman with mod- steroids. The initial dose of steroids (drip infusion of erate iridocyclitis and swelling of the optic disc with betamethasone 16–20 mg per day) was tapered to exudative retinal detachment surrounding the optic oral prednisolone (30 mg per day) for 2 weeks. Then, disc in both eyes (Figure 5). Because she showed it was gradually tapered off in 4–6 months. Despite common cold–like symptoms and cerebrospinal fluid treatment, some of these VKH disease patients pleocytosis, we diagnosed her as having VKH dis- showed prolonged inflammation. ease. She was treated with a high-dose of systemic Patient fundus slides (35 mm) were scanned by a steroids that was tapered over 4 months. After the film scanner (Coolscan; Nikon, Tokyo), and placed systemic steroid treatment, we could not find any in- in the file of a personal computer (Quadra 800; Ap- flammation in her eyes. Her vision remained 1.2 in ple Computer, Cupertino, CA, USA) (Figure 1). both eyes. However, her “sunset glow” indices grad- The images were then analyzed by image analyzing ually increased over the follow-up period of 2 years software (Photoshop version 3.0; Adobe Systems, after her initial treatment. Figure 5 shows the rela- Mountain View, CA, USA) under full color condi- tionship between the photographs and the “sunset tions (16,400,000 colors). We measured the posterior glow” indices. Her “sunset glow” indices continued part of the fundus, which did not contain the optic to increase during the course of her disease. disc. On the monitor, the fundus images consisted of red, green, and blue components (the RGB images). As shown in Figure 2, we measured the number of Case 2 red, green, and blue pixels that composed the RGB A 23-year-old man showed granulomatous iri- images of the fundus to determine the “sunset glow” docyclitis with exudative retinal detachment in both S. SUZUKI 329 “SUNSET GLOW” FUNDUS IN VKH DISEASE Figure 1. Fundus photograph scanned and displayed on monitor. Area sur- rounded by dotted line was measured. Figure 2. RGB (red, green, and blue) images of fundus are divided into three histograms. In histograms, horizontal bar shows brightness of each color. Below each histogram, mean, standard deviation, median, and total number of pixels for each color are shown. This figure is the mean of three measurements. 330 Jpn J Ophthalmol Vol 43: 327–333, 1999 ure 7, top row of asterisks), the “sunset glow” indices of patients did not show significant increases at 1 month. Three months after onset, there were statisti- cally significant increases in the “sunset glow” indi- ces of all VKH patients. As compared with the stage (Figure 7, bottom row of asterisks) at which the exu- dative retinal detachments disappeared (1 M 5 1 month after onset), the “sunset glow” indices at on- set and those at 3 months after onset did not show statistical differences. However, 6 months after on- set, the “sunset glow” indices showed statistically significant increases and continued to increase dur- ing the course of the disease. Figure 8 shows the course of the different types of VKH disease. In the Harada type patients (open symbols) who were treated with high-dose, systemic steroid therapy and were cured without prolonged Figure 3.