LONGITUDINAL ANALYSIS OF DIABETIC CHOROIDOPATHY IN PROLIFERATIVE DIABETIC RETINOPATHY TREATED WITH PANRETINAL PHOTOCOAGULATION USING WIDEFIELD SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY

Long-Term Effects of Intravitreal Ranibizumab Compared With Panretinal Photocoagulation on Optical Coherence Tomography Measured Choroidal Thickness and Vascularity

Purpose

Compare choroidal changes in ranibizumab versus panretinal photocoagulation (PRP)-treated eyes with proliferative diabetic retinopathy (PDR).

Methods

DRCR Retina Network Protocol S post hoc analysis evaluated optical coherence tomography change in choroidal thickness (subfoveal and 3mm superior and inferior to the fovea) through five years; choroidal vascularity index (CVI) was assessed at baseline and one year. Mixed linear models for choroidal change included adjustments for the baseline choroidal value and age.

Results

This study included 328 eyes (158 ranibizumab and 170 PRP) from 256 participants (88 ranibizumab and 95 PRP eyes at five years). Mean change in choroidal thickness from baseline to five years at the fovea was -12 µm in ranibizumab versus -8 µm in PRP (difference [95% confidence interval]: -4 [-18 to 10], P = 0.57), superior was -14 µm versus -19 µm (difference: 5 [-8 to 17], P = 0.45) and inferior was -26 µm versus -32 µm [difference: 5 (-9 to 20), P = 0.45]; change at all three points within the ranibizumab group, and the superior and inferior points for PRP, were statistically significant (P < .05). Mean change in CVI at one year was -0.02% in ranibizumab versus -0.95% in PRP (difference: 0.93 [-0.35 to 2.21], P = 0.14).

Conclusions

In patients with PDR, treatment with ranibizumab versus PRP did not result in statistically significant differences in five-year choroidal thickness or one-year CVI change. Both groups had significant decreases in choroidal thickness at five years.

Translational Relevance

Ranibizumab treatment for PDR did not statistically significantly affect choroidal thickness or vascularity differently than PRP.

Choroidal Changes After Anti-VEGF Therapy in AMD Eyes With Different Types of Macular Neovascularization Using Swept-Source OCT Angiography

Purpose

Choroidal changes before and after anti-VEGF therapy were investigated in eyes with exudative AMD to determine if there was a difference between eyes with macular neovascularization (MNV) that arises from the choroid (type 1 or 2) versus the retinal circulation (type 3).

Methods

Patients with treatment-naïve AMD were imaged with swept-source optical coherence tomography angiography using a 12 × 12-mm scan pattern. The mean choroidal thickness and choroidal vascularity index (CVI) were measured within 5-mm and 11-mm fovea-centered circles before, at the onset of, and after anti-VEGF therapy.

Results

Forty-one eyes of 37 patients were included; 24 eyes with type 1 MNV, 4 eyes with type 2 MNV, and 13 eyes with type 3 MNV. Within the 5-mm and 11-mm circles, the mean choroidal thickness and CVI measurements increased from pretreatment to the onset of exudation (P ≤ 0.03). The mean choroidal thickness and CVI measurements decreased from the onset of exudation to after treatment (P < 0.001). No significant changes in mean choroidal thickness or CVI were observed when comparing measurements before or after treatment (P ≥ 0.38). No significant differences in mean choroidal thickness or CVI measurements were observed between eyes with type 1 or 2 MNV and type 3 MNV.

Conclusions

In treatment-naïve AMD eyes with MNV, the choroidal thickness and vascularity increased at the onset of exudation and then decreased after anti-VEGF therapy. This finding suggests that these choroidal changes develop in response to the proangiogenic milieu before treatment and in response to treatment, regardless of the site of origin for the MNV.

Unleashing the power of optical attenuation coefficients to facilitate segmentation strategies in OCT imaging of age-related macular degeneration: perspective

The use of optical attenuation coefficients (OAC) in optical coherence tomography (OCT) imaging of the retina has improved the segmentation of anatomic layers compared with traditional intensity-based algorithms. Optical attenuation correction has improved our ability to measure the choroidal thickness and choroidal vascularity index using dense volume scans. Algorithms that combine conventional intensity-based segmentation with depth-resolved OAC OCT imaging have been used to detect elevations of the retinal pigment epithelium (RPE) due to drusen and basal laminar deposits, the location of hyperpigmentation within the retina and along the RPE, the identification of macular atrophy, the thickness of the outer retinal (photoreceptor) layer, and the presence of calcified drusen. OAC OCT algorithms can identify the risk-factors that predict disease progression in age-related macular degeneration.

The Role of Diabetic Choroidopathy in the Pathogenesis and Progression of Diabetic Retinopathy

Diabetic choroidopathy was first described on histopathological specimens of diabetic eyes. This alteration was characterized by the accumulation of PAS-positive material within the intracapillary stroma. Inflammation and polymorphonuclear neutrophils (PMNs) activation are crucial elements in choriocapillaris impairment. The evidence of diabetic choroidopathy in vivo was confirmed with multimodal imaging, which provides key quantitative and qualitative features to characterize the choroidal involvement. The choroid can be virtually affected in each vascular layer, from Haller's layer to the choriocapillaris. However, the damage on the outer retina and photoreceptor cells is essentially driven by a choriocapillaris deficiency, which can be assessed through optical coherence tomography angiography (OCTA). The identification of characteristic features of diabetic choroidopathy can be significant for understanding the potential pathogenic and prognostic implications in diabetic retinopathy.

The Royal College of Ophthalmologists' National Ophthalmology Database Study of Cataract Surgery: Report 12, Risk factors for suprachoroidal haemorrhage during cataract surgery

OBJECTIVE

To establish the incidence of acute intraoperative suprachoroidal haemorrhage (AISH) during cataract surgery and identify the risk factors for this complication.

METHODS

Data from the Royal College of Ophthalmologists' National Ophthalmology Database was analysed. During the 11-year study period, from 01/04/2010 to 31/03/2021, 709 083 operations performed on 498 170 patients from 65 centres were eligible for inclusion.

RESULTS

AISH occurred in 0.03% (204/709 083, approximately 1 in 3 500) of eligible cataract operations performed during the study period. Posterior capsule rupture was the risk factor most strongly associated with AISH (OR: 17.6, 95% CI: 12.4-24.9, p < 0.001). Other ocular risk factors identified were raised intraocular pressure (IOP) preoperatively (OR: 3.7, 95% CI: 2.5-5.5, p < 0.001), glaucoma (OR: 1.7, 95% CI: 1.2-2.4, p = 0.004). Risk increased with age and patients aged over 90 years were at greatest risk (OR: 6.7, 95% CI: 3.5-12.8, p < 0.001). The addition of intracameral anaesthetic when performing surgery under topical anaesthetic appears to be protective (OR: 0.5, 95% CI: 0.3-0.8, p = 0.003), compared to topical anaesthetic alone. There was a 16-fold increase in the incidence of vision loss when AISH occurred.

CONCLUSIONS

The risk of AISH during modern cataract surgery is approximately 1 in 3 500 and is associated with a significant increase in the risk of vision loss should it occur. Posterior capsule rupture is the risk factor most strongly associated with AISH. Preoperative IOP control is a modifiable risk factor. The use of intracameral anaesthesia may reduce the risk of AISH.

Choriocapillaris Flow Deficit as a Biomarker for Diabetic Retinopathy and Diabetic Macular Edema: 3-Year Longitudinal Cohort

PURPOSE

To investigate the relationship between choriocapillaris flow deficit percentage (CC FD%) by swept-source optical coherence tomography angiography (SS-OCTA) and 3-year risk of diabetic retinopathy (DR) progression and diabetic macular edema (DME) development.

DESIGN

Prospective, observational cohort study.

METHODS

A total of 903 participants with type 2 diabetes mellitus (T2DM) without DR or with mild nonproliferative DR (NPDR) free of DME at baseline were followed up annually for 3 years. All participants underwent standard 7-field fundus photography and spectral-domain OCT. SS-OCTA was used for retinal and choriocapillaris imaging and 3 × 3-mm2 macular CC FD% was quantified. Univariate and multivariate logistic models were used to evaluate the association between CC FD% and 2 or more steps of DR progression and DME development. The additional predictive value of CC FD% for outcome events was assessed using C statistic, net reclassification index (NRI), and integrated discrimination improvement index (IDI).

RESULTS

Over 3 years, 295 of 1805 eyes (16.34%) developed DR progression, and 118 eyes (6.54%) developed DME. A higher average CC FD% was correlated with DR progression (odds ratio [OR], 3.41 per SD increase, 95% CI: 2.65-4.39, P < .001) and DME development (OR, 1.37 per SD increase, 95% CI: 1.06-1.77, P = .016) after adjusting for confounders. In the ETDRS regions, increased CC FD% in all fields was associated with DR progression; however, increased CC FD% in the inferior field was associated with DME development. Compared with the models based on established risk factors, the addition of average CC FD% significantly improved the C statistics for DR progression (0.712 to 0.777, P < .001) and DME occurrence (0.743 to 0.773, P = .044). The estimated NRIs and IDIs (all >0) indicated that the addition of CC FD% led to a significant improvement in the discriminative performance for end points.

CONCLUSION

CC FD% is independently associated with DR progression and DME development in the Chinese T2DM population and provides incremental predictive value beyond traditional risk factors and retinal microvascular parameters. Further inclusion of CC FD% in DR prediction models helps guide population-based screening and personalized management.

Wide-field OCT-angiography assessment of choroidal thickness and choriocapillaris in eyes with central serous chorioretinopathy

Purpose: To assess wide-field changes in choroidal thickness and choriocapillaris in eyes with central serous chorioretinopathy (CSC) compared with the fellow eyes and eyes from healthy individuals using wide-field swept-source (SS) OCT-Angiography (OCTA).

Methods: A cross-sectional study in which 68 eyes from 34 individual patients affected by unilateral CSC and 32 eyes of 32 age- and sex-matched healthy subjects were evaluated. All subjects underwent wide-field SS-OCTA examination to quantify choroidal thickness and vascular density of the choriocapillaris. To assess the wide-field changes, we developed five 4-by-4 mm square regions located in the posterior pole and in the four quadrants of the peripheral retina (superotemporal, inferotemporal, superonasal, and inferonasal subfields, respectively).

Results: The choroidal thickness of eyes with CSC was greater than that of the fellow eyes in the central and inferonasal subfields (p < 0.001 for the central subfield and p = 0.006 for the inferonasal subfield, respectively). Compared with the choroidal thickness of healthy eyes, that of patients with CSC were significantly greater in all the subfields (p < 0.05 for the fellow eyes and p < 0.05 for eyes with CSC, respectively). Compared with that of healthy eyes, the vascular density of choriocapillaris in eyes of patients with CSC were significantly greater in the central and superotemporal subfields (p < 0.05 for the fellow eyes and p < 0.05 for eyes with CSC, respectively). In the central region, the vascular density of choriocapillaris of the fellow eyes was greater than eyes with CSC (p = 0.023).

Conclusion: CSC appears to be a bilateral disease with asymmetric manifestations. Local factors of the diseased eyes may play an important role in the development of CSC, during which dynamic and regional changes in the choriocapillaris may have happened. Wide-field swept-source OCTA provided a useful tool to study the pathogenesis of CSC.

The Essential Role of the Choriocapillaris in Vision: Novel Insights from Imaging and Molecular Biology

The choriocapillaris, a dense capillary network located at the posterior pole of the eye, is essential for supporting normal vision, supplying nutrients, and removing waste products from photoreceptor cells and the retinal pigment epithelium. The anatomical location, heterogeneity, and homeostatic interactions with surrounding cell types make the choroid complex to study both in vivo and in vitro. Recent advances in single-cell RNA sequencing, in vivo imaging, and in vitro cell modeling are vastly improving our knowledge of the choroid and its role in normal health and in age-related macular degeneration (AMD). Histologically, loss of endothelial cells (ECs) of the choriocapillaris occurs early in AMD concomitant with elevated formation of the membrane attack complex of complement. Advanced imaging has allowed us to visualize early choroidal blood flow changes in AMD in living patients, supporting histological findings of loss of choroidal ECs. Single-cell RNA sequencing is being used to characterize choroidal cell types transcriptionally and discover their altered patterns of gene expression in aging and disease. Advances in induced pluripotent stem cell protocols and 3D cultures will allow us to closely mimic the in vivo microenvironment of the choroid in vitro to better understand the mechanism leading to choriocapillaris loss in AMD.