Yozo Tsuchida

Risk factors for diabetic choroidopathy in patients with diabetic retinopathy

AbstractPurpose. To identify risk factors for diabetic choroidopathy in patients with type 2 diabetes. Methods. Forty-five consecutive patients with diabetic retinopathy underwent simultaneous indocyanine green angiography (ICG) and fluorescein angiography using a double detector and confocal scanning laser ophthalmoscopy in both eyes. Choroidal vascular abnormalities were evaluated by comparing the angiographic findings derived from the two methods. We analyzed the association between the presence of abnormal choroidal lesions evident on ICG angiography and several risk factors. Results. Choroidal abnormalities evident on ICG angiography but not on fluorescein angiography included hypofluorescent spots in 72 eyes (80%) of 40 patients (89%), small hyperfluorescent spots in 61 eyes (68%) of 35 patients (78%), and large hyperfluorescent spots in 32 eyes (36%) of 21 patients (47%). The severity of diabetic retinopathy was significantly associated with the presence of hypofluorescent spots (P=0.002, Cochran–Armitage test) in both eyes and with the small hyperfluorescent spots in the right eyes (P=0.047, Cochran–Armitage test). Glycosylated hemoglobin levels were significantly associated with the large hyperfluorescent spots in the right eyes (P=0.003, Fishers exact probability test), and the treatment regimen was significantly associated with the small hyperfluorescent spots in the left eyes (P=0.048, chi-square test). Conclusion. These data suggest that risk factors influencing the prevalence of diabetic choroidopathy in patients with type 2 diabetes mellitus may include severity of diabetic retinopathy, degree of diabetic control and treatment regimen.

Trehalose eye drops in the treatment of dry eye syndrome

OBJECTIVE Trehalose can protect human corneal epithelial cells in culture from death from desiccation. This study was designed to test the efficacy and safety of trehalose eyedrops in the treatment of moderate to severe dry eye syndrome. DESIGN A randomized, double-masked, dose-ranging, fellow eye-controlled clinical trial. PARTICIPANTS Thirty-four patients with moderate to severe dry eye syndrome. METHODS The patients used either 100 or 200 mM trehalose dissolved in saline six times daily in one eye and control saline in the other eye for 4 weeks. MAIN OUTCOME MEASURES Symptoms and signs in both eyes were recorded separately at baseline, 2 weeks, and 4 weeks. RESULTS Fluorescein and rose bengal staining scores of the ocular surface improved at both 2 weeks and 4 weeks in the eyes with 100 and 200 mM trehalose, compared with eyes with control saline (P = 0.0030 to P < 0.0001, respectively, Mann-Whitney U test). Tear film breakup time became significantly longer at 2 weeks and 4 weeks with 100 mM trehalose (P = 0.0024 and P < 0.0001, respectively), but not with 200 mM trehalose. No adverse effect attributable to trehalose solution was noted. CONCLUSIONS Trehalose solution was an effective and safe eyedrop for the treatment of moderate to severe dry eye syndrome in this group of patients.

Choroidal abnormalities in Behçet disease observed by simultaneous indocyanine green and fluorescein angiography with scanning laser ophthalmoscopy

OBJECTIVE To examine choroidopathy in patients with Behçet disease. DESIGN Prospective clinical study. PARTICIPANTS Thirty-three patients (63 eyes) with Behçet disease. INTERVENTION Patients underwent simultaneous indocyanine green (ICG) and fluorescein angiography with a double detector of scanning laser ophthalmoscopy. MAIN OUTCOME MEASURES Angiographic findings recorded on videotapes were evaluated. The relation of angiographic findings with systemic activity and aqueous inflammation was also analyzed. RESULTS Fluorescein angiography showed leakage in varying degrees from retinal vessels in 30 patients (53 eyes, 84%). The ICG angiographic findings were choroidal vascular wall staining in 16 eyes (25%), hyperfluorescent spots in 42 eyes (66%) and hypofluorescent plaques in 22 eyes (35%), both of which were not evident with fluorescein, leakage from choroidal vessels in 3 eyes (5%), and irregular filling of choriocapillaris in 11 eyes (17%). These findings did not have a statistically significant correlation with the presence or absence of aqueous inflammation or oral aphthous ulcerations. CONCLUSIONS The patients with Behçet disease showed choroidal abnormalities, which could be revealed only by ICG angiography, but not with funduscopy or fluorescein angiography. Simultaneous ICG and fluorescein angiography would be useful for examining choroidal lesions in Behçet disease.

Retinal circulation times in quantitative fluorescein angiography.

We tried to obtain an overview of the quantitative state of the retinal circulation. Optical density measurements by an image analyzer were performed on video fluorescein angiograms for the determination of dye-dilution curves. To ensure that curves with a sharp peak were obtained, 1 ml sodium fluorescein 10% was flushed with 20 ml physiological saline. From dilution curves of a retinal arteriole and the corresponding venule, various retinal circulation times, T (x) (x=1, 25, 50, 75, and 100) and Tm, were calculated. T(1) corresponds to the difference in the time of initial dye appearance; T(50), to the so-called half-maxim time difference; T(100), to the difference in the time to peak intensity; and Tm, to the mean circulation time. T(50) showed the best reproducibility when it was examined at 49 retinal regions of 10 healthy volunteers with a double video-fluorescein angiogram that was obtained within 1 min. Normal values (mean ± SD) at the temporal superior region of 37 healthy volunteers were as follows: T (1) = 0.87 ± 0.66 s, T(25)=1.52±0.48 s, T(50)=1.83±0.50 s, T(75)=2.12±0.56 s, T(t00) = 2.73±0.76 s, and Tm = 2.69±1.25 s. We believe that these values give a general overview of the quantitative state of normal retinal circulation.

Time-Frequency Analysis of Electronystagmogram Signals in Patients with Congenital Nystagmus

PurposeTo evaluate the usefulness of the short-time Fourier transform (STFT) in the analysis of temporal congenital nystagmus characteristics.MethodsWe carried out an observational case series in patients with congenital nystagmus. An electronystagmogram (ENG) recording was performed for 300s in 13 consecutive subjects with congenital nystagmus (age: 7–68 years). Digitized ENG signals (12 bits, 100Hz) were divided into 2-s segments with a Hanning window, and a Fourier transform was carried out for each segment. The power spectrum obtained for each segment was graphically reconstructed as a function of time. The results were compared among the patients.ResultsClear periodicity in the time-frequency distribution was observed in 3 of the 13 patients (23%). One of the three patients was diagnosed with periodic alternating nystagmus, but the other two patients showed periodicity without alternation of beat direction. No significant difference was observed in clinical characteristics, except for sex, between patients who showed periodicity and those who did not.ConclusionsSome patients with congenital nystagmus showed clear periodicity in the nystagmus waveform without alternation of beat direction. The STFT is a useful tool to evaluate the temporal characteristics of congenital nystagmus in clinics.

Evaluation of the Dynamics of Choroidal Circulation in Experimental Acute Hypertension Using Indocyanine Green-stained Leukocytes

PURPOSE To evaluate the dynamics of choroidal circulation in experimental acute hypertension, using the indocyanine green leukocyte angiography (ILA) method, which the authors have developed for the evaluation of leukocyte dynamics in choroidal circulation. METHODS Japan White rabbits were used in the present study. Leukocytes were collected by centrifugal separation of the autologous blood, and were stained with indocyanine green (ICG) dye. The ICG-stained leukocyte fluid was injected into an ear vein, and fundus images were obtained by infrared laser and a scanning laser ophthalmoscope. Experimental acute hypertension was induced by the intravenous drip injection of angiotensin II (AII). RESULTS The fluorescent dots rapidly moved in choroidal arteries at a decreasing velocity, passed very slowly through choroidal capillaries and drained into choroidal veins. Under normal blood pressure, the mean leukocyte velocities in arteries, capillaries and veins were 8.63+/-1.68, 0.52+/-0.07, and 6.96+/-2.20 mm/s, respectively. On the other hand, the respective mean velocities in acute hypertension induced by AII were 13.50+/-1.82, 0.81+/-0.09, and 10.54+/-3.91 mm/s. Besides flow velocity, no change in leukocyte dynamics was observed. CONCLUSIONS Under the condition of acute hypertension induced by AII, leukocytes moved faster in the total choroidal circulation (from arteries to veins) compared to their velocity under the condition of normal blood pressure. Blood velocities might increase in the total choroidal circulation at an early stage in acute hypertension induced by AII, resulting in increased choroidal blood flow. ILA makes it possible to evaluate the changes in choroidal circulation under various pathologic conditions.