A comparative study between intravitreal triamcinolone and bevacizumab for macular edema due to central retinal vein occlusion with poor vision

Aim:

To compare the effect of intravitreal bevacizumab and triamcinolone in patients with macular edema after central retinal vein occlusion (CRVO), presenting with poor visual acuity.

Materials and Methods:

It was a retrospective, comparative case series of 38 consecutive eyes, with macular edema secondary to CRVO, with 20/200 or worse vision, which were treated primarily either with intravitreal bevacizumab (1.25 mg; 24 eyes) or intravitreal triamcinolone (4 mg; 14 eyes). During follow-up, 3.6 ± 0.8 re-injections of bevacizumab and 2.4 ± 0.5 re-injections of triamcinolone were administered (P = 0.080). The main outcome measures were the best-corrected visual acuity and the central macular thickness by optical coherence tomography during 12 months of follow-up.

Results:

At 12 months, visual acuity (logMAR) was changed from 1.03 ± 0.39 (baseline) to 0.92 ± 0.39 (P = 0.374) and the central macular thickness was reduced from a baseline of 713.6 ± 179.3 µm to 310.8 ± 205.2 µm (P = 0.000). Neither the bevacizumab nor triamcinolone groups varied significantly in visual acuity and central macular thickness at 1, 3, 6, and 12 months after treatment. Neovascular glaucoma developed in two of the 14 eyes (14%) in the triamcinolone group.

Conclusion:

In patients with CRVO and poor vision, intravitreal bevacizumab and intravitreal triamcinolone were associated with a reduction in macular edema; however, neither treatment achieved significant visual acuity improvement by the 12-month follow-up.     

Principal components' analysis of multifocal electroretinogram in retinitis pigmentosa

Aims:

To determine waveforms of multifocal electroretinogram (mfERG) in patients with retinitis pigmentosa (RP) contributing significantly to the overall retinal response by using principal components’ analysis.

Settings and Design:

Prospective, non-randomized, single-visit, observational, case-control study from a single tertiary ophthalmic center.

Materials and Methods:

Patients with various forms of RP underwent mfERG testing for a period of one year. The first-order kernel responses of RP cases were compared with concurrently recruited healthy controls.

Statistical Analysis Used:

Parametric data was analyzed using the unpaired t test for differences between the implicit time and amplitudes of cases and controls. Principal components’ analysis was done for each implicit time and amplitude in cases with RP using the Varimax rotation method.

Results:

From March 2006 to March 2007, 24 cases with typical RP (56%, 47 eyes) were included in the final analysis. Their mean age was 33.7 years (19-69 ± 15.5 years). Comparison of latencies and amplitudes among RP cases with log MAR acuity ≤ 0.18 and those > 0.18, revealed significant difference in the implicit time (P1) in Ring 2 only (P=0.028). Two components (predominently from Ring 1 and 2) each contributing 66.8% and 88.8% of the total variance in the data for latencies and amplitudes respectively, were seen.

Conclusions:

The first two rings of the mfERG contributed to the variance of waveforms in RP, irrespective of the visual acuity and poor visual field results.     

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 serum glycosylated hemoglobin levels in patients with diabetic cystoid macular edema with and without serous macular detachment

Aim:

A clinical comparative trial was conducted to compare the levels of glycosylated hemoglobin (HbA1c) in patients with diabetic cystoid macular edema (CME) with and without serous macula detachment (SMD).

Materials and Methods:

Thirty patients (group 1) with diabetic CME in both eyes, but without SMD, and 30 patients (group 2) with diabetic CME and SMD in both eyes documented by optical coherence tomography (OCT) and fundus fluorescein angiography (FFA), were included in the study. In addition to the measurement of central macular thickness by OCT and visual acuity (VA) (as logMAR) using the the early treatment diabetic retinopathy study (ETDRS) chart, the concentrations of HbA1c were measured by high performance liquid chromatography (HPLC). Statistical analysis was done by independent samples t test.

Results:

The mean logMAR VA was 0.8 ± 0.22 (1.0–0.5) in group 1and 0.7 ± 0.16 (1.0–0.6) in group 2. The mean central macular thickness, as determined by OCT, was 468.70 ± 70.44 μm (344–602 μm) in group 1 and 477.80 ± 73.34 μm (354–612 μm) in group 2. The difference between the groups was not statistically significant (P = 0.626). The mean HbA1c levels were 8.16 ± 0.99% in group 1 and 10.05 ± 1.66% in group 2. The difference between the groups was statistically significant (P < 0.001).

Conclusions:

The presence of SMD and high HbA1c levels in the patients with diabetic CME may be indirectly suggestive of retinal pigment epithelium dysfunction.     

Comparison of the short-term effects of intravitreal triamcinolone acetonide and bevacizumab injection for diabetic macular edema

Purpose

To compare the short-term effects of intravitreal triamcinolone acetonide (IVTA) with those of intravitreal bevacizumab (IVB) injection for diabetic macular edema (DME).

Methods

The present retrospective, comparative case study included 58 eyes of 35 consecutive patients (IVTA group, 20 eyes; IVB group, 38 eyes) with DME. IVTA (4 mg) or IVB (1.25 mg) injection was performed under local anesthesia. The effects of injection for DME were evaluated using best-corrected visual acuity (BCVA), central macular thickness (CMT) by optical coherence tomography and intraocular pressure (IOP) by applanation tonometer. Patients underwent eye examinations, including BCVA, CMT, and IOP at pre-injection, 2, 4, and 8 weeks after injection.

Results

BCVA (logarithm of the minimum angle of resolution) ± SD at pre-injection, 2, 4, and 8 weeks after injection was 0.67 ± 0.40, 0.56 ± 0.35 (p = 0.033), 0.55 ± 0.33 (p = 0.041), and 0.43 ± 0.31 (p = 0.001) in the IVTA group and 0.51 ± 0.31, 0.42 ± 0.26 (p = 0.003), 0.43 ± 0.32 (p = 0.001), and 0.43 ± 0.27 (p = 0.015) in the IVB group, respectively. CMT (µm) ± SD at pre-injection, 2, 4, and 8 weeks after injection was 400.4 ± 94.9, 332.8 ± 47.4 (p = 0.002), 287.5 ± 49.1 (p = 0.007), and 282.5 ± 49.6 (p = 0.043) in the IVTA group and 372.6 ± 99.5, 323.2 ± 72.4 (p = 0.077), 360.9 ± 50.3 (p = 0.668), 368.2 ± 88.6 (p = 0.830) in the IVB group, respectively.

Conclusions

The effects of IVTA for BCVA were more favorable than were those of IVB and were consistent throughout the eight weeks after injection. IVTA significantly reduced CMT during the eight weeks after injection, while IVB did not.     

Comparison of Photocoagulation With Combined Intravitreal Triamcinolone for Diabetic Macular Edema

Purpose

To compare the efficacy between macular laser grid (MLG) photocoagulation and MLG plus intravitreal triamcinolone acetonide (IVTA; MLG+IVTA) therapy in diabetic macular edema (DME) patients.

Methods

A prospective, randomized, clinical trial was conducted of DME patients. A total of 60 eyes (54 patients) affected by DME were observed for a minimum of 6 months. Thirty eyes of 28 patients who received MLG treatment and 30 eyes of 26 patients who received the combined MLG+IVTA treatment were included in the study. Main outcome measures were BCVA and central macular thickness (CMT) as measured by optical coherence tomography (OCT) at 1, 3, and 6 months after treatment. Additionally, the authors examined retrospectively 20 eyes of 20 patients who were treated with only IVTA and compared with the 2 groups (MLG group and MLG+IVTA group).

Results

Baseline BCVA was 0.53±0.32 and CMT was 513.9±55.1 µm in the MLG group. At 1 and 3 months after treatment, the MLG group showed no significant improvement of BCVA and CMT, although there was significant improvement after 6 months. In the MLG+IVTA group, the baseline BCVA was 0.59±0.29 and CMT was 498.2±19.8 µm. After treatment, significant improvement of BCVA and CMT was observed at all follow-up time periods. When comparing the MLG group with the MLG+IVTA group, the latter had better results after 1 and 3 months, although at 6 months, there was no significant difference of BCVA and CMT between the 2 groups. Additionally, the IVTA group showed more improvement than the MLG group at 1 and 3 months but showed no significant difference at 6 months. In addition, the IVTA group showed no significant difference with the MLG+IVTA group at all follow-up time periods.

Conclusions

For DME patients, the combined MLG+IVTA treatment had a better therapeutic effect than the MLG treatment for improving BCVA and CMT at the early follow-up time periods. IVTA treatment alone could be an additional alternative therapeutic option to combined therapy.     

Matrix γ-carboxyglutamate protein and Fetuin-A, in wet type age-related macular degeneration

AIM:To compare therapeutic effects of intravitreal triamcinolone acetonide (IVTA) versus intravitreal bevacizumab (IVB) injections for bilateral diffuse diabetic macular edema (DDME).METHODS: Forty eyes of 20 patients with bilateral DDME participated in this study. For each patient, 4 mg/0.1 mL IVTA was injected to one eye and 2.5 mg/0.1 mL IVB was injected to the other eye. The effects of injection for diabetic macular edema (DME) were evaluated using best-corrected visual acuity (BCVA), central macular thickness (CMT) by optical coherence tomography (OCT) and intraocular pressure (IOP) by applanation tonometer. Patients underwent eye examinations, including BCVA, CMT, and IOP at pre-injection, 1, 4, 8, 12 and 24wk after injection. During the follow-up, second injections were performed to eyes which have CMT greater than 400 µm at 12wk for salvage therapy.RESULTS: BCVA (logarithm of the minimum angle of resolution) at pre-injection, 1, 4, 8, 12 and 24wk after injection was 0.71±0.19, 0.62±0.23, 0.63±0.12, 0.63±0.13, 0.63±0.14 and 0.61±0.24 in the IVTA group and 0.68±0.25, 0.61±0.22, 0.60±0.24, 0.62±0.25, 0.65±0.26 and 0.59±0.25 in the IVB group, respectively. CMT (μm) at pre-injection, 1, 4, 8, 12 and 24wk after injection was 544±125, 383±96, 335±87, 323±87, 333±92, 335±61 in the IVTA group and 514±100, 431±86, 428±107, 442±106, 478±112, 430±88 in the IVB group respectively. Reduction ratios of mean CMT were 29% at 1wk, 38% at 4wk, 40% at 8wk, 38% at 12wk, and 38% at 24wk in the IVTA group. Second IVTA injections were performed to the 6 eyes (30%) at 12wk. Reduction ratios of mean CMT were 16% at 1wk, 17% at 4wk, 14% at 8wk, 7% at 12wk, and 16% at 24wk in the IVB group. Second IVB injections were performed to the 15 eyes (75%) at 12wk.CONCLUSION:This study showed earlier and more frequent macular edema recurrences in the eyes treated with bevacizumab compared with the ones treated with triamcinolone acetonide. Triamcinolone acetonide was found to provide more efficient and long-standing effect in terms of reducing CMT compared with the bevacizumab.     

X-linked retinoschisis maculopathy treated with topical dorzolamide, and relationship to genotype

Purpose

To correlate the response of topical dorzolamide (Trusopt; Merck) in patients with X-linked retinoschisis (XLRS) with genotype.

Methods

We carried out a retrospective evaluation of four patients (seven eyes) with XLRS, treated with topical dorzolamide. The change in best-corrected visual acuity (VA) and central macular thickness (CMT; central 1 mm subfield thickness) from optical coherence tomography (OCT) was analysed over the follow-up period, using Student''s t-test. Each patient also had genetic analysis for mutations in the retinoschisisgene (RS1).

Results

The mean age at the start of treatment was 14.7±11 years, and mean follow-up duration was 21.7±7.7 months. Mean CMT at the final follow-up was significantly better than at baseline (291±123 vs352±119 μm, P=0.007); however, mean VA was worse (0.38±0.25 vs0.31±0.24 logMAR score, P=0.041). All four patients had a mutation in the RS1gene; there was no apparent association between the type of mutation and the response to topical dorzolamide.

Conclusion

Topical dorzolamide may have some effect in reducing central macular thickness in patients with XLRS, but this does not necessarily correlate with improvement in VA. In our case series, genotypic information did not predict the response to this treatment.     

Multifocal electroretinogram in non-pathological myopic subjects: correlation with optical coherence tomography

AIM: To investigate the changes of retinal function in non-pathological myopic subjects using multifocal electroretinography (mfERG) and to correlate the data with the central macular thickness obtained using optical coherence tomography (OCT). METHODS: One hundred and thirteen subjects (113 eyes) with age range from 18 to 35y were enrolled in the study. The subjects were divided into four groups according to spherical equivalent (SE) and axial length (AL): emmetropia group (EG, n=31; SE: +0.75 to -0.50 D; AL: 22 to 24 mm), low and medium myopia group (LMMG, n=26; SE: ＞-0.50 to -6.00 D; AL: ＞24 to 26 mm), high myopia group (HMG, n=34; SE: ＞-6.00 to -10.00 D; AL: ＞26 to 28 mm) and super high myopia group (SHMG, n=22; SE: ＞-10.00 D; AL:＞28 mm). The P1 amplitude density, P1 amplitude, and P1 implicit time of the first-order kernel mfERG responses were obtained and grouped into five rings. The central subfield macular thickness (CST) was obtained using macular cube 512×218 scan of Cirrus HD-OCT. RESULTS: With the increasing of eccentricity, the first positive peak (P1) amplitude density (P=0.0000, 0.0001, 0.0021 in ring 1-3 respectively) and P1 amplitude (all P=0.0000 in ring 1-5) of each group decreased. With the increasing of myopia, P1 implicit time gradually extended (all P=0.0000 in ring 1-3). The average CST in four diagnostic groups was 241.56±12.72 μm, 244.56±12.19 μm, 254.33±11.61 μm, 261.75±11.83 μm respectively. With the increasing of myopia, CST increased (P<0.001). There was negative relationship between CST and P1 amplitude, P1 amplitude density (r=-0.402, P<0.001; r=-0.261, P=0.003). There was positive relationship between CST and P1 implicit time (r=0.34, P<0.001). CONCLUSION: With the increasing of myopia, P1 amplitude density and P1 amplitude of the first-order reaction gradually reduced. This showed potential decline in retinal function in myopia. To some extent it may reflect the functional disorder or depression of the visual cells. The exact mechanism needs further study.     

Application of multifocal visual evoked potentials in the assessment of visual dysfunction in macular diseases

Purpose

To evaluate the use of AccuMap multifocal visual evoked potentials (mfVEP) in visual dysfunction caused by macular diseases.

Methods

Forty-eight eyes with known macular diseases underwent AccuMap mfVEP and microperimetry 1 (MP1) assessments. Evaluation of mfVEP abnormality was based on an amplitude deviation probability plot and the AccuMap Severity Index (ASI). Correlation analyses of the mean mfVEP amplitude corresponding to a radius of 2°, 5°, and 10° of the central visual field, minimum angle of resolution best-corrected visual acuity (BCVA), and MP1 mean sensitivity of the corresponding areas were performed.

Results

Among the 48 affected eyes, AccuMap mfVEP detected an abnormality of the central visual field in 45 eyes, with a sensitivity of 93.8%. The mean mfVEP amplitudes within a radius of 2°, 5°, and 10° of the central visual field were found to be positively correlated with BCVA (P<0.01 for all groups). The mean amplitudes also positively correlated with the MP1 mean sensitivity value of the corresponding visual field (P<0.01 for all groups). In the group with stable fixation or predominantly central fixation, the mean mfVEP amplitudes did not correlate with the BCVA or the MP1 mean sensitivity value. Regardless of the fixation status, the ASI was found to correlate with both the BCVA and the total MP1 mean defect value.

Conclusion

Objective perimetry using AccuMap mfVEP might be applied in the assessment of macular function, with the ASI offering a potentially useful indicator for evaluating macular dysfunction.     

Results of intravitreal dexamethasone implant 0.7 mg (Ozurdex®) in non-infectious posterior uveitis

AIM:To evaluate the safety and efficacy of dexamethasone implant in patients with non-infectious posterior uveitis withcystoid macular edema (CME).METHODS:Retrospective analysis of patients reports with CME secondary to non-infectious uveitis treated with dexamethasone implant. Data included type of posterior uveitis, any systemic immunosuppressive therapy, Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography (OCT) and signs of intraocular inflammation at baseline and then at 2wk postoperatively and monthly thereafter. Follow-up is up to 10mo. Any per-operative and post-operative complications were recorded.RESULTS:Six eyes of 4 patients with CME due to non-infectious posterior uveitis treated with dexamethasone implant. Diagnosis included idiopathic panuveitis, birdshot chorioretinopathy and idiopathic intermediate uveitis. At baseline mean ETDRS BCVA was 63 letters and mean CMT 556 μm at 2wk postoperatively mean ETDRS BCVA improved to 70 letters and mean CMT decreased to 329 μm. All eyes showed clinical evidence of decreased inflammation. The duration of effect of the implant was 5 to 6mo and retreatment was required in 2 eyes. Two patients required antiglaucoma therapy for increased intraocular pressures.CONCLUSION: In patients with non-infectious posterior uveitis dexamethasone implant can be a short-term effective treatment option for controlling intraocular inflammation.     

Comparison of the effects of intravitreal bevacizumab and triamcinolone acetonide in the treatment of macular edema secondary to central retinal vein occlusion

Aim:

To compare the effects of intravitrealbevacizumab (IVB) and intravitreal triamcinolone acetonide (IVT) in the treatment of macular edema (ME) secondary to central retinal vein occlusion (CRVO).

Materials and Methods:

There were 20 patients treated with IVB (1.25 mg/0.05 mL) and 16 treated with IVT (4 mg/0.1 mL). The two groups were compared with regard to best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography (OCT), slit-lamp biomicroscopy and fundus fluorescein angiography results, intraocular pressure (IOP), numbers of injections, and adverse events.

Results:

The mean follow-up times in the IVB and IVT groups were 17.45±8.1 months (range: 8–33 months) and 19.94±10.59 months (range: 6–40 months), respectively (P = 0.431). Visual acuity increased and CMT decreased significantly within both groups, but no differences were observed between the groups (P = 0.718). The percentages of patients with increased IOP and iatrogenic cataracts were significantly higher in the IVT group than in the IVB group.

Conclusions:

Treatment with IVB and IVT both resulted in significant improvement in visual acuity and a decrease in CMT in patients with ME secondary to non-ischemic CRVO, with no difference between the two treatments. The incidence of adverse events, however, was significantly greater in the IVT group than in the IVB group. IVB may be preferred over IVT for the treatment of ME in patients with non-ischemic CRVO.     

Segmentation error and macular thickness measurements obtained with spectral-domain optical coherence tomography devices in neovascular age-related macular degeneration

Purpose:

To evaluate frequency and severity of segmentation errors of two spectral-domain optical coherence tomography (SD-OCT) devices and error effect on central macular thickness (CMT) measurements.

Materials and Methods:

Twenty-seven eyes of 25 patients with neovascular age-related macular degeneration, examined using the Cirrus HD-OCT and Spectralis HRA + OCT, were retrospectively reviewed. Macular cube 512 × 128 and 5-line raster scans were performed with the Cirrus and 512 × 25 volume scans with the Spectralis. Frequency and severity of segmentation errors were compared between scans.

Results:

Segmentation error frequency was 47.4% (baseline), 40.7% (1 month), 40.7% (2 months), and 48.1% (6 months) for the Cirrus, and 59.3%, 62.2%, 57.8%, and 63.7%, respectively, for the Spectralis, differing significantly between devices at all examinations (P < 0.05), except at baseline. Average error score was 1.21 ± 1.65 (baseline), 0.79 ± 1.18 (1 month), 0.74 ± 1.12 (2 months), and 0.96 ± 1.11 (6 months) for the Cirrus, and 1.73 ± 1.50, 1.54 ± 1.35, 1.38 ± 1.40, and 1.49 ± 1.30, respectively, for the Spectralis, differing significantly at 1 month and 2 months (P < 0.02). Automated and manual CMT measurements by the Spectralis were larger than those by the Cirrus.

Conclusions:

The Cirrus HD-OCT had a lower frequency and severity of segmentation error than the Spectralis HRA + OCT. SD-OCT error should be considered when evaluating retinal thickness.     

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.     

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.     

Comparison and interchangeability of macular thickness measured with Cirrus OCT and Stratus OCT in myopic eyes

AIM: To investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices. METHODS: Eighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices. RESULTS: Average macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 μm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices. CONCLUSION: Macular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.     

Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects

Context:

Retinal perfusion variability impacts ocular disease and physiology.

Aim:

To evaluate the response of central retinal artery (CRA) blood flow to temperature alterations in 20 healthy volunteers.

Setting and Design:

Non-interventional experimental human study.

Materials and Methods:

Baseline data recorded: Ocular surface temperature (OST) in °C (thermo-anemometer), CRA peak systolic velocity (PSV) and end diastolic velocity (EDV) in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack) were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP) immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling.

Statistical Analysis:

Repeated measures ANOVA.

Results:

(n = 20; μ ± SD): Pre-warming values were; OST: 34.5 ± 1.02°C, CRA-PSV: 9.3 ± 2.33 cm/s, CRA-EDV: 4.6 ± 1.27 cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37) after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21 cm/s (95% CI: 0.51to1.91). Pre-cooling values were: OST: 34.5 ± 0.96°C, CRA-PSV: 9.7 ± 2.45 cm/s, CRA-EDV: 4.7 ± 1.12 cm/s. OST significantly decreased by 2.81°C (95% CI: −2.30 to −3.37) after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10cm/s (95% CI: −2.05 to −0.15) and CRA-EDV by 0.81 (95% CI: −1.47 to −0.14) at three minutes. At six minutes both PSV (95% CI: −1.38 to −0.03) and EDV (95% CI: −1.26 to −0.02) were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: −0.17 to 1.57mmHg), but was significantly lower after cooling (95% CI: −2.95 to −4.30mmHg). After ten minutes, IOP had returned to baseline.

Conclusion:

This study confirms that CRA flow significantly increases on warming and decreases on cooling, the latter despite a significant lowering of IOP.     

Comparison of central macular thickness between two spectral-domain optical coherence tomography in elderly non-mydriatic eyes

AIM: To compare central macular thickness (CMT) measurements obtained by two spectral-domain optical coherence tomography (SD-OCT) exams, and to evaluate measurement reproducibility and agreement between these two exams, and to investigate the relationship between CMT and possible influencing factors such as age, sex, eye (OD/OS), and operators in elderly non-mydriatic eyes. METHODS: Seventy-two normal subjects were included. Every subject underwent CMT measurement twice using one of two SD-OCT (OSE-2000, Moptim, Shenzhen, China & 3-D OCT-1000, Topcon, Tokyo, Japan) instruments respectively where we randomly chose one eye in each patient for the test; these exams were performed by two operators over an hour period with a brief rest between sessions. Comparison of the OSE-2000 and 3-D OCT-1000 CMT measurements was based on paired-t test. The mean difference between the CMT measurements was calculated. General linear model analyzed the relationships among eye (OD/OS), operator, sex, and CMT values using age as co-variant. All tests were considered statistically significant at P<0.05. The main outcome measures included CMT. RESULTS: When evaluated with general linear model analysis, CMT measurements were found to have high reproducibility across the two instruments between the two operators for the OSE-2000 single line scan and 3-D OCT-1000 macular scans (P=0.731; P=0.443). There was statistically significant difference in CMT values between the two instruments (P<0.001) and the mean difference was -46.83μm at 95% confidence limits (-49.15,-44.51). Age was positively correlated with CMT (beta coefficient = 0.516, P=0.001; beta coefficient = 0.453, P=0.009) and sex was correlated with CMT from the OSE-2000 (P=0.021) but not with the 3-D OCT-1000 (P=0.056). According to the actual thickness measurements, the CMT of the male was thicker than the female’s but there was no statistical difference. There was interaction between sex and eye in OSE-2000 and not in 3-D OCT-1000 (P=0.02; P=0.374). No significant correlation was found between CMT and the influencing factor of eye in both of the instruments (P=0.884; P=0.492). CONCLUSION: Reproducibility of CMT measurement using the two SD-OCTs is excellent in normal eyes according to the operator factor analysis. OSE-2000 has a different posterior retinal boundary of CMT measurement, which results in the CMT value differences, compared with the 3-D OCT-1000. Age is positively correlated with CMT measurement while sex is correlated with CMT in the OSE-2000 but not in the 3-D OCT-1000 and eye (OD/OS) had no correlation with CMT values. Mydriatic drops may not be necessary for CMT measurement using high scan rate SD-OCT in normal eyes in dark room.     

Macular and peripapillary retinal nerve fiber layer thickness in children with hyperopic anisometropic amblyopia

AIM:To compare the retinal nerve fiber layer (RNFL) thickness and macular thickness in the amblyopic eye with that in the sound eye of children with hyperopic anisometropic amblyopia using optical coherence tomography (OCT).METHODS: A prospective, nonrandom, intraindividual comparative cohort study includes 72 children with hyperopic anisometropic amblyopia in a single center. Macular thickness, macular foveola thickness, and peripapillary RNFL thickness were compared between the amblyopia eyes and the contralateral sound eyes.RESULTS:There were 38 male and 34 female patients, with a mean age as 9.7±1.9 years (range, 5–16 years). Hyperopic was +3.62±1.16D (range +2.00D to +6.50D) in the amblyopic eyes, which was significantly higher in the control eyes with +0.76±0.90D (range 0D to +2.00D) (P < 0.01). The mean peripapillary RNFL thickness was 113.9±7.2µm and 109.2±6.9µm in the amblyopic eye and the normal eye, respectively, reaching statistical significance (P = 0.02). The mean macular foveola thickness was significantly thicker in the amblyopic eyes than the contralateral sound eyes (181.4±14.2µm vs 175.2±13.3µm, P < 0.01), but the 1mm, 3mm or 6mm macular thickness central macular thickness was not significantly different. Degree of anisometropia in the contralateral eyes was not significantly correlated with differences of peripapillary RNFL, macular foveola thickness or central macular thickness.CONCLUSION:Eyes with hyperopic anisometropic amblyopia are found thicker macular foveola and peripapillary RNFL than the contralateral eyes in children.     

Sensitivity and specificity of time-domain versus spectral-domain optical coherence tomography in diabetic macular edema

Purpose:

The purpose was to evaluate the sensitivity and specificity of measurements of central macular thickness (CMT) in diabetic macular edema using stratus time-domain and cirrus spectral-domain optical coherence tomography (OCT; Carl Zeiss Meditec, Dublin, CA).

Materials and Methods:

A total of 36 eyes from 19 patients with clinically significant diabetic macular edema (DME) were included. All participants underwent automated scanning patterns using cirrus HD-OCT and stratus OCT examinations on the same day. The sensitivity/specificity of retinal thickness measurements was calculated from published normative data. Agreement was calculated using Bland--Altman method. The receiver operating characteristic curves (ROC) and areas under the ROC were plotted.

Results:

The mean difference between the cirrus HD-OCT and stratus OCT in the central foveal zone was 49.89 μm. Bland--Altman analysis confirmed that the retinal thickness measurements had poor agreement in patients with DME. The areas under the ROC for retinal thickness measurements were 0.88 using cirrus HD-OCT and 0.94 with stratus.

Conclusions:

In patients with DME, the cirrus HD-OCT gives a higher reading than stratus OCT with poor agreement between the devices in most regions within the nine subfield zones. The sensitivity and specificity of the stratus OCT was comparable to the cirrus.