Measurement of choroidal thickness and macular thickness during and after pregnancy

AIM: To investigate the effect of pregnancy on subfoveal choroidal thickness (SFCT) and macular thickness in both pregnant and not pregnant healthy women. METHODS: Twenty-nine healthy pregnant women in their third trimester and 36 age-matched healthy women were enrolled in a prospective, cross-sectional study. Foveal and parafoveal thickness in the four quadrants and SFCT were measured by optical coherence tomography (OCT) in the healthy pregnant women (i.e. study group) and healthy women (i.e. control group). OCT measurements were again measured 3mo after delivery in the study group. RESULTS: Mean SFCT measurements in the control group, pregnant women of the study group, and after delivery of the study group were 320.86±59.18 μm, 387.97±59.91 μm, and 332.40±26.03 μm, respectively. There was a statistically significant difference in the mean SFCT values between pregnant women of the study group and the control group (P=0.000). Foveal and parafoveal thickness values were not statistically significant in either the study or control group. CONCLUSION: SFCT increases during pregnancy and returns to normal range in the three months after delivery. Macular thickness does not show any change during pregnancy.     

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.     

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.     

Change in subfoveal choroidal thickness in central serous chorioretinopathy following spontaneous resolution and low-fluence photodynamic therapy

Purpose

To assess the change in subfoveal choroidal thickness (SFCT) in central serous chorioretinopathy (CSC) following spontaneous resolution and low-fluence photodynamic therapy (PDT) using the enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

A total of 36 consecutive eyes of 36 patients were included in this retrospective study: 16 eyes with spontaneously resolved CSC and 20 eyes with PDT-treated CSC. Best-corrected visual acuity and SFCT were evaluated at each visit until complete absorption of the subretinal fluid. SFCT of 32 normal subjects were also measured, as the control group. Wilcoxon''s singed-rank test was used to evaluate the effects of spontaneous resolution and PDT. To compare the SFCT of the eyes with resolved CSC with that of the normal eyes, Mann–Whitney U-test with Bonferroni correction was also employed.

Results

SFCT of patients was 459.16±77.50 μm at the baseline, and decreased to 419.31±54.49μm after a spontaneous resolution (P=0.015). However, SFCT was not normalized in comparison with that of the normal subjects (P<0.001). SFCT in PDT group was also reduced from 416.43±74.01 to 349.50±88.99 μm (P<0.001), with no significant difference with the normal value (P=0.087).

Conclusions

SFCT in patients with CSC decreased both after spontaneous resolution and low-fluence PDT. However, only in the PDT group, after disappearance of subretinal fluid, did it decrease to that of normal subjects.     

Measurement of retinal thickness in macular region of high myopic eyes using spectral domain OCT

AIM:To investigate the changes of retinal thickness in macula of high myopic eyes using spectral domain optical coherence tomography (OCT).METHODS: Middle-aged and young myopic patients were divided into three groups according to their refractive error/axial length:low and medium myopia group (LMMG), high myopia group (HMG) and super high myopia group (SHMG). Cirrus HD-OCT was used to evaluate total average macular thickness, central subfield thickness, inner/outer macular thickness and macular volume. The differences among experimental groups were analyzed by one-factor analysis of variance. Associations between macular thickness and refractive error/axial length were analyzed by Pearson correlation analysis.RESULTS: There was no significant difference in age among the three groups (P=0.2789). The mean refraction error in the LMMG, HMG, and SHMG groups was -2.49±1.38D, -8.53±1.95D and -13.88±1.76D, respectively (P＜0.001). The central subfield thickness of three groups was 244.56±12.19μm, 254.33±11.61μm and 261.75±11.83μm, respectively, and there were statistically significance between random two groups. The total average macular thickness, inner/outer macular thickness, and macular volume decreased with increased myopia/axial length. Average foveal thickness had negative correlations with refractive error (P＜0.001), and positive correlations with axial length. The inferior and temporal inner macular thickness, all the quadrants of outer ring, total average macular thickness and macular volume featured positive correlations with refractive error, and negative correlations with axial length. Average foveal thickness, superior and temporal inner macular thicknesses, and temporal outer macular thickness was lower in females compared to males.CONCLUSION:With an increase in myopia degree/axial length, the average foveal thickness increased and the inner/outer macular thickness decreased. Females featured thicker average foveal thickness, and thinner macular thickness compared to males.     

Correlation of leaking microaneurysms with retinal thickening in diabetic retinopathy

AIM: To investigate the contribution of fluorescein angiographic leaking microaneurysms (leak-MA) versus non-leaking microaneurysms (non-leak-MA) to retinal thickening in diabetic retinopathy. METHODS: A consecutive series of 38 eyes from 24 patients with diabetic retinopathy was included. Leak-MA and non-leak-MA in each eye were selected in pairs at corresponding topographic location. Leaking was defined by late phase fluorescein angiograms compared to early phase. Retinal thickness was measured with Heidelberg Spectralis OCT topographically aligned on early phase angiograms at the MA site and within a 1 mm circle. RESULTS: In all eyes, significant retinal thickening at the site of leaking compared to non-leaking microaneurysms was observed (356±69μm vs 318±56μm, P <0.001), showing a mean increase in thickness in the areas of leak-MA vs non-leak-MA of 38±39μm (95% confidence interval 25-51μm, P<0.001). All 1mm area measurements also showed significant (P<0.001) thickening of the leak-MA with average thickness of leak-MA vs non-leak-MA as 351±67μm vs 319±59μm; minimum thickness 311±62μm vs 284±60μm; maximum thickness 389±78μm vs 352±66μm; and retina volume 26.4±6.0mm vs 23.6±3.7mm3, respectively. CONCLUSION: Leaking of microaneurysms on fluorescein angiography appears to cause focal thickening of retina, which can be measured with high-resolution OCT. Therefore, targeting leaking microaneursyms in diabetic retinopathy has the potential to reduce retinal thickening.     

Combined treatment of photodynamic therapy and bevacizumab for choroidal neovascularization secondary to age-related macular degeneration

Purpose

To evaluate the outcome of a combined photodynamic therapy and intravitreal injection of bevacizumab in choroidal neovascularization secondary to age-related macular degeneration.

Methods

Photodynamic therapy (PDT) was administered to 28 eyes followed by 3 consecutive bevacizumab injections. Patients were followed-up for more than 12 months. At baseline, 1, 3, 6, and 12 months post PDT, visual acuity (VA) and central macular thickness were measured using optical coherence tomography.

Results

The mean VA was significantly improved from logarithm of the minimal angle of resolution 0.86 at baseline to 0.69 at 1 month (p = 0.011), 0.63 at 3 months (p = 0.003), 0.64 at 6 months (p = 0.004) and 0.60 at 12 months (p < 0.001). Central macular thickness decreased significantly from 328.3 µm at baseline to 230.0 µm at 6 months and 229.9 µm at 1 year (p < 0.001). Reinjection mean number was 0.4 for 6 months and 0.8 for 12 months. By 1 year, retreatment was performed in 10 eyes (36%).

Conclusions

PDT combined with three consecutive intraviteal bevacizumab injections was effective in improving VA and reducing central macular thickness.     

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.     

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.     

Chorio-retinal thickness measurements in patients with acromegaly

Purpose

To compare choroidal, foveal, and peripapillary retinal thickness between patients with acromegaly and healthy adults.

Methods

This prospective, cross-sectional, and comparative study included 30 patients with acromegaly (study group) and 30 healthy subjects (control group). The subfoveal choroidal thickness (SFCT), foveal thickness, and peripapillary retinal nerve fibre layer thickness were measured with spectral domain optical coherence tomography.

Results

The mean SFCT in the study group and in the control eyes was 374.4±98.1 and 308.6±77.3 μm, respectively (P<0.001). The mean thinnest foveal thickness value was 233.2±22.4 μm in the acromegaly group and 222.8±13.9 μm in the control group (P=0.003). The mean peripapillary retinal nerve fibre layer thickness did not differ significantly between the groups (P=0.34).

Conclusion

The SFCT and foveal thickness were significantly higher in patients with acromegaly, whereas peripapillary retinal nerve fibre layer thickness was similar between the groups.     

Flat choroidal nevus inaccessible to ultrasound sonography evaluated by enhanced depth imaging optical coherence tomography

Purpose

To demonstrate the usefulness of enhanced depth imaging optical coherence tomography (EDI-OCT) in investigating choroidal lesions inaccessible to ultrasound sonography.

Methods

In a 60-year-old woman with an asymptomatic choroidal nevus, normal OCT was used to observe the macula and EDI-OCT to image the choroidal nevus that was inaccessible to ultrasound. The exact location of the lesion in the choroid and the dimensions of the nevus were measured.

Results

The lesion was located in the superior macula, and the nevus was homogeneous in its reflectivity. We observed a thickened choroid delineated by the shadow cone behind it, measuring 1,376 × 325 μm in the larger vertical cut and 1,220 × 325 μm in the larger horizontal cut in an image with a 1:1 pixel mapping and automatic zoom. The macular profile and thickness were both normal.

Conclusions

EDI-OCT appears to be an excellent technique for measuring choroidal nevi and all choroidal lesions accessible to OCT imaging by depicting their exact location in the choroid, their dimensions, and their demarcation from the surrounding healthy tissue, thus allowing for a more efficient and accurate follow-up.Key Words: Choroidal nevus, Enhanced depth imaging, Optical coherence tomography     

Effect of pan-retinal laser photocoagulation on plasma VEGF, endothelin-1 and nitric oxide in PDR

AIM: To study plasma levels of vascular endothelial growth factor (VEGF), endothelin-1(ET-1) and nitric oxide (NO) in patients with proliferative diabetic retinopathy (PDR) before and after pan-retinal photocoagulation (PRP). · METHODS: Forty patients (23 females and 17 males, mean age 48.5±12.2 years) with PDR without previous PRP therapy were studied. Blood samples were obtained before and 3 months after the last PRP session. Baseline (prelaser) plasma levels of VEGF, ET-1 and NO were compared with their levels in 30 healthy age- and sex- matched controls and also with plasma levels 3 months post-PRP. · RESULTS: Patients with PDR had significantly raised plasma VEGF (375±89ng/L), ET-1(20±5ng/L) and NO (135±53μmol/L) when compared with healthy control group (P <0.01). After PRP, there was a significant reduction in plasma VEGF (179±66ng/L), ET-1 (11±5ng/L) and NO (91±49μmol/L) levels at 3 months' follow-up but still significantly higher than healthy controls. · CONCLUSION: Patients with PDR demonstrate elevated VEGF, ET-1 and NO, which decrease after successful laser treatment.     

The Effect of Pattern Scan Laser Photocoagulation on Peripapillary Retinal Nerve Fiber Layer Thickness and Optic Nerve Morphology in Diabetic Retinopathy

Purpose

To evaluate the effect of pattern scan laser (PASCAL) photocoagulation on peripapillary retinal nerve fiber layer (RNFL) thickness, central macular thickness (CMT), and optic nerve morphology in patients with diabetic retinopathy.

Methods

Subjects included 35 eyes for the PASCAL group and 49 eyes for a control group. Peripapillary RNFL thickness, cup-disc area ratio and CMT were measured before PASCAL photocoagulation and at 2 and 6 months after PASCAL photocoagulation in the PASCAL or control groups.

Results

The average RNFL thickness had increased by 0.84 µm two months after and decreased by 0.4 µm six months after PASCAL photocoagulation compared to baseline, but these changes were not significant (p = 0.83, 0.39). The cup-disc area ratio was unchanged after PASCAL photocoagulation. CMT increased by 18.11 µm (p = 0.048) at two months compared to baseline thickness, and partially recovered to 11.82 µm (p = 0.11) at six months in the PASCAL group.

Conclusions

PASCAL photocoagulation may not cause significant change in the peripapillary RNFL thickness, CMT, and optic nerve morphology in patients with diabetic retinopathy.     

Diabetic Retinopathy and Peripapillary Retinal Thickness

Purpose

To assess the diagnostic efficacy of macular and peripapillary retinal thickness measurements for the staging of diabetic retinopathy (DR) and the prediction of disease progression.

Methods

In this prospective study, 149 diabetic patients (149 eyes) and 50 non-diabetic control subjects were included. Baseline optical coherence tomography was employed to measure retinal thickness in the macula (horizontal, vertical, and central) and the peripapillary zone (superior, inferior, nasal, and concentric to the optic disc). Seven baseline parameters were correlated with the DR stages identified by fluorescein angiography. Baseline retinal thickness was compared between groups of patients requiring panretinal photocoagulation (PRP) within 6 months (PRP group) and patients not requiring PRP (No-PRP group).

Results

Macular and peripapillary retinal thicknesses in diabetic subjects were significantly greater than that in normal controls (p<0.05). All retinal thickness parameters, and particularly peripapillary circular scans, tended to increase with increasing DR severity (p<0.05). The baseline thicknesses of the peripapillary circular scans were greater in the PRP group than in the no-PRP group (p<0.05).

Conclusions

Peripapillary retinal thickness may prove to be a useful criterion for DR severity and may also serve as an indicator of disease progression.     

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.     

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.     

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.     

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.     

Evaluation of peripapillary retinal nerve fiber layer, macula and ganglion cell thickness in amblyopia using spectral optical coherence tomography

AIM:To investigate peripapillary retinal nerve fiber layer (RNFL), macula and ganglion cell layer thicknesses (GCC) in amblyopic eyes with spectral domain optical coherence tomography (SD-OCT).METHODS:Thirty six patients with a history of unilateral amblyopia and thirty two children who had emmetropia without amblyopia were included in this study.In this institutional study, 36 eyes of 36 patients with amblyopia (AE), 36 fellow eyes without amblyopia (FE), and 32 eyes of 32 normal subjects (NE) were included. RNFL, GCC and macular thickness measurements were performed with RS-3000 OCT Retina Scan (Nidek Inc CA. USA).RESULTS:The mean global thicknesses of the RNFL were 113.22±21.47, 111.57±18.25, 109.96±11.31µm in the AE, FE, and NE, respectively. There was no statistically significant difference for mean global RNFL thickness among the eyes (P=0.13). The mean thicknesses of the macula were 258.25±18.31, 258.75±19.54, 248.62±10.57μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of macula among the eyes (P=0.06). The GCC was investigated into two parts:superior and inferior. The mean thicknesses of superior GCC were 102.57±13.32, 103.32±10.64, 100.52±5.88μm in the AE, FE, and NE, respectively. The mean thicknesses of inferior GCC were 103.82±12.60, 107.82±12.33, 105.86±10.79μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of superior and inferior GCC between the eyes (P=0.63, P=0.46).CONCLUSION:The macular thicknesses of AE and FEwere greater than the NE, although it was not statistically significant. Amblyopia does not seem to have a profound effect on the RNFL, macula and GCC.     

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.