Choroidal Structural Changes Assessed with Swept-Source Optical Coherence Tomography after Cataract Surgery in Eyes with Diabetic Retinopathy

Impact of Delayed Sequential Bilateral Cataract Surgery on Diabetic Macular Edema: A Real-World Study in Northwestern China

Objectives

To assess the incidence and characteristics of treatment-requiring diabetic macular edema (TR-DME) in eyes after delayed sequential bilateral cataract surgery in patients with diabetes mellitus.

Methods

This was a retrospective study involving patients with diabetes who underwent cataract surgery at Shaanxi Eye Hospital between January 2019 and December 2021. The incidence and characteristics of a first episode of TR-DME after delayed sequential bilateral cataract surgery were observed.

Results

A total of 1553 individuals (3106 eyes) were included in the study. All patients underwent bilateral cataract surgery with the prescribed interval of surgery within one month. The incidence of TR-DME was 0.52% in the year before surgery versus 1.87% in the year after surgery (p < 0.05). The highest risk period was between 2 and 4 months after surgery. A first episode of TR-DME was observed in 58 eyes of 35 patients after delayed sequential bilateral cataract surgery. The patients were divided into four groups according to the interval between bilateral cataract surgeries. A higher incidence of TR-DME was observed when the interval between the surgeries was less than two weeks.

Conclusions

This is the first real-world study of the effects of cataract surgery on the development of TR-DME. The study was performed at the largest ophthalmic center in Northwestern China. The findings demonstrate that the incidence of TR-DME increased significantly after cataract surgery, with the highest incidence between two and four months after surgery. Patients with shorter intervals between bilateral cataract surgeries were at a high risk.

Macular changes following cataract surgery in eyes with early diabetic retinopathy: an OCT and OCT angiography study

Background

To evaluate changes in macular status and choroidal thickness (CT) following phacoemulsification in patients with mild to moderate nonproliferative diabetic retinopathy (NPDR) using optical coherence tomography.

Methods

In this prospective study, all of the patients underwent uncomplicated phacoemulsification. Retinal superficial capillary plexus vascular density (SCP-VD), macular thickness (MT), and CT were measured pre- and postoperatively.

Results

Twenty-two eyes of 22 cataract patients with mild to moderate NPDR without diabetic macular edema (DME) and 22 controls were enrolled. BCVA increased in two groups at 3 months postoperatively. At 1 and 3 months postoperatively, SCP-VD in the diabetic retinopathy (DR) group significantly increased; changes in SCP-VD in parafovea were significantly greater in the DR group than in the control group. MT and CT in the DR group significantly increased at all visits postoperatively in the fovea and perifovea. Changes in parafoveal MT were significantly greater in the DR group than in the control group at all visits postoperatively. Changes in CT and MT in the fovea were significantly greater in patients with DR than in the controls 1 and 3 months postoperatively.

Conclusion

Uncomplicated phacoemulsification resulted in greater increases in SCP-VD, MT and CT in patients with early DR without preoperative DME than in controls.

The Association between Decreased Choriocapillary Flow and Electroretinogram Impairments in Patients with Diabetes

PURPOSE

To evaluate the association between choriocapillary flow (CCF) and electroretinogram (ERG) in patients with diabetes.

METHOD

This was a cross-sectional study. Patients with type 2 diabetes and healthy controls who had undergone both flicker ERG and optical coherence tomography angiography (OCTA) were included, while patients with severe diabetic retinopathy (DR) and macular edema were excluded. Correlations among OCTA and ERG parameters were conducted by generalized linear mixed models (GLMM).

RESULT

One hundred ninety-four eyes of 102 patients with diabetes and fifty-six eyes of 28 controls were included. The implicit time of 30-Hz flicker ERG successively increased, while the amplitudes, inner-retina vessel density and CCF were decreased from the control to the nondiabetic retinopathy (NDR) to DR group. In patients with diabetes, all GLMM models of ERG parameters had statistically significance (P<0.05), and CCF was correlated with ERG parameters (coefficient index=-0.601, P< 0.001 with 16 Td-s implicit time; coefficient index=-0.687, P< 0.001 with 32 Td-s implicit time; coefficient index=0.933, P=0.035 with 32 Td-s amplitude) and the thickness of retinal pigment epithelium, while in the GLMM model of CCF, it was correlated with the thickness of retinal pigment epithelium and the level of glycosylated hemoglobin(both P= 0.001).

CONCLUSION

CCF decreased in patients with diabetes, and it was related with ERG. Choroidopathy and its functional impairment in the retina may occur very early in patients with diabetes by influencing the outer retina.

Evaluation of structural and vascular changes in the choroid after uneventful phacoemulsification surgery

Objective: The aim of this study was to evaluate structural and vascular changes in the choroid after phacoemulsification surgery. Methods: This research comprised 50 eyes of 50 individuals who received uneventful surgical treatment for cataracts. Intraocular pressure, axial length, subfoveal choroidal thickness, and choroidal thickness in the nasal and temporal areas at 1,500-micron distance from the fovea were measured before surgery and at one and three months after surgery. At the same evaluation times, the choroidal luminal area and choroidal stromal area were calculated with the binarization method using image J software, and the choroidal vascular index (CVI) was calculated by dividing the luminal area by the total area. In addition, total surgery time and effective phacoemulsification time were recorded. Results: The patients had a mean age of 64.7 ± 8.5 years. The mean total operative time was 13.9 ± 3.8 minutes, and the mean effective phacoemulsification time was 3.8 ± 2.1 minutes. The mean intraocular pressure value was 14.4 ± 3.4 mmHg before surgery, and 13.2 ± 2.9 mmHg at the first month and 13.0 ± 2.1 mmHg at the third month postoperatively. Although there was a decrease in the intraocular pressure after surgery, no significant difference was found (p>0.05 for all). The axial length measured during the first and third months postoperatively did not significantly differ from the evaluation undertaken preoperatively (p>0.05 for all). A significant increase was detected in the subfoveal, nasal, and temporal choroidal thicknesses at the first postoperative month compared to the preoperative values (p<0.05), but no significant difference was found at the third month postoperatively (p>0.05). The mean CVI was 61.6 ± 3.5% preoperatively, 65.2 ± 4.2% at the first postoperative month, and 65.9 ± 3.9% at the third postoperative month. The increase at the first and third postoperative months was significant when compared to the evaluation made preoperatively (p=0.004 and p<0.001, respectively). Conclusion: Structural and vascular choroidal changes in the after-cataract surgery are important. In this study, it was observed that after uneventful phacoemulsification, the choroidal thickness increased at the first postoperative month and reached the preoperative values at the third month. It was also determined that CVI increased at the first and third postoperative months. CVI can offer an idea about whether cataract surgery is a predisposing factor in diseases involving the choroid. Abbreviations: CVI = choroidal vascular index.

Analysis of the Choroid and Its Relationship with the Outer Retina in Patients with Diabetes Mellitus Using Binarization Techniques Based on Spectral-Domain Optical Coherence Tomography

(1) Background: We aimed to reveal the relationship between the choroid and the outer retina with optical coherence tomography (OCT) in patients with diabetes mellitus (DM) with mild or no diabetic retinopathy (DR) in order to find early biomarkers for progressing retinopathy. (2) Methods: We performed a prospective study including 61 eyes of patients with type 1 or type 2 DM and 36 eyes of healthy controls. All subjects were imaged with Spectralis OCT. The choroid was assesseed using enhanced depth imaging OCT (EDI-OCT). Binarization of subfoveal choroidal images was done with public domain software, ImageJ (version 1.53a; National Institutes of Health, Bethesda, Maryland, USA). (3) Results: Luminal area, stromal area and total choroidal area were significantly decreased in diabetic patients compared to control: 0.23 ± 0.07 vs. 0.28 ± 0.08, p = 0.012; 0.08 ± 0.03 vs. 0.10 ± 0.04, p = 0.026; 0.31 ± 0.09 vs. 0.38 ± 0.11, p = 0.008. The thickness of retinal pigment epithelium (RPE) correlated positively with the choroidal vascularity index (CVI). The correlations between outer nuclear layer (ONL), photoreceptors (PR) and foveal choroidal thickness (FChT) were moderately negative. (4) Conclusion: Thicker RPE and a thinner PR layer may be assigned the role of early biomarkers signaling the conversion time to progressing retinopathy.