Emmetropia Research Articles

VEGFA may be a potential marker of myopic choroidal thickness and vascular density changes

To evaluate the changes of choroidal thickness (CT) and blood flow related to myopia, and its effects of vascular endothelial growth factor (VEGFA) on choroidal vessels in myopia. Subjects were included and divided into emmetropia (EM), non-high myopia (Non-HM) and high myopia (HM) groups. we measured choroidal thickness (CT), choriocapillaris vessel density (VD), and VEGFA content in tears in humans (137 subjects for CT, VD and 84 for tear) and detected the role of VEGFA in the choroid in form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs were divided into control and FDM groups, and the expression changes of choroidal vessels and VEGFA were observed and compared using immunohistochemistry and Western blotting. Twenty-one guinea pigs were divided into control, FDM + Vehicle and FDM + Conbercept groups. The changes of diopter, axis length and choroidal vessels after intravitreal injection of Conbercept were observed. There were significant differences in CT and VD among the three groups (p < 0.05). VEGFA levels in tears were significantly lower in the myopic groups, with a decreasing trend from EM to Non-HM to HM. The choroidal vascular area fraction of FDM decreased compared to the control group. FDM guinea pigs exhibited reduced choroidal vasculature and significant downregulation of VEGFA expression. Following intravitreal injection of conbercept, the FDM + Conbercept group showed greater myopia, longer axial length, and lower choroidal vascular area fraction compared to the control group. VEGFA may participate in the regulation of choroidal blood vessels and blood flow in the progression of myopia. The reduction in VEGFA may accelerates the progression of myopia.

Reduced contrast sensitivity function is correlated with changes to cone photoreceptors in simple high myopia.

To investigate the contrast sensitivity function (CSF) changes in simple high myopia (SHM) and evaluate the correlations between these changes with the early changes in the retinal microstructure. This prospective study comprised 81 subjects, 20 with emmetropia (EM), 26 with low myopia and moderate myopia (LM/MM), and 35 with SHM. The area under the log CSF curve (AULCSF) and the cut-off spatial frequency (Cut-off SF) were employed as measures of CSF. Adaptive optics (AO) was employed to quantify the cone density, spacing, and regularity. The thickness and blood flow of the retinal sublayers were determined from vertical and horizontal optical coherence tomography angiography (OCTA) A-scans. Swept-source optical coherence tomography (SS-OCT) was employed to analyze the choroidal thickness (CT) and choroidal vascularity using a custom algorithm. Differences in the retinal and choroidal parameters, cone distribution, AULCSF, and Cut-off SF were compared among the three groups. Multivariate linear mixed models were used to elucidate the associations between photoreceptor morphological alterations, retinal and choroidal parameters, and AULCSF. The AULCSF and Cut-off SF were significantly lower in the SHM group compared to the EM and LM groups (p < 0.05). The SHM group had less cone density, larger cone spacing, and lower cone regularity than the EM and LM/MM groups (p < 0.05). Moreover, the thickness of the inner segment of photoreceptors (IS), retinal pigment epithelium (RPE) layer and choroid were reduced, and the outer segment of photoreceptors (OS) was thicker in the SHM group compared to the EM and LM/MM groups (all p < 0.05). A longer axial length (AL) was correlated with decreased AULCSF, cone density, and cone spacing (r = -0.800 to 0.752, all p < 0.050). Additionally, decreased CSF was correlated with lower cone density (r = 0.338, p = 0.035). Decreased contrast sensitivity was observed in patients with SHM and cone density was significantly correlated with reduced AUCSF.

Quantitative Evaluation of the Topographical Maps of Three-Dimensional Choroidal Vascularity Index in Children With Different Degrees of Myopia.

To investigate topographical maps of the three-dimensional choroidal vascularity index (3D-CVI) in children with different levels of myopia. We enrolled 274 eyes from 143 children with various severity of myopia, including emmetropia (EM), low myopia (LM), and moderate-high myopia (MHM). The choroidal vessel volume (CVV), choroidal stroma volume (CSV), and 3D-CVI in different eccentricities (fovea, parafovea, and perifovea) and quadrants (nasal, temporal, superior, and inferior) were obtained from swept-source optical coherence tomography angiography (SS-OCTA) volume scans. All choroidal parameters were compared among groups, and the associated factors contributing to different 3D-CVIs were analyzed. Compared to the less myopic group, the more myopic group showed a significant decrease in CVV and CSV (MHM < LM < EM) and a significant increase in the 3D-CVI (MHM > LM > EM) in most areas (all P < 0.05). The nasal quadrant had the greatest 3D-CVI and lowest CSV and CVV, and vice versa in the temporal quadrant. The 3D-CVIs of the EM and LM groups gradually increased from the fovea to the perifovea, whereas the 3D-CVI of the MHM group first decreased and then increased. Regression analysis showed that axial length was an independent risk factor affecting foveal and parafoveal 3D-CVIs. Restricted cubic spline analysis revealed that the 3D-CVI increased with spherical equivalent (SE) when the SE was less than threshold and decreased when the SE was greater than threshold (SE thresholds for foveal, parafoveal, and perifoveal 3D-CVIs were -5.25 D, -5.125 D, and -2.00 D, respectively; all P < 0.05). Children with myopia exhibited decreased CSV and CVV, increased 3D-CVIs, and altered 3D-CVI eccentricity characteristics (from the fovea to the perifovea). The quadratic relationship between the 3D-CVI and SE should be explored in longitudinal investigations.

Handheld chromatic pupillometry can reliably detect functional glaucomatous damage in eyes with high myopia

Background/aimsTo assess pupillary light responses (PLRs) in eyes with high myopia (HM) and evaluate the ability of handheld chromatic pupillometry (HCP) to identify glaucomatous functional loss in eyes with HM.MethodsThis...

EFEMP1 is a potential biomarker of choroid thickness change in myopia.

To explore the possible molecular mechanism by which epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) regulates choroid thickness (CT) in the development of myopia. In total, 131 subjects were divided into the emmetropia (EM) group, non-high myopia (non-HM) group and high myopia (HM) group. Their age, refraction, intraocular pressure, and other ocular biometric parameters were collected. A 6 × 6 mm area centered on the optic disc was scanned by coherent optical tomography angiography (OCTA) to measure CT, and the tear concentrations of EFEMP1 were quantified using enzyme-linked immunosorbent assay (ELISA) analysis. Twenty-two guinea pigs were divided into the control group and the form-deprivation myopia (FDM) group. The right eye of the guinea pig in the FDM group was covered for 4 weeks, and the diopter and axial length of the right eye of the guinea pig were measured before and after the treatment. After the measurement, the guinea pig was euthanized, and the eyeball was removed. Quantitative reverse transcription polymerase chain reaction, western blotting assays and immunohistochemistry were used to assess the expression of EFEMP1 in the choroid. There were significant differences in CT among the three groups (p < 0.001). CT was positively correlated with age in HM (r = -0.3613, p = 0.0021), but no significant correlation with SE (p > 0.05) was observed. Furthermore, there were increased levels of EFEMP1 in the tears of myopic patients. After 4 weeks of covering the right eye of the FDM guinea pigs, there was a significant increase in axial length and a decrease in diopter (p < 0.05). The mRNA and protein expression of EFEMP1 was significantly increased in the choroid. Choroidal thickness was significantly thinner in myopic patients, and the expression level of EFEMP1 in the choroid increased during the development of FDM. Therefore, EFEMP1 may be involved in the regulation of choroidal thickness in myopia patients.

Compartmental analysis of three-dimensional choroidal vascularity and thickness of myopic eyes in young adults using SS-OCTA.

Purpose: We aimed to investigate the change of three-dimensional (3D) choroidal thickness (ChT), choroidal vessel volume (CVV), and choroidal vessel index (CVI) in young myopic adults using swept-source optical coherence tomography angiography (SS-OCTA) and compare the difference of these indicators in different quadrants of the macula and optic disc. Methods: A total of 248 eye samples from 135 participants were used in this cross-sectional study. Each participant underwent detailed history taking and ocular examinations. Based on axial length (AL), patients were divided into the emmetropia (EM) group, mild-myopia (MIM) group, moderate-myopia (MOM) group, and high-myopia (HM) group. 6 mm × 6 mm (1,024 × 1024 B-scans) SS-OCTA scans were performed centered on the fovea and optic disc. 3D ChT, CVV, and CVI were measured based on a built-in deep learning algorithm. Differences in ChT, CVV, and CVI were analyzed in different regions and different myopic groups. Results: Significant reduction in the global CVV were found in the HM group (1.930 ± 0.865) in comparison with the EM (3.486 ± 0.992), MIM (3.238 ± 1.033), and MOM (2.589 ± 1.083) groups (p < 0.001). The global CVI was also lower in the HM group (0.258 ± 0.061) than in the EM (0.320 ± 0.055), MIM (0.320 ± 0.051), and MOM (0.286 ± 0.066) groups (p < 0.001). The ChT was thinner in eyes with HM (242.753 ± 65.641) than in eyes with EM (377.532 ± 80.593), MIM (348.367 ± 78.191), or MOM (300.197 ± 87.175) (p < 0.001). Compartmental analysis revealed that ChT, CVV, and CVI in the nasal quadrant of the macula and temporal and inferior quadrants of the optic disc were much lower than those in other quadrants (p < 0.05). Correlation analyses found that ChT, CVV, and CVI were negatively correlated with AL and spherical equivalence. Conclusion: 3D ChT, CVV, and CVI gradually decreased as the degree of myopia increased. The changes were more dramatic on the nasal side of the macula and the temporal and inferior sides of the optic disc. These findings demonstrated the 3D choroidal change and highlighted the papillo-macular bundle as a sensitive region in myopic development.

Nomogram of peripapillary retinal nerve fiber layer thickness in myopic eyes of north Indian population

Purpose:To evaluate peripapillary-RNFL thickness in myopia by Cirrus OCT among north Indian population by spherical equivalent (SE), age, gender, and axial length (AL).Methods:This was a cross-sectional study held during 2019–2020. Patients aged 18–60 years underwent ophthalmic examination including retinoscopy, AL, and OCT RNFL thickness. Persons with previous ocular surgery or ocular ailment other than refractive error were excluded. The peripapillary-RNFL thickness was noted and compared by demographic determinants.Results:We examined 300 eyes of 300 persons (mean age: 30.75 ± 8.57 years; 144 males/156 females). Among them, 224 were myopes and 76 were emmetropes (EM). The mean SE was − 3.3 ± 0.4D (range: −11.0D to + 0.37D). The mean AL was 24.61 ± 1.92 mm (22.1–29.5). Overall temporal, nasal, superior, inferior, and mean peripapillary-RNFL thickness was 66.31 ± 7.58, 78.57 ± 16.00, 120.63 ± 11.69, 116.60 ± 15.80, and 95.50 ± 10.84 mm, respectively. Temporal, nasal, superior, inferior, and mean peripapillary-RNFL thickness was 73.97 ± 8.36, 94.84 ± 7.63, 127.96 ± 8.96, 136.89 ± 6.53, and 108.34 ± 6.28 mm, respectively, in EM eyes as compared to 63.71 ± 6.18, 73.05 ± 14.24, 118.21 ± 11.53, 109.71 ± 11.50, and 91.14 ± 8.31 mm, respectively, in myopic eyes (P < 0.001). Association of peripapillary-RNFL thickness with myopia and its different grades was P < 0.001. Association of mean peripapillary-RNFL thickness with age was P > 0.005 and gender was P = 0.168. Correlation between SE and RNFL thickness was positive and significant. Correlation between AL and RNFL thickness was negative but statistically significant. Association of AL with SE was P < 0.001.Conclusion:We provide normative peripapillary-RNFL thickness in the north Indian population in order to help in screening for myopia with comorbidity such as glaucoma based on RNFL thickness.

The Effect of Pathological Retinal Changes on Retinal Capillary Circulation in Myopic Patients.

Myopia is a common ocular disorder worldwide, leading to degenerative changes in the retina which is highly susceptible to vascular impairment. The aim of the study was to investigate the effects of pathological retinal changes on the retinal capillary structures using optical coherence tomography angiography (OCTA) in myopic patients. Thirty-two patients with high myopia (HM), 29 patients with pathological myopia (PM), and 38 healthy subjects with emmetropia (EM) were enrolled in this study. OCTA was performed to measure the following parameters: Foveal avascular zone (FAZ) area; FAZ perimeter; FAZ acircularity index (AI); and superficial, deep, and radial peripapillary capillary (RPC) vessel densities. Axial length (AL), spherical equivalent, and anterior chamber depth were evaluated. Significant differences in the mean AL values were observed between the EM group and the other groups (p<0.001 for all); however, no significant differences were observed between the HM and PM groups (p=0.135). Significant differences in FAZ parameters, except for AI, were found among the three groups (p<0.05 for all). In all regions, except for the fovea and inside disc, the capillary plexus vessel densities were significantly lower in the PM group than in the other groups and were lower in the HM group than in the EM group (p<0.05 for all). Significant differences identified in capillary densities between the HM and PM groups, both of which present similar AL measurements, suggest that pathological retinal findings have significant effects on retinal perfusion independent of the effect of AL.

Vessel Density and Retinal Thickness from Optical Coherence Tomography Angiography as New Indexes in Adolescent Myopia.

Purpose To evaluate and quantify blood perfusion and retinal thickness (RT) from the perspective of quadrants by optical coherence tomography angiography (OCTA) in adolescents with myopia and explore the relationship between axial elongation and related indexes of OCTA. Methods A total of 88 subjects (149 eyes) with different degrees of myopia were included in this cross-sectional study. Vessel density (VD) and RT of quadrants in macular and peripheral regions were measured through OCTA. Results The superficial VD (SVD) of the parainferior region was significantly correlated with axial length (AL) between the emmetropia (EM) group and high myopia (HI) group (P=0.012). There were significant differences in deep VD (DVD) in all quadrants, except for the foveal, perifoveal, and peri-inferior regions (P > 0.05). However, there were significant alterations in the whole, parainferior, and perinasal regions (P=0.030, 0.023, and 0.035) in the low-to-moderate myopia (L–M) group compared with those in the HI group. There were significant differences in the RT in all quadrants, except for the foveal, paratemporal, and paranasal regions (P > 0.05) between the EM and L–M groups and the foveal region (P > 0.05) between the EM and HI groups. Nevertheless, only RT in the peri-inferior region of the L–M and HI groups showed significant differences. AL was negatively correlated with SVD in the perifoveal and parainferior regions (r = −0.179, P=0.029; r = −0.227, P=0.005) and inversely correlated with DVD and RT in almost all quadrants, except for the foveal region (r = −0.020, P=0.811; r = 0.135, P=1.000). Conclusion DVD and RT were closely associated with the severity of myopia and might be new indexes in assessing and detecting myopia development via OCTA.

Meridional Anisotropy of Foveal and Peripheral Resolution Acuity in Adults With Emmetropia, Myopia, and Astigmatism.

PurposeTo quantify astigmatism-related meridional anisotropy in visual resolution at central, nasal, and inferior visual fields.MethodsThree groups of young adults (range, 18–30 years) with corrected-to-normal visual acuity (logMAR 0) were recruited: (1) myopic astigmats (MA): spherical-equivalent error (SE) < −0.75D, with-the-rule astigmatism ≥ 2.00D, n = 19; (2) simple myopes (SM): SE < −0.75D, astigmatism ≤ 0.50D, n = 20; and (3) emmetropes (EM): SE ± 0.50D, astigmatism ≤ 0.50D, n = 14. Resolution acuity was measured for the horizontal and vertical gratings at central and peripheral visual fields (eccentricity: 15°) using a 3-down 1-up staircase paradigm. On- and off-axis refractive errors were corrected by ophthalmic lenses.ResultsThe MA group exhibited meridional anisotropy preferring vertical gratings. At the central field, the MA group had better resolution acuity for vertical than horizontal gratings, and their resolution acuity for horizontal gratings was significantly worse than the SM and EM groups. At peripheral visual fields, both the SM and EM groups showed better resolution acuity for the radial (i.e., nasal field: horizontal gratings; inferior field: vertical gratings) than tangential orientation. However, the MA group tended to have better resolution acuity for the tangential orientation (i.e., vertical gratings), and their resolution acuity for horizontal gratings was significantly lower than the SM and EM groups at the nasal field. No significant differences were found in the inferior field among the three groups.ConclusionsThis study provided evidence of astigmatism-related meridional anisotropy at the fovea and nasal visual fields, underscoring the significant impact of astigmatism on orientation-dependent visual functions.

The effect of optical magnification during retinal nerve fiber layer thickness measurement in different degrees of myopia by using frequency domain OCT

Objective To investigate the effect of optical magnification on retinal nerve fiber layer (RNFL) thickness in different degrees of myopia by using spectral domain optical coherence tonmography (SD-OCT). Methods A retrospective case control study was designed.Eighty-five healthy people who underwent myopia correction and physical examination in the ophthalmology department of the Second Affiliated Hospital of Zhengzhou University from September to December in 2017 were selected, one eye was randomly selected from each subject.All the subjects were divided into 20 cases of emmetropic group, 21 cases of low myopia group, 20 cases of moderate myopia group, and 24 cases of high myopia group according to diopter.The visual acuity, best corrected visual acuity, slit lamp microscopy, fundoscopy, intraocular pressure and axial measurement, SD-OCT and visual field examination were performed on all the subjects.The difference of the mean RNFL and the thickness of the peripapillary quadrants among different groups, and relationship between RNFL and length of eye axis or diopter were analyzed before and after the correction of optical magnification.This study followed the Declaration of Helsinki. Results Before optical magnification correction, the average thickness of average, upper, lower and nasal quadrants RNFL were negatively correlated with the length of ocular axis (r=-0.595, -0.493, -0.639, -0.500; all at P=0.000), positively correlated with the diopter (r=0.005, 0.565, 0.600, 0.464; all at P=0.000); the thickness of temporal quadrant RNFL was positively correlated with the length of ocular axis (r=0.683, P=0.000), negatively correlated with the diopter (r=-0.730, P=0.000). After optical magnification correction, the thickness of average, upper, lower and nasal quadrants RNFL had no correlation with the length of ocular axis and diopter (all at P>0.05); the thickness of temporal quadrant RNFL was positively correlated with the length of ocular axis (r=0.840, P=0.000), negatively correlated with the diopter (r=-0.855, P=0.000). Before optical magnification correction, the thickness of average, upper, lower and nasal quadrants RNFL in emmetropic group were significantly higher than those of the other three groups (all at P 0.05). After optical magnification correction, the thickness of average, upper, lower and nasal quadrants RNFL showed no significant differences among the 4 groups (all at P>0.05). The thickness of temporal quadrant RNFL was significantly different among the 4 groups (F=58.313, P=0.000). Conclusions When measuring RNFL thickness in myopic eyes by SD-OCT, the longer the axial length, the more obvious the optical magnification effect.The thickness of temporal quadrant RNFL increases in high myopia patients, so glaucoma should be vigilant when the thickness of temporal quadrant RNFL decreases. Key words: Myopia; Frequency domain optical coherence tomography; Optical magnification; Retinal nerve fiber thickness

Analysis of the clinical features and surgical efficacy of acute acquired comitant esotropia

Objective To analyze the clinical features and surgical efficacy of acute acquired comitant esotropia(AACE). Methods Clinical intact data of 25 patients with AACE who underwent strabismus surgery in Shanxi Ophthalmological Hospital from Sep. 2013 to May 2018 were analyzed retrospectively. Among them 20 patients underwent binocular visual function test. Different surgical procedures were designed, according to the objective and subjective esodeviations measured at near and distance. The efficacy was observed. Results There were 1 patient with hight hyperopia, 3 patients with emmetropia or mild hyperopia and 21 patients with myopia. The objective preoperative angle of deviation was (37±19) prism diopters(PD)at 33 cm and (42±19) PD at 6 m. There were 10 patients whose subjective esodeviations were 10 PD more than objective esodeviations and 15 patients whose subjective and objective esodeviations were equal. There were 19 cases with poor accommodative facility. Four patients underwent unilateral medial rectus recession, 2 patients underwent unilateral lateral rectus resection, and 19 patients underwent unilateral medial rectus recession and lateral rectus resection. All surgery succeeded. Conclusion Poor accommodative facility may be related to the onset of AACE. The combination of the objective and subjective esodeviations measured at near and distance is an effective method for the treatment of AACE. Key words: Esotropia, comitant, acquired, acute; Diplopia; Facility, accommodative; Surgery

Evaluation of corneal biomechanical properties modification following intrastromal correction of presbyopia using femtosecond laser

Objective To investigate the changes of corneal biomechanics of intrastromal correction (INTRACOR) femtosecond technique to treat presbyopia. Methods A prospective, clinical self-control clinical trial was designed.Twenty-four presbyopic patients with emmetropia or mild hyperopia were enrolled in this study.The INTRACOR procedure was performed using the Technolas femtosecond laser in the nondominant eye.Uncorrected distance visual acuity (UCDVA), uncorrected near visual acuity (UCNVA) and spherical equivalent (SE) were recorded in preoperation and postoperative 12 months, and the quality of life of postoperative patients was evaluated.The corneal deformation parameters including highest concavity deformation amplitude (HC-DA), highest concavity peak distance (HC-PD), highest concavity radius (HC-R), non-contact intraocular pressure and the central corneal thickness (CCT) were measured using the Corvis ST visualization biomechanical analyzer in preoperation and postoperative 1 month, 3, 6 and 12 months, respectively.This study followed the Declaration of Helsinki.Written informed consent was obtained from each subject prior to entering study cohort.This study protocol was approved by Ethic Committee of Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine (No.SDZYYDXYKYYLL2011.06). Results Compared with preoperation, UCNVA of all 24 (100%) eyes was improved at 12 months postoperatively with minimal or no change in UCDVA.The mean spherical equivalent was (+ 0.35 ± 0.29)D and (-0.37 ± 0.29)D before and 12 months after operation, with a significant difference beteeen them (t=-7.39, P 0.05). Compared with preoperation, the postoperative 1 month, 3, 6, 12 months HC-R values were significantly declined, HC-DA values were significantly increased, with significant differences between them (all at P 0.05). Corneal aspherical index (Q Value) was -0.28±0.10 at 12 months postoperatively, which was increased compared with the preoperation, and the maximum value added value (diff-K) of the central corneal curvature was (2.55±0.81)D. Conclusions INTRACOR treatment of presbyopia can effectively improve near vision, increase postoperative corneal biomechanical maximum HC-R and HC-DA, negatively increase the corneal central curvature increased aspheric index, which suggests that corneal biomechanics of central cornea is weakened after intrastromal femtosecond presbyopic treatment, and the hyperprolate mutifocal corneal shape is formed under normal intraocular pressure. Key words: Presbyopia; Femtosecond laser; Intrastromal correction; Perspective study; Corneal biomechanics; Corneal aspherical index

Clinical analysis of 426 emmetropia patients with unilateral rhegmatogenous retinal detachment and retinal lesions in the contralateral eyes

Objective To summarize the clinical features and visual outcome of posterior scleritis presented with symptoms involving affected optic nerve. Methods Retrospective case series study. Twelve eyes of 12 female patients with posterior scleritis were included in this study. The average age was 35.2±14.31 years old. The patients got diagnosed with an average of 24.75±22.91 days. Ocular pain was complained in all patients, and blurred vision in 11 patients. The best corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp microscope examination, B-scan ultrasound, optical coherence tomography (OCT), fundus photography, fundus fluorescein angiography (FFA) and ocular wall thickness measurement were performed in all patients. Nine eyes received visual field examination. All patients received systemic corticosteroid and steroidal eye drops for 3 months. Clinical features and outcome were retrospectively studied. Results Before treatment, the BCVA was from 0.8. There were 3 eyes with scleral hyperemia, 3 eyes with anterior chamber flares, 12 eyes with papilledema and different degrees of retinal vein dilatation, 3 eyes with star-shaped macular exudates and 2 eyes with macular retinal pigment epithelium detachment. B-scan ultrasound demonstrated that the ocular walls were thickening in all eyes with typical T-sign, and the average thickness was 2.76±0.68 mm. OCT demonstrated optic disc swelling, and the macular retinal detachment in 2 eyes. In the FFA examination, the fluorescein leakage of the disc was enhanced with time. In the Humphrey test, the value of mean deviation (MD) was 12.56±5.73 dB and pattern standard deviation (PSD) was 8.15±4.23 dB in 9 eyes before the treatment. After treatment for 3 months, the symptoms were attenuated and the visual acuity was obviously improved with BCVA>0.1 in all eyes. Scleral hyperemia and anterior chamber flares were only found in 1 eye. The optic disc edema gradually faded away. The ocular wall thickness in the poster part of the eyeball decreased, and the T-sign disappeared in all eyes, the average thickness was 1.53±0.41 mm. Compared with parameters before the treatment, the difference was statistically significant (t=0.003 5, P<0.05). OCT demonstrated the recovery of the macular retinal detachment. There was no abnormal leakage evidenced in FFA in the optic disc and macular. After treatment, the value of MD and PSD was 5.19±4.82 dB and (4.33±3.76) dB, respectively. The difference of MD value between before and after the treatment was significant (t=0.026, P<0.05). Conclusions Posterior scleritis with an initial symptom of optic nerve was tend to affect middle-aged patients, with clinical manifestations of anterior segment signs in some patients and optic disc swelling with retinal vein dilatation in all patients. B ultrasound examination showed typical T sign. Systemic corticosteroid treatment always obtained remission of the ocular inflammatory activity, and could achieve favorable visual outcome. Key words: Scleritis/diagnosis; Scleritis/therapy; Optic neuritis; Disease attributes

Comparison of peripapillary retinal nerve fiber layer thickness between myopia severity groups and controls.

To compare the peripapillary retinal nerve fiber layer (RNFL) thickness measured via optical coherence tomography (OCT) between different groups of myopia severity and controls. This was a prospective cross-sectional study. All subjects underwent a full ophthalmic examination, refraction, visual field analysis and A-scan biometry. Myopic patients were classified as low myopia (LM) [spherical equivalent (SE) from greater than -0.5 D, up to -3.0 D], moderate myopia (MM; SE greater than -3.0 D, up to -6.0 D) and high myopia (HM; SE greater than -6.0 D). The control group consisted of emmetropic (EM) patients (SE from +0.5 D to -0.5 D). A Zeiss Cirrus HD-OCT machine was used to measure the peripapillary RNFL thickness of both eyes of each subject. The mean peripapillary RNFL thickness between groups was compared using both analysis of variance and analysis of covariance. A total of 403 eyes of 403 subjects were included in this study. The mean age was 31.48±10.23y. There were 180 (44.7%) eyes with EM, 124 (30.8%) with LM, 73 (18.1%) with MM and 26 (6.5%) with HM. All groups of myopia severity had a thinner average RNFL than the EM group, but after controlling for gender, age, and axial eye length, only the HM group differed significantly from the EM group (P=0.017). Likewise, the superior, inferior and nasal RNFL was thinner in all myopia groups compared to controls, but after controlling for confounders, only the inferior quadrant RNFL was significantly thinner in the HM group, when compared to the EM group (P=0.017). The average and inferior quadrant RNFL is thinner in highly myopic eyes compared to emmetropic eyes. Refractive status must be taken into consideration when interpreting the OCT of myopic patients, as RNFL thickness varies with the degree of myopia.

Pattern of wavefront aberrations in Indian children with ametropia

Purpose: The aim of this study was to evaluate the distribution of wavefront aberrations in Indian children with refractive errors and to determine the correlation between the degree of refractive error and aberration. Materials and Methods: A prospective study was conducted on 216 eyes of 108 consecutive children attending the outpatient clinic. Based on refractive error, the children were allocated to five groups: “Emmetropic,” “hyperopic,” “simple astigmatism,” “compound astigmatism,” and “myopic” group. Lower order aberrations (LOAs) and higher order aberrations (HOAs) were analyzed within and between the groups. Results: Mean age of the children was 10.9 years. Of the total 216 eyes, 40 eyes had emmetropia, 52 had simple astigmatism, 54 had compound astigmatism, 43 had myopia, and 27 had hyperopia. In all the groups, increase in spherical equivalent was associated with increase in LOAs of defocus and astigmatism and the root mean square (RMS) of total HOAs. In comparison with the “emmetropic” group, all other groups showed a significant increase in LOAs (P < 0.001) and RMS of total HOAs (P < 0.001), with the “compound astigmatism” group showing higher values. Spherical aberrations were found to be associated with simple astigmatism, compound astigmatism (P = 0.008), and myopia (P = 0.041). Statistical analysis was done using analysis of variance applying Bonferroni correction factor and Pearson's correlation coefficient. Conclusions: Ametropic eyes are associated with HOAs. Indian children were found to have higher values of aberrations when compared to other races. Practitioners may need to factor this while treating children for refractive errors.

Effect of Experimental Conditions in the Accommodation Response in Myopia.

The accommodative response is more affected by the type of refractive error than the method of stimulation, field of view (FOV), or stimulus depth. This study aims to analyze the effect of stimulation method, stimulus depth, and FOV on the accommodation response (AR) for emmetropes (EMM), late-onset myopes (LOM), and early-onset myopes (EOM). Monocular AR was measured in 26 young observers (n = 9 EMM, n = 8 LOM, n = 9 EOM) under 60 different viewing conditions that were the result of permuting the following factors: (1) stimulation method (free space or Badal lens viewing), (2) stimulus depth (flat or volumetric), (3) FOV (2.5, 4, 8, 10, and 30°), and (4) accommodative stimulus (AS: 0.17, 2.50, and 5.00 diopters [D]). Mixed analysis of variance for 2.50 D of AS resulted in a significant effect of refractive group (F = 6.77, P < .01) and FOV (F = 1.26, P = .04). There was also a significant interaction between stimulus depth and FOV (F = 2.73, P = .03) and among stimulation method, FOV, and refractive group (F = 2.42, P = .02). For AS of 5.00 D, there was a significant effect of refractive group (F = 13.88, P < .01) and stimulation method (F = 5.16, P = .03). There was also a significant interaction of stimulation method, stimulus depth, and refractive group (F = 4.08, P = .03). When controlling for all interactions, LOM showed larger lags than EMM and EOM; the AR did not significantly change for fields of 8, 10, and 30°, and it did not significantly differ for different stimulation methods or stimulus depth. Previously reported differences in AR when using lens-based methods compared with free space viewing may be explained by the effect of other factors such as the FOV or the depth of the stimulus. Targets with an FOV of 8 or 10° may be optimal for accurate ARs.

Dynamic expression changes of Smad3 and type I collagen in sclera of progressive myopia in guinea pigs

Background Sclera remodeling process in axial elongation is one of the main pathological mechanisms of axial myopia progression.Studies confirmed that transforming growth factor-β1 (TGF-β1) participates in the sclera remodeling process, and Smad3 is one of TGF-β1 downstream signal gene transcriptive factors, so to explore its role in sclera remodeling process of myopic eyes is of great significance for pathogenesis and prevention research of myopia. Objective This study was to investigate the expressions of type Ⅰ collagen and Smad3, a TGF-β1 downstream target, in sclera of form deprivation myopic (FDM) eyes and explore the impact of TGF-β1-Smad3-type I collagen signaling pathway on collagen remodeling in myopic sclera. Methods Seventy-five 1-week-old guinea pigs were randomly divided into normal control group (25 guinea pigs) and FDM group (50 guinea pigs). Monocular FDM was induced by occluding the left eyes of guinea pigs in FDM group with translucent latex balloons for 2, 4, 6 weeks, respectively, and consecutive occluding for 4 weeks followed by uncovering for 1 week (4/-1 weeks). The refractive power was detected by retinoscopy and axial length was measured with A-type ultrasound.Immunohistochemistry and reverse transcription-PCR were employed to detect the dynamic expressions of type Ⅰ collagen and Smad3 protein ad mRNA in the sclera of guinea pigs with emmetropia and experimental myopia, and the relationship between collagen Ⅰ and Smad3 levels was analyzed. Results The refraction was hypermetropic in both normal control group and FDM group before occluding of eyes (P>0.05), and the hypermetropic power was gradually reduced over time in the normal control group.In the FDM group, the refractive power was gradually changed from (+ 2.09 ± 0.31)D before occluding to (-1.23±0.69), (-4.17±0.59), (-7.07±0.56) and (-4.30±0.58)D, and the axial length was increased from (5.93±0.39)mm to (6.62±0.36), (7.30±0.34), (7.99±0.32), and (7.21±0.36)mm at weeks 2, 4, 6, and 4/-1 after occluding, respectively, indicating significant differences in refractive power and axial length over time in the FDM group from normal control group and self-control group (all at P<0.05). The expressions of Smad3 and type Ⅰ collagen protein and mRNA in the sclera of the FDM group was significantly lower than those of the control group and self-control group in various time points (all at P<0.05). The positive correlation were found in the expression of Smad3 on the myopic sclera with that of type Ⅰ collagen in both protein and mRNA levels (protein: r=0.993, P<0.05; mRNA: r=0.954, P<0.05). Conclusions The myopic power and ocular axis increase dependent upon occluding time, and the expressions of Smad3 and type Ⅰ collagen in the sclera are correspondingly weakened in FDM eyes.A consistent expression trend is found between Smad3 and type Ⅰ collage, suggesting Smad3 and type Ⅰ collagen participate in the regulation of sclera remodeling in myopia by TGF-β1-Smad3-CollagenⅠsignaling pathway. Key words: Form-deprivation; Myopia; Sclera/metabolism; Disease progression; TGF-β1-Smad3-Collagen Ⅰ signaling pathway; Disease models, animal; Guinea pigs

A cross-sectional study to compare the complications of cataract surgery with phacoemulsification in eyes with high and normal axial length

Introduction: High myopia is a risk factor for cataract formation. A relationship between myopia and higher complications in cataract surgeries has long been suggested. Materials and methods: After obtaining ethics committee clearance, this cross-sectional, case-control observational study was conducted in 100 participants of age above 18 years. They underwent cataract surgery. Participants were divided into two groups:- Group A & B - Participants with axial length between 21 and 26 mm and more than 26 mm respectively. Results and discussion: This shift of myopic individuals undergoing cataract surgery at an earlier age was found to be statistically significant. There was a statistically significant association between increasing age and PCR. Most common type of cataract in group A is cortical (30.8%) followed by nuclear (28.8%). Most common type of cataract in a group B is PSC (50%) followed by nuclear (22.9%). There was no statistical association between type of cataract and any complication. Conclusions: Intraoperative complications of cataract surgery do not increase significantly with increase in axial length. Myopic individuals are prone to develop cataracts earlier. NS and PSC type of cataracts are more common compared to cortical type of cataracts in emmetropic individuals.

The three-dimensional MRI for estimating the shape of eyeball of emmetropia and myopia

Objective To investigate the morphologic characteristics of eyeballs in myopia with three-dimensional magnetic resonance imaging(3-D MRI). Methods The emmetropia (10 cases, 20 eyes), low myopia (10 cases, 20 eyes), medium myopia (10 cases, 20 eyes), high myopia (10 cases, 20 eyes) were enrolled. Patients which had eye diseases, history of ocular injury or surgery were excluded. In all cases the 3-D MRI were taken for the measurement of the sagittal, horizontal and vertical diameter of eyeball, eyeball volume and the ending points of eye muscle and optic nerve. Results The average value of sagittal, horizontal and vertical length of low myopia, medium myopia and high myopia group were much bigger than those of emmetropia group, especially the axial length. The average value of eyeball volume of myopia group was much bigger than that of emmetropia group. The eyeball, eye muscles and optic nerve were showed clearly in the 3-D MRI. The low and medium myopia group did not present obvious posterior staphyloma. Fifteen of 20 eyeballs in the high myopia group showed posterior staphyloma. Conclusion The sagittal, horizontal and vertical diameters and volume of the eyeball of low myopia, medium myopia and high myopia are significantly bigger than those of emmetropia. The 3-D MRI can show the eyeball shape, eye muscles and optic nerve clearly, which has the certain value in clinical work especially for eye surgery. Key words: Myopia; Diameter, eyeball; Volume, eyeball; Three-dimensional MRI