R. Sugawara

Alteration of choroidal circulation in the foveal region in patients with type 2 diabetes

Aim: To investigate changes in choroidal blood flow (CBF) in the foveal region in patients with type 2 diabetes. Methods: Laser Doppler flowmetry was used to determine the CBF in the foveal region in 70 patients with type 2 diabetes and 36 age and sex matched healthy subjects (control group). The patients were classified into three groups: 33 patients (33 eyes) with no diabetic retinopathy (NDR), 20 patients (20 eyes) with non-proliferative diabetic retinopathy and no macular oedema (NPDR/MO−), and 17 patients (17 eyes) with NPDR and MO (NPDR/MO+). Optical coherence tomography was also used to measure the foveal thickness. Results: The group averaged CBF values were 13.5 (4.9), 9.4 (2.5), 10.8 (4.8), and 5.6 (2.0) (arbitrary units) in the control, NDR, NPDR/MO−, and NPDR/MO+ groups, respectively. The group averaged CBF values in the NDR group decreased (30.2%; p<0.01) compared with the control group. The average CBF value in the NPDR/MO+ group was also significantly lower (48.2%; p<0.01) compared with that in the NPDR/MO− group. Conclusion: The CBF in the foveal region significantly decreases in patients with diabetes, especially those with macular oedema.

Features of abnormal choroidal circulation in central serous chorioretinopathy

Aims: To evaluate abnormalities in the choroidal circulation in cases of central serous chorioretinopathy (CSC). Methods: A complete clinical ophthalmological examination was performed using simultaneous fluorescein and indocyanine green (ICG) angiography with a confocal scanning laser ophthalmoscopy and the digital images analysed in 36 consecutive patients with acute CSC. To quantify the choroidal circulation, the foveal choroidal blood flow was measured in 11 patients using laser Doppler flowmetry. Results: Fluorescein angiography showed focal leakage from the retinal pigment epithelium in all patients. ICG angiography revealed delays in arterial filling in 27 eyes (75%), and fluorescein angiography showed small hypofluorescent points around the leakage in 27 eyes (75%). Abnormal choroidal hyperfluorescence was observed in 30 eyes (83%). The choroidal blood flow in eyes with CSC was 45% lower than in fellow eyes (p<0.01). Conclusion: Decreased choroidal blood flow in CSC was demonstrated for the first time. The decreased choroidal blood flow might be correlated with the small, localised hypofluorescent areas, which may indicate non-perfused areas of the choriocapillaris that are frequently seen during ICG angiography.

Choroidal blood flow in the foveal region in eyes with rhegmatogenous retinal detachment and scleral buckling procedures

Aims: To investigate changes in choroidal blood flow (ChBF) in the foveal region of the human eye with rhegmatogenous retinal detachment induced by scleral buckling. Methods: ChBF was measured in the foveal region using laser Doppler flowmetry in patients with a rhegmatogenous retinal detachment and no macular involvement before and after scleral buckling. The ChBF ratio was evaluated (ChBF of the affected eye to ChBF of the fellow control eye) to minimise individual variations. Results: Retinal reattachment was confirmed by 2 weeks after scleral buckling in all patients. The ChBF in the foveal region of the affected eyes did not differ from the fellow eyes before scleral buckling. The ChBF ratio significantly (p<0.05) decreased 2 and 4 weeks after scleral buckling compared with that before scleral buckling and returned to baseline 12 weeks after scleral buckling. Conclusions: The results suggest that ChBF in the foveal region transiently decreases after scleral buckling and recovers to the baseline level within 12 weeks in patients with a retinal detachment and no macular involvement.

Pulsatile ocular blood flow: Changes associated with scleral buckling procedures

PurposeTo determine the changes in the pulse amplitude (PA) and the pulsatile ocular blood flow (POBF) after scleral buckling (SB).MethodsRetrospectively, we studied 24 patients (average age, 52 years) who had undergone SB to repair a retinal detachment in one eye. The patients were divided into two groups: those in whom SB had been performed less than 6 months earlier (n = 10), and those in whom the procedure had been performed more than 6 months previously (n = 14). In each group, the PA and the POBF were determined with a computerized tonometry system, and the values in the SB eyes were compared with those in the control fellow eyes.ResultsWithin 6 months postoperatively, the mean PA in the SB eyes (0.66 ± 0.30 mmHg) was significantly lower than that in the control eyes (1.43 ± 0.34 mmHg; P < 0.05). The mean POBF in the SB eyes (349.5 ± 154.1 µl/min) was also significantly lower than that in the control eyes (631.0 ± 226.6 µl/min; P < 0.05). After more than 6 months postoperatively, there were no significant differences in the PA or the POBF between the SB eyes (1.08 ± 0.49 mmHg and 612.4 ± 341.2 µl/min, respectively) and the control eyes (1.50 ± 0.51 mmHg and 589.5 ± 278.4 µl/min, respectively).ConclusionsThese results indicate that the choroidal blood flow decreases after SB but returns to normal levels after 6 months.