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 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.
ObjectivesTo evaluate the reproducibility of Heidelberg retina tomograph (HRT) macular edema module(MEM) measuring the macular retinal thickness.MethodsSixty-two healthy volunteers (9-68 years old) were examined by HRT-II procedure. The retinal signal width (SW) at macula and fovea and macular edema index (E) were recorded for t-test, Pearson linear-correlation analysis. Intra-subject variation repeatedly measured was analyzed with coefficient of variation, 95% tolerance limits of change (TC), and intraclass coefficient of correlation (ICC). ResultsIn healthy individuals, retinal SW was (0.734±0.236) mm at macula，and (0.781±0.243) mm at fovea; macular E was (1.169±0.619). The coefficient of variation repeatedly measured: retinal SW was (8.7±68)%，retinal SW at the fovea was (8.5±6.7)%, and the average was (15.6±13.9)%; 95%TC of intra-subject sequential repeated measurement was 0.131 (8.9%) of retinal SW, 0.137 (10.5%)of fovea SW，and 0.198 (7.4%) of average E. ICC of one individual repeatedly measured by one operator was 0.950 of macular SW, 0.949 of fovea SW, and 0.898 of average edema index.ConclusionsHRT-II MEM is noninvasive, fast and highly reproducible, which provides a new technique to monitor the objective quantification of macular diseases related to retinal thickness. ( Chin J Ocul Fundus Dis, 2005,21:103-105)
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.
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)
Purpose To verify the effectiveness of combined B-scan ultrasonoscopy and ultrasound biomicroscopy(UBM)imagings in diagnosis of retinal detachments. Methods To contrast the manifestations in vitrectomy operations with the findings of preoperative combined B-scan ultrasonic and UBM examinations in 25 eyes of 25 cases in which 18 eyes with rhegmatogenous retinal detachment and 7 eyes with traumatic retinal detachment were included. Results B-scan ultrasonic imagings were divided into four types: type C,type V,type upsilon; and type gamma;,which included 6 eyes,2 eyes,4 eyes and 11 eyes respectively,and from type C to type gamma;,the retinal detachments manifested themselves from simple posterior segment proliferative vitreoretinopathy(PVR)to both anterior and posterior PVR.The imagings of UBM were divided into 3 types:shallow retinal detachment,retinal circumferential contraction and retinal anterior displacement,which reflected the degree of anterior PVR from lightness to severeness. Conclusions The technique of combined B-scan ultrasonoscopy and UBM can be used to access the severity of the retinal detachments,hence would be beneficial in diagnosing anterior and posterior PVR,designing the surgical precedures and assessing the prognosis. (Chin J Ocul Fundus Dis,1998,14:16-20)
ObjectiveTo compare the imaging characteristics and detection of various types of lesions in diabetic retinopathy (DR) with colorful laser scanning fundus imaging (MSLI) and traditional color fundus photography (CFP).MethodsProspective case series observational study. A total of 38 eyes of 38 patients with DR diagnosed by clinical examination were included in the study. Among them, 21 were male and 17 were female; the mean age was 62.6±11.2 years; the average duration of diabetes was 14.3±7.5 years. All the patients were performed CFP, MSLI, frequency domain optical coherence tomography (SD-OCT), fluorescein angiography (FFA) examination. Using the Helielberg Spectralis HRA+OCT MSLI inspection, one scan simultaneously obtained 488 nm blue reflection (BR), 515 nm green light reflection (GR), 820 nm infrared light reflection (IR), and multicolor image (MC). The detection of traditional CFP and MC on microaneurysm (MA), hard exudation (HEX), cotton plaque (CWS), intraretinal hemorrhage (IRH), intraretinal microvascular abnormality (IRMA), venous bead (VB), venous ring (VL), macular edema (DME), macular anterior membrane (MEM) and laser photocoagulation (LB) were comparatively observed. The results of FFA examination were used as the diagnostic criteria for lesions. SD-OCT was used to determine the location and depth of lesions and the diagnostic reference for DME and MEM.ResultsThe numbers of eyes with MA (χ2=10.460), DME (χ2=4.006), MEM (χ2=4.444) was significantly higher in MC than that of traditional CFP. But the number of eyes with IRH (χ2=0.103), CWS (χ2=1.515), HEX (χ2=0.227), IRMA (χ2=0.051), VB (χ2=0.001), VL (χ2=0.149), VH (χ2=0.693) and LB (χ2=0.720) were not statistically significant between two methods (P>0.05). The imaging quality of MSLI mode is obviously better than that of traditional CFP. Among them, GR imaging shows the best structural changes of superficial retina in MA, CWS, HEX, MEM, etc. IR imaging shows clear depth in deep retina such as LB. DME was green on MC and the weak low-reflection dark area was visible on the IR image, which were consistent with the DME range indicated by the SD-OCT examination.ConclusionsCompared with the traditional CFP, the MSLI can clearly show the DR lesion. The number of checkouts is high on MA, DME and MEM by MC image.
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.
Objective To study on the ultrastructural characteristic of segments of photoreceptors from neonatal retinas for supporting donor retina choice of retinal transplantation． Methods Photoreceptors from neonatal calf and adult calf were analysed by scanning electron microscopy and transmission electron microscopy． Results Segments of photoreceptors from neonatal calf appeared the mushroom pattern, in which, distal end of outer segment which was ball-shaped formed the head with mushrooms appearance, and the inner segments along with some of outer segments formed the body with mushrooms appearance． Within the outer segment, plasma membranes of adjacent evaginations form a disk subsequently． The a rray of most disks were vertical to the entire length of segments, but some were parallel and slope to．Owing to the incomplete formation, some rim of disk near distal end of outer segment revealed step-shaped appearance． The distal end of outer segment displays some processes consisted of membranous discs, much vesicular material and mitochondria, much rough endoplasmic reticulum (RER) and numerous polyso mes．Segments of photoreceptor connected with outer nuclear layer via the external limiting membrane． Conclusion The typical morphol ogical structures of outer segments suggest the immature and b gowth ability of photoreceptors of the retina of neonatal calf, and therefore the competence for donor material of retinal transplantation． (Chin J Ocul Fundus Dis, 2001,227-229)
Objective To observe the dimensions of the capillary blood vessel arch in central fovea of macula and the foveal avascular area (FAZ), and their relationships with age.Methods Retina in macula of 32 cadavers eyes were isolated . Retinal vessels were immunostained by collagen type IV and examined by confocal laser scanning microscopy. The area and diameter of the FAZ were measured, and the relationship between FAZ and age was analysed. Results The parafoveolar capillary network was observed clearly by confocal laser scanning microscopy. The average area of the FAZ was (0.24±0.13) mm2, and the average diameter was (0.54±0.15) mm. The area and diameter of the FAZ did not show any correlation with age.Conclusions The parafoveolar capillary network could be observed by confocal laser scanning microscopy. The size of the FAZ does not change with age. The dimensions of the parafoveolar capillary network may not be influenced by age. (Chin J Ocul Fundus Dis，2003，19：73-75)