Types of Descemet Membrane Detachment After Ocular Surface Burns: The Factor Long Been Ignored.

PURPOSE: The aim of this study was to explore types of Descemet membrane detachment (DMD) after ocular surface burns by anterior segment optical coherence tomography. METHODS: This is a pilot, case series, observational study. Patients with DMD after ocular surface burns were enrolled. Ophthalmologic examinations were performed in all patients including slit-lamp photography and anterior segment optical coherence tomography. RESULTS: Three types of DMDs in 9 eyes of 9 patients with ocular surface burns were identified depending on the detachment components involved with the pre-Descemet layer (PDL). Type A was referred as a taut chord that the PDL and Descemet membrane (DM) detached simultaneously but were remained attached to each other, while type B was identified as a wavy line separated from the stroma by a dark slit that demonstrated the detachment of DM from the PDL and stroma. Type C was defined as the DM detached with or without PDL but they were separated from each other. We found that DM and PDL were detached simultaneously in most condition, with type A in 4 cases, type C in 5 cases, and type B in only 1 case. CONCLUSIONS: Our study demonstrated 3 types of DMDs after ocular surface burns and revealed that the limbal involvement and retrocorneal exudations may give clues to DMD in the corresponding areas. DMDs may be neglected for long in patients with extensive limbal involvement in early stages and also play an important role in unstable ocular surface condition until the late stages of conjunctivalization after ocular surface burns.

Albuminuria and retinal vessel density in diabetes without diabetic retinopathy: the Kailuan Eye Study.

BACKGROUND: Diabetic retinopathy and chronic kidney disease are both major complications of diabetes mellitus. We explored the relationship between retinal vessel density (VD) and albuminuria in diabetic patients without conventionally defined diabetic retinopathy. METHODS: The cross-sectional community-based Kailuan Diabetic Retinopathy Study included patients with type 2 diabetes without diabetic retinopathy who participated in the community-based longitudinal Kailuan study and who had undergone ocular fundus photography, kidney function assessment, and optical coherence tomographic angiography (OCT-angiography) for the assessment the retinal perfusion density (PD) and retinal VD. RESULTS: The study included 447 patients (mean age: 60.9 ± 9.7 years). Higher PD and VD were associated with a lower urinary albumin-creatinine ratio (uACR) (macular region: p = 0.007: standardized regression coefficient beta: -0.14; and p = 0.008, beta: -0.13, respectively; parafoveal region: p = 0.006, beta: -0.14; and p = 0.007, beta: -0.14, respectively) after adjusting for age and ocular axial length. In a reverse manner, higher uACR was associated with lower PD and VD (macular region: p = 0.009, beta: -0.14; and p = 0.01, beta: -0.14, respectively; parafoveal region: p = 0.008, beta: -0.14; and p = 0.01, beta: -0.14, respectively), after adjusting for diabetes duration, blood pressure, serum concentration of C-reactive protein and high-density lipoprotein cholesterol and ocular axial length. In a multivariable model, the prevalence of macroalbuminuria increased by 11% (95% CI: 2%, 18%) and 17% (95% CI: 3%, 30%), respectively, for each mm-1 decrease in VD and each unit decrease in PD. CONCLUSIONS AND RELEVANCE: After adjusting for systemic and ocular parameters, diabetic patients without diabetic retinopathy showed a reduction in OCT-angiographic retinal vascular measurements in association with systemic parameters indicating chronic kidney disease. Optical coherence tomographic (OCT)-angiographic retinal microvascular parameters may serve as markers for chronic kidney disease.

Thickness of individual layers at the macula and associated factors: the Beijing Eye Study 2011.

BACKGROUND: Diagnosis and follow-up of retinal diseases may be improved if the thickness of the various retinal layers, in addition to the total retinal thickness, is taken into account. Here we measured the thickness of the macular retinal layers in a population-based study group to assess the normative values and their associations. METHODS: Using spectral-domain optical coherence tomographic images (Spectralis®, wavelength: 870 nm; Heidelberg Engineering Co, Heidelberg, Germany), we measured the thickness of the macular retinal layers in participants of the population-based Beijing Eye Study without ocular diseases and without systematic diseases, such as arterial hypertension, hyperlipidemia, diabetes mellitus, cardiovascular diseases, previous myocardial infarction, cerebral trauma and stroke. Segmentation and measurement of the retinal layers was performed automatically in each of the horizontal scans. RESULTS: The study included 384 subjects (mean age:60.0 ± 8.0 years). The mean thickness of the whole retina, outer plexiform layer, outer nuclear layer,retinal pigment epithelium, inner retinal layer and photoreceptor layer was 259.8 ± 18.9 µm, 19.4 ± 3.9 µm, 93.4 ± 9.6 µm, 17.6 ± 1.9 µm, 169.8 ± 18.6 µm, and 90.0 ± 4.2 µm, respectively. In multivariable analysis, the thickness of the foveola and of all retinal layers in the foveal, parafoveal and perifoveal region decreased with older age (all P < 0.05), except for the thickness of the parafoveal outer plexiform layer which increased with age. Men as compared to women had higher thickness measurements of the photoreceptor layer and outer nuclear layer in all areas, and of all layers between the retinal nerve fiber layer and inner nuclear layer in the parafoveal area (all P < 0.05). The associations between the macular retinal layers thickness and axial length were not consistent. The inner plexiform layer was thicker, and the ganglion cell layer and inner nuclear layer were thinner, in the temporal areas than in the nasal areas, CONCLUSIONS: The associations between decreasing thickness of most retinal layers with older age and the correlation of a higher thickness of some retinal layers with male gender may clinically be taken into account.

Ocular Axial Length and Diabetic Retinopathy: The Kailuan Eye Study.

Purpose: To examine the role of ocular axial length as an ocular parameter for the prevalence and severity of diabetic retinopathy (DR). Methods: The cross-sectional Kailuan Diabetic Retinopathy Study included patients with diabetes who participated in the community-based longitudinal Kailuan Study and who had undergone ocular fundus photography. The fundus photographs were graded using the Early Treatment of Diabetic Retinopathy Study criteria. Results: The study included 1096 patients with diabetes (mean age: 60.8 ± 9.4 years; axial length: 23.37 ± 0.92 mm). In binary regression analysis, a higher DR prevalence was associated with shorter axial length (P = 0.007; odds ratio [OR]: 0.81; 95% confidence interval [CI]: 0.70, 0.95) after adjusting for longer known duration of diabetes (P = 0.02; OR: 1.13; 95%CI: 1.02, 1.24) and higher fasting blood glucose concentration (P < 0.001; OR: 1.38; 95%CI: 1.26, 1.52). A more severe DR stage was associated (regression coefficient r: 0.46) with shorter ocular axial length (P = 0.047; standardized regression coefficient ß: -0.06) after adjusting for higher fasting blood glucose (P < 0.001; ß: 0.41) and longer known duration of diabetes (P = 0.045; ß: 0.07). Longer axial length was associated with a lower DR prevalence (P = 0.003; ß: -0.10) after adjusting for younger age (P < 0.001), male sex (P < 0.001), higher body mass index (P = 0.016), and lower fasting blood glucose concentration (P = 0.036). Conclusions: After adjusting for systemic risk factors, DR prevalence decreased by 19% (95%CI: 5, 30) for each millimeter increase in axial length. With longer axial length being a surrogate for axial myopia, the marked increase in myopia prevalence worldwide may lead to a relative decrease in the prevalence and incidence of DR in future.

Optical coherent tomographic angiographic pattern of the deep choroidal layer and choriocapillaris after photodynamic therapy for central serous chorioretinopathy.

PURPOSE: To study the changes in the choroidal vascular pattern of the deep choroidal layer and choriocapillaris in the eyes with central serous chorioretinopathy (CSC) before versus after photodynamic therapy (PDT) as visualized by optical coherence tomography angiography (OCTA). METHODS: This comparative case series study included patients who underwent a half-dose of PDT as a therapy for CSC. Using OCTA and manually shifting the reference level into the deep choroidal layer, we assessed the density of the deep choroidal vascular layer and choriocapillaris. RESULTS: The study included 20 patients (17 men; mean age, 43.3 ± 10.9 years), with two patients showing bilateral CSC. In the eyes affected by CSC, the mean vascular density of the deep choroidal layer and choriocapillaris increased significantly from 54.2 ± 6.7% at baseline to 58.0 ± 4.7% at 1 month after PDT (P = 0.002) and from 58.1 ± 2.7% at baseline to 60.5 ± 2.7% at 1 month after PDT (P = 0.004), respectively. The difference between affected and unaffected eyes was significantly larger at baseline than at 1 month after PDT (deep choroidal layer 4.79 ± 6.02 versus 0.39 ± 3.46, P = 0.002; choriocapillaris 4.26 ± 3.94 versus 1.25 ± 3.44, P = 0.002) and larger than at 3 months after baseline (n = 11 patients), when the affected and unaffected fellow eyes no longer differed significantly (P = 0.66 and P = 0.37, respectively). As a corollary, the width of the large choroidal vessels in the deep choroidal layer decreased after the PDT. Comparing assessments by two blinded examiners revealed a kappa value of 0.90, indicating a good agreement for examination of the deep choroidal layer. CONCLUSION: In conclusion, OCTA can be helpful to visualize the deep choroidal vascular layer by manually shifting the reference layer deeper into the choroid.

Localization of Corneal Neovascularization Using Optical Coherence Tomography Angiography.

PURPOSE: This article explores the application of optical coherence tomography angiography (OCTA) in assessing corneal neovascularization (CoNV) and investigates the features of CoNV in eyes with corneal transplantation. METHODS: A pilot, case series, observational study was conducted to enroll patients who underwent corneal transplantation including penetrating keratoplasty (PKP) and deep lamellar keratoplasty (DLKP) with or without additional keratolimbal allograft transplantation. All patients were followed with a series of ophthalmologic examinations including slit-lamp photography and were then imaged with the anterior segment OCTA. RESULTS: The study included 15 eyes of 14 patients (12 men; mean age of 37.4 ± 13.3 years), of which 9 eyes had undergone PKP and 6 eyes DLKP. OCTA was able to clearly identify the features of CoNV in eyes with significant CoNV and to confirm the presence of CoNV in eyes suspected of having CoNV. Four types of CoNV (superficial, stromal, fringe, and recipient-bed CoNV) were discovered by OCTA based on their location and depth. Superficial CoNV was mainly discovered in eyes that had undergone PKP (88.9% ± 11.1%), whereas the recipient-bed CoNV, once thought to be located in the host-graft interface, was discovered to grow in the host cornea only in eyes that had undergone DLKP (83.3% ± 16.7%). Comparing the assessment by 2 masked observers revealed a kappa value of 0.94, indicating excellent agreement. CONCLUSIONS: OCTA can be useful to visualize CoNV, which may be valuable in assessing corneal graft rejection.

Optical coherence tomography angiography in retinal vein occlusions.

PURPOSE: To examine the vascular density in different retinal layers and in the choriocapillaris in eyes with retinal vein occlusions (RVO). METHODS: Applying optical coherence tomography angiography (OCTA), we examined patients with unilateral RVOs and normal individuals of a control group. RESULTS: The study group included 48 patients with unilateral RVO and the control group 17 normal individuals. Eyes affected by RVO as compared to the contralateral unaffected eyes (all P < 0.001), and the contralateral unaffected eyes as compared to the eyes of the control group (P < 0.05), showed a lower vessel density in the superficial and deep retinal layers in all regions except for the foveal region. Choriocapillaris density was lower (P < 0.001), foveal retinal thickness and subfoveal choroidal thickness (P < 0.001) were thicker, and the foveal avascular zone was larger (P = 0.003) in the RVO eyes than in the contralateral eyes. For 29 eyes undergoing OCTA and fluorescein angiography, two examiners independently rated the retinas to be ischemic in fluorescein angiography in 14 eyes and in OCTA in 9 of these 14 eyes. CONCLUSIONS: Upon OCTA, unaffected eyes of patients with unilateral RVOs showed vascular abnormalities in the superficial and deep retinal layers when compared to those of healthy individuals.

Optical Coherence Tomography Angiography Vessel Density Changes after Acute Intraocular Pressure Elevation.

To investigate changes in retinal vessel density in optic nerve head (ONH) and macula after acute intraocular pressure (IOP) elevation, we conducted a prospective observational study. Eyes with IOP rise ≥5 mmHg after 2-hour dark room prone provocative test (DRPPT) were included. Vasculature of ONH and macula was examined by optical coherence tomography angiography (OCTA) at baseline and after DRPPT. Among the 65 eyes of 42 individuals, 40 eyes with qualified images were enrolled. Mean IOP rise was 9.6 ± 4.2 mmHg (5.0-23.3 mmHg) after DRPPT. Retinal vessel density did not differ after IOP rise for either the papillary region (optic nerve head and radial peripapillary capillary layer) or the macula region (superficial, deep and outer retinal layer) (P > 0.05). Vessel density in each subregion did not change either. If only enrolled eyes with IOP rise ≥10 mmHg, similar results were obtained in condition of IOP increase by 15.0 ± 3.6 mmHg. To conclude, eyes with an acute IOP elevation by 10 or 15 mmHg for two hours, while the blood pressure remained constant, the vessel density in both ONH and macula region examined by OCTA did not show significant changes. The observations fit with an IOP-related autoregulation in retinal blood flow for a moderate elevation of IOP.

POLYPOIDAL CHOROIDAL VASCULOPATHY UPON OPTICAL COHERENCE TOMOGRAPHIC ANGIOGRAPHY.

PURPOSE: To study polypoidal lesions and branching choroidal vascular networks in eyes with polypoidal choroidal vasculopathy by optical coherence tomography (OCT)-based angiography (OCTA). METHODS: In the observational cross-sectional study, patients with polypoidal choroidal vasculopathy, as diagnosed by indocyanine green angiography, underwent OCTA. RESULTS: Thirty-two eyes of 31 patients with an age of 61.1 ± 7.6 years were included. Branching choroidal vascular networks were detected by indocyanine green angiography and OCTA in 25 of 32 (78 ± 73%) and in 30 of 32 (94 ± 4%) eyes, respectively, with a marginally significant difference (P = 0.06) in the detection rate between both techniques. A total of 72 polyps (area, 0.06 ± 0.06 mm; range, 0.01-0.27 mm) were detected by indocyanine green angiography, and they were consistently present on the OCTA images. By moving the reference level in the OCT angiograms to the corresponding layer, the polypoidal lesions showed cluster-like structures in 53 of 72 polypoidal lesions (74%). In 60 of the 72 polypoidal lesions (83%), cluster-like structures were detected in the en face structural OCT images at the reference plane of the OCTA images. On the cross-sectional OCT images, some internal channels of flow were seen in 50 of the 72 polypoidal lesions (69%). Larger size of the polypoidal lesions was associated with a higher prevalence of cluster-like structures on the OCTA images, some internal channels of flow on the en face structural images, and clustered vascular structures on the cross-sectional OCT images. CONCLUSION: In conclusion, OCTA is a useful technique for the noninvasive detection of branching choroidal vascular networks including visualization of details such as cluster-like structures and flow. In some eyes, OCTA was superior to indocyanine green angiography to detect polypoidal choroidal vasculopathy and to show branching choroidal vascular networks.

Retinal vessel oxygen saturation in healthy subjects and early branch retinal vein occlusion.

AIM: To measure the retinal oxygen saturation in healthy subjects and early branch retinal vein occlusion (BRVO) in Chinese population. METHODS: The retinal vessel oxygen saturation of the healthy subjects and BRVO patients were measured by a noninvasive retinal oximeter (Oxymap ehf., Reykjavik, Iceland). RESULTS: The study included 22 patients with unilateral BRVO (mean age: 55.1±8.8y) in the study group and 91 healthy participants (mean age: 37.5±14.0y) in the control group. In the healthy individuals, mean arterial and venous oxygen saturation were significantly (P<0.001) higher in the superior nasal quadrant (98.5%±10.1% and 57.3%±8.7%, respectively) than in the inferior nasal quadrant (94.2%±9.0% and 54.1%±9.6%, respectively), followed by the superior temporal quadrant (89.1%±10.1% and 51.9%±8.9%, respectively) and the inferior temporal quadrant (86.4%±9.4% and 46.6%±9.6%, respectively). In patients with ischemic BRVO, arterial oxymetric values were significantly higher and venous measurements significantly lower for the affected vessel (107.5%±9.7% and 46.4%±14.2%, respectively) than the unaffected vessel in the same eye (99.2%±12.2% and 55.5%±7.9%, respectively) and as compared to the vessel in the unaffected fellow eye (93.1%±6.9% and 55.7%±6.8%) (P=0.005 and P=0.02, respectively). In the patients with non-ischemic BRVO, mean venous oxygen saturation was lower in the affected vein (39.8%±12.2%) than in the unaffected vessels of the same eye (50.8%±10.5%) and in the fellow eye (58.21%±5.7%) (P=0.03). Mean arterial oxygen saturation did not differ significantly (P=0.42) between all three groups. CONCLUSION: In patients with BRVO, the venous oxygen saturation in the affected vessels is decreased potentially due to decreased blood velocity and flow. Interestingly, the arterial oxygen saturation in eyes with ischemic BRVO is increased in the affected arteries.

Application of optical coherence tomography angiography in assessment of posterior scleral reinforcement for pathologic myopia.

AIM: To investigate the effect of posterior scleral reinforcement (PSR) on circulation of pathologic myopia eyes with posterior staphyloma by optical coherence tomography angiography (OCTA). METHODS: The study included 30 pathologic myopia eyes with posterior staphyloma which underwent PSR (PSR group) for 6 to 18mo ago, and 30 age and myopia matched eyes without PSR surgery as control group. Macular, choriocapillaris and radial peripapillary capillary (RPC) flow density were measured by OCTA, and the measurements were compared between groups. RESULTS: OCTA found no significant differences in macular flow density between PSR and control groups. For the superficial flow, whole enface flow density (WED), fovea density (FD), and parafoveal density (PD) were 46.55%±5.19% vs 47.29%±4.12% (P=0.542), 31.45%±6.35% vs 31.17%±4.48% (P=0.841), and 48.82%±5.66% vs 49.21%±4.15% (P=0.756) in PSR and control groups, respectively. For the deep flow, WED, FD, and PD were 52.07%±5.78% vs 53.95%±4.62% (P=0.168), 29.62%±6.55% vs 29.50%±6.38% (P=0.940), and 56.93%±6.17% vs 58.15%±5.13% (P=0.407) in PSR and control groups, respectively. The choriocapillary flow density was 61.18±3.25% in PSR group vs 60.88%±2.56% in control group (P=0.692). Also, OCTA found no significant differences in RPCs flow density between PSR and control groups. The optic disc WED, inside disc flow density and peripapillary flow density were 48.47%±4.77% vs 48.11%±4.57% (P=0.813), 45.47%±11.44% vs 46.68%±9.02% (P=0.709), 54.32%±5.29% vs 52.47%±6.62% (P=0.349) in PSR and control groups, respectively. CONCLUSION: OCTA provides a non-invasive and quantitative approach for monitoring macular and papillary blood flow in pathologic myopia. PSR can not improve but may maintain the circulation of pathologic myopia eyes with posterior staphyloma.

OPTICAL COHERENCE TOMOGRAPHIC ANGIOGRAPHY IN CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: Using optical coherence tomographic angiography (OCT-angiography), we examined the vasculature of the choriocapillaris in patients with central serous chorioretinopathy (CSC). METHODS: The prospective observational clinical study included patients with CSC defined by painless loss of central visual acuity and presence of a serous macular detachment as visualized by spectral-domain OCT. All eyes underwent OCT-angiography. Subfoveal choroidal thickness and choriocapillaris width were measured. RESULTS: The study included 26 eyes of 21 patients with a mean age of 47.0 ± 7.9 years (range: 34-65 years). All 26 eyes showed an image pattern of high signal intensity, and 21 eyes additionally demonstrated dilated capillaries in the OCT-angio images. The areas showing abnormalities in the OCT-angiography were congruent with leaking areas in fluorescein angiography or areas with hyperpermeability in indocyanine green angiography. Among 16 patients with unilateral CSC, 1 patient showed a high intensity pattern in the OCT-angiogram in the contralateral, clinically unaffected eye. Parallel to thicker choroidal thickness measurements in affected eyes as compared with contralateral unaffected eyes in unilateral CSC, OCT-angiography revealed significantly thicker choriocapillaris measurements in the affected eyes. Conventional fluorescein angiography did not demonstrate leakage in 14 of 18 eyes with clinically diagnosed CSC. CONCLUSION: Optical coherence tomographic angiography showed an image pattern of high signal intensity in all eyes with CSC and dilated vessels in the choriocapillaris in most eyes with clinically diagnosed CSC. The results indicate that OCT-angiography may become a noninvasive valuable tool for the diagnosis of CSC in particular and for the diagnosis of macular disorders in general.