Coats' disease and retrobulbar haemodynamics

Quantitative evaluation of primary retinitis pigmentosa patients using colour Doppler flow imaging and optical coherence tomography angiography

PURPOSE

To find the potential relation between changes in retinal large vessels and terminal vessels using colour Doppler flow imaging (CDFI) and optical coherence tomography angiography (OCTA) and to compare the respective advantages of CDFI and OCTA in evaluating vascular changes in retinitis pigmentosa (RP) patients.

METHODS

A prospective series of case study was conducted to enrol RP patients and age-matched controls, who were, respectively, imaged by CDFI and OCTA. Repeatability and reproducibility of both CDFI and OCTA were performed among healthy volunteers. The central retinal artery (CRA) was detected by CDFI analysis to provide parameters of peak systolic velocity (PSV), end-diastolic velocity (EDV) and time-averaged maximum velocity (TAMV). Retinal parameters were evaluated from OCTA images, including vascular area density (VAD) of the superficial vascular layer, the fovea avascular zone (FAZ) area and retinal thickness. RP patients were separated into a high-vision group and a low-vision group, according to median vision (0.3, LogMAR 0.5). Multiple comparisons were used to analyse the data between groups. A correlation analysis was used to determine the correlation between CDFI and OCTA parameters.

RESULTS

Twenty RP patients (40 eyes) and thirteen normal volunteers (26 eyes) were enrolled in this study. Repeatability and reproducibility of the measurements by CDFI had higher CVs, from 4.5% to 15.4%, than those measurements by OCTA (<5%). All the CDFI and OCTA parameters examined had significant reductions in RP patients compared to those in the controls (p < 0.01). Compared to the high-vision group, the low-vision group exhibited a statistically significant decrease in vascular parameters of the FAZ area, fovea VAD and parafovea nasal side VAD (p < 0.05); as well as in the parameters of the fovea thickness, and the parafovea nasal, superior and inferior side thickness (p < 0.05). From the correlation analysis, a significant association was found between the vision and CDFI parameters (PSV and time-averaged maximum velocity (TAMX), p < 0.05), and the vision and OCTA parameters (FAZ area, fovea and nasal side VAD, retinal thickness in all sides, p < 0.05). PSV and TAMX of the CRA were closely related to the OCTA superficial VAD in all sides, whereas the CDFI parameters showed poor correlation with retinal thickness.

CONCLUSIONS

Colour Doppler flow imaging (CDFI) and OCTA parameters revealed a significant reduction in RP patients when compared to the controls. OCTA can detect vision-related microvascular and thickness changes around the macula between high- and low-vision groups, which happen earlier than the changes in large vessels. In addition to good repeatability and reproducibility, OCTA may have significant utility in the diagnosis and monitoring of disease progression in RP patients.

Recent advances in the diagnosis and treatment of Coats' disease

PURPOSE

To review and summarize the recent progress in the diagnosis and treatment of Coats' disease.

METHODS

Literature was collected from Web of Science, Medline and Pubmed, through searching of these keywords: "Coats' disease", "diagnosis" and "treatment".

RESULTS

Coats' disease is characterized by idiopathic leaky retinal vascular telangiectasia and microvascular abnormalities often accompanied by intraretinal or subretinal exudation and retinal detachment. Neovascular glaucoma and phthisis bulbi often occur in advanced cases. Coats' disease has significant diversity in terms of its clinical presentation and morphology. Anti-VEGF therapy combined with laser photocoagulation for early Coats' disease and anti-VEGF therapy combined with minimally invasive vitrectomy for advanced Coats' disease can achieve good efficacy.

CONCLUSION

Early diagnosis and timely treatment based on clinical stage are critical to retaining the patient's visual function. Patients should be aware that close long-term follow-up is necessary.