The pathogensis of choroidal vascular changes in traumatic rtinopethy remains uncertain.We performed scanning electron micrmcopie (SEM) observation of methyl methalerylare vascular corrosion casts in a rabbi model with severe retinal contusion. Areas of filling defects in corrosion casts of the choriocapillaries, correspending to the areas of impact retinal lesions were noted in the traumatized eyes one to 28 days after trauma.No neovascularization was found in the eyes 56 days after trauma. The results confirm that obstruction and disappearance of involved choriocapillaries are the main changes of choroidal vasculatrue in severe blunt tram. The changes may be associated with continuous necrosis, of the photoreceptors 4 weeks after injury. （Chin J Ocul Fundus Dis,1993,9:5-7）
Objective To study the progressive development of the retinas through an observation on the histological changes of the retinas from neonatal mice of different day-ages. Methods The retinas from the mice of 1 to 20 days of age were examined by light microscopy,and from 1 to 3 days,by autoradiography. Results The retinas of the mice below 3 days of age only had the RPE cells layer,the neuroblast layer and the ganglion cell layer.With the increase in dayage,the retinas developed gradually and would be mature in the 20th day. Conclusions The retinas of mice is a kind of immature tissue before the 20th days,so it can be considered as transplantation donors. (Chin J Ocul Fundus Dis, 1999, 15: 174-176)
Objective To observe the retinal ultrastructure of the human fetal at the age of 9 months, and to investigate the clinical significance of the observation on retinal neuron development during the prenatal period.Methods Four human fetal eyes of 2 fetus at the gestational age of 9 months, including 1 at 35 and the other at 36 weeks, were obtained after termination of pregnancy due to trauma. The gestational ages of the fetus were estimated according to both last menstrual period (LMP) of the pregnant women and the weight/crownheel length of fetus at the delivery. From each eyeball, 4 pieces of retina at the posterior pole were obtained and observed after specimens handling according to the procedure of routine electron microscopy. Eight pieces of retina which were randomly selected from total of 16 pieces of retina in each group were processed and observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Permissions from pregnant women and family members were guaranteed.Results At the gestational age of 9 months, the outer nuclear layer of fetal retina contained 5 to 6 layers of photoreceptor cells (PRC), and sphericallike membrane structures were found outside of the outer limiting membrane (OLM). Among many tightaligned inner segments of PRCs there was zonula adherens of OLM, mitochondrias at inner side of OLM, and cilium at outer side of OLM. Outer segment of PRCs were short and contained a few irregularly arranged disc membrane. Some PRC had a multishaped nucleus in which equal amount of euchromatin and heterochromatin. There were only few and thin axon branches from photoreceptor cells, and very few axons contacted with inner nuclear layer (INL) and no typical synapse was found. The INL contained 4 to 5 layers of cell bodies, in which many cellular nuclear had uneven density of euchromatin and heterochromatin; some were lobulated nucleus with clear karyotheca. In inner plexiform layer (IPL), the nerve cells had small branches, and only little connection among the synapses and few synapse structures were found. Although not many retinal ganglion cells (RGC) existed,RGC had both intact cell membrane and some rough endoplasmic reticulum (RER).The karyotheca of RGC had double-layers structures, and the nucleus was mainly consisted of euchromatin. Internal limiting membrane (ILM) had doublelayer membrane structures, and the wellarranged nerve fiber layer was located at the outer side of ILM, with some micropores on the surface. Conclusions At the gestational age of 9 months, all layers of the human retinal has been formed, but some cell structure and cell connections are not yet mature, suggesting that at this time of period, human retina is still at an important stage of developing and remodeling.
Purpose To explore the role of scanning laser tomography in the assessment of macular hole surgery. Methods Fifteen eyes of 14 patients with macular holes underwent scanning of their affected macular area using the Heidelberg retina tomograph (HRT). The significance of topographic changes postoperatively were determined in eleven eyes which received vitrectomy surgery. The scan field was set at 15°of the retina and the depth was set to 1.5 mm or 2.0 mm. All the measurements were taken for 3 times and the average value of the 3 measurements was used. Results The average hole area was (0.499±0.34) mm 2 and the maximal depth of the hole was (0.284±0.11) mm. Topographic difference analysis of the eleven eyes showed a significant reduction in the height of the retina after vitrectomy. The maximal depth of the hole was (0.063±0.04) mm postoperatively. Conclusion Scanning laser tomography provides an objective evaluation of the anatomic outcome of the macular hole surgery. (Chin J Ocul Fundus Dis, 2002, 18: 125-127)
Objective To test the hypothesis that the macular pigment may be a marker of foveal cone function and consequently the structural integrity of foveal cones.Methods Sixteen patients (32 eyes) diagnosed to have Stargardt dystrophy and three patients with full thickness macular holes by clinical criteria were studied with a scanning laser ophthalmoscopy (SLO) comparing argon laser blue and infrared images for the presence or absence of macular pigment (MP) in the fovea. An C++ computer based program was used to evaluate the density of MP. Eyes were graded into three categories: those without foveal macular pigment, those with partial pigment and those with normal amounts of macular pigment. These categories were compared with visual acuity determined by the Snellen chart. Results Thirteen eyes with a visual acuity of 20/200 or worse had no macular pigment in the fovea. Eleven eyes with visual acuity of 20/40 or better had a normal amount of macular pigment in the fovea and 1 eye had partial macular pigment. Eleven eyes with partial macular pigment had intermediary acuity value.Conclusions Foveal macular pigment is closely related to foveal cone acuity and therefore may be a marker for the presence of foveal cones. Infrared light is a sensitive indicator of early macular diseases.(Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To observe the expression of Nogo66 receptor （NgR）in ratsprime; retina during the postnatal development． Methods The expression of NgR in 48 rats were observed by immunofluorescence histochemistry and laserconfocal microscopy 0, 3, 7, 14, 21, 35, 49, 63 days after birth, with 6 rats in each group, respectively． Results The expression of NgR is positive in the retina in the whole duration of growth, and the fluorescence pigmentation was located around the ganglion cell nuclaear. Conclusion The positive expression of NgR suggests that the interaction of NgR and CNS myelin inhibitors not only inhibit neuronal plasticity but also promote it, which could regulate neuronal plasticity.
ObjectiveTo analyze the diagnostic value of multicolor scanning laser imaging (confocal scanning laser ophthalmoscopy, cSLO) combined with swept-source optical coherence tomography (SS-OCT) for lacquer cracks (LC) and myopia stretch lines (MSL) of pathological myopia.MethodsA observational study. A total of 83 eyes of 58 patients with pathological myopia were recruited from May 2017 to January 2018 in Department of Ophthalmology of The First People’s Hospital Affiliated to Shanghai Jiao Tong University. Among 58 patients, 20 were males (30 eyes) and 38 were females (53 eyes). The mean age was 50.65±12.02 (range from 24 to 70) years old; the average BCVA was 0.37±0.32; the average diopter was −11.38±4.96 D; and the average axial length was 28.91±2.15 mm. All participants underwent FFA and ICGA examination to obtain FFA, ICGA, infrared light reflection (IR) and autofluorescence (AF) images. SS-OCT was applied for scanning macular and optic disc at 9 mm × 9 mm range. cSLO was performed with macular as the center. All images were inspected carefully by three independent observers and the consistency test was detect. LC were diagnosed as hyperreflective line in FFA and hypofluorescent linear lesions in late ICGA. MSL were defined as both hypofluorescent linear lesions in FFA and late ICGA. The accuracy of each inspection item in the diagnosis of LC was detected. The optimal technique was applied with SS-OCT to further explore the detection rate of LC.ResultsThe intra-observer reproducibility was good to excellent for all measurements (Kappa=0.938, P＜0.01). The positive detection rate of LC and MSL was highest in the standard images of cSLO (77.1%), followed by SS-OCT red free (73.1%), fundus photography (72.3%), IR (72.3%) and AF (49.4%). The cSLO was optimal in the test consistency (Kappa=0.520, P＜0.01) and accuracy (the area under the receiver operating characteristic was 0.750). SS-OCT and cSLO were jointly applied to diagnosis of LC and MSL in high myopia. The positive detection rate of LC, MSL and LC+MSL were 91.7%, 91.2% and 93.3% respectively. The characteristics of LC in SS-OCT were irregularities and discontinuous of the RPE-Bruch membrane line, discontinuous inner ellipsoid zone, thinner choroid, an increased light penetrance into deeper tissues, and RPE fracture in severe cases. MSL was mainly manifested as RPE clumps, visible large choroidal vessels protruding and pushing the overlying RPE toward the vitreous.ConclusionsThe diagnosis rate of LC in pathological myopia by cSLO is 77.1%. The standard images of cSLO combined with SS-OCT can diagnose LC, MSL and LC+MSL at rates of 91.7%, 91.2% and 93.3% respectively.
Objective To observe the distribution of human photoreceptor cells at the posterior pole, detect the change of density of the cells affected by eccentricity, and analyze the relationship between the density distribution and the visual sensitivity. Methods Twenty human eye cups with the cornea removed were fixed in 4% polyformaldehyde for 1-4 weeks, and the retinal mounts were observed by differential interference contrast microscope to reveal the retinal cellular configuration and density. The inner segments of photoreceptor cells were first observed from the center to the temporal peripheral part of the retinal mounts. Results The highest density of visual cone cells was at the central fovea (134 000-267 000/mm2, mean 198 090/mm2; CV value:18.2%). The density and individual variation decreased rapidly in the peripheral area. The high density area of rod cells was at the 4 mm of the eccentricity, with the highest value of 72 610-182 350/mm2 and with the high density between 3 and 5 mm. Conclusions The inner segment of photoreceptor cells was monolayer, which may tell the cellular absolute value. The high density of retinal cone cells at the central fovea provide the basis of sensitive central visual acuity, which relates to the individual variation and development. The rod cells have the peak density at the eccentricity with 4 mm, and this area has the greatest sensitivity of dim vision.
Adaptive optics (AO) is a technique to improve the performance of optical systems by reducing the influence of optical aberrations. Combined with scanning laser ophthalmoscope (AOSLO), the aberration of human refractive system can be corrected. Thus, the resolution and quality of imaging can be greatly improved to the cellular level in vivo retina (such as photoreceptor, nerve fibers, vascular parietal cell), therefore the earlier changes of the diseases can be detected. At the same time, microstructure changes of retinal can also be observed during the follow-up of the disease. Due to inherent technical defects of AOSLO, its wide application in clinical practice is limited. With the continuous progress of AO technology and the further improvement of related software functions, the function of the system will become more stronger and will play a more and more important role in scientific research and clinic.
Diabetic retinopathy (DR) is one of the most common causes of visual impairment and blindness in diabetic patients. It is particularly important to set up simpler, safer, non-invasive and highly effective methods for diagnosis as well as monitoring DR. A variety of new fundus imaging techniques show great advantages in early diagnosis, treatment and monitoring of DR in recent years. The main characteristics of wide-field scanning laser imaging system is achieving a large range of retinal image in a single photograph and without mydriasis. It provides several options for color images, FFA and FAF, which satisfy to detect the retina, choroid and vascular structure. Multi spectral fundus imaging system is suitable for DR screening, because it is able to recognize the typical characteristics of DR, such as microaneurysms, hemorrhage and exudation, and is non-invasive and convenient. OCT angiography is a quantitative examination that provides foveal avascular zone area, macular blood flow density, which provides strong evidence for DR diagnosis. The improvement of these new techniques will help us to build up a personalized evaluation system of DR.