Thickness In Diabetic Macular Edema Research Articles

Hybrid threshold laser to treat diabetic macular edema: A retrospective analysis single center cohort study

BackgroundDiabetic patients suffers from reduction of vision that one of its main causes is clinically significant macular edema (CSME).The purpose of this study to determine if hybrid threshold can reduce macular thickness in Diabetic Macular Edema. Materials and methodsThis study is a retrospective analysis single center cohort study. 12 eyes in 10 patients diagnosed with diabetic macular edema using SD-OCT treated with Hybridthreshold laser as the leaking microaneurysms were treated with threshold laser on the 5% duty cycle settings.A complete fundus exam, including best-corrected visual acuity changes, and monthly measuring retinal thickness using SD-OCT for 24 weeks follow up. ResultsReduction of retinal thickness from 336.58 ± 86.26 μm to 264.33 ± 61.41 μm (p = 0.02) at 24 weeks follow up without significant changes of best-corrected visual acuity from 0.16 LogMAR to 0.08 LogMAR (p = 0.2) with minimal scar formation in 24 weeks follow up. Conclusion532 nm Hybridthreshold laser reduces macular thickness up to 20% and stabilizes diabetic macular edema for 24 weeks follow up.

Latent Diabetic Macular Edema in Chinese Diabetic Retinopathy Patients.

Purpose: To compare the detection rates of optical coherence tomography (OCT) and fluorescein angiography (FA) in a diabetic macular edema (DME) and the severity of diabetic retinopathy in both color fundus images (CFI) and FA, and to investigate the predictive factors in macular leakages in FA.Methods: This was a retrospective study, and a total of 132 eyes of 77 patients with diabetic retinopathy were enrolled. Macular OCT, FA, and CFI were reviewed and measured. Central foveal thickness was also measured.Results: The severity of diabetic retinopathy in FA was significantly higher than that in CFI (p < 0.001). OCT detected 26 eyes with DMEs, which included the following: 13 eyes with cystoid macular edemas; 13 eyes with serous retinal detachments; 11 eyes with diffuse retinal thickening; 4 eyes with vitreomacular interface abnormalities. In contrast, 72 out of 132 eyes (54.5%) showed macular leakages in FA, which was significantly higher than that detected by OCT (p < 0.001). Compared with FA, the sensitivity and the specificity of OCT in detecting DMEs were 30.6 and 93.3%, respectively. However, central foveal thickness was not significantly different between the patients with non-clinically significant macular edema (CSME, 253.1 ± 26.95 μm) and slight CSME (270.9 ± 37.11 μm, p = 0.204). The mean central foveal thickness in diabetic macular edema (FA) eyes was 271.8 ± 66.02 μm, which was significantly higher than that (253. ± 25.21 μm) in non-DME (FA) eyes (p = 0.039). The central foveal thickness in DME (FA) eyes was significantly lower than that in eyes with DME (OCT) (p = 0.014). After adjusting for age and sex, a logistic regression analysis showed that the classification of diabetic retinopathy in FA was positively associated with macular leakage in FA (p < 0.001).Conclusions: The severity of diabetic retinopathy is underestimated in CFI compared with that in FA. FA can detect latent DMEs, which appeared normal on OCT. The central foveal thickness is not a sensitive parameter for detecting latent DMEs.

MON-669 Diabetic Macular Edema Thickness in Asians and Caucasians: Is There a Difference?

Background: Diabetic macular edema (DME) is a manifestation of diabetic retinopathy (DR) which can result in vision loss. DME affects over 750,000 US adults over the age of 40, costing 33% more in Medicare dollars than those patients without DME. Ethnicity plays a role in the development of DR but there are no studies about DME and HbA1c in Asians versus Caucasians. As Asians are the fastest growing ethnic group in the US and are at an increased risk of developing Type 2 Diabetes Mellitus (T2DM), there is a need for more knowledge about DME compared to Caucasians. Purpose: Evaluation of diabetic macular edema thickness between Asian and Caucasian Diabetic patients. Methods: A retrospective chart review (2017-2019) of consecutive diabetic patients were performed at California Retina Clinic. Inclusion criteria: DME thickness was measured by Optical Coherence Tomography (OCT) (Heidelberg Spectralis, Heidelberg, Germany), OCT +/- 3 months of their HbA1c lab test, control (C) non-diabetic patients=HbA1c <6.0%; For T2DM patients diagnosed by primary care physician: HbA1c ≥6.0%. Exclusion criteria: Age under 18 or over 90 years. Data analysis: R Project version 3.6.1 (R Foundation for Statistical Computing, Vienna, Austria). Two-way ANOVA was used to determine the difference between the four groups. The post-hoc test, Tukey’s HSD was used for p-values (<0.05). Results: Of 500 consecutive patients: 80 patients met inclusion criteria: T2DM Asian (ADM), T2DM Caucasian (CDM), C Asian (CA), C Caucasian (CC). n=80 pts, avg age=59.187 years (sd=15.42, range 23-89 years), Female=44, Male=36; ADM: n=20, avg age=60.90 years (sd=11.22, range 37-79 years), Female=10,Male=10, HbA1c range = 6.7-11.9%, Avg HbA1c = 7.59%, Avg DME=276.28 um (sd=25.93 um, range = 238.5-342 um); CDM: n=20, avg age=68.05 years (sd=10.54, range 46-87 years), Female=9, Male=11, HbA1c range = 6.0-11.5%, Avg HbA1c = 7.52%, Avg DME=298.68 um (sd=33.84 um, range = 253.5-397.5 um); HbA1c in ADM v CDM: p=0.8(ns) CA: n=20, avg age=52.85 years (sd=16.81 years, range 34-84 years), Female=10, Male=10, HbA1c range = 4.8-5.5%; Avg DME=267.05 um (sd=21.09 um, range = 230-310 um). CC: n=20, avg age=62.95 years (sd=13.47 years, range 40-89 years), Female=14, Male=6, HbA1c range = 4.8-5.6%, Avg DME=285.68 um (sd=16.58 um, range = 248.5-312.0 um).ADM v CDM and DME [F(1, 76)=13.267, p = 0.00049]. Tukey’s HSD post hoc tests were carried out. CDM v ADM had a significantly higher avg DME: 22.4 um (p=0.031). Body Mass Index (BMI): ADM patients (avg= 25.6) compared to CDM patients (28.5):(p=0.05, t-test). Conclusion: In this small study, T2DM Asians had less macular edema thickness than T2DM Caucasians with similar HbA1c. T2DM Asian patients had lower Body Mass Index than T2DM Caucasians. Body Mass Index may be an additional factor to consider in the evaluation of diabetic macular edema in Asians and Caucasian Diabetic patients.

Central Macular Thickness in Diabetic Macular Edema

Retinal microvascular dysfunction differs in macular edema lesions in the two eyes of the same patient with diabetic retinopathy. To evaluate the relationship between central macular thickness (CMT) and metabolic/systemic factors including anthropometric and laboratory findings, in patients with regressed diabetic retinopathy and a history of pars plana vitrectomy (PPV) combined with internal limiting membrane peeling in one eye. Forty-two eyes with PPV and the same patients' fellow 42 eyes (without PPV) included this study. Fasting blood samples of these 42 diabetics were collected to study adiponectin levels and other routine parameters. The average hemoglobinA1c value was 7.3±1.3%. CMT of the vitrectomized eyes were significantly correlated with atherogenic index of plasma, total cholesterol, low density lipoprotein cholesterol and uric acid (UA). On the other hand, CMT of the nonvitrectomized fellow eyes significantly correlated with glucose levels and diabetes duration. Adiponectin, adiponectin/body mass index, adiponectin/fibrinogen were found significantly higher in the subgroup with CMT≥300μm in the vitrectomized eyes (P<0.05). UA levels were higher in the subgroup with CMT≥300μm in the fellow (nonvitrectomized) eyes (P<0.05). Although there was no relationship between CMT and hemoglobinA1c values, CMT seemed to be affected by atherogenicity, prooxidant chemical alterations in the course of inflammation, so determination of adiponectin and UA levels may be suggested before surgery to predict the atherosclerotic damage and the postoperative CMT value. Vitrectomy performed at the proper time may be helpful in metabolic remodeling process of the retinal tissue along with life style changes, well control of diabetes, and intraocular treatments.

Subfoveal choroidal thickness in diabetic macular edema.

Purpose: To evaluate subfoveal choroidal thickness (SFCT) in eyes with diabetic macular edema (DME) using spectral domain OCT (SD-OCT).Materials and methods: Ninety eyes were divided into three equal groups: group A, non-proliferative diabetic retinopathy (NPDR) with no DME; group B, NPDR having DME; and group C, non-diabetic patients. The central subfield retinal thickness (CSRT) and SFCT were measured using spectral domain OCT.Results: There was a moderate negative correlation between age and SFCT in group B (r=−0.455, P=0.012). We found no significant correlation between best corrected visual acuity (BCVA) and SFCT in all groups (for groups A, B, and C, respectively: r=0.189, P=0.316; r=−0.195, P=0.302; and r=−0.181, P=0.337). There was no significant correlation between duration of diabetes and SFCT (r=−0.118, P=0.534 and r=−0.136, P=0.475 for groups A and B, respectively). The CSRT was 229.13±16.2, 336.4±74.85, and 223.13±16.9 µm in groups A, B, and C, respectively. The mean SFCT was 260.6±49.2, 259±50.8, and 252±50 µm in groups A, B, and C, respectively. We found no significant correlation between CSRT and SFCT in all groups (for groups A, B, and C, respectively: r=−0.049, P=0.796, r=0.239, P=0.204, r=−0.021, P=0.914). There was no significant difference in SFCT between group B (DME) on one hand and groups A and C on the other hand (P=0.9 and 0.59, respectively).Conclusion: There is no significant correlation between CSRT and SFCT in DME. Choroidal thickness assessment is not an indicator of the severity of DME and cannot be used as a monitor of its progression.

Retinal thickness in diabetic macular edema: A study using optical coherence tomography (OCT)

Introduction: Macular edema is the most frequent cause of visual impairment in patients with Nonproliferative Diabetic Retinopathy (NPDR). Clinically they are differentiated as focal and diffuse. Optical coherence tomography (OCT) can measure the retinal thickness and assess the response of surgery. This study was done to evaluate the efficacy of OCT as an investigative tool in diabetic macular edema. Materials and Methods: A prospective study was done among 30 consecutive eyes with Clinically Significant Macular Edema (CSME) over 8 months in our institution and divided into two groups with 15 each as focal and diffuse on the basis of fundus bio-microscopy and fluorescein angiography. Baseline measurements were done by OCT. Patients were followed up after surgery at 4 weeks and 12 weeks with repeat measurements. Data entered in excel sheet and analyzed using SPSS software. Data presented as tables and graphs with Spearman’s correlation and Paired t test. Results: Among 15 eyes with focal macular edema mean age of patients was 59.80 ± 5.13 years whereas among diffuse macular edema, it was 67.80 ± 3.76 years. There was negative correlation between BCVAb and FOVb among both the groups which was significant. (p=0.033, p Conclusion: Optical coherence tomography is a useful modality of investigation in patients with diabetic macular edema. Thus OCT can be used for quantitative assessment in response to surgery. Keywords: Diabetes, Investigative tool, Macular edema, Retinal thickness.

The thickness and volume of the choroid, outer retinal layers and retinal pigment epithelium layer changes in patients with diabetic retinopathy.

To evaluate the thickness and volume changes of the choroidal, outer retinal layers (ORL) and retinal pigment epithelium (RPE) in patients with diabetic retinopathy (DR) using optical coherence tomography (OCT) and correlate them with visual acuity. We carried out a retrospective observational case series. Consecutive DR patients were recruited for color fundus photography and OCT assessment. The RPE, ORL and choroidal thickness were measured. The correlation with the best-corrected visual acuity (BCVA) was also investigated. The study included 128 eyes, comprising 45 eyes of 25 diabetic macular edema (DME) patients, 34 eyes of 20 DR without DME (non-DME) patients, and 49 eyes of 25 age-matched normal individuals. The choroidal thickness in DR patients were decreased statistically significantly compared with the control group (P<0.05). The mean macular ORL thickness in DME (73.02±15.34 µm) and non-DME groups (76.35±7.32 µm) were decreased statistically significantly compared with the control group (80.20±5.85 µm; P=0.006, P=0.013, respectively). In both the non-DME and DME groups, the RPE thickness were decreased compared with the control group (P<0.05), except in the macular and central ring. The BCVA were significant interactions with the total inner retinal volume and macular RPE thickness in the DME group (r=0.115, P<0.001, r=-0.013, P=0.017, respectively). The choroid, ORL and RPE thickness are significantly decreased in DR patients compared with controls in different segments.

OUTER RETINAL LAYER THICKNESS AS GOOD VISUAL PREDICTOR IN PATIENTS WITH DIABETIC MACULAR EDEMA.

To evaluate the relationship between outer retinal layer (ORL) thickness in diabetic macular edema to visual acuity (VA). Ninety-five eyes were included in this prospective nonrandomized case-control study. They divided into 30 cases of healthy normal subjects and 65 cases of nonproliferative diabetic retinopathy with diabetic macular edema. Complete ophthalmic examination and spectral domain-optical coherence tomography were done for all cases and analyzed to measure central foveal point thickness (CFT), ORL thickness at fovea, and subfoveal choroidal thickness. The ORL thickness was significantly thinner in diabetic macular edema group (85.3 μm) than controls (99.9 μm) (P = 0.002). There was higher significant correlation between ORL thickness and logMAR VA (r = -0.87, P < 0.001) than correlation between CFT and VA (r = 0.18, P = 0.16). The cutoff point of the relationship between ORL thickness and VA was 88 μm with moderate sensitivity (81%) and high specificity (88%), below which vision is affected. Outer retinal layer thickness is significantly related to subfoveal choroidal thickness but not CFT. This study revealed reduction in ORL thickness in diabetic macular edema. There is a higher and stronger correlation between ORL thickness and vision than that between CFT and vision.

Correlation of Quantitative Metamorphopsia Measurement and Central Retinal Thickness in Diabetic Macular Edema and Age-Related Exsudative Macular Degeneration

Amsler Test is the standard used to detect metamorphopsia. To develop a tool to quantitatively measure and monitor metamorphopsia, the computer-based test "AMD - A Metamorphopsia Detector®" was developed. This study was performed to examine the correlation of metamorphopsia index (MI) and central retinal thickness (CRT) in exsudative age-related macular degeneration (AMD) and diabetic macular edema (DME). Sixty-six eyes of 66 patients, DME: 19 (11 males, 8 females; age 42 - 76); AMD: 47 (13 male, 34female; age 56 - 93) were included in this convenient sample study and classified as having or not having macular edema (central 500 µm, Cirrus HD-OCT). Best corrected monocular distance visual acuity (BCVA), Amsler Test, Metamorphopsia Index of AMD - A Metamorphopsia Detector, binocular ophthalmoscopy, central retinal thickness (SD-OCT) and fluorescein angiography, if necessary, were performed. Correlation of central retinal thickness and metamorphopsia index was evaluated by Spearman correlation. Mean BCVA (logMAR) was 0.27 (SD 0.3) in DME and 0.29 (SD 0.2) in AMD. Spearman's rho as a measure for correlation between CRT and MI was 0.88 (p < 0.001) in DME and 0.56 (p < 0.001) in AMD. Correlation of CRT und MI was high in DME and moderate in AMD. Future studies will examine if metamorphopsia measurement is a feasible tool for detection of conversion into neovascular AMD and for (self-)monitoring.

Efficiency of fenofibrate in facilitating the reduction of central macular thickness in diabetic macular edema.

Purpose:The purpose of this study is to study the benefit of addition of oral fenofibrate to the current regimen of diabetic macular edema (DME) management and quantify its effect on macular thickness and visual function in DME.Methods:Fifty-three eyes of 50 patients were randomized into treatment (Group A) (oral fenofibrate 160 mg/day) and control groups (Group B). Both groups underwent treatment of DME as per the standard treatment protocol of our hospital including intravitreal injections (anti-vascular endothelial growth factor/steroid) and grid laser. Patients were followed up every 2 months to note the visual acuity and central macular thickness (CMT) for 6 months.Results:Our groups were matched with respect to age (P = 0.802), mean diabetic age (P = 0.878), serum HbA1C levels (P = 0.523), and serum triglyceride levels (P = 0.793). The mean reduction in CMT was 136 μ in Group A and 83 μ in Group B at the end of 6 months. This difference was statistically significant (P = 0.031). Visual acuity improvement was 0.15 in Group A and 0.11 in Group B at the end of 6 months (P = 0.186). On subgroup analysis in Group A, we found that there was no difference in reduction of CMT between hypertensives and normotensives (P = 0.916), in patients with normal triglyceride levels and increased triglyceride levels (P = 0.975).Conclusion:Addition of fenofibrate to the standard protocol of DME management seems to facilitate reduction of CMT and probably have an added benefit on the visual functions.

Evaluation of Choroidal Thickness in Diabetic Macular Edema Using Spectral - Domain Optical Coherence Tomography Enhanced Depth Imaging Mode

Purpose: to evaluate the choroidal thickness (CH-T) and the central macular thickness (CMT) in eyes with diabetic macular edema (DME) and to detect if CH-T varies according to the type of DME. Patients and methods: One hundred forty two eyes of 96 patients were enrolled in the study. Eyes of diabetic patients with non-proliferative diabetic retinopathy (NPDR) with/without DME were evaluated. Eyes of normal subjects with no ocular or systemic diseases were included as a control group. The CMT and the underlying choroidal thickness were estimated using enhanced depth imaging mode of spectral-domain optical coherence tomography (EDI SD-OCT). CH-T thickness was measured at the subfoveal area and at an interval of 500 μm up to 1500 μm from the center of the fovea (nasal, temporal, superior and inferior). In eyes with DME, the type of DME was detected. Results: DME included cystoid DME (19 eyes), diffuse DME (27 eyes), and DME with serous retinal detachment (SRD) (23 eyes). 33 eyes with NPDR without DME and 40 non diabetic normal eyes were examined. Estimation of the choroidal thickness was performed and the subfoveal CH-T was thickest in the control group and significantly decreased in the diabetic groups especially with DME. The sub-foveal CH-T was 326±25.75 μm in the control group, 256.27±30.5 μm in NPDR without DME group, 210±23.96 μm in Cystoid DME group, 215.5±27.0 μm Diffuse DME group and 195.2±23.9 μm in DME with SRD group. The CMT was 238.75 ± 14.7 μm, 260.85 ± 24 μm, 530± 120.5 μm, 420.8± 101.6 μm and 506.60± 131.87 μm in the control group, NPDR without DME group, Cystoid DME, Diffuse DME and DME with SRD groups respectively. There was a statistically insignificant negative correlation between the subfoveal choroidal thickness and the CMT. Conclusion; there is an overall decrease in the CH-T in patients with NPDR and this thinning become more pronounced with the presence of diabetic macular edema.

Changes in subfoveal choroidal thickness in diabetic macular edema

Purpose: The objective of this study is to detect the changes in subfoveal choroidal thickness (SFCT) in eyes with diabetic macular edema (DME) with the use of enhanced depth imaging optical coherence tomography (EDI-OCT). Patients and Methods: One hundred and eighty eyes were included in this prospective nonrandomized study. They were divided into three groups, each including sixty eyes; Group I with patients with DME, Group II included diabetic patients without maculopathy, and Group III were normal persons. All eyes were examined with fluorescein angiography to detect the retinopathy stage, and all eyes were examined by EDI spectral domain-OCT to measure the thickness of the choroid. Central macular thickness (CMT) and best-corrected visual acuity (BCVA) were measured in all groups to find the correlation between them and SFCT. Results: The SFCT was significantly decreased in DME group (215.12 ± 5.6 μm) compared with the other two groups (in Group II, it was 253.1 ± 9.3 μm and in Group III, it was 255.93 ± 9.2 μm) (P < 0.001). A negative correlation (r = −0.6) was detected between CMT and SFCT in patients with DME while no correlation between them was found in other two groups (in Group II, r = 0.17 and Group III, r = 0.2). A significant correlation (r = 0.5) was observed between BCVA and SFCT in Group I, while in other two groups, no correlation between the two measures was detected (in Group II, r = −0.1 and Group III, r = −0.1). Conclusion: In eyes with DME, there is a choroidal thinning on EDI OCT. There is a negative correlation between SFCT and CMT in eyes with DME.

Evaluation of ocular pulse amplitude and choroidal thickness in diabetic macular edema.

The aim of this study is to evaluate the ocular pulse amplitude (OPA) and choroidal thickness (CT) measurements in patients with diabetic macular edema (DME) and healthy subjects. A total of 34 patients (12 male and 22 female) who had type 2 diabetes mellitus with DME and 34 sex-matched healthy subjects (13 male and 21 female) were included in this prospective study. The intraocular pressure (IOP) and OPA were measured with Dynamic contour tonometer (Pascal DCT, Switzerland). The subfoveal CT was measured using the Cirrus HD-OCT (Carl Zeiss Meditec). The CT at 1500 μm and 3000 μm nasal and temporal to the central fovea was also measured. The mean IOP values were 18.4±3.5 and 17.1±2.1 mm Hg in DME patients and healthy controls, respectively (P= 0.091). The mean OPA values in patients with DME (2.58±0.96) and controls (3.52±1.03) were statistically different (P<0.001). The mean subfoveal CT value was 273.5±30.2 μm in the eyes with DME and 321.4±36.5 μm in the control group (P< 0.001). In both groups, linear regression analysis showed no significant association between OPA and CT measurements. The IOP showed a significantly positive correlation with OPA in both DME (P=0.002, r=0.526) and controls (P=0.004, r=0.483). The current study suggests that both pulsatile choroidal blood flow and CT are decreased in patients with DME.

Correlation of visual acuity and central macular thickness in diabetic macular edema

PurposeTo investigate the correlation of retinal thickness measured with SD OCT and visual acuity in eyes with diabetic macular edema (DME) before and after intravitreal injection of anti‐VEGFMethodsSeventy‐four patients (96 eyes) with DME who underwent three monthly intravitreal injection of bevacizumab (IVB) as their first treatment. Type of DM, duration, treatment, laboratory examinations, history of cardiovascular disease, hypertension, hyperlipidemia, diabetic nephropathy, were documented. Logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity (BCVA) was evaluated using the international vision test chart. Foveal thickness was measured by SD OCT.ResultsThe correlation coefficients for visual acuity (VA) versus OCT center point thickness were 0.57 at baseline and 0.47, 0.38, and 0.40 at 1, 3, and 6 months post‐laser photocoagulation. A subset of eyes showed paradoxical improvements in VA with increased center point thickening (5–13% at the three time points) or paradoxical worsening of VA with a decrease in center point thickening (12–24% at the three time points).ConclusionsThere is modest correlation between OCT‐measured center point thickness and VA, and modest correlation of changes in retinal thickening and visual acuity following focal laser treatment for DME. In addition, paradoxical changes in VA and retinal thickening may be observed. Indeed, retinal thickness only accounts for up to 27% of variability in concurrently measured VA suggesting that other factors are important determinants of VA in the presence of diabetic macular edema.

Effect of Anti–Vascular Endothelial Growth Factor Therapy on Choroidal Thickness in Diabetic Macular Edema

To determine the effect of anti-vascular endothelial growth factor (VEGF) therapy on choroidal thickness in eyes with diabetic macular edema (DME). A retrospective, cohort analysis of 59 eyes from 59 patients with DME without prior anti-VEGF therapy. Choroidal thickness was measured using semiautomated segmentation of enhanced depth imaging optical coherence tomography images at 0.5-mm intervals from 2.5 mm nasal to 2.5 mm temporal to the fovea. Changes in choroidal thickness with and without anti-VEGF treatment over 6 months were compared. Best-corrected visual acuity and central foveal thickness were analyzed to evaluate the association of choroidal thickness with functional and anatomic outcomes. Of the 59 eyes with DME, 26 eyes were observed without treatment, whereas 33 underwent intravitreal anti-VEGF therapy (mean number of injections, 2.73) over 6 months. In untreated eyes, there was no significant change in best-corrected visual acuity (P = .098), central foveal thickness (P = .472), or choroidal thickness at all measurements along the macula (P = .057 at the fovea). In eyes treated with anti-VEGF injections, choroidal thickness decreased significantly at the fovea (246.6 to 224.8 μm; P < .001) and at 0.5 mm nasal (240.9 to 221.9 μm; P = .002) and 0.5 mm temporal (249.3 to 224.8 μm; P = .011) to the fovea. The decrease in subfoveal choroidal thickness after anti-VEGF treatment was not associated with the cumulative number of anti-VEGF injections (R(2) = 0.031; P = .327) or to changes in best-corrected visual acuity (R(2) = 0.017; P = .470) or central foveal thickness (R(2) = 0.040; P = .263). Central choroidal thickness decreases after anti-VEGF therapy for DME after 6 months, but may not be associated with functional or anatomic outcomes in eyes with DME.

Structural changes in individual retinal layers in diabetic macular edema.

Optical coherence tomography (OCT) has enabled objective measurement of the total retinal thickness in diabetic macular edema (DME). The central retinal thickness is correlated modestly with visual impairment and changes paradoxically after treatments compared to the visual acuity. This suggests the clinical relevance of the central retinal thickness in DME and the presence of other factors that affect visual disturbance. Recent advances in spectral-domain (SD) OCT have provided better delineation of the structural changes and fine lesions in the individual retinal layers. Cystoid spaces in the inner nuclear layer and outer plexiform layer are related to quantitative and qualitative parameters in fluorescein angiography. OCT often shows vitreoretinal interface abnormalities in eyes with sponge-like retinal swelling. Serous retinal detachment is sometimes accompanied by hyperreflective foci in the subretinal fluid, which exacerbates the pathogenesis at the interface of the photoreceptors and retinal pigment epithelium. Photoreceptor damage at the fovea is thought to be represented by disruption of the external limiting membrane or the junction between the inner and outer segment lines and is correlated with visual impairment. Hyperreflective foci in the outer retinal layers on SD-OCT images, another marker of visual disturbance, are associated with foveal photoreceptor damage.

24-Hour variation of optical coherence tomography–measured retinal thickness in diabetic macular edema

To investigate 24-hour variation in retinal thickness in patients with diabetic macular edema (DME) using optical coherence tomography (OCT). Fifty-three eyes of 53 diabetic patients with clinically significant macular edema and central subfield thickness (CST) >225 µm, 36 eyes of 36 healthy individuals (normal controls), and 22 eyes of 22 diabetic patients without macular pathology (diabetic controls) underwent 5 OCT measurements at 7 am, 10 am, 3 pm, 8 pm, and 1 am. Visual acuity, blood pressure, blood glucose, and body temperature were measured as well. The CST (p<0.0005), total macular volume (p<0.0005), and visual acuity (p<0.0005) showed significant variation in patients. The CST (450 µm at 7 am) reached a minimum at 3 pm (absolute change of -49 µm, relative change of -17%) before increasing again. Thickening changes were higher in more thickened retinas (p<0.0005, p=0.024, absolute and relative change, respectively). Visual acuity was worse in the morning (0.38 logMAR) and improved to a maximum at 8 pm (0.30 logMAR) (p<0.0005). Blood pressure, blood glucose, and body temperature did not vary over time. The 24-hour variation of retinal thickness is observed in a large proportion of patients with DME, with a decrease from morning to afternoon. Time of examination should be taken into account when managing such patients.

Comparison of macular thickness in diabetic macular edema using spectral-domain optical coherence tomography and time-domain optical coherence tomography.

Purpose. To compare the macular thicknesses in diabetic macular edema (DME) measured with spectral-domain optical coherence tomography (SD-OCT) and time-domain (TD) OCT. Patients and Methods. The average macular thicknesses of 50 eyes of 29 patients with DME were measured using SD-OCT and TD-OCT. Results. The mean macular thicknesses measured with TD-OCT and SD-OCT were 401.5 ± 117.8 μm (mean ± SD) and 446.2 ± 123.5 μm, respectively. The macular thicknesses measured with the two devices were well correlated (Pearson's product moment correlation, r = 0.977, P < 0.001). A significant correlation was found between the best-corrected visual acuity and the retinal thickness measured by TD-OCT and SD-OCT (Pearson's product moment correlation, TD-OCT, r = 0.34; P < 0.05; SD-OCT, r = 0.32; P < 0.05). Discussion. The mean macular thickness measured with SD-OCT was about 45 μm thicker than that measured with TD-OCT. Attention should be paid when comparing data obtained using different OCT machines.

Comparing central retinal thickness in diabetic macular edema measured by two different spectral-domain optical coherence tomography devices

We evaluated central retinal thickness (CRT) in diabetic macular edema (DME) using two different spectral-domain (SD) optical coherence tomography (OCT) instruments: the Cirrus and Spectralis OCTs. CRT was measured in 63 eyes of 32 patients with DME using both instruments on the same day. CRT measurements were significantly greater for the Spectralis than the Cirrus (p < 0.0003, n = 63, paired t test); mean CRT values were 382 ± 136 μm with the Cirrus and 394 ± 139 μm with the Spectralis. In eyes with poor best-corrected visual acuity (BCVA) (<20/40), mean CRT was 378 ± 130 μm with the Cirrus and 395 ± 139 μm with the Spectralis (p < 0.007, n = 29). In eyes with good acuity (equal to or better than 20/40), the mean CRT was 385 ± 142 μm with the Cirrus and 393 ± 140 μm with the Spectralis (p < 0.005, n = 34). Foveal retinal thickness measurements may vary among SD-OCT devices. The differences between instruments could affect the results of a multicenter study.

Subtenon injection of natural leucocytic interferon‐α for treatment of diabetic macular edema

AbstractPurpose To report the effect of subtenon injection of natural leucocytic interferon‐α (IFN‐α) on visual acuity (VA) and macular thickness (MT) in diabetic macular edema (DME).Methods 3 patients affected by diabetic macular edema refractory to intravitreal injection of bevacizumab received a complete ophthalmic examination including best‐corrected visual acuity (BCVA )and spectral domain ocular coherence tomography (SD‐OCT) before and after 1 week, 1 month and 4 months of a cycle of 3 parabulbar subtenonian injections in a week of IFN‐α (1x106 UL/ml, Alfaferone, AlfaWassermann).Results BCVA and MT significantly improved after a week in patient 2 (male, age 66): 20/50 vs 20/30 and 498μm vs 237μm. The result was stable during the third and fourth visits (299μm and 254 μm). BCVA and MT improved after a week in patient 1 (male, age 64): 20/40 vs 20/32 and 467μm vs 244μm, respectively; BCVA was stable during the follow up period, but MT increased significantly (610 μm and 603μm during the third and fourth visits). BCVA improved in patient 3 (female, age 75) after one week (20/50 vs 20/32) and was stable during the follow up period, but she had only a little improvement in MT (533μm, 483μm, 498μm and 493μm during the 4 visits).Conclusion BCVA improved in all the patients, and was stable after 4 months. MT greatly improved in two patients after 1 week but only in one patient was the result stable. IFN‐α, with its immunomodulatory, antiproliferative and antiangiogenic actions, was effective in improving VA and reducing macular thickness in DME. Randomized controlled studies will be useful to understand how long the effect of IFN‐α lasts, how many injections are needed and which patients might have the best results.