Relationship between the macular retina vascular density and retinal circulation time in CRAO patients / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe the macular retina vascular density of patients with acute central retinal artery occlusion(CRAO)by optical coherence tomography angiography(OCTA)and to analyze the relationship with retinal circulation time of these patients on fundus fluorescein angiography(FFA).METHODS: Retrospective case analysis. A total of 43 patients(43 eyes)from January 2019 to March 2021 admitted to Shaanxi Eye Hospital with clinical diagnosis of acute CRAO(course of disease ≤7d)were included. All patients underwent FFA, OCTA, best corrected visual acuity(BCVA)examination and thrombolytic therapy. The patients with enhanced or unchanged retinal blood flow signal in the affected eye showed on OCTA before treatment compared with the contralateral healthy eye were assigned to group A, and the patients with retinal blood flow signal of the affected eye was lower than that in the contralateral healthy eye by OCTA were assigned to group B. Image J software was used for OCTA image processing to evaluate the macular retina vascular density before treatment, and FFA examination was performed to record the affected retinal circulation time before treatment.RESULTS: The retinal vascular density of patients in the affected eye and the contralateral healthy eye in group A was higher than that in group B(25.08%±4.40% vs 12.24%±3.41%, 25.72%±2.70% vs 17.89%±4.55%, all P<0.001), the filling time(FT)of retinal artery trunk to terminal in group B [96(20.50, 193.50)s] was longer than that in group A [11(5.00, 19.50)s](P<0.001). The course of disease, the retinal vascular density of contralateral healthy eye and FT were related factors of retinal vascular density of the affected eye(all P<0.05), and the influence strength order was FT, course of disease and the retinal vascular density of contralateral healthy eye, in which the course of disease and FT was negatively correlated with the retinal vascular density.CONCLUSION: OCTA retinal vascular density was correlated with FFA retinal circulation time in CRAO patients.

Changes of retinal circulation time before and after panretinal laser photocoagulation in patients with diabetic retinopathy / 眼科新进展

Objective To observe the changes of preoperative and postoperative retinal circulation time in partretinal laser photocoagulation (PRP) in patients with diabetic retinopathy (DR).Methods Together 16 patients (16 eyes) were collected as the subjects in this study,who was diagnosed as severe non-proliferative and proliferative DR by fundus fluorescein angiography (FFA) examination and had PRP indications for undergoing pan-retinal laser photocoagulation.Then retinal arterial and venous cir culation time in all patients was recorded using FFA before and 1 to 3 months after treatment.Meanwhile,it was necessary to observe the following variables,including the developing duration and complete filling time of the four branches of the retinal artery,as well as the duration of the laminar flow and complete filling time of the four branches of the venous artery,followed by calculating mean transition time of retinal artery,retinal capillary,retinal vein,retinal arteriovenous flow for comparison and analysis of changes in transit time of retina in different time-periods before and after treatment.Results The mean transition time of the retinal capillary in patient was (1.58 ± 0.99) s before treatment and (2.19 + 1.23)s after treatment,and the difference was statistically significant(P =0.011),but there was no significant difference in the mean transition time of the retinal artery,retinal vein and arteriovenous flow (all P ＞ 0.05).Conclusion The transit time of the retinal capillary at 1 to 3 months after PRP is significantly longer than that before treatment.

Changes of retinal circulation time before and after panretinal laser photocoagulation in patients with diabetic retinopathy / 眼科新进展

Objective To observe the changes of preoperative and postoperative retinal circulation time in partretinal laser photocoagulation (PRP) in patients with diabetic retinopathy (DR).Methods Together 16 patients (16 eyes) were collected as the subjects in this study,who was diagnosed as severe non-proliferative and proliferative DR by fundus fluorescein angiography (FFA) examination and had PRP indications for undergoing pan-retinal laser photocoagulation.Then retinal arterial and venous cir culation time in all patients was recorded using FFA before and 1 to 3 months after treatment.Meanwhile,it was necessary to observe the following variables,including the developing duration and complete filling time of the four branches of the retinal artery,as well as the duration of the laminar flow and complete filling time of the four branches of the venous artery,followed by calculating mean transition time of retinal artery,retinal capillary,retinal vein,retinal arteriovenous flow for comparison and analysis of changes in transit time of retina in different time-periods before and after treatment.Results The mean transition time of the retinal capillary in patient was (1.58 ± 0.99) s before treatment and (2.19 + 1.23)s after treatment,and the difference was statistically significant(P =0.011),but there was no significant difference in the mean transition time of the retinal artery,retinal vein and arteriovenous flow (all P ＞ 0.05).Conclusion The transit time of the retinal capillary at 1 to 3 months after PRP is significantly longer than that before treatment.

Retinal Oximetry: The Indian Experience in Healthy and Diseased Eyes.

To study the alterations in retinal oxygen saturations in healthy and diseased eyes. Patients presenting to our hospital underwent an additional non-invasive procedure to measure oxygen saturation in their retinal vessels. After dilatation, oximetry was done using the Oxymap T1 retinal oximeter (Oxymap hf, Reykjavik, Iceland). Normal patients and patients with arteriolar and venous occlusions, retinal dystrophies and glaucoma, were evaluated. Arteriolar, venous and arteryvenous saturation difference (AVSD) values were determined for each of the groups. In the normal subjects (n = 98), the average arteriolar saturation was 90.3 ± 6.5, and the venous saturation was 56.9 ± 6.3. The average AVSD was 33.4 ± 5.0. In arterial occlusions (n = 10), we have seen an initial fall in arteriolar (85.8%) and venous (49.7%) saturations in the acute stage in eyes with central retinal artery occlusion with subsequent increase in saturations. In venous occlusions (n = 18), there was an initial increase in all global saturation parameters in the acute stage (arteriolar: 105.8%, venous: 62.7%, AVSD: 43.3%), followed by a gradual decrease in saturations in the chronic stage (arteriolar: 99.8%, venous: 60.1%, AVSD: 39.8%). Eyes with retinitis pigmentosa (n=62) showed higher saturations (104.15%) and higher AVSD (44.15%) compared to macular dystrophies (n = 23) (96.7% and 41.61%) and normal controls (90.6% and 33.3%). Macular dystrophies showed higher global arteriolar values and AVSD but comparable venous values to the control group. In glaucoma (n = 44), we have seen raised arteriolar and AVSD values. Oximetry is sensitive in picking up changes in diseased eyes that are distinct from normal values. In the future, it may prove to be useful in pre-clinical screening studies and in therapeutic decision making.

Sildenafil citrate on retrobulbar and retinal circulation of rabbits / Citrato de sildenafil sobre a circulação retrobulbar e retiniana de coelhos

The effects of sildenafil on retrobulbar and retinal circulation were studied in 18 adult male, albino, homozygous rabbits, of the New Zealand White breed, randomly divided into 3 groups of 6 animals, for drug treatment at a dose of 3.5mg kg-1 every 24 hours, for 7, 15 and 30 days. Nine animals used for control were treated with saline solution at 0.9%. It was evaluated intraocular pressure (IOP), mean arterial pressure (MAP), ocular perfusion pressure (PPO), B-mode ultrasonography and fluorescein angiography before and at the end of treatments. A slight decrease in results of IOP, MAP and PPO after treatment with sildenafil was evident, however, there was no statistical significance. It was observed significant increased diameter of the ophthalmic artery after 7 and 30 days of treatment and decreased mean arterial pressure after 7, 15 and 30 days of treatment, with no statistical difference. On fluorescein angiography, it was observed that the arterial, arteriovenous and venous stages initiated more rapidly in animals after treatment, with significant difference on the arteriovenous stage at the 7th and 15th days. It was possible to admit that the sildenafil citrate improves blood circulation in the retina of rabbits, by increasing the speed of blood flow and decreasing the perfusion pressure.

Os efeitos do sildenafil sobre a circulação retrobulbar e a retiniana foram estudados em 18 coelhos machos adultos, albinos, homozigotos, da raça Nova Zelândia Branco, distribuídos aleatoriamente em 3 grupos de 6 animais, para tratamento com o fármaco na dose de 3,5mg kg-1 a cada 24 horas, por 7, 15 e 30 dias. Nove animais foram utilizados para controle, tratados com solução fisiológica a 0.9%. Foram avaliadas a pressão intraocular (PIO), a pressão arterial média (PAM) e a pressão de perfusão ocular (PPO), ultrassonografia em modo-B e a angiografia fluoresceínica, antes e ao término dos tratamentos. Evidenciou-se discreta diminuição nos resultados da PIO, da PAM e da PPO após tratamento com sildenafil, entretanto não houve significância estatística. Observou-se aumento significativo do diâmetro da artéria oftálmica após 7 e 30 dias de tratamento e diminuição da pressão arterial média após 7, 15 e 30 dias de tratamento, sem diferença estatística. À angiografia fluoresceínica, observou-se que as fases arterial, artério-venosa e venosa iniciaram-se mais rapidamente nos animais após o tratamento, com diferença significativa na fase artério-venosa ao 7o e 15o dias. Foi possível admitir que o citrato de sildenafil melhora a circulação de sangue na retina de coelhos, através do aumento da velocidade do fluxo de sangue e diminuição da pressão de perfusão.

Peripheral Vascular Leakage Findings of Asymptomatic Eyes Based on Fluorescein Angiography

PURPOSE: To report peripheral vascular retinal leakage findings of asymptomatic eyes based on fluorescein angiography, and investigate the associated factors. METHODS: Data were collected retrospectively from 47 subjects (94 eyes) and the peripheral leakage results based on fluorescein angiography were analyzed. The relationship between peripheral leakage findings and other factors including-arm-retinal circulation time (ARCT) and venous filling time (VFT), refractive error, age, hypertension, and diabetes- was evaluated. RESULTS: Ten eyes had peripheral leakage (21.3%). The mean age was 34.7 +/- 7.86 years in the non-leakage group and 44.3 +/- 9.63 years in the leakage group; the difference between the groups was statistically significant (p = 0.001). The mean spherical equivalent was -2.85 +/- 2.71 diopter in the non-leakage group and -3.46 +/- 3.62 diopter in the leakage group; the difference between the groups were not significant (p = 0.471). The mean ARCT was 10.50 +/- 2.06 seconds in the non-leakage group and 11.76 +/- 2.47 seconds in the leakage group; the difference between the groups was statistically significant (p = 0.041). The mean VFT was 9.70 +/- 1.91 seconds in the non-leakage group and 10.75 +/- 1.40 seconds in the leakage group; the difference between the groups was statistically significant (p = 0.048). CONCLUSIONS: Peripheral leakage can be found in asymptomatic eyes. Age, VFT, and ARCT were correlated to peripheral leakage findings based on angiography. These leakage findings were thought to be related with histological properties and physiological changes in peripheral retina.

Evaluation of Retinal Circulation Times in Rhegmatogeneous Retinal Detachment with SLO

This study was designed to evaluate the association between rhegmatogenous retinal detachment and retinal circulation times. We observed retinal circulation times in 30 patients with rhegmatogeneous retinal detachment before and after operation using the scanning laser ophthalmoscope. We measured arm to retina time(ART) and arteriovenous passage time(AVT) before the operations and after(average 2.5 weeks) successful reattachment of detached retina. Preoperative ART and AVP were 13.83 +/- 3.08 see and 2.91 +/- 0.69 see respectively, whereas postoperative ART and AVP were 13.60 +/- 2.99 see and 2.90 +/- 0.63 see in detached areas. There was no statistically significant difference between pre- and post-operative ART and AVP in detached retina(P>0.05). Preoperative ART and AVP in flat retinal area were 13.82 +/- 3.08 and 2.91 +/- 0.69 see respectively. There was no statistically significant difference between flat and detached area preoperatively (P>0.05). No significant correlation was noted between retinal circulation times and rhegmatogeneous retinal detachments by scanning laser ophthalmoscope.

Evaluation of Retinal Circulation Times in Branch Retinal Vein Occlusions with Scanning Laser Ophthalmoscope

To investigate retinal hemodynamics in branch retinal vein occlusion(BRVO), we measured retinal circulation times using scanning laser ophthalmoscope(SLO) and studied the relationships with clinical findings. Arm-retina time(ART) and arteriovenous passage time(AVP) were measured in 35 eyes of 35 patients. Mean ART was 13.05 sec. ART showed no difference with sex and systemic diseases, but increased withage. AVP of occluded branch was much longer than those of other branches. AVP was delayed according to the size of capillary nonperfusion area, but showed no difference according to the duration of disease and macular edema. These results suggest that SLO is an useful method for studying retinal hemodynamics in BRVO.

Retinal circulation times in branch retinal vein occlusion

To investigate the retinal hemodynamics in branch retinal vein occlusion (BRVO), we measured retinal circulation times using scanning laser ophthalmoscope (SLO) and studied their relationships with clinical findings. Arm-retina time (ART) and arteriovenous passage time (AVP) were measured in 30 eyes of 30 patients. Mean ART was 13.07 seconds. ART showed no difference in relation to sex and systemic diseases, but increased with age. Mean AVPs were 3.00 sec. and 3.39 sec. in superotemporal and inferotemporal BRVO, respectively. AVPs were delayed significantly in occluded branch of retinal veins. AVP was delayed three-fold when the area of capillary nonperfusion was over 6 disc area, but showed no difference according to the duration of disease or macular edema. These results suggest that SLO may be a useful tool for studying retinal hemodynamics in BRVO.

ERG b/a ratio and retinal circulation time of CRVO

Fourteen cases of central retinal vein occlusion (CRVO) were studied with electroretinogram (ERG) and fluorescein angiogram. The cases were divided into a venous stasis retinopathy group (VSR,9 cases) and a hemorrhagic retinopathy group(HR, 5 cases). The b/a ratio and retinal circualtion time (RCT) were measured and compared with the control group. The mean b/a ratio of the HR group (0.86) was decreased as compared with the VSR group (1.18) and the control group (1.23). The RCT of the HR group was markedly delayed to 13.68 seconds as compared with the VSR group (11.09 sec) and the control group (6.4 sec). These facts suggest that both the b/a ratio and the RCT are possible parameters for estimating retinal ischemia and that the ERG is a reliable examination method for classification of CRVO.