Swetha Bindu Velaga

Choroidal thickness in non-ocular Behçet's disease – A spectral-domain OCT study

Purpose To evaluate choroidal thickness in patients with non-ocular Behçets disease (BD) using spectral domain optical coherence tomography (SD-OCT) and to compare the results to normal eyes. Methods In this retrospective observational comparative study, we collected OCT and clinical data from the charts of 4 patients (7 eyes) with BD who had been referred for a screening eye exam and had a normal ocular examination. Data from 9 healthy volunteers (17 eyes) were collected as age-matched controls. The choroid was manually segmented from volume OCT scans using custom Doheny Image Reading Center OCT grading software (3D-OCTOR). Main outcome measures were choroidal thickness and intensity were compared between eyes of patients with BD and those of healthy controls. Results Eyes of patients with non-ocular BD had significantly thinner mean central subfield choroidal thickness (227.5 ± 56.93 versus 306.85 ± 17.85, P = 0.04) and central subfield choroidal volume (0.18 ± 0.04 vs 0.24 ± 0.02, P = 0.005). There was no significant difference in mean choroidal thickness in the whole ETDRS grid or in mean choroidal intensity in the central subfield and the whole ETDRS grid between eyes of patients with non-ocular BD and those of controls. Conclusion This study demonstrates that BD may have subclinical manifestations in the choroid, resulting in thinning of the choroid relative to normal eyes, even without overt signs of ocular involvement.

Correlation between retinal sensitivity and cystoid space characteristics in diabetic macular edema.

Purpose: To evaluate the correlation between retinal sensitivity and cystoid space characteristics in eyes with diabetic macular edema (DME). Materials and Methods: Prospective cross-sectional study of 22 subjects with DME (32 treatment-naïve eyes). All study subjects underwent complete ophthalmic examination, including slit-lamp biomicroscopy and dilated fundus examination. All subjects underwent spectral domain optical coherence tomography (SD-OCT) and microperimetry (MP). Intraretinal cystoid space (ICS) volume was generated after manual delineation of cystoid space boundaries using the three-dimensional-OCT software. Various SD-OCT parameters, including retinal thickness, retinal volume, cystoid space volume, cystoid space intensity, and outer retinal structure integrity, were correlated with MP parameters and best-corrected visual acuity (BCVA). Results: Subject′s mean age was 57 ± 9 years. The mean logarithm of minimum angle of resolution BCVA was 0.4 ± 0.2. The intraclass correlation coefficient for inter- and intra-grader assessment of cystoid space volume by manual delineation was 0.99 and 0.99, respectively. Mean total ICS volume was 0.4 ± 0.4 mm 3 and for the foveal center, subfield was 0.1 ± 0.1 mm 3 . Mean retinal sensitivity was 12.89 ± 10 dB; however, foveal retinal sensitivity was 12.3 ± 11.1 dB. We found no significant correlation between BCVA and total cystoid space volume (r = 0.33, P = 0.06). Correlation between total retinal sensitivity and total ICS was negative and nonsignificant (r = −0.17, P = 0.36). Correlation between foveal retinal sensitivity and foveal cystoid space intensity was moderate and marginally significant (r = −0.43, P = 0.05). Conclusion: Total cystoid space volume was not significantly correlated with BCVA or total retinal sensitivity in subjects with DME. Foveal cystoid space optical intensity was negatively correlated with foveal retinal sensitivity. These findings suggest further investigation of cystoid space characteristics in the setting of DME may be of value.

Interdevice comparison of retinal sensitivity assessments in a healthy population: the CenterVue MAIA and the Nidek MP-3 microperimeters

Background To compare and correlate the retinal sensitivity measurements obtained with Nidek Microperimetry-3 (MP-3) and the CenterVue Macular Integrity Assessment (MAIA) microperimeters among healthy subjects. Methods In this prospective comparative study, 31 eyes of 23 subjects underwent complete ophthalmological examination including retinal sensitivity assessments using two microperimeters, the MP-3 (Nidek Technologies) and the MAIA (CenterVue). The mean retinal sensitivity (dB) and its corresponding luminance (asb) and contrast (log units) were analysed between the two instruments. The interdevice reproducibility and level of agreement between the sensitivity values of the devices were assessed. Results The mean retinal sensitivity (dB) measured by the MP-3 (25.02±1.06 dB, range: 20.90–26.70) was significantly (p<0.0001) lower compared with the MAIA (30.68±0.74 dB, range: 28–31.84). The luminosity levels were significantly (p<0.0001) higher with the MP3 (7.75±1.31 asb, range: 6.44–9.06) compared with the MAIA (0.92±0.14 asb, range: 0.78–1.06). The contrast sensitivity was significantly higher for the MP-3 (0.94±0.33 log units, range: 0.61–1.27) compared with the MAIA (0.23±0.03 log units, range: 0.20–0.26). Despite these absolute differences, the intraclass coefficient was 0.85 (95% CI 0.70 to 0.92) between the two devices after applying a standard correction factor to each data point (MAIA sensitivity=MP-3 sensitivity+5.65) with a mean difference between MAIA and MP-3 of 0.01. Conclusion Retinal sensitivity measures higher, but luminance and contrast sensitivity measure lower for MAIA-generated values compared with the MP-3. The relationships, however, appeared fairly consistent, and application of a standard correction factor allowed the data to be inter-related, at least for normal eyes.

Automated detection of diabetic retinopathy lesions on ultrawidefield pseudocolour images

We examined the sensitivity and specificity of an automated algorithm for detecting referral‐warranted diabetic retinopathy (DR) on Optos ultrawidefield (UWF) pseudocolour images.

ASSOCIATION OF DRUSEN VOLUME WITH CHOROIDAL PARAMETERS IN NONNEOVASCULAR AGE-RELATED MACULAR DEGENERATION

Purpose: The choroid is thought to be relevant to the pathogenesis of nonneovascular age-related macular degeneration, but its role has not yet been fully defined. In this study, we evaluate the relationship between the extent of macular drusen and specific choroidal parameters, including thickness and intensity. Methods: Spectral domain optical coherence tomography images were collected from two distinct, independent cohorts with nonneovascular age-related macular degeneration: Amish (53 eyes of 34 subjects) and non-Amish (40 eyes from 26 subjects). All spectral domain optical coherence tomography scans were obtained using the Cirrus HD-OCT with a 512 × 128 macular cube (6 × 6 mm) protocol. The Cirrus advanced retinal pigment epithelium analysis tool was used to automatically compute drusen volume within 3 mm (DV3) and 5 mm (DV5) circles centered on the fovea. The inner and outer borders of the choroid were manually segmented, and the mean choroidal thickness and choroidal intensity (i.e., brightness) were calculated. The choroidal intensity was normalized against the vitreous and nerve fiber layer reflectivity. The correlation between DV and these choroidal parameters was assessed using Pearson and linear regression analysis. Results: A significant positive correlation was observed between normalized choroidal intensity and DV5 in the Amish (r = 0.42, P = 0.002) and non-Amish (r = 0.33, P = 0.03) cohorts. Also, DV3 showed a significant positive correlation with normalized choroidal intensity in both the groups (Amish: r = 0.30, P = 0.02; non-Amish: r = 0.32, P = 0.04). Choroidal thickness was negatively correlated with normalized choroidal intensity in both Amish (r = −0.71, P = 0.001) and non-Amish (r = −0.43, P = 0.01) groups. Normalized choroidal intensity was the most significant constant predictor of DV in both the Amish and non-Amish groups. Conclusion: Choroidal intensity, but not choroidal thickness, seems to be associated with drusen volume in Amish and non-Amish populations. These observations suggest that choroidal parameters beyond thickness warrant further study in the setting of age-related macular degeneration.