病理性近视的相干光断层扫描

目的研究病理性近视的相干光断层扫描(OCT)的图像特征。方法对100例(195只眼)高度近视患者行OCT检查。患者年龄16～76岁。屈光度数-6．00～-36．00D。结果OCT检查正常者7只眼(3．6％),视网膜色素上皮及脉络膜毛细血管光带不均匀和薄变者161只眼(82．6％),黄斑全层裂孔21只眼(10．8％),其中合并视网膜脱离10只眼(5．1％),黄斑限局性视网膜浅脱离24只眼(12．3％),其中合并视网膜劈裂7只眼(3．6％),黄斑脉络膜新生血管膜19只眼(9．7％),Fuchs斑9只眼(4．6％),厚的黄斑出血3只眼,黄斑前膜18只眼(9．2％),常合并有视网膜水肿。黄斑视网膜神经上皮薄变5只眼(2．6％),漆裂纹3只眼(1．5％)。结论与裂隙灯全视网膜显微镜检查比较,OCT在观察视网膜色素上皮和脉络膜毛细血管改变,确诊黄斑裂孔,发现小的神经上皮脱离和劈裂,诊断黄斑前膜,神经上皮薄变等方面均有优越性。但对薄的黄斑出血及小色素点不能分辨,对厚出血与色素难以分辨,因而也有其局限性。     

Investigation of changes in the myopic retina using multifocal electroretinograms, optical coherence tomography and peripheral resolution acuity

We investigated relationships between retinal structure using optical coherence tomography (OCT) and retinal function using peripheral resolution acuity and multifocal electroretinograms (mfERG) in 56 subjects with a range of refractive errors (+0.50 to -15.00 D). Retinal thinning occurred in moderate and high myopia which appeared to be primarily due to reduced thickness of the middle to inner retina (MIR) (outer plexiform layer to the nerve fiber layer). MIR thickness was correlated with reduced spatial resolution and delayed mfERG timing in the peripheral retina. The findings suggest the structure and function of the post-receptor retina is susceptible to disruption in moderately and highly myopic eyes.     

Retinal ganglion cell population in adult albino and pigmented mice: A computerized analysis of the entire population and its spatial distribution

In adult Swiss albino and C57 pigmented mice, RGCs were identified with a retrogradely transported neuronal tracer applied to both optic nerves (ON) or superior colliculi (SCi). After histological processing, the retinas were prepared as whole-mounts, examined and photographed under a fluorescence microscope equipped with a motorized stage controlled by a commercial computer image analysis system: Image-Pro Plus^® (IPP). Retinas were imaged as a stack of 24-bit color images (140 frames per retina) using IPP with the Scope-Pro plug-in 5.0 and the images montaged to create a high-resolution composite of the retinal whole-mount when required. Single images were also processed by specific macros written in IPP that apply a sequence of filters and transformations in order to separate individual cells for automatic counting. Cell counts were later transferred to a spreadsheet for statistical analysis and used to generate a RGC density map for each retina. Results: The mean total numbers of RGCs labeled from the ON, in Swiss (49,493 ± 3936; n = 18) or C57 mice (42,658 ± 1540; n = 10) were slightly higher than the mean numbers of RGCs labeled from the SCi, in Swiss (48,733 ± 3954; n = 43) or C57 mice (41,192 ± 2821; n = 42), respectively. RGCs were distributed throughout the retina and density maps revealed a horizontal region in the superior retina near the optic disk with highest RGC densities. In conclusion, the population of mice RGCs may be counted automatically with a level of confidence comparable to manual counts. The distribution of RGCs adopts a form of regional specialization that resembles a horizontal visual streak.     

Imaging retinal nerve fiber bundles using optical coherence tomography with adaptive optics

Early detection of axonal tissue loss in retinal nerve fiber layer (RNFL) is critical for effective treatment and management of diseases such as glaucoma. This study aims to evaluate the capability of ultrahigh-resolution optical coherence tomography with adaptive optics (UHR-AO-OCT) for imaging the RNFL axonal bundles (RNFBs) with 3 × 3 × 3 μm³ resolution in the eye. We used a research-grade UHR-AO-OCT system to acquire 3° × 3° volumes in four normal subjects and one subject with an arcuate retinal nerve fiber layer defect (n = 5; 29-62 years). Cross section (B-scans) and en face (C-scan) slices extracted from the volumes were used to assess visibility and size distribution of individual RNFBs. In one subject, we reimaged the same RNFBs twice over a 7 month interval and compared bundle width and thickness between the two imaging sessions. Lastly we compared images of an arcuate RNFL defect acquired with UHR-AO-OCT and commercial OCT (Heidelberg Spectralis). Individual RNFBs were distinguishable in all subjects at 3° retinal eccentricity in both cross-sectional and en face views (width: 30-50 μm, thickness: 10-15 μm). At 6° retinal eccentricity, RNFBs were distinguishable in three of the five subjects in both views (width: 30-45 μm, thickness: 20-40 μm). Width and thickness RNFB measurements taken 7 months apart were strongly correlated (p < 0.0005). Mean difference and standard deviation of the differences between the two measurement sessions were −0.1 ± 4.0 μm (width) and 0.3 ± 1.5 μm (thickness). UHR-AO-OCT outperformed commercial OCT in terms of clarity of the microscopic retina. To our knowledge, these are the first measurements of RNFB cross section reported in the living human eye.     

Intravitreal bevacizumab for pediatric exudative retinal diseases

Purpose

To detect if intravitreal bevacizumab can reduce retinal exudation, improve visual and anatomical outcomes, and facilitate the treatment in various pediatric exudative retinal diseases.

Patients and methods

Prospective, non-randomized, case series of nine eyes of pediatric exudative retinal diseases less than 18 years old which included six eyes with juvenile diabetic retinopathy, two eyes in children with Coats’ disease, and one eye with myopic choroidal neovascular membrane (CNV). All eyes received only intravitreal bevacizumab injection 1.25 mg/0.05 ml as the primary treatment. The need for adjuvant ablative procedures, including laser photocoagulation or cryotherapy, were performed and recorded. The need for supplementary intravitreal bevacizumab injection was recorded. The changes in pre- and post-operative best-corrected visual acuity (BCVA) and central macular thickness (CMT) were recorded. Serial optical coherent tomography (OCT) and fundus flourescein angiography (FFA) were performed to follow treatment efficacy.

Results

The study included 19 eyes of 11 patients with age equal to or less than eighteen years with exudative retinal diseases including type I DM (n = sixteen eyes), Coats’ disease (n = 2 eyes), and due to myopic CNV (n = 1 eye). Mean pre-injection log MAR for all was 0.605 ± 0.174 and mean post-injection for all log MAR was 0.284 ± 0.247. While Mean pre-injection log MAR for DR and myopic CNV patients was 0.576 + 0.152 SD and mean post-injection log MAR for DR and myopic CNV patients was 0.229 + 0.189 at one year. Serial OCT measurements showed that mean CMT for all eyes was 355.8 ± 35.3 μm SD at baseline, which was decreased to 222.42 + 26.2 μm SD. The two eyes of Coats’ disease needed another two supplementary intravitreal bevacizumab injections. No ocular or systemic complications related to bevacizumab were noted during the entire course of follow-up.

Conclusion

Intravitreal bevacizumab appears to be a well-tolerated treatment for pediatric age group with various exudative retinal diseases. It has the potential as an adjuvant therapy for ablative procedures to improve final visual and anatomical outcome.     

Binocular lens treatment in tree shrews: Effect of age and comparison of plus lens wear with recovery from minus lens-induced myopia

We examined normal emmetropization and the refractive responses to binocular plus or minus lenses in young (late infantile) and juvenile tree shrews. In addition, recovery from lens-induced myopia was compared with the response to a similar amount of myopia produced with plus lenses in age-matched juvenile animals. Normal emmetropization was examined with daily noncycloplegic autorefractor measures from 11 days after natural eye-opening (days of visual experience [VE]) when the eyes were in the infantile, rapid growth phase and their refractions were substantially hyperopic, to 35 days of VE when the eyes had entered the juvenile, slower growth phase and the refractions were near emmetropia. Starting at 11 days of VE, two groups of young tree shrews wore binocular +4 D lenses (n = 6) or −5 D lenses (n = 5). Starting at 24 days of VE, four groups of juvenile tree shrews (n = 5 each) wore binocular +3 D, +5 D, −3 D, or −5 D lenses. Non-cycloplegic measures of refractive state were made frequently while the animals wore the assigned lenses. The refractive response of the juvenile plus-lens wearing animals was compared with the refractive recovery of an age-matched group of animals (n = 5) that were myopic after wearing a −5 D lens from 11 to 24 days of VE. In normal tree shrews, refractions (corrected for the small eye artifact) declined rapidly from (mean ± SEM) 6.6 ± 0.6 D of hyperopia at 11 VE to 1.4 ± 0.2 D at 24 VE and 0.8 ± 0.4 D at 35 VE. Plus 4 D lens treatment applied at 11 days of VE initially corrected or over-corrected the young animals’ hyperopia and produced a compensatory response in most animals; the eyes became nearly emmetropic while wearing the +4 D lenses. In contrast, plus-lens treatment starting at 24 days of VE initially made the juvenile eyes myopic (over-correction) and, on average, was less effective. The response ranged from no change in refractive state (eye continued to experience myopia) to full compensation (emmetropic with the lens in place). Minus-lens wear in both the young and juvenile groups, which initially made eyes more hyperopic, consistently produced compensation to the minus lens so that eyes reached age-appropriate refractions while wearing the lenses. When the minus lenses were removed, the eyes recovered quickly to age-matched normal values. The consistent recovery response from myopia in juvenile eyes after minus-lens compensation, compared with the highly variable response to plus lens wear in age-matched juvenile animals suggests that eyes retain the ability to detect the myopic refractive state, but there is an age-related decrease in the ability of normal eyes to use myopia to slow their elongation rate below normal. If juvenile human eyes, compared with infants, have a similar difficulty in using myopia to slow axial elongation, this may contribute to myopia development, especially in eyes with a genetic pre-disposition to elongate.     

The structural effect of intravitreal Brilliant blue G and Indocyanine green in rats eyes

Purpose

To compare the potential retinal toxicity of two commercially Brilliant blue G dyes (Brilliant Peel and Ocublue Plus) and Indocyanine green (ICG) at usual clinical concentration.

Methods

Brilliant Peel 0.025% (n=9), Ocublue Plus 0.025% (n=9), and ICG 0.05% (n=9) were injected intravitreally into Sprague–Dawley rat left eyes with balanced salt solution injected in the contralateral eyes as control. Evaluation of the effect of the dyes on retinal architecture was done by histological analysis of neurosensory retinal thickness and retinal ganglion cell (RGC) counts 7 days after intravitreal injection. Paired t-test was done to detect the presence of biologically significant thinning in neurosensory retina and five retinal layers for each dye (paired t-tests). One-way ANOVA and Tukey''s Honestly Significant Difference test were used to assess whether different dyes caused significant thinning in mean neurosensory retinal thickness and reduction of mean RGC density.

Results

Eyes treated with ICG had significantly thinner mean total neurosensory retinal thickness compared with the control eyes (P-value=0.01), followed by those treated with Ocublue Plus (P-value=0.03). Brilliant Peel did not cause significant thinning in any of the five retinal layers (all P-values>0.05). No significant difference in mean thinning of the total retinal thickness was detected between dyes (P-value=0.11). The mean thickness of the photoreceptor outer segment and outer plexiform layers were significantly reduced in ICG-injected eyes when compared with the control eyes (P-value=0.02). No significant difference in mean thinning between the three dyes was detected at all five retinal layers using one-way ANOVA (all P-values>0.35). RGC density was significantly reduced for ICG (P-value=0.01) but only marginally for Ocublue Plus (P-value=0.05). No significant reduction in RGC density was observed for Brilliant Peel (P-value=0.2).

Conclusion

Intravitreal Brilliant Peel is safe to rats retina. The retinal thinning and reduction in RGC density induced by Ocublue Plus requires further studies to determine the safety profile of this product. Potential retinal toxicity is seen with ICG 0.05%.     

近视及近视性弱视儿童视网膜神经纤维层OCT检测及分析

目的分析近视及近视性弱视儿童视网膜光学相干断层扫描（OCT）各项指标的变化,研究近视及近视性弱视儿童的视网膜结构的变化特征。方法对52只眼近视性弱视组和32只眼单纯近视组行视网膜OCT检查,记录黄斑中心凹中心视网膜厚度和视盘上方、下方、鼻侧、颞侧及平均视网膜神经纤维层（RNFL）厚度,并与32只眼正常对照组进行比较。结果近视性弱视组和正常对照组比较,视盘下方和视盘周围平均RNFL厚度变薄,且有统计学意义（P〈0.05）,而视盘上方、颞侧和鼻侧RNFL厚度和黄斑中心凹中心视网膜厚度均无显著差异（P〉0.05）。单纯近视组和正常对照组比较,视盘周围RNFL厚度和黄斑中心凹视网膜厚度均无显著差异（P〉0.05）。近视性弱视组高度近视儿童的视盘上方、下方、鼻侧和视网膜平均RNFL厚度较健眼变薄（P〈0.05）,而颞侧和黄斑中心凹中心视网膜厚度无明显变化（P〉0.05）,单纯近视组中高度近视儿童的视盘颞侧RNFL层厚度和黄斑中心凹中心视网膜厚度增加明显（P〈0.05）。结论近视及近视性弱视儿童的视网膜结构存在异常。     

A computerized analysis of the entire retinal ganglion cell population and its spatial distribution in adult rats

In adult albino (SD) and pigmented (PVG) rats the entire population of retinal ganglion cells (RGCs) was quantified and their spatial distribution analyzed using a computerized technique. RGCs were back-labelled from the optic nerves (ON) or the superior colliculi (SCi) with Fluorogold (FG). Numbers of RGCs labelled from the ON [SD: 82,818 ± 3,949, n = 27; PVG: 89,241 ± 3,576, n = 6) were comparable to those labelled from the SCi [SD: 81,486 ± 4,340, n = 37; PVG: 87,229 ± 3,199; n = 59]. Detailed methodology to provide cell density information at small scales demonstrated the presence of a horizontal region in the dorsal retina with highest densities, resembling a visual streak.     

Axial myopia induced by hyperopic defocus in guinea pigs: A detailed assessment on susceptibility and recovery

This study investigated whether adolescent guinea pigs can develop myopia induced by negative lenses, and whether they can recover from the induced myopia. Forty-nine pigmented guinea pigs (age of 3 weeks) were randomly assigned to 4 groups: 2-week defocus (n = 16), 4-week defocus (n = 9), 2-week control (n = 15) and 4-week control (n = 9). A −4.00 D lens was worn in the defocus groups and a plano lens worn in the control groups monocularly. The lenses were worn from 3 weeks to 5 weeks of age in the 2-week treatment groups with the biometry measured at 2, 4, 6, 10 and 14 days of lens wear. The lenses were worn from 3 weeks to 7 weeks of age in the 4-week treatment groups with the biometry measured immediately and at 2, 4, 6, 10 and 14 days after lens removal. Refractions in the defocused eyes developed towards myopia rapidly within 2 days of lens wear, followed by a slower development. The defocused eyes were at least 3.00 D more myopic with a greater increase in vitreous length by 0.08 mm compared to the fellow eyes at 14 days (p < 0.05). The estimated choroidal thickness of the defocused eyes decreased rapidly within 2 days of lens wear, followed by a slower decrease over the next 4 days. Relative myopia induced by 4 weeks of negative-lens treatment declined rapidly following lens removal. A complete recovery occurred 14 days after lens removal when compared to the fellow controls. The refractive changes during the recovery corresponded to a slower vitreous lengthening and a rapid thickening of the choroid. The plano-lens wearing eyes showed a slight but significant myopic shift (<−0.80 D) with no associated biometrical changes. Guinea pigs aged 3 weeks can still develop negative lens induced myopia and this myopia is reversible after removal of the lens. The myopia and recovery are mainly due to changes in vitreous length and choroidal thickness.     

Viral delivery of heme oxygenase-1 attenuates photoreceptor apoptosis in an experimental model of retinal detachment

This study was designed to evaluate the efficacy of subretinal injection of recombinant adeno-associated virus vector expressing heme oxygenase-1 (rAAV-HO-1) in attenuating photoreceptor apoptosis induced by experimental retinal detachment (RD) in Sprague-Dawley rats. Our results disclosed that subretinal rAAV-HO-1 delivery achieved localized high HO-1 gene expression in retinal outer nuclear layer (ONL) compared with rAAV-lacZ-injected eyes and eyes with RD left untreated both at 2 (p = 0.003) and 28 (p = 0.007) days of RD. The ONL thickness (p = 0.018) and mean photoreceptor nuclei count (p = 0.009) in eyes receiving rAAV-HO-1 injection was significantly higher than in rAAV-lacZ-injected or eyes with RD left untreated at 28 days of RD. There were fewer apoptotic photoreceptor nuclei at 2 (p = 0.008) and 5 (p = 0.018) days of RD and less activated caspase-3 expression (p = 0.008) at 2 days of RD in rAAV-HO-1 treated eyes than in control eyes. These data supported that gene transfer approach might attenuate photoreceptor apoptosis caused by RD with a resultant better ONL preservation.     

Effect of myopia and age on optic disc margin anatomy within the parapapillary atrophy area

Purpose

To evaluate the effect of myopia and age on temporal optic disc margin anatomy within the parapapillary atrophy (PPA) area by use of spectral-domain optical coherence tomography (OCT).

Methods

Fifty young myopic eyes with PPA (myopic PPA group), 50 aged non-myopic eyes with PPA (aged PPA group), and 50 young non-myopic eyes without PPA (control group) were enrolled. High-definition OCT scanning was used to obtain horizontal cross-sectional optic nerve head (ONH) images. By use of these OCT scans we investigated three temporal optic disc margin structures: the configuration of the border tissue of Elschnig; the cross-sectional ONH structure coinciding with the clinically detected optic disc margin; and the integrity of the retinal layers within the PPA area.

Results

The distribution of the configuration of the border tissue of Elschnig and the cross-sectional ONH structure coinciding with the clinically detected optic disc margin of the myopic PPA group differed significantly from those of the control group (P < 0.01) whereas those of the aged PPA group did not (P > 0.05). Other than the photoreceptor layer, the retinal layers within the PPA area were more commonly impaired in the myopic PPA group than in the aged PPA group (P < 0.001).

Conclusions

Myopia and aging led to different structural changes in temporal optic disc margin anatomy within the PPA area. This finding implies that different mechanisms may underlie myopic and age-related PPA development.     

猴光学离焦性与形觉剥夺性近视眼视网膜形态及超微结构比较

目的对比观察光学离焦性和形觉剥夺两种诱导方法所致恒河猴近视眼视网膜形态与超微结构的变化。方法年龄1.0～1.5个月的健康恒河猴15只,1只眼为实验眼配戴-3.00D镜片(9只眼)或散射镜片(6只眼),造成光学离焦或形觉剥夺;另1只眼作为对照眼。处理后不同时间用角膜地形图、睫状肌麻痹下验光、A超动态观察猴眼屈光状态和眼轴的变化;用相干光断层扫描术(OCT)动态观察视网膜厚度的变化,并与组织学测量值进行比较;3个月后,光镜和电镜下对比观察光学离焦、形觉剥夺性近视眼和对照眼视网膜超微结构的变化。结果15只猴实验眼均形成近视眼,光学离焦和形觉剥夺性近视眼视网膜均可见视杆细胞外节较长,视锥细胞膜盘减少,膜盘间隙增大,视网膜神经上皮层均较对照眼薄(均P<0.05);视网膜神经上皮层和色素上皮层厚度的OCT测量值与经校正后的组织学测量值比较差异均无统计学意义(P>0.05)。结论实验性近视眼视网膜超微结构与对照眼明显不同,但光学离焦和形觉剥夺性近视眼视网膜超微结构变化很相似。这种改变在近视眼发生、发展过程中的意义有待进一步探讨。     

Total ocular, anterior corneal and lenticular higher order aberrations in hyperopic, myopic and emmetropic eyes

Total ocular higher order aberrations and corneal topography of myopic, emmetropic and hyperopic eyes of 675 adolescents (16.9 ± 0.7 years) were measured after cycloplegia using COAS aberrometer and Medmont videokeratoscope. Corneal higher order aberrations were computed from the corneal topography maps and lenticular (internal) higher order aberrations derived by subtraction of corneal aberrations from total ocular aberrations. Aberrations were measured for a pupil diameter of 5 mm. Multivariate analysis of variance followed by multiple regression analysis found significant difference in the fourth order aberrations (SA RMS, primary spherical aberration coefficient) between the refractive error groups. Hyperopic eyes (+0.083 ± 0.05 μm) had more positive total ocular primary spherical aberration compared to emmetropic (+0.036 ± 0.04 μm) and myopic eyes (low myopia = +0.038 ± 0.05 μm, moderate myopia = +0.026 ± 0.06 μm) (p < 0.05). No difference was observed for the anterior corneal spherical aberration. Significantly less negative lenticular spherical aberration was observed for the hyperopic eyes (−0.038 ± 0.05 μm) than myopic (low myopia = −0.088 ± 0.04 μm, moderate myopia = −0.095 ± 0.05 μm) and emmetropic eyes (−0.081 ± 0.04 μm) (p < 0.05). These findings suggest the existence of differences in the characteristics of the crystalline lens (asphericity, curvature and gradient refractive index) of hyperopic eyes versus other eyes.     

Macular retinal detachment associated with peripapillary detachment in pathologic myopia

Purpose A peripapillary detachment in pathologic myopia (PDPM) appears as a yellowish-orange lesion around the optic disc in highly myopic eyes. We report a case in which a macular retinal detachment (RD) accompanied a PDPM. Method A case report was used in this study. Results The right eye in a 48-year-old man showed a macular RD and a PDPM. Fluorescein fundus angiography showed no dye leakage, suggestive of an optic pit within the optic disc. Optical coherence tomography (OCT) examination revealed that there was a full-thickness tissue defect in the retina overlying PDPM, the vitreous cavity was connected to PDPM through this defect, and the PDPM was continuous with the RD through the subretinal path at the conus area. Conclusions These findings suggest that this eye had a macular RD associated with a PDPM, and eyes with a PDPM might be at risk of developing macular RD.     

Neuroprotective effects of recombinant human granulocyte colony-stimulating factor (G-CSF) in neurodegeneration after optic nerve crush in rats

The purpose of the present study was to investigate the effects of granulocyte colony-stimulating factor (G-CSF) on neurodegeneration of optic nerve (ON) and retinal ganglion cells (RGCs) in a rat model of ON crush. The ONs of adult male Wistar rats (150-180 g) were crushed by a standardized method. The control eyes received a sham operation. G-CSF (100 μg/kg/day in 0.2 ml phosphate-buffered saline) or phosphate-buffered saline (PBS control) was immediately administered after ON crush for 5 days by subcutaneous injection. Rats were euthanized at 1 or 2 weeks after the crush injury. RGC density was counted by retrograde labeling with FluoroGold application to the superior colliculus, and visual function was assessed by flash visual evoked potentials (FVEP). TUNEL assay, Western blot analysis and immunohistochemistry of p-AKT in the retina and ED1 (marker of macrophage/microglia) in the ON were conducted. 2 weeks after the insult, the RGC densities in the central and mid-peripheral retinas in ON-crushed, G-CSF-treated rats were significantly higher than that of the corresponding ON-crushed, PBS-treated rats (survival rate was 60% vs. 19.6% in the central retina; 46.5% vs. 23.9% in mid-peripheral retina, respectively; p < 0.001). FVEP measurements showed a significantly better preserved latency of the p1 wave in the ON-crushed, G-CSF-treated rats than the ON-crushed, PBS-treated rats (78 ± 9 ms in the sham operation group, 98 ± 16 ms in the G-CSF-treated group, and 174 ± 16 ms in the PBS-treated group; p < 0.001). TUNEL assays showed fewer apoptotic cells in the retinal sections in the ON-crushed, G-CSF-treated rats. p-AKT immunoreactivity was up-regulated in the retinas of the ON-crushed, G-CSF-treated rats at 1 and 2 weeks. In addition, the number of ED1-positive cells was attenuated at the lesion site of the optic nerve in the ON-crushed, G-CSF-treated group. From these results, we gather that administration of G-CSF is neuroprotective in the rat model of optic nerve crush, as demonstrated both structurally by RGC density and functionally by FVEP. G-CSF may work by being anti-apoptotic involving the p-AKT signaling pathway as well as by attenuation of the inflammatory responses at the injury site, as evidenced by less ED1-positive cell infiltration in the optic nerve.     

Associations of refractive errors and retinal changes measured by optical coherence tomography: A systematic review and meta-analysis

Studies reporting alteration in retinal thickness using optical coherence tomography (OCT) have been performed in different populations with various degrees of refractive error, producing inconsistent results. Therefore, we performed a meta-analysis to evaluate the alterations in retinal OCT measurements in myopic and hyperopic patients compared to controls. Evaluation of different retinal layers’ thickness may have significance for developing novel approaches for preventing, diagnosing, and treating refractive errors and their complications. We searched PubMed and EMBASE to identify articles that reported OCT measurements of different retinal layers and regions, including macular, foveal, parafoveal, perifoveal, foveolar, ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell and inner plexiform layer (GC-IPL) thickness in addition to macular volume, and optic disc area in myopes and hyperopes comparing their differences with controls. We applied either a fixed-effects or random-effects model for the meta-analysis of these differences based on the assessed heterogeneity level. Furthermore, subgroup analyses and metaregression, as well as publication bias and quality assessment, were conducted for the eligible studies.Forty-seven studies with a total of 12223 eyes, including 8600 cases and 3623 non-cases, are included in this meta-analysis. Our results showed that, in comparison to controls, highly myopic eyes had a significantly lower value for mean macular thickness, macular GCC, macular GC-IPL, parafoveal, perifoveal, foveal, foveolar, RNFL, and pRNFL thickness. Compared to controls, moderately myopic eyes showed a significantly thinner mean macular GCC layer and pRNFL. On the other hand, hyperopic eyes had significantly thicker average pRNFL than controls. Several other significant differences were also observed in various regional analyses. The findings of the current study affirm the retinal OCT measurement differences between myopic and hyperopic eyes compared to controls, emphasizing OCT measurements' advantages as potential biomarkers of ocular pathologies.     

高度近视眼LASIK术后早期黄斑部视网膜厚度变化的研究

目的探讨准分子激光角膜原位磨镶术（excimer laser in situ keratomileusis,LASIK）对高度近视眼黄斑区视网膜神经纤维层厚度的影响及其影响因素。方法随机选择接受LASIK手术矫正视力≥1.0高度近视眼患者18例36眼。采用Zeiss-Humphrey光学相干断层成像仪（Optical Coherence Tomography,OCT）第三代测量近视眼LASIK术前,术后1天、1周眼底以黄斑中心凹为中心3mm半径内的视网膜平均厚度,以地形图分9个区域显示。结果18例36眼高度近视患者LASIK术后1天、1周测量黄斑区视网膜厚度包括黄斑中心凹最小值、黄斑中心凹平均值、内圈平均值、外圈平均值和黄斑区6mm直径范围的视网膜体积与术前值相比均无显著差异（p〉0.05）,术后2次测量值间也无显著差异。结论LASIK对高度近视眼患者术后早期的黄斑区视网膜厚度无明显影响。     

Alterations in the differentiation of chick retina caused by an intraocular injection of an alkaline phosphatase inhibitor

Intense alkaline phosphatase (ALPase) activity has been localized in the outer plexiform layer of the developing chick retina. To elucidate the functional significance of this enzymatic activity, we have injected an ALPase inhibitor, levamisole, into embryonic eyes on either the 13th or 15th day of incubation. The retina was fixed between the 15th and 20th day of incubation and examined by electron microscopy. Levamisole injection on the 13th day caused various morphological alterations in retinal development, including the appearance of solitary photoreceptor cells in the subretinal space as well as folding of both the outer plexiform and outer nuclear layers. Pedicles of photoreceptor cells in the outer plexiform layer displayed rather smooth configurations with a reduced number of invaginations by post-synaptic neurites. The outer plexiform layer was thinned and the neuritic extensions in this layer appeared much less developed than in the control (PBS-injected) retina. Photoreceptor outer segments were seldom observed. Besides these alterations, layers of optic fibers and ganglion cells were also affected, as shown by evidence of degeneration in the ganglion cells and thinning of the nerve-fiber layer. Injection of levamisole into day 15 embryonic eyes exerted less influence on retinal development, but some photoreceptor cells were still found in the subretinal space. Some of these observations have been reported in the retinas of aged normal animals or in retinas with hereditary or induced retinal dystrophy. It is suggested that ALPase activity in the outer plexiform layer of the developing chick retina may be important for the onset of normal development of synapses in the outer plexiform layer and differentiation of the photoreceptor cells.