Qualitative and quantitative OCT response of diffuse diabetic macular oedema to macular laser photocoagulation

Purpose

To assess the quantitative and morphological changes of the macula in response to macular grid laser for diabetic macular oedema (DMO) using optical coherence tomography (OCT).

Patients and Methods

Cirrus OCT macular cube scans of 30 eyes of 25 patients were retrospectively analysed before and 4 months after macular grid laser for diffuse DMO. The oedema was quantified and response evaluated in the nine early-treatment diabetic retinopathy study (ETDRS) zones of the macula. Post-laser OCT changes were compared with the baseline features, including morphology patterns, changes in both logarithmic transformed (logOCT) and standardised average macular thickness (AMT), total macular volume, number of parafoveal quadrants involved, and the presence of intact 3rd hyper-reflective band (HRB).

Results

The rate of change of retinal thickness in response to laser was maximum in the central (8.17%) and perifoveal inferior quadrants (0.04%). Diffuse retinal thickening on OCT responded best to treatment. The AMT of 300–350 μm had the worst response (+0.94%). Eyes with less than four quadrants of oedema showed good response. Disrupted HRB was associated with poor visual gain (−0.33 ETDRS letters).

Conclusion

The topographic location of oedema on the retinal map and the morphological patterns of the oedema on OCT are useful predictors of treatment response in diffuse DMO.     

Regression of early diabetic macular oedema is associated with prevention of dark adaptation

Hypothesis

Dark-adapted rods consume oxygen at high rates and light adaptation decreases this oxygen burden and can have therapeutic effects on diabetic macular oedema (DMO).

Methods

Patients with mild non-proliferative diabetic retinopathy (DR) and early, untreated non-sight-threatening DMO slept for 6 months wearing masks that illuminated the eyelid of one closed eye by 505 nm light. Exclusion criteria were any concomitant eye disease, DR >ETDRS grade 35, and other systemic diseases. Primary outcome: change of OCT retinal thickness in the local region where oedema was present.

Results

A total of 34 out of 40 patients completed the study. Mean baseline OCT macular cube thickness was equivalent for study and fellow eyes. But study eyes had a greater mean thickness in the central subfield zone 1 (282±53 μm) vs (256±19 μm) the fellow eyes. Twenty-eight study eyes showed intraretinal cysts compared with nine in the fellow eyes. At 6 months, only 19 study eyes had cysts while cysts were seen in 20 fellow eyes. After 6 months, the worst affected ETDRS zone and the central subfield zone 1 reduced in thickness in study eyes only by 12 μm (95% CI 20 to −7, P=0.01). The secondary outcomes of change in visual acuity, achromatic contrast sensitivity, and microperimetric thresholds improved significantly in study eyes and deteriorated in fellow eyes.

Conclusions

Sleeping in dim light that can keep rods light adapted may reverse the changes of DMO.     

Macular findings on optical coherence tomography in cat-scratch disease neuroretinitis

Purpose

To describe the macular findings on optical coherence tomography (OCT) in patients with cat-scratch disease (CSD) neuroretinitis.

Methods

Medical records of all patients diagnosed with CSD neuroretinitis at the Tel Aviv Medical Center between April 2006 and May 2010 were retrospectively reviewed. All patients underwent Stratus OCT macular examination.

Results

Eight eyes of seven patients with confirmed CSD neuroretinitis, (mean age 33±9.9 years, range 6–48 years) were included in the study. All patients presented clinically with optic nerve swelling and macular edema or macular exudates. OCT demonstrated flattening of the foveal contour, thickening of the neurosensory retina, and accumulation of subretinal fluid (SRF) in all studied eyes. Retinal exudates appeared as multiple hyper-reflective foci in the outer plexiform layer. The average central macular thickness was 460 μm (range 170–906 μm) and the average maximal retinal thickness was 613 μm (range 387–1103 μm), at presentation. The macula appeared normal on repeated exams during follow-up.

Conclusion

Similar OCT findings were demonstrated in patients with CSD neuroretinitis. SRF was found in all eyes, although was not visible on clinical examination or fluorescein angiography. OCT may be used as an adjunct imaging tool in the diagnosis and follow-up of patients with CSD neuroretinitis.     

Fourier-domain optical coherence tomography of eyes with idiopathic epiretinal membrane: correlation between macular morphology and visual function

Purpose

The purpose of this study is to evaluate the macular morphological changes associated with idiopathic epiretinal membrane (iERM) using high-resolution Fourier-domain optical coherence tomography (FD-OCT), as they correlate with visual acuity and microperimetry (MP-1).

Methods

In all, 24 eyes (19 subjects) with iERM were imaged prospectively using FD-OCT with axial resolution of 4.5 μm and transverse resolution of 10 to 15 μm. MP-1 and Stratus OCT were carried out in a subset of eyes.

Results

The mean log of the minimum angle of resolution best-corrected visual acuity (BCVA) was 0.18±0.16 (range: −0.08 to 0.48, Snellen equivalent 20/15⁻¹ to 20/60). ERM was visualized in all 24 eyes with FD-OCT and in 17 eyes (85%) of 20 eyes imaged with Stratus OCT. Although BCVA correlated with macular thickening in the central 1 mm sub-field of the Stratus ETDRS (P=0.0005) and macular volume (central 3 mm area) on FD-OCT (P<0.0001), macular thickening on thickness map and volume correlated poorly with decrease in macular sensitivity on MP-1 (P=0.16). On FD-OCT, foveal morphological changes correlated best with decrease in BCVA, the strongest being central foveal thickness (P<0.0001). Other significant changes included blurring of the foveal inner segment–outer segment (IS–OS) junction and/or Verhoeff''s membrane, vitreal displacement of foveal outer nuclear layer and foveal detachment (P<0.05). Foveal IS–OS junction disruption was seen in 25% of eyes on Stratus OCT but in none of the eyes on FD-OCT.

Conclusion

FD-OCT allowed improved visualization of ERM and associated foveal morphological changes that correlated best with BCVA. Macular thickening correlated weakly with decreased macular function as assessed by MP-1.     

Detection of progressive macular thickness loss using optical coherence tomography in glaucoma suspect and glaucomatous eyes

Aims

To examine the rate of macular thickness loss using time-domain optical coherence tomography (OCT) in functionally progressing versus non-progressing eyes, determined by standard automated perimetry (SAP).

Methods

Glaucoma suspects (GS) and glaucomatous (G) eyes underwent SAP and OCT imaging every 6 months. Functional progression was determined using pointwise linear regression, defined as 2 contiguous locations losing ≥1.0 dB/year at P<1.0% in the same hemifield. The annual rate of macular thickness loss was calculated from inner and outer regions of the macular map.

Results

72 eyes (43 GS and 29G) with ≥30 months of follow-up were enroled. Fourteen eyes demonstrated SAP progression. The annual rate of macular thickness loss (μm/year) in progressing eyes was faster (all P<0.05) than non-progressing eyes in temporal outer (−1.90±2.97 vs 0.33±2.77), nasal inner (−1.70±2.66 vs 0.14±2.76), superior inner (−2.15±4.57 vs 0.51±2.99), temporal inner quadrants (−2.58±5.05 vs −0.38±2.34), and the average of inner macular quadrants (−1.84±2.90 vs 0.03±2.10). The rate of loss in the nasal inner (P=0.02) and temporal outer (P=0.02) macular regions was associated with optic disc haemorrhage.

Conclusions

Eyes with SAP progression have significantly greater rates of macular thickness loss consistent with glaucomatous retinal ganglion cell atrophy, as compared with non-progressing eyes.     

Pretreatment clinical variables associated with the response to intravitreal bevacizumab (Avastin) injection in patients with persistent diabetic macular edema

Background

The purpose of the study is to determine whether the pre-treatment clinical systemic variables and optical coherence tomography (OCT) findings are associated with the subsequent response to the intravitreal bevacizumab (IVB) in eyes with persistent diabetic macular edema (DME).

Design

Prospective, interventional non-comparative case series study.

Methods

38 Patients (45 eyes) with refractory diabetic macular edema; 16 females, 22 males with a mean aged 57.5 year. All patients had persistent DME not responded to other forms of treatments. Complete eye examination; best corrected visual acuity (BCVA) (represented as LOGMAR for adequate statistical analysis), slit-lamp exam, intraocular pressure measurement, stereoscopic biomicroscopy of the macula, and morphologic patterns of diabetic macular edema demonstrated by OCT.All patients had intravitreal injection of 0.05 mL = 1.25 mg bevacizumab (Avastin; Genentech, Inc., San Francisco, CA), and were followed up for 3 months. The pre and post-injection follow-up data were analyzed by Student-t test and Mann–Whitney test for two main outcome measures; visual acuity (LOGMAR) and central foveal thickness (CFT) changes over a period of three months, and the data included demographic factors, type, duration and the control of diabetes mellitus (HbA1C%), grade of diabetic retinopathy, renal function (serum creatinine level), serum cholesterol, blood pressure control and previous treatment by focal laser and/or intravitreal triamcinolone injection.

Results

The LOGMAR and central foveal thickness (CRT) improved in 30/45 eyes (67%) and 32/45 eyes (72%), respectively during a mean follow-up time of three months. The mean LOGMAR visual acuities were 0.64 (SD ± 0.34), 0.61 (SD ± 0.31) and 0.60 (SD ± 0.32) at pre-injection, at 1 month post-injection and at 3 months post-injection, respectively; but this mean increase in vision was statistically not significant (P value = 0.099). The mean foveal thicknesses were 444.95 μm (SD ± 127.36), 394.95 μm (SD ± 138.03) and 378.32 μm (SD ± 112.01) at pre-injection, 1 month post-injection and 3 months post-injection, respectively, this decrease in the foveal thickness was statistically significant (P value <0.001). The pre and post-injections values of the variables for diabetic duration, diabetic control (HbA1c) and OCT pattern of macular edema showed significant statistical correlations (P < 0.05) with LOGMAR only, however the values of the variables for serum creatinine and cholesterol show statistical correlation (P < 0.05) with both LOGMAR and CFT.

Conclusions

Chronicity and inadequate control of diabetes mellitus, nephropathy, hyperlipidemia and presence of vitreomacular attachment (VMA) are factors associated with poor vision progress after intravitreal bevacizumab injection.     

Normative spectral domain optical coherence tomography data on macular and retinal nerve fiber layer thickness in Indians

Aim:

To provide the normative data of macular and retinal nerve fiber layer (RNFL) thickness in Indians using spectral domain OCT (Spectralis OCT, Heidelberg Engineering, Germany) and to evaluate the effects of age, gender, and refraction on these parameters.

Design:

Observational, cross-sectional study.

Materials and Methods:

The eyes of 105 healthy patients aged between 20-75 years, with no ocular disease and best corrected visual acuity of 20/20, were scanned using standard scanning protocols by a single examiner. Exclusion criteria included glaucoma, retinal diseases, diabetes, history of prior intraocular surgery or laser treatment. The mean macular and RNFL thickness were recorded, and the effects of age, gender, and refraction on these parameters were evaluated. This data was compared with published literature on Caucasians to assess the ethnic variations of these parameters.

Results:

The normal central foveal thickness in healthy Indian eyes measured using Spectralis OCT was 260.1 ± 18.19 μm. The nasal inner quadrant showed maximum retinal thickness (338.88 ± 18.17 μm). The mean RNFL thickness was 101.43 ± 8.63 μm with maximum thickness in the inferior quadrant. The central foveal thickness showed a gender-based difference (P = 0.005) but did not correlate significantly with age (P = 0.134), whereas the parafoveal, perifoveal thickness, macular volume, and RNFL thickness showed significant negative correlation with age.

Conclusions:

Our study provides the normative database for Indians on Spectralis OCT. It also suggests that age should be considered while interpreting the macular thickness and RNFL, whereas gender should also be given consideration in central foveal thickness.     

Retinal sensitivity improvement after intravitreal triamcinolone acetonide injection for macular edema secondary to branch retinal vein occlusion

Purpose:

To evaluate the effect of intravitreal triamcinolone acetonide (IVTA) on retinal sensitivity in cases of macular edema(ME) secondary to branch retinal vein occlusion (BRVO).

Materials and Methods:

Total of 14 eyes of 14 cases of BRVO were included in this prospective study. In each eye, at baseline and 1, 3, and 6 months after IVTA injection, logMAR visual acuity, central 4° retinal sensitivity by MP-1 microperimetry, and optical coherence tomography foveal thickness were assessed.

Results:

Cases ages ranged from 60 to 79 years (mean 68 ± 8 years). At 1, 3, and 6 months, the logMAR visual acuity had increased from 0.71 ± 0.21 to 0.42 ± 0.21, 0.46 ± 0.30, and 0.46 ± 0.27; the mean foveal thickness had decreased from 540 ± 88 μm to 254 ± 51 μm, 288 ± 84 μm, and 280 ± 91 μm; and the mean retinal sensitivity had increased from 4.7 ± 2.5 dB to 7.9 ± 2.7 dB, 8.2 ± 3.6 dB, and 8.3 ± 4.6 dB, respectively.

Conclusion:

In eyes with ME secondary to BRVO, IVTA injections result in a significant increase in not only the visual acuity but also the central 4° retinal sensitivity in 6 months follow-up.     

Comparison of retinal nerve fiber layer and macular thickness measurements with Stratus OCT and OPKO/OTI OCT devices in healthy subjects

AIM: To compare retinal nerve fiber layer (RNFL) and macular thickness measurements obtained with the Stratus optical coherence tomography (OCT) and OPKO/OTI OCT devices. METHODS: Included in the study were 59 eyes of 30 participants. All measurements for each eye were done on the same day with both devices. Student’s paired t-tests were used to compare the central macular thickness and RNFL measurements of the Stratus OCT and OPKO/OTI OCT. Pearson correlation was used to assess the relationship between the devices. Coefficient of variation (COV) was calculated to assess intersession repeatability. RESULTS: Using both the Stratus OCT and OPKO/OTI OCT, respectively, the measured mean average RNFL thicknesses were 98.9±11.1 μm and 115.1±9.6 μm (P=0.001), and the measured mean central retinal thicknesses (CRT) were 196.2±18.8 μm and 204.5±21.1 μm (P<0.001). Measured by the two devices, the RNFL thickness values were correlated in all quadrants, as were the retinal thickness values except the inferior outer sector. COV for average RNFL and CRT thickness were 2.9% and 4.6% for Stratus OCT, and 2.1% and 4.2% for OPKO/OTI OCT, respectively. CONCLUSION: We found good reproducibility of RNFL and retina thickness measurements for both Stratus OCT and OPKO/OTI OCT devices. However, even though the two OCT systems provided statistically correlated results, the values for both RNFL and macular thickness were statistically different. RNFL and macular thickness measurements with the OPKO/OTI OCT were higher than that of the Stratus OCT; therefore, the two OCT systems cannot be used interchangeably for the measurements of RNFL and macular thickness.     

Morphological and functional changes in spectral domain optical coherence tomography and microperimetry in macular microhole variants: spectral domain optical coherence tomography and microperimetry correlation

Purpose:

To evaluate the relationship between the morphology and retinal function of macular microhole (MMH) variants.

Materials and Methods:

We evaluated 12 eyes of 11 patients with defects in the IS/OS junction of photoreceptor layer with SD-OCT. All patients underwent comprehensive ophthalmic examination including spectral domain optical coherence tomography (SD-OCT) and microperimetry.

Results:

The mean logMAR visual acuity in the affected eye was 0.15 ± 0.17 (range 0.00–0.5). Mean horizontal diameter of the MMH was 163 ± 99 μm; the mean retinal sensitivity in the area corresponding to the MMH was 13.79 ± 4.6 dB. Negative correlation was found between the MMH diameter and the retinal sensitivity (r = -0.65, p = 0.02). Three morphological patterns of MMH variants were recognized on SD-OCT, which did not differ in retinal sensitivities.

Conclusion:

We described and classified the MMH variants and made an assessment on the physiological functions using microperimeter.     

Multifocal electroretinogram in normal emmetropic subjects: correlation with optical coherence tomography

Aim of the Study:

To establish the normative database for multifocal electroretinogram (mfERG) parameters in a normal emmetropic population. To correlate the data so obtained with the central macular thickness obtained using the optical coherence tomography (OCT) scan.

Materials and Methods:

mfERG data were obtained from 222 eyes of 111 emmetropic subjects. The amplitude (nv/deg²) and implicit times (ms) of the first-order kernel mfERG responses (N1, P1, and N2 waves) were obtained and grouped into five rings (Ring 1: Central 2°, Ring 2: 2–5°, Ring 3: 5–10°, Ring 4: 10–15°, Ring 5: >15°). The central macular thickness (CMT) was obtained using the macular thickness scan protocol of the OCT.

Results:

The mfERG data obtained were used to create a normative database. The amplitudes of the mfERG waves were maximum in the fovea and progressively decreased with increasing eccentricity (P = 0.0001). The latencies of the P1 and N2 waves were longest in the central ring and progressively shortened with eccentricity (P = 0.0001). No statistically significant correlations were observed between central ring 1 parameters and the CMT.

Conclusion:

This study establishes normative database for mfERG parameters in an emmetropic population. No statistically significant correlation was noted between CMT and mfERG parameters.     

Intraocular soluble intracellular adhesion molecule-1 correlates with subretinal fluid height of diabetic macular edema

Objective:

To investigate the correlations between aqueous concentrations of vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), soluble intracellular adhesion molecule-1 (sICAM-1) and diabetic macular edema (DME).

Materials and Methods:

VEGF, MCP-1 and sICAM-1 concentrations in aqueous humor samples of 22 patients with DME and 23 patients with cataract of a control group were measured with solid-phase chemiluminescence immunoassay.

Results:

Aqueous VEGF (89.2 ± 58.5 pg/ml versus 48.5 ± 27.8 pg/ml, P = 0.006), MCP-1 (684.2 ± 423.4 pg/ml versus 432.4 ± 230.4 pg/ml, P = 0.019) and sICAM-1 (3213.8 ± 2581.6 pg/ml versus 260.2 ± 212.2 pg/ml, P < 0.001) all vary significantly between DME group and control group. Maximum height of submacular fluid measured by Optical coherence tomography (OCT) was significantly associated with aqueous sICAM-1 (r = -0.45, P = 0.034). The maximum height of macular thickness measured by OCT was not significantly associated with either VEGF (P = 0.300), MCP-1 (P = 0.320) or sICAM-1 (P = 0.285).

Conclusions:

Our results suggest that sICAM-1 may majorly contribute to the formation of subretinal fluid in DME patients and imply that MCP-1 and sICAM-1 may be the potential therapy targets, besides VEGF.     

Ganglion cell complex thickness in nonexudative age-related macular degeneration

Purpose

To evaluate ganglion cell complex (GCC) thickness with spectral domain optical coherence tomography (SD-OCT) in eyes with nonexudative age-related macular degeneration (NEAMD).

Methods

Forty-seven eyes of 28 patients with nonexudative age-related macular degeneration (NEAMD) and 54 eyes of 28 age-matched healthy subjects were enrolled. Each subject underwent a complete ophthalmic examination before SD-OCT were obtained. Macular scans were taken with software version 6.0 of the ganglion cell analysis (GCA) algorithm. GCC thickness was evaluated automatically as the average, minimum, temporal superior, superior, nasal superior, nasal inferior, inferior, and temporal-inferior segments by SD-OCT and parameters were compared between groups.

Results

The mean age was 68.7±8.73 years in patient group, and 61.51±5.66 years in control group. There were no significant differences in mean age, gender distribution, intraocular pressure, and sferic equivalent at imaging between the groups (P>0.05). The mean (±SD) GCC thicknesses were as follows; average 71.53±16.53 μm, minumum 62.36±21.51 μm, temporal superior 72.23±14.60 μm, superior 72.76±20.40 μm, nasal superior 72.31±20.13 μm, nasal inferior 69.74±20.51 μm, inferior 69.38±19.03 μm, and temporal-inferior 73.12±15.44 μm in patient group. Corresponding values in control group were 81.46±4.90 μm, 78.66±6.00 μm, 81.51±4.66 μm, 82.94±5.14 μm, 81.79±5.86 μm, 80.94±6.18 μm, 80.14±6.30 μm, and 81.75±5.26 μm, respectively. There were significant differences between two groups in each segments (Mann–Whitney U-test, P<0.05).

Conclusion

The average GCC thickness values (in all segments) of NEAMD patients were lower than control group. NEAMD, which is considered as a disease of outer layers of retina, may be accompanied with a decrease of ganglion cell thickness, so inner layers of retina may be affected.     

Macular edema after cataract surgery in diabetic eyes evaluated by optical coherence tomography

AIM: To assess quantitative changes of the macula in diabetic eyes after cataract surgery using optical coherence tomography (OCT) and to estimate the incidence of development or worsening of macular edema (ME) in diabetic eyes with or without pre-existing ME. METHODS: In this prospective, observational study, 92 eyes of 60 diabetic patients who underwent cataract surgery were evaluated before surgery and 1, 3mo after surgery using OCT. Macular thickness was measured with OCT at nine macular subfields defined by the 9 zones early treatment of diabetic retinopathy study (ETDRS), as well as total macular volume obtained by OCT at 1, 3mo after surgery were compared with baseline features obtained before surgery. In addition, the incidence of development or worsening of ME was analyzed in diabetic eyes with or without pre-existing ME. RESULTS: The central subfield mean thickness increased 21.0 μm and 25.5 μm at 1, 3mo follow-up, respectively (P<0.01). The average thickness of inner ring and outer ring increased 14.2 μm and 9.5 μm at 1mo, 18.2 μm and 12.9 μm at 3mo. Central-involved ME developed in 12 eyes at 3mo, including 4 eyes with pre-existing central-involved and 8 eyes with pre-existing non-central involved ME. Pre-existing diabetic macular edema (DME) was significantly associated with central-involved ME development (P<0.001). CONCLUSION: A statistically significant increase could be detected in the central subfield as well as perifoveal and parafoveal sectors though the increase was mild. And eyes with pre-operative DME prior to cataract surgery are at higher risk for developing central-involved ME.     

Observational study of subclinical diabetic macular edema

Purpose

To determine the rate of progression of eyes with subclinical diabetic macular edema (DME) to clinically apparent DME or DME necessitating treatment during a 2-year period.

Methods

In all, 43 eyes from 39 study participants with subclinical DME, defined as absence of foveal center edema as determined with slit lamp biomicroscopy but a center point thickness (CPT) between 225 and 299 μm on time domain (Stratus, Carl Zeiss Meditec) optical coherence tomography (OCT) scan, were enrolled from 891 eyes of 582 subjects screened. Eyes were evaluated annually for up to 2 years for the primary outcome, which was an increase in OCT CPT of at least 50 μm from baseline and a CPT of at least 300 μm, or treatment for DME (performed at the discretion of the investigator).

Results

The cumulative probability of meeting an increase in OCT CPT of at least 50 μm from baseline and a CPT of at least 300 μm, or treatment for DME was 27% (95% confidence interval (CI): 14%, 38%) by 1 year and 38% (95% CI: 23%, 50%) by 2 years.

Conclusions

Although subclinical DME may be uncommon, this study suggests that between approximately one-quarter and one-half of eyes with subclinical DME will progress to more definite thickening or be judged to need treatment for DME within 2 years after its identification.     

Cystic macular oedema on spectral-domain optical coherence tomography in choroideremia patients without cystic changes on fundus examination

Purpose

To determine the prevalence of cystic macular oedema (CME) in patients with choroideremia (CHM) by using spectral-domain optical coherence tomography (SD-OCT).

Methods

A total 16 patients affected with CHM were enroled in the study. All patients underwent a complete eye examination. SD-OCT was performed using an OPKO spectral-domain OCT/SLO instrument.

Results

The average age of the study patients was 44.0±16.0 years (range, 13–63 years). Out of the 16 patients with CHM, 10 patients (62.5%) showed a degree of CME on SD-OCT testing in at least one eye, and 8 patients (50%) showed CME in both eyes.

Conclusions

Because of its notable prevalence, it would seem prudent to screen CHM patients by SD-OCT for the possible presence of CME and to identify those amenable to future treatment strategies for their macular oedema.     

Spectral domain optical coherence tomography changes following intravitreal dexamethasone implant,Ozurdex? in patients with uveitic cystoid macular edema

Purpose:

To correlate the structural and functional changes following intravitreal injection of dexamethasone 0.7 mg (Ozurdex^®) implant in patients with recalcitrant uveitic cystoid macular edema (CME).

Materials and Methods:

In a prospective, interventional, nonrandomized study, 30 eyes (27 patients) with uveitic CME received Ozurdex^® implant and were followed-up for 24 weeks at periodic intervals to monitor structural alterations seen on spectral domain optical coherence tomography (SD-OCT). The outcome measures included change in central macular thickness (CMT) and best-corrected visual acuity (BCVA) as well as structural alterations seen on OCT such as change in the height of cystoid spaces (CSs) and sub-foveal serous retinal detachment (SSRD). The integrity of external limiting membrane and inner-outer segment junction was assessed at baseline and follow-up visits.

Results:

Mean age of the patients was 46.09 ± 15.66 years. The mean CMT decreased by 96 μm at 1-day, 231.64 μm at 1-week, 254.21 μm at 4 weeks and 249.14 μm at 12 weeks (P < 0.001) compared with baseline. BCVA improved from a baseline mean of 0.62 LogMAR units to 0.49 on day 1 to 0.31 at 24 weeks (P < 0.001). A decrease in the mean height of CS, that is, 133.28 μm from a baseline of 317.71 μm was noted on the 1^st day (P < 0.001). 4 eyes demonstrated the presence of CS at 4 weeks, 1 eye at 6 weeks and 3 eyes at 12 weeks. At baseline, 16 eyes (53.33%) demonstrated the presence of SSRD. Among these, 11 eyes showed resolution of SSRD on day 1. SSRD resolved in all patients at 4 weeks and was maintained up to 24 weeks.

Conclusions:

Ozurdex^® implant improves the visual outcome of patients with recalcitrant uveitic CME. Reversibility of retinal changes may be possible following treatment with dexamethasone implant. Thus final visual outcome may be independent of pretreatment CMT, the height of CS or SSRD.     

Fellow eye effect of unilateral intravitreal bevacizumab injection in eyes with diabetic macular edema

Aims

Anti-vascular endothelial growth factor compounds are routinely used for the treatment of diabetic macular edema (DME). We aim to evaluate for the existence and magnitude of treatment effect on fellow un-injected eyes.

Methods

A consecutive group of patients with bilateral DME who received unilateral bevacizumab injections was retrospectively evaluated. Data collected included demographics, ophthalmic and systemic findings, and optical coherence tomography (OCT) measurements of macular thickness.

Results

Thirty-five patients were evaluated. Mean follow-up was 245 days (range: 30–800), and the mean number of bevacizumab injections was 3.6 (range: 1–11). At end of follow-up, the mean (SD) OCT central subfield thickness reduced by 72±112 micron in the injected eye (from 469±139 to 397±120 micron; P=0.001), while in the non-injected eye it reduced by 49±75 micron (from 380±130 to 331±106 micron; P<0.001). Sixteen injected eyes (45.7%) showed central subfield thickness reduction of ≥50 micron while 10 (28.6%) non-injected eyes showed such thickness reduction. Improved VA following treatment was detected in 14 (40%) injected eyes and in 15 (43%) non-injected eyes.

Conclusions

Unilateral bevacizumab injections in patients with bilateral DME are often associated with bilateral response.

Summary Statement

Anti-vascular endothelial growth factor compounds are routinely used for the treatment of diabetic macular edema (DME). In this retrospective study, we show that unilateral bevacizumab injections often result in reduction of the macular thickness in the fellow un-injected eye.     

Improvement of visual acuity based on optical coherence tomography patterns following intravitreal bevacizumab treatment in patients with diabetic macular edema

AIM:To report the visual outcome based on various patterns of optical coherence tomography (OCT) morphology in diabetic macular edema (DME), following treatment with anti-VEGF intravitreal bevacizumab (IVB) injection.METHODS:Sixty-seven consecutive subjects with centre involving DME underwent intravitreal injection of Bevacizumab (1.25 mg/0.05 mL) in this retrospective, comparative, non randomized study. The DME was classified into one of four categories:focal, diffuse, focal cystoid and neurosensory detachment based on OCT. Best corrected visual acuity (BCVA), macular appearance, and OCT findings were used to decide whether the subject should have a repeat injection of intravitreal bevacizumab. Outcome measures were a change in mean BCVA (Snellen converted to logMAR) and central macular thickness (CMT) in each group during the six month follow-up period.RESULTS:The mean BCVA improved to logMAR 0.23 at final follow-up from a baseline of 0.32 logMAR (P=0.040) in the focal group, logMAR 0.80 at final follow-up from a baseline of 0.82 logMAR (P=0.838) in the diffuse group, worsened to logMAR 0.53 at final follow-up from a baseline of 0.43 logMAR (P=0.276) in the focal cystoid group, and improved to logMAR 0.79 at final follow-up from a baseline of 0.93 logMAR (P=0.490) in the neurosensory detachment group. The mean CMT before treatment were 298.8±25.03 μm in the focal group, 310.8±40.6 μm in the diffuse group, 397.15±31.05 μm in the focal cystoid group and 401.03±75.1 μm in the neurosensory detachment group. A mean of 2.05 (range:1-5) injections in the focal group, 1.32 (range:1-2) in the diffuse group, 2.6 (range:1-6) in the focal cystoid group and 2.6 (range:1-6) in the neurosensory detachment group were performed during the six month follow-up period. Following intravitreal bevacizumab treatment, vision improved, remained unchanged or worsened in 11, 7 and 2 subjects in focal group; 11, 9 and 8 in diffuse group; 0, 2 and 4 in focal cystoid group and 5, 5 and 3 subjects respectively in neurosensory detachment group.CONCLUSION:OCT morpholgy patterns in DME may predict the effects of intravitreal bevacizumab treatment, and patients with focal DME are most likely to benefit from the improvent of visual acuity from this treatment.     

Effect of OCT volume scan density on thickness measurements in diabetic macular edema

Purpose

To evaluate the impact of reducing B-scan frame-sampling density on retinal thickness measurements using spectral domain optical coherence tomography (SD-OCT) in eyes with diabetic macular edema (DME).

Methods

We retrospectively collected OCT data for 64 eyes of 43 patients undergoing imaging for DME using the Cirrus HD-OCT 512 × 128 macular cube protocol. For each case, raw OCT data were imported into the 3D-OCTOR software, and retinal thickness maps were generated using all 128 B-scans and for lower densities of B-scans ranging from every other scan to only four scans (every 30-s B-scan). Maps were generated before and after manual correction of retinal boundary segmentation errors. The foveal central subfield (FCS) and total macular volume (TMV) values were used to compare thickness maps of varying densities.

Results

The mean difference in FCS retinal thickness and TMV increased as the B-scan density was reduced, particularly when the density was reduced to fewer than 16 B-scans over 6 mm. At a density of 16 B-scans, the mean absolute difference in FCS thickness was 2.43 μm (0.79%), with a maximum of 10.1 μm (4.09%). At this density, the mean difference in TMV was 0.012 mm³ (0.13%), with a maximum difference of 0.04 mm³ (0.47%). Manual correction of OCT segmentation errors resulted in a difference in FCS thickness of ≥10 μm in only 12.5% of cases, with a maximum difference of 115.7 μm.

Conclusion

A minimum of 16 equally spaced B-scans appear necessary to generate retinal thickness measurements similar to those produced using all 128 B-scans in eyes with DME. Manual correction of segmentation errors appeared to have a clinically meaningful effect in a small minority of cases. These results may have implications for the design of SD-OCT imaging and grading protocols in clinical trials of DME, particularly when using multiple SD-OCT instruments that acquire varying numbers of B-scans.