Long-term Effect of Panretinal Photocoagulation Combined With Intravitreal Bevacizumab in High-risk Proliferative Diabetic Retinopathy

PURPOSE: To evaluate long-term effects and usefulness of combined intravitreal injection of bevacizumab and panretinal photocoagulation (PRP) in patients with high-risk proliferative diabetic retinopathy. METHODS: The authors retrospectively reviewed the records of 40 patients (40 eyes) with high-risk proliferative diabetic retinopathy who had been treated with PRP alone (laser treatment group, n=20) or intravitreal bevacizumab before PRP (combined treatment group, n=20). Changes in best corrected visual acuity (BCVA), central macular thickness (CMT) and the total area of leakage from active new vessels (NVs) were compared between the groups at one, three, and six months and at one year post-treatment. RESULTS: In the combined treatment group, CMT decreased significantly at one month (p=0.021), and the areas of active NVs decreased significantly at one month (p=0.001) and three months (p=0.014) compared to those of the laser treatment group. However, there were no differences between the two groups after three months. In the combined treatment group, elevated intraocular pressures were found in three cases after one month, and there were vitreous hemorrhages in two cases after three months. CONCLUSIONS: The combined treatment showed significant early improvements in BCVA, CMT, and NVs regression for up to three months. However, long-term follow-up and additional treatment was necessary in the patients with persistent or recurred NVs and macular edema after three months.

Macular Thickness and Visual Acuity Before and After Panretinal Photocoagulation in Severe Diabetic Retinopathy

PURPOSE:To compare macular thickness and visual acuity before and after panretinal photocoagulation in patients with severe diabetic retinopathy without diabetic macular edema. METHODS: Macular thickness and visual acuity (LogMAR) of 40 eyes were compared before and after panretinal photocoagulation, for severe diabetic retinopathy. Macular thickness was measured by optical coherence tomography(OCT). In addition, changes in macular thickness and visual acuity were compared with the patient's level of HbA1c, blood pressure, and diabetic nephropathy. RESULTS: Mean visual acuity before and 1.47+/-0.80 months after panretinal photocoagulation were 0.28+/-0.23 and 0.33+/-0.27, respectively, which was not a significant decrease (p=0.131). However mean central macular thickness (216.98+/-34.09 microm to 255.22+/-73.40 microm), and mean peripheral macular thickness (269.26+/-34.59 microm to 291.96+/-46.49 microm) did increase significantly after panretinal photocoagulation (p=0.001). The decrease of mean visual acuity and increase of mean macular thickness were greater in patients with high blood glucose, high blood pressure and diabetic nephropathy. CONCLUSIONS: In eyes with severe diabetic retinopathy treated with panretinal photocoagulation, mean visual acuity did not decrease significantly, but mean central and peripheral macular thickness significantly increased after treatment. We posit that visual prognosis after panretinal photocoagulation in eyes with severe diabetic retinopathy without macular edema is influenced by the control of blood glucose and blood pressure and the presence of diabetic nephropathy.

The Clinical Significance of Venous Filling Time through Panretinal Photocoagulation in Proliferative Diabetic Retinopathy

PURPOSE: To verify the clinical correlation between retinopathy progression and the change of venous filling time (VFT), measured before and after panretinal photocoagulation (PRP), in proliferative diabetic retinopathy (PDR) patients. METHODS: We conducted this study on 32 patients (32 eyes) who received PRP for PDR. These patients were subdivided into two groups in accordance with the clinical course of PRP: the stabilized group in which retinal neovascularization was regressed and the progressed group in which retinal neovascularization was continued and a complication, such as vitreous hemorrhage or tractional retinal detachment, was developed within 12 months of laser treatment. Arteriovenous passage time (AVP) and VFT were measured by video fluorescein angiogram (FAG) using scanning laser ophthalmoscope (SLO) before and after PRP. VFT values were assigned by measuring by the time duration from start of venous lamina flow to the fullness of fluorescence on the vascular arch. RESULTS: In the stabilized group, AVP was decreased by 0.20+/-0.89sec and VFT was decreased by 0.30+/-1.69 sec through PRP. In the progressed group, AVP was increased in 0.12+/-1.22 sec and VFT was increased by 0.99+/-1.60 sec through PRP. In both groups, the VFT changes were significant (P=0.04) but the AVP changes were not (P=0.34). CONCLUSIONS: VFT was significantly decreased in the stabilized group and significantly increased in the progressed group after PRP. Accordingly, we suggest that VFT changes after PRP can be utilized as a prognostic indicator for evaluating clinical course of diabetic retinopathy after performing PRP and for monitoring the clinical effect of PRP.

Effect of PRP on Visual Acuity, Visual Field and Subjective Symptoms in Very Severe NPDR

PURPOSE: To evaluate the effect of panretinal photocoagulation (PRP) on visual acuity, visual field and subjective symptoms in very severe non-proliferative diabetic retinopathy (NPDR) patients. METHODS: Forty eyes of 20 patients with NPDR were evaluated. Complete ophthalmic examination, visual acuity, Humphrey field test and interview of questionnaire were evaluated before, 2 and 8 weeks after PRP. RESULTS: The mean corrected visual acuity was not significantly changed from before PRP to 2, 8 weeks after PRP (p>0.05). Visual field deteriorated in 2 weeks and then improved in 8 weeks after PRP, however the recovery did not reach to pre-PRP level (p0.05). Thoses number decreased in 15~30degrees field (p<0.01) following PRP. In spite of deterioration of visual field after PRP, subjective symptoms was rarely noted. CONCLUSIONS: Our result suggest that early PRP may be advisable for very severe NPDR patients to prevent the development of possible visual field deterioration following PRP.

The Comparision of Venous Filling Time Before and After Panretinal Photocoagulation in Proliferative Diabetic Retinopathy

PURPOSE: Diabetic retinopathy (DR) has influence on peripheral retina, and progression of DR is thought to make prolongation of peripheral retinal circulation. However, there has been no study on circulation of peripheral retina. This study is to make a comparision of peripheral retinal microcirculation between control, non-proliferative diabetic retin-opathy (NPDR), and pre-and post-panretinal photocoagulation (PRP) of proliferative diabetic retinopathy (PDR). METHODS: The authors performed the study on 19 control eyes and 68 DR eyes (NPDR 31, PDR 37) and PDR group was subdivided into before and after PRP. The authors measured arm to retinal circulation time (ART), arteriovenous passage time (AVP), venous filling time (VFT) by scanning laser ophthalmoscope in upper temporal retinal vessel in order to evaluate peripheral retinal microcirculation. RESULTS: VFT was 9.4+/-0.3 sec in pre-PRP of PDR, 7.5+/-0.6 sec (p<0.05) in post-PRP of PDR and 6.4+/-2.2 sec in control, 8.17+/-1.90 sec (p<0.05) in NPDR. However, there is no significant difference in ART, AVP. CONCLUSIONS: Patients with NPDR showed prolongation of VFT compared to normal indivisuals. There was shortening of VFT in post-PRP of PDR similar to NPDR. Peripheral retinal circulation time after PRP can be utilized as an indicator of PRP effect.