Foveal Minimum Thickness Research Articles

Avaliação do endotélio corneano através de microscopia especular em participantes com edema macular diabético

Introduction: While the morphological and functional integrity of the corneal endothelium, which is essential for corneal transparency, is affected by diabetes mellitus (DM), its relationship with the severity of diabetic retinopathy and the presence of diabetic macular edema is unclear. Aims: To assess the morphological characteristics of the corneal endothelium in patients with Type 2 Diabetes Mellitus (T2DM) with different therapeutic response profiles to diabetic macular edema (DME). Methods: With a cross-sectional approach, 24 participants with T2DM were divided into 2 groups (without DME versus with DME). Subsequently, the group with DME was subdivided according to the type of therapeutic response (responder versus persistent). Parameters obtained through specular microscopy (endothelial cell density, coefficient of variation, hexagonality, and central corneal thickness) and optical coherence tomography (minimum foveal thickness, central 1mm thickness, macular ganglion cell layer thickness, and peripapillary retinal nerve fiber layer thickness) were analyzed and compared in the different groups. Results: No significant changes were found in the corneal endothelium between the groups with and without DME (p>0.05). However, differences were found in the density of endothelial cells (p=0.04) in participants with persistent DME (1900.3 ± 270.1) compared to participants with responding DME (2307.9 ± 121.2) and control group (2191.7 ± 165.5). Conclusion: There were no differences in the different parameters of the corneal endothelium between participants with and without DME. However, the kind of therapeutic response to DME seems to be associated with a decrease in endothelial cell density.

The effect of intraocular lens and lens eye on the treatment of macular splits in high myopia.

Macular retinoschisis in patients with high myopia is one of the main reasons for a decline in visual function and the perceived deformation of visual objects. This study aimed to investigate the therapeutic effect of cataract phacoemulsification and foldable intraocular lens implantation (FILI) combined with internal limiting membrane stripping (ILMS) in the treatment of macular retinoschisis in patients with high myopia. A total of 52 patients (55 eyes) who had been diagnosed with macular retinoschisis with high myopia between June 2019 and June 2020 were enrolled in the present study. Patients in the control group (25 eyes) received 23G vitreous surgery and macular ILMS and long-term inert gas (C3F8) filling of the vitreous cavity; patients in the research group (30 eyes) were additionally treated with cataract phacoemulsification and soft intraocular lens on the same treatment basis as the control group. The difference in average BCVA between the control and the research groups was not statistically significant before the surgery (P> 0.05) but was statistically significant 12 months after the procedure (P< 0.05). The minimum foveal thickness was significantly decreased in the two groups after the surgery compared with before the procedure (P< 0.05). Cataract phacoemulsification and FILI further improved the therapeutic effect of ILMS in the treatment of macular retinoschisis in patients with high myopia.

Macular thickness variation and interocular symmetry by gestational age in preterm school-age children

To determine changes in macular thickness profile according to gestational age (GA) and to assess interocular symmetry in the macula of children born very preterm. In this cross-sectional study of preterm (n = 106) and term-born (n = 49) children 5-8 years of age at time of examination, optical coherence tomography was used to measure macula thickness as described in the ETDRS study. Statistical analyses included stratified and multivariable analyses. Foveal minimum thickness increased with decreasing GA (P for trend, <0.001; 254.7 ± 32.8 μm for children born at 24-25 weeks and 193.2 ± 32.8 μm in term-born children). Inner and outer area thickness differed for term and preterm children, but did not vary with the degree of prematurity (inner area, 267.0 ± 11.0 μm for 24-25 weeks' GA and 305.4 ± 11.8 μm for term children [P < 0.01]; outer ring, 305.5 ± 10.4 μm in extreme preterm and 271.0 ± 10.4 μm in term children [P < 0.01]). Interocular asymmetry in preterm children was not significant for most areas; the largest interocular difference was found in the central zone (16.3 ±16.6 μm). In our study cohort, children born very preterm examined at school age compared to term born children had greater central thickness with decreased foveal pit, decreased inner ring, and increased thickness of the outer ring. They did not show greater interocular asymmetry.

Quantitative measures of the vascular and neural components of the retina in adult individuals with congenital and untreated growth hormone deficiency

BackgroundThe somatotrophic axis, including hypothalamic growth hormone (GH)-releasing hormone (GHRH), pituitary GH and circulating IGF-I, is critical for body size. However, the local production of GH/IGF-I (and IGF-II) and other peptides is relevant for other body functions, such as vascular, brain, and retinal function. The consequences of GH deficiency (GHD) on the retinal structure are still unclear, possibly reflecting the heterogeneity of patients and the different types of assessment in previous publications. Our purpose was to assess quantitative measures of the vascular and neural components of the retina in subjects with severe congenital isolated GHD (IGHD).MethodsA cross-sectional study was carried out in 25 adult IGHD subjects and 25 age- and gender-matched controls. Interview, physical examination, laboratory data, optical coherence tomography (OCT) and OCT angiography (OCTA) were performed.ResultsOCT revealed no difference in the areas of the nerve fiber layer average, nor in the areas of superior, inferior, or nasal quadrants, between the two groups. However, areas of the temporal quadrant (p = 0.041), the optical disc (p = 0.042), the cup (p < 0.0001), as well as the cup/disc ratio (p < 0.0001), were higher in IGHD subjects than controls. The rim area was smaller (p = 0.002), although still normal. In OCTA, there was no difference in the minimum foveal thickness, central fovea, foveal avascular zone, and retinal density in any assessed area.ConclusionsIn conclusion, congenital IGHD does not affect quantitative measures of the vascular and neural retina, and it is associated with increased optical disc in this genetically homogeneous cohort.

Short Term Presence of Subretinal Fluid in Central Serous Chorioretinopathy Affects Retinal Thickness and Function.

Background: Acute central serous chorioretinopathy (CSCR), with subretinal fluid (SRF) resolving spontaneously within a few months from disease onset, has been considered as a benign and self-limiting disease for many years. This study sought to discover if a short presence of SRF can result in morphological and functional damage to the retina. Materials and methods: The study included patients treated by subthreshold diode micropulse laser (SDM) application for acute CSCR at the Dobry Wzrok Ophthalmological Clinic between January 2018 and November 2019. Inclusion criteria were: first episode of CSCR; duration of symptoms of two months or less; complete resolution of subretinal fluid (SRF) after a single session of SDM; and a lack of any retinal pathology, previous CSCR episode, significant anisometropia or amblyopia in the collateral eye. Fifteen patients fulfilled the inclusion criteria, including 13 males and two females aged 42.3 ± 9.5 years. The mean duration of symptoms before treatment was 4.7 ± 1.3 weeks on average. Baseline and follow-up examinations were performed in both the affected and collateral eyes and included best-corrected visual acuity (BCVA); spectral-domain optical coherent tomography measurements such as central retinal thickness (CRT) and minimal foveal thickness (MFT) (at the follow-up visit only); fluorescein angiography (at presentation only) and fundus autofluorescence. The first follow-up visit, when the total resolution of SRF was noted, was conducted between 8 and 12 weeks after SDM. Results: Resolved CSCR eyes had significantly poorer BCVA, CRT, and MFT findings in comparison with healthy collateral eyes (respectively, 0.11 +/− 0.1 vs. 0.01 +/− 0.04 logMAR; 238.80 +/− 23.39 vs. 264.87 +/− 21.22 µm and 178.93 +/− 16.88 vs. 199.47 +/− 17.87 µm) despite the short period of CSCR duration (maximum of 14 ± 2.15 weeks on average). Conclusion: Short presence of SRF typical for acute CSCR can affect retinal function and morphology resulting in poorer visual outcome.

The Association between Foveal Floor Measurements and Macular Hole Size

Determining which factors influence idiopathic macular hole (MH) size is important because it is a major prognostic indicator of treatment success. Foveal pit morphologic features are highly symmetrical within individuals and may influence idiopathic MH size. Using a series of patients with unilateral idiopathic MHs, we examined the foveal floor size of the fellow eye to evaluate its relationship with idiopathic MH size and postoperative outcomes. Retrospective observational study. Two hundred forty-one participants with a unilateral idiopathic MH treated with surgery and a fellow eye with no ocular pathologic features. Both eyes underwent spectral-domain (SD) OCT imaging at the time of surgery. Minimum linear diameter (MLD) and base diameter (BD) defined idiopathic MH size. Foveal floor width (FFW) and minimal foveal thickness defined foveal pit morphologic features of the fellow eye. Baseline characteristics, SD OCT measurements, and preoperative variables were compared to determine their relationship with idiopathic MH size and postoperative visual acuity (VA) in logarithm of the minimum angle of resolution units. Foveal floor width was correlated with MLD (r= 0.36; P ≤ 0.001) and BD (r= 0.30; P ≤ 0.001), but not postoperative VA. Minimum linear diameter correlated with preoperative VA (r= 0.49; P ≤ 0.0001) and postoperative VA (r= 0.54; P ≤ 0.0001). A 2-stage regression model was developed to predict postoperative VA (r2= 0.28): preoperative VA (β= 0.36; P= 0.002) explained 13% of variability and MLD (β= 0.29; P= 0.002), and idiopathic MH duration (β= 0.23; P= 0.004) explained a further 16%. Foveal floor width of the fellow eye in patients with a unilateral idiopathic MH was correlated significantly with idiopathic MH size and may explain some of the variability in idiopathic MH size observed between individuals. However, FFW could not predict postoperative vision.

The optic nerve head, lamina cribrosa, and nerve fiber layer in non-myopic and myopic children

The purpose of this study was to evaluate the optic nerve head, lamina cribrosa, retina, and choroid in school age children using spectral domain optical coherence tomography (SD-OCT) and to assess these structural parameters in relation to age, axial length, and refractive error. Healthy children, ages 11.15 ± 2.62 years (range 6–15 years, n = 53), underwent cycloplegic autorefraction, biometry, and SD-OCT imaging in both eyes. Images were analyzed using custom written programs in MATLAB, after adjustment for lateral magnification. Peripapillary retinal nerve fiber layer (RNFL) thickness, retinal and choroidal thicknesses, Bruch's membrane opening (BMO) area, minimum rim width (MRW), and anterior lamina cribrosa surface depth (ALCSD) were determined and analyzed with age, axial length, and refraction. Results show that axial length increased and refractive error became more myopic with increasing age (R2 = 0.25, β = 0.18, P < 0.0001 and R2 = 0.27, β = −0.37, P < 0.0001, respectively). Minimum foveal thickness and central 1 mm retinal thickness increased with increasing age (R2 = 0.15, β = 2.38, P < 0.01 and R2 = 0.11, β = 3.16, P < 0.05, respectively). Age-adjusted raw values for peripapillary RNFL thickness decreased with increasing axial length (R2 = 0.11, β = −3.18, P < 0.05); however, this relationship was not present when image magnification was corrected (R2 = 0.07, β = 2.72, P = 0.09). BMO area increased with myopic refractive error (R2 = 0.16, β = −0.10, P < 0.01). Age-adjusted vertical cup-to-disc ratio decreased with increasing axial length and myopic refractive error (R2 = 0.12, β = −0.05, P < 0.05 and R2 = 0.11, β = 0.03, P = 0.05, respectively). Mean MRW, mean ALCSD, and peripapillary choroidal thickness were not associated with age, axial length, or refraction. Mean MRW was significantly thinner in eyes with deeper ALCS (R2 = 0.41, β = −0.83, P < 0.0001). These findings provide normal values for retinal and optic nerve head parameters in school age children, and also suggest that ocular remodeling occurs in some structures in school age children with normal eye growth and during early stages of myopia development.

FOVEAL SPARING INTERNAL LIMITING MEMBRANE PEELING FOR IDIOPATHIC MACULAR HOLES: EFFECTS ON ANATOMICAL RESTORATION OF THE FOVEA AND VISUAL FUNCTION.

Muller cells seem to be important in maintaining foveal morphology through connections between their foot processes and the internal limiting membrane (ILM). Internal limiting membrane peeling causes Muller cell trauma. We hypothesized that leaving a rim of unpeeled ILM around idiopathic macular holes undergoing vitrectomy surgery would improve postoperative foveal morphology and vision. Prospective pilot study of fovea-sparing ILM peeling in a consecutive cohort of patients with macular holes over a 12-month period. Spectral-domain optical coherence tomography and Early Treatment Diabetic Retinopathy Study letters best-corrected visual acuity were assessed preoperatively and postoperatively, and foveal morphology and metamorphopsia postoperatively. The foveal sparing group was compared with a second consecutive cohort who received standard ILM peeling (control group). Thirty-four eyes of 34 patients were included in each group. Groups showed no significant preoperative differences. 34/34 holes were successfully closed with surgery in the foveal sparing group and 32/34 in the control group. The foveal sparing group showed better postoperative best-corrected visual acuity (67.7 vs. 63.8, P = 0.003) and best-corrected visual acuity improvement (25.1 vs. 20.2, P = 0.03). The foveal sparing group demonstrated thicker minimum foveal thickness (211 vs. 173 μm, P = 0.002) and less steep foveal depression (158 vs. 149, P = 0.002). Preserving nonpeeled ILM around macular holes resulted in a high closure rate, improved foveal morphology, and better postoperative best-corrected visual acuity. An appropriately powered randomized controlled study is warranted.

Foveal avascular zone and macular vessel density after correction for magnification error in unilateral amblyopia using optical coherence tomography angiography

BackgroundTo investigate the area of foveal avascular zone (FAZ) and macular vessel density (VD) after correction for magnification error in unilateral amblyopia using optical coherence tomography angiography (OCTA).MethodsParticipants comprised 15 patients with unilateral amblyopia due to anisometropia with or without strabismus (mean age, 9.8 ± 3.4 years; range, 6–17 years). OCTA images were obtained by using spectral-domain OCT with angiography software. The OCTA scanning protocol used was 3 × 3-mm volume scan centered on the fovea. OCTA images were corrected for magnification errors using individual axial length (AL), and an adjusted 2.3 × 2.3-mm square was derived as a region of interest. The FAZ area and VD in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) layers, foveal minimum thickness (FMT) were assessed using built-in OCTA software and ImageJ software (NIH, Bethesda, MD).ResultsLogMAR in the amblyopic eyes was significantly poorer than that of the fellow eye (p < 0.001). AL was significantly shorter in the amblyopic eye than in the fellow eye (p < 0.001). FAZ area of SCP in amblyopic eyes was significantly smaller than that of fellow eyes (p < 0.001). No significant differences were seen in FAZ area of DCP, VD of SCP, VD of DCP, and FMT between amblyopic and fellow eyes (p = 0.07, 0.43, 0.55, and 0.25, respectively).ConclusionsOur present study after magnification error correction found smaller FAZ area of SCP in the amblyopic eye compared with the fellow eyes, but there was no significant difference in the macular VD between the amblyopic and fellow eyes.

Ophthalmologic evaluation of severely obese patients undergoing bariatric surgery: A pilot, monocentric, prospective, open-label study.

PurposeThe aim of this study was to investigate the pathogenic role of obesity on blinding eye diseases in a population of severely obese patients with no history of eye diseases, and to verify whether weight loss induced by bariatric surgery may have a protective effect.MethodsThis was a pilot, monocentric, prospective, and open label study conducted at the University Hospital of Pisa. Fifty-seven severely obese patients with a mean body mass index value of 44.1 ± 6 kg/m2 were consecutively recruited and received a complete ophthalmological evaluation and optical coherence tomography. Twenty-nine patients who underwent gastric bypass were evaluated also 3 months, and 1 year after surgery.ResultsAt baseline, blood pressure value were directly and significantly related to intraocular pressure values (p<0.05, R = 0.35). Blood pressure values were also significantly and inversely related to retinal nerve fiber layer thickness, particularly in the temporal sector (RE p<0.05 r-0.30; LE p<0.01, R = -0.43). Moreover, minimum foveal thickness values were significantly and inversely associated with body mass index (RE p<0.02, R = -0.40; LE p<0.02, R = -0.30). A significant reduction of body mass index (p<0.05) and a significant (p<0.05) improvement of blood pressure was observed three months and one year after gastric bypass, which were significantly associated with an increase in retinal nerve fiber layer thickness and minimum foveal thickness values in both eyes (p<0.05).ConclusionsThe results of this study suggest that obese patients may have a greater susceptibility to develop glaucomatous optic nerve head damage and age-related macular degeneration. Moreover, weight reduction and improvement of comorbidities obtained by bariatric surgery may be effective in preventing eye disease development by improving retinal nerve fiber layer and foveal thickness.

Immediate Postoperative Intraocular Pressure Adjustment Reduces Risk of Cystoid Macular Edema after Uncomplicated Micro Incision Coaxial Phacoemulsification Cataract Surgery.

PurposeTo determine the accuracy of visual estimation of immediate postoperative intraocular pressure (IOP) following microincision cataract surgery (MICS) and the effect of immediate postoperative IOP adjustment on prevention of cystoid macular edema (CME).SettingAmbulatory surgical center.MethodsProspective, randomized analysis of 170 eyes in 135 patients with MICS, performed in a Medicare approved outpatient ambulatory surgery center. Surgical parameters included a keratome incision of 1.5 mm to 2.8 mm, topical anesthetic, case completion IOP estimation by palpation and patient visualization of light, and IOP adjustment before exiting the operating theater. IOPs were classified into three groups: low (<16 mmHg), normal (16 to 21 mmHg), and elevated (>21 to 30 mmHg). IOP measurements were repeated 1 day after surgery. Optical coherence tomography (Stratus OCT, Zeiss) was measured at 2 weeks. An increase in foveal thickness greater than 15 µm was used to indicate CME. Statistical analysis was performed using one- and two-tailed Student's t-tests.ResultsMean minimal foveal thickness averaged 207.15 µm in the low pressure group, 205.14 µm in the normal IOP group, and 210.48 µm in the elevated IOP group 2 weeks following surgery. CME occurred in 14 of 170 eyes (8.2%) at 2 weeks (low IOP, 35.7%; normal IOP, 14.2%; elevated IOP, 50.0%). Change in IOP from the operating theater to 1 day after surgery was within +/−5 mmHg in 54 eyes (31.7%), elevated by 6 to 15 mmHg in 22 eyes (12.9%), and elevated more than 15 mmHg in four eyes (2.3%). IOP was reduced by 6 mmHg to 15 mmHg in 39 eyes (22.9%) and reduced by more than 15 mmHg in nine eyes (5.3%).ConclusionsImmediate postoperative adjustment of IOP may prevent CME in MICS. Physicians can improve their ability to estimate postoperative IOP with experience in tonometry to verify immediate postoperative IOP. There are patient safety and economic benefits to immediate IOP adjustment in the operating theater.SynopsisImmediate postoperative IOP adjustment following cataract surgery before the patient leaves the operating theater may reduce the incidence of CME and provide patient safety and economic benefits.

Repeatability of Foveal Measurements Using Spectralis Optical Coherence Tomography Segmentation Software.

PurposeTo investigate repeatability and reproducibility of thickness of eight individual retinal layers at axial and lateral foveal locations, as well as foveal width, measured from Spectralis spectral domain optical coherence tomography (SD-OCT) scans using newly available retinal layer segmentation software.MethodsHigh-resolution SD-OCT scans were acquired for 40 eyes of 40 young healthy volunteers. Two scans were obtained in a single visit for each participant. Using new Spectralis segmentation software, two investigators independently obtained thickness of each of eight individual retinal layers at 0°, 2° and 5° eccentricities nasal and temporal to foveal centre, as well as foveal width measurements. Bland-Altman Coefficient of Repeatability (CoR) was calculated for inter-investigator and inter-scan agreement of all retinal measurements. Spearman's ρ indicated correlation of manually located central retinal thickness (RT0) with automated minimum foveal thickness (MFT) measurements. In addition, we investigated nasal-temporal symmetry of individual retinal layer thickness within the foveal pit.ResultsInter-scan CoR values ranged from 3.1μm for axial retinal nerve fibre layer thickness to 15.0μm for the ganglion cell layer at 5° eccentricity. Mean foveal width was 2550μm ± 322μm with a CoR of 13μm for inter-investigator and 40μm for inter-scan agreement. Correlation of RT0 and MFT was very good (ρ = 0.97, P < 0.0005). There were no significant differences in thickness of any individual retinal layers at 2° nasal compared to temporal to fovea (P > 0.05); however this symmetry could not be found at 5° eccentricity.ConclusionsWe demonstrate excellent repeatability and reproducibility of each of eight individual retinal layer thickness measurements within the fovea as well as foveal width using Spectralis SD-OCT segmentation software in a young, healthy cohort. Thickness of all individual retinal layers were symmetrical at 2°, but not at 5° eccentricity away from the fovea.

Meta-analysis of retinal changes in unilateral amblyopia using optical coherence tomography.

To evaluate retinal changes in unilateral amblyopia using optical coherence tomography. Major literature databases were searched for relevant studies. The primary outcome parameters were foveal minimum thickness (FMT), mean foveal thickness (MFT), mean macular thickness (MMT), and peripapillary retinal nerve fiber layer (pRNFL) thickness. Efficacy estimates were evaluated by standardized mean difference (SMD) and 95% confidence interval (CI) for changes in the outcomes of interest. This meta-analysis included 28 clinical trials involving 408 patients .The FMT, MFT, and MMT in the amblyopic eyes was significantly greater than that of the fellow eyes (SMD = 0.22, 95% CI 0.05-0.39, p = 0.011; SMD = 0.21, 95% CI 0.06-0.36, p = 0.005; SMD = 0.21, 95% CI 0.08-0.35, p = 0.002, respectively). Only FMT was significantly increased in the amblyopia group compared with the normal control group (SMD = 0.38, 95% CI 0.19-0.57, p&lt;0.00001). Analysis showed that pRNFL thickness in the amblyopic eyes was thicker than in the fellow eyes (SMD = 0.13, 95% CI 0.02-0.24, p = 0.016). We did not find that those outcome measures differ between strabismic and anisometropic amblyopia. The pooled evidence indicates that the amblyopic process may involve the retina, especially the macula. A thicker foveola was found in the amblyopic eyes when compared with visually normal control eyes. Further larger-scale studies especially involving emmetropic normal subjects will be valuable.

Morphologic parameters of macula and optic nerve head in patients with Type 1 Diabetes mellitus and relation to metabolic control

Object: To detect differences between the thickness of the central foveal and the retinal nerve fiber layer in children with Type 1 Diabetes Mellitus (DM) and to detect neurodegenerative effects of diabetes on retina by assessing the effect of hypo-hyperglycemic attack existence. Material and Methods: The children with Type 1 DM who applied to our policlinic with the aim of controlling possible diabetes complications and who had no diabetic retinopathy were prospectively evaluated. The healthy children in the same age group who applied to our policlinic for eye control and who had no systemic or eye disease were included in the control group. The following measurements from each patient were recorded: age, sex, DM period, HbA1C level, hyperglycemic and hypoglycemic attack number and central foveal thickness (CFT), minimum foveal thickness (MFT), parafoveal (ParaFT) and perifoveal thickness (PeriFT), central foveal of inner and outer retina, parafoveal and perifoveal thickness, and retinal nerve fiber layer thickness in 9 quadrants. OCT DEVICE RTVue version 4.0 (Optovue®, USA) was used in the measurement of retinal and foveal thicknesses. Findings: In the comparison of macula parameters of the study group and control group, there was no difference in terms of central foveal thickness, minimum foveal thickness, parafoveal thickness, perifoveal thickness, central foveal thickness of the inner retina, central foveal thickness of the outer retina, parafoveal thickness of the inner retina, parafoveal thickness of the outer retina, perifoveal thickness of the inner retina, perifoveal thickness of the outer retina values (p>0.05). In addition, no statistically significant differences were found between the groups in terms of average retinal nerve fiber layer (RNFL), temporal rim thickness, rim thickness nasal, upper / lower temporal rim thickness and upper / lower nasal rim thickness (p>0.05). Result: In our study, no statistically significant differences were found in the RNFL and macula thicknesses of the patients with Type 1 DM who had no retinopathy compared to the control group. However, it was observed that the parafoveal thickness is related to the level of HbA1C and the period of diabetes.

Evaluation of Choroidal Thickness and Volume during the Third Trimester of Pregnancy using Enhanced Depth Imaging Optical Coherence Tomography: A Pilot Study.

During pregnancy the maternal choroid is exposed to the multiple haemodynamic and hormonal alterations inherent to this physiological condition. These changes may influence choroidal anatomy. In this study a quantitative assessment of overall choroidal structure is performed, by constructing a 3-dimensional topographic map of this vascular bed. To compare the thickness and volume of the maternal choroidal in the third trimester of pregnancy with that of an age-matched control group of women. Twenty-four eyes of 12 pregnant women in the last trimester and 12 age-matched healthy controls (24 eyes) were included. Optical coherence tomography in enhanced depth imaging mode was used to construct maps of the choroid of the macular area. Choroidal thickness and volume were automatically calculated for the 9 subfields defined by the Early Treatment Diabetic Retinopathy Study (ETDRS). A comparative analysis between the two groups was performed using the two-way ANOVA test. The average thickness of the choroid for the entire ETDRS area of the pregnant group was 295.15 ±42.40μm and 271.56 ±37.65μm in the control group (p=0.051). The average choroidal volume was 8.05 ±1.12mm(3) and 7.46 ±1.03mm(3), respectively (p=0.067). Although the choroid of the pregnant group had larger thickness and volume in all subfields compared to the control group, this difference was statistically significant only in three regions - the central subfield, minimum foveal thickness and inferior inner macula (p<0.05). Our study suggests that in the third trimester of pregnancy the choroid may be subjected to physiological changes in structure. Whether these changes are a result of hormonal and/or haemodynamic adaptations of pregnancy remains to be studied.

Macular thickness in unilateral amblyopia as measured by optical coherence tomography: a meta analysis

To offer a clue for the etiology of amblyopia by systematically comparing the macular thickness measured by optical coherence tomography (OCT) between the amblyopic eye and the fellow normal eye in patients with unilateral amblyopia. Databases including Wanfang, PubMed and others were searched, and data were extracted after quality assessment, then the Meta analysis was performed by the RevMan 5.02 software. Four studies using the time-domain OCT (TD-OCT) were enrolled in the analysis and all those were anisometropic amblyopic patients. The only one study showed that the foveal minimum thickness is thicker in the amblyopic eyes than the fellow ones (P = 0.045). The meta analysis indicated the amblyopic eyes were 6.82 µm (P < 0.05, 95% CI: 2.81-10.83) thicker in the fovea (1 mm diameter region ). Five trials using the spectral-domain OCT (SD-OCT) were included in the analysis. It showed no significant difference in the foveal minimum thickness between amblyopic and fellow eyes. Also, no significant difference were detected in either anisometropic or strabismic subgroup (P = 0.50). Amblyopic eyes were 7.38 µm thicker in the fovea (1 mm diameter region) (P < 0.05, 95% CI: 3.13 -11.63) and significant difference in the anisometropic subgroup while no significant difference in the strabismic subgroup were detected. The macular fovea is thicker in the amblyopic eyes than the fellow ones by the use of OCT, so it is effective to measure the macular thickness of amblyopia in searching evidence for the etiology of amblyopia.

Macular Measurements Using Optical Coherence Tomography in Healthy Chinese School Age Children

To evaluate macular thickness/volume in a Chinese population of primary school children using optical coherence tomography (OCT), and assess its association with age, sex, spherical equivalent refraction (SE), body mass index (BMI), and intraocular pressure (IOP). Healthy Chinese children (n = 806) from six randomly selected primary schools in Chongming County, Shanghai, China, were enrolled. Comprehensive standardized ophthalmic examinations included visual acuity, cycloplegic refraction, IOP, and fast macular scans using Stratus OCT. Mean values for the nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas, foveal minimum thickness, and macular volume were calculated. OCT data from right eyes with high-quality scans were evaluated in 720 children (89.3% of total participants; 46.5% boys). Macular thickness and volume were normally distributed. The mean foveal minimum thickness was 140.0 ± 12.3 μm. There were significant differences between the boys and the girls in mean foveal volume (P = 0.023) and sectoral macular thickness in all the quadrants of the inner ring (P < 0.001 and P = 0.001) and temporal outer quadrant (P = 0.009). SE refraction correlated positively with inner and outer macular thickness and total macular volume (P < 0.001) and negatively with central macular volume (P = 0.012). BMI correlated significantly only with outer macular thickness (r = 0.074, P = 0.048). No age- and IOP-related differences were found in the macular parameters. OCT demonstrated that macular thickness/volume was normally distributed in this sample of Chinese children, with variations in sex and SE. The variables in macular thickness/volume should be considered when diagnosing and monitoring school-aged children with diseases that affect the macula.

Association of Birth Parameters with OCT Measured Macular and Retinal Nerve Fiber Layer Thickness

To examine whether birth parameters have associations with macular and retinal nerve fiber layer (RNFL) thickness measurements. The Sydney Myopia Study examined secondary school children for ocular conditions, with all eligible year 7 students from 21 high schools invited to participate. Macular and RNFL measurements were acquired from optical coherence tomography (OCT) scans. Birth variables, including birth weight and gestational duration, were obtained from parental questionnaires and health records. Mixed linear models were used in analyses, after adjustment for age, sex, height, axial length, and ethnicity. In children with complete gestational duration data, adequate quality scans of the RNFL and macula were obtained from 1756 and 1698 children, respectively. Children with low birth weight (<2500 g) had a thinner mean RNFL (98.2 μm vs. 103.5 μm; P < 0.0001) and a thicker mean foveal minimum (164.3 μm vs. 158.5 μm; P = 0.004) than did children of normal birth weight (2500-4000 g). With increasing birth weight, average RNFL thickness increased (mixed model coefficient, β = 2.97 μm/kg; P < 0.0001) and foveal minimum thickness decreased (β = -2.16 μm/kg; P = 0.008). Children born before 32 weeks' gestation had significantly thicker mean foveal minimum and central macular thickness (205.5 μm vs. 193.4 μm; P = 0.001) measurements than did children born after 37 weeks' gestation. Low birth weight and prematurity are associated with thickening of the fovea, and decreased birth weight is associated with decreased RNFL thickness, as measured by OCT. These findings suggest that premature birth and low birth weight impair retinal development and may predispose these children to ocular problems later in life.

Interchangeability of macular thickness measurements between different volumetric protocols of Spectralis optical coherence tomography in normal eyes

To evaluate in healthy eyes the interchangeability of retinal thickness measurements resulting from different protocols of Spectralis optical coherence tomography (OCT, Heidelberg Engineering, Germany). Three different central volumetric protocols were performed in one session by one single operator in a randomly selected eye of 31 healthy adults (range, 19-30 years): (1) area 6 × 6 mm, 25 scan pattern (SP), (2) area 6 × 6 mm, 49 SP, (3) area 6 × 3 mm, 97 SP. Nine ETDRS areas were analyzed, except outer areas for 97 SP. Interclass correlation coefficients (ICC) and limits of agreement (Bland-Altman) were calculated. Mean minimal foveal thickness was 224.0 ± 15.8 μm and central retinal thickness 280.8 ± 16.5 μm. ICC ranged from 0.973 to 0.993. Ninety-five percent limits of agreement between the protocols were <7 μm in all ETDRS areas. The difference between two measurements never exceeded 9 μm. Spectralis OCT retinal thickness measurements in healthy subjects showed good protocol interchangeability for all tested protocols. Larger differences are to be expected in eyes with macular pathology.

Retinal Thickness in the Offspring of Diabetic Pregnancies

To compare macular and peripapillary retinal nerve fiber layer (RNFL) thickness in children from diabetic compared with nondiabetic pregnancy. Cross-sectional study. As part of the Sydney Myopia Study, 2367 children from grade 7 (age range 11.1 to 14.4 years) completed detailed ocular examinations during 2004-2005. Examination included determination of best-corrected visual acuity (logarithm of minimal angle of resolution) and autorefraction after cycloplegia. Axial length was measured using noncontact interferometry. Optical coherence tomography (OCT) was performed using Stratus OCT through dilated pupils. Participants and parents completed comprehensive questionnaires including questions on birth parameters and medical history. There were 1741 and 1687 children with adequate-quality RNFL and macular scans respectively, who had complete examination and questionnaire data. There were 57 children from diabetic pregnancies who had both RNFL and macular scans. Children from diabetic pregnancies had significantly thinner inner (264.9 μm vs 270.2 μm, P = .007) and outer (231.9 μm vs 238.6 μm, P = .0001) macular thickness and macular volume (6.75 mm(3) vs 6.92 mm(3), P = .0003) compared with children from nondiabetic pregnancies. However, central macular thickness, foveal minimum thickness, and RNFL parameters were not significantly different between the 2 groups. Diabetes during pregnancy is associated with changes in retinal morphology in the offspring. Thinning of the pericentral macular parameters was evident in Stratus OCT scans of children from diabetic pregnancies. These findings suggest the possibility that maternal diabetes impacts on the development of the retina.