1.
Region-specific ischemia, neovascularization and macular oedema in treatment-naïve proliferative diabetic retinopathy.
Lange, J, Hadziahmetovic, M, Zhang, J, Li, W
Clinical & experimental ophthalmology. 2018;(7):757-766
Abstract
IMPORTANCE Region-specific pathology in proliferative diabetic retinopathy enhances our understanding and management of this disease. BACKGROUND To investigate non-perfusion, neovascularization and macular oedema. DESIGN A cross-sectional, observational, non-randomized study. PARTICIPANTS Consecutive 43 eyes of 27 treatment-naïve patients. METHODS Ultra-widefield fluorescein angiography for studying specific zones, that is, far-peripheral zone, mid-peripheral zone and central retina (cr), and spectral-domain optical coherence tomography for analysing thickness of macular layers. MAIN OUTCOME MEASURES Non-perfusion index (NPI) and neovascularization index (NVI) in different zones, thickness of cr, retinal nerve fibre layer, ganglion cell layer (GCL), inner nuclear layer (INL) and outer plexiform layer in parafoveal regions. RESULTS The NPI of far-periphery and NVI of mid-periphery were the highest by one-way analysis of variance testing. Ischemic retina defined as high NPI in far-periphery was significantly related to macular oedema via a binary classification approach (P < 0.05). The ischemic retina was correlated with a decreased thickness of both retinal nerve fibre and GCL (P < 0.05); macular oedema was correlated with increased INL thickness (P < 0.0001). CONCLUSIONS AND RELEVANCE The region-specific correlation of NPI of far-periphery and NVI of mid-periphery, but not with central retinal thickness, suggests different pathogeneses of neovascularization and macular oedema. Retinal nerve fibre layer and GCL, both biomarkers of diabetic retinal neuronopathy, are associated with retinal ischemia, but not with macular oedema, suggesting that diabetic microangiopathy and neuronopathy possess distinct pathogenic pathways. The strong correlation between macular oedema and INL indicates that intracellular oedema is a determining factor of diabetic macular oedema.
2.
The Clinical Importance of Changes in Diabetic Retinopathy Severity Score.
Ip, MS, Zhang, J, Ehrlich, JS
Ophthalmology. 2017;(5):596-603
Abstract
PURPOSE To investigate the clinical importance of changes in diabetic retinopathy severity score (DRSS) in patients with diabetic macular edema (DME) treated with intravitreal ranibizumab. DESIGN Post hoc analysis of the phase III RIDE and RISE studies of ranibizumab for treatment of DME. PARTICIPANTS Four hundred sixty-eight eyes treated with ranibizumab from randomization with gradable DRSS on baseline fundus photographs. METHODS Visual and anatomic outcomes were examined in eyes grouped according to DRSS change from baseline to month 24. MAIN OUTCOME MEASURES Mean best-corrected visual acuity (BCVA) letter score change, proportion of patients with 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letter score change, mean contrast sensitivity change, proportion of patients with resolved macular edema, and leakage on fluorescein angiography. RESULTS Most (56.8%) patients treated with ranibizumab experienced 1-step or more improvement in DRSS from baseline to month 24; 40.0% had no change, and 3.2% experienced DRSS worsening. Patients with DRSS stability or improvement had greater mean BCVA letter score changes (+15.1, +14.2, +11.3, and +11.2 letters for ≥3-step improvement, ≥2-step improvement, 1-step improvement, and no DRSS change, respectively) compared with +5.0 letters in patients who had any DRSS worsening. Best-corrected visual acuity letter score gain of 15 letters or more was more common in patients with 2-step or 3-step or more DRSS improvement (51.9% and 44.6%, respectively) compared with those with a 1-step DRSS improvement, no change, or worsening (37.9%, 39.6%, and 26.7%, respectively). A loss of 15 letters or more in BCVA was more common in patients with any DRSS worsening (13.3%) compared with patients who had stable or improved DRSS (0%-2.8%). Resolution of macular edema was more common in patients with DRSS improvement: 84.2%, 87.7%, and 92.3% of patients with 1-step, 2-step or more, and 3-step or more improvement in DRSS achieved central foveal thickness of 250 μm or less, compared with 65.2% and 53.3% of patients who had no DRSS change or any DRSS worsening. CONCLUSIONS These findings provide further support that improvement in DRSS is a clinically important outcome that should be evaluated as a measure of treatment effectiveness in future studies of diabetic eye disease.