Objective
By using a newly developed animal model of limited macular translocation (LMT) in rabbit eyes, to explore the complications,indications and predictability of LMT.
Methods
LMT models were performed in 15 rabbit eyes, and were divided into 4.5 mm group and 3.5 mm group by the length of scleral shortening.The effect of retinal translocation (distance and direction) and its complications were analyzed. In a separated group, postoperative corneal astigmatism was studied after release of scleral shortening suture 1 month after LMT. In order to study the impact of neuroretina-retinal pigment epithelium (RPE) adhesion on LMT, retinas and choroids in 4 pigmented rabbit eyes were pretreated with photocoagulation.
Results
Success rate of LMT was 86.7%. In these cases, retinal translocations were achieved［(distance of 610 to 2690 μm, [AKx-]±s=(1395±636)μm; translocation angle α of 10-38°, [AKx-]±s=(22.7±8.3) °］. The difference in scleral shortening between 4.5 mm and 3.5 mm groups did not significantly influence the final translocation. Major complications of LMT included intraocular bleeding, retinal break, and corneal astigmatism. Release of scleral shortening suture reduced corneal astigmatism and made it more regular, meanwhile, retinal translocation did not regress. The neuroretina-RPE adhesion induced by retinal photocoagulation made neuroretinal hydrodissection difficult, and led to retinal break readily.
Conclusion
Sufficient LMT models in rabbit eye were obtained with few postoperative complications. Direction of retinal translocation is an important factor influencing the effect of LMT, except for distance. Release of scleral shortening suture can effectively reduce corneal astigmatism without causing regression of retinal translocation. For the patients with a history of macular or para-macular photocoagulation, LMT should be performed carefully.
(Chin J Ocul Fundus Dis, 2002, 18: 203-207)
ObjectiveTo observe and analyze the macular microvascular system changes in unilateral pediatric uveitis (PU) and healthy contralateral eyes. MethodsA cross-sectional case-control study. From January 2019 to July 2021, 21 eyes of 21 patients with PU diagnosed in one eye (PU group), 21 unaffected contralateral eyes (contralateral eye group), and 21 age-matched volunteers with 21 eyes (NC group) during the same period were examined in Peking Union Medical College Hospital. Optical coherence tomography angiography was used to scan the 6 mm × 6 mm fundus macular area in the three groups of selected eyes to measure the vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the retina, the area of the avascular zone (FAZ) in the fovea of the macula, the choroidal thickness under the fovea (SFCT), and the retinal thickness in the fovea of the macula (CRT). The device comes with a software choriocapillary flow measurement tool, which can obtain the macula's choriocapillary density (CCD) with the fovea as the center and the diameter of the annular area of 1.0 mm, 1.5 mm, and 3.0 mm, respectively. They were recorded as CCD-1.0, CCD-1.5, and CCD-3.0. The measurement data of multiple groups were compared by analysis of variance; if the variance of the three groups of data was not uniform, the Kruskal-Wallis test was used. Multiple linear regression analysis was used to evaluate the potentially related factors of CCD. ResultsCompared with the contralateral eye group and the NC group, the vessel density of SCP (H=－13.857, －25.500; P=0.043, P<0.001), DCP (H=－15.333, －31.595; P=0.007, P<0.001) and CCD-1.0 (H=－14.000, －16.214; P=0.040, 0.012) of the clinically quiescent PU group were significantly decreased. CRT and FAZ were not statistically different between PU and NC groups (F=0.955; P=1.000, 0.661). Compared with the NC group, the mean vessel density of SCP and DCP in the contralateral eye group decreased, and the difference in DCP vessel density was statistically significant (H=－16.262, P=0.004). There was no statistically significant difference between the CCD of two groups (P=1.000). The SFCT of the PU group was significantly thicker than that of the NC group (F=5.552, P=0.004), however, difference was not statistically significant from the fellow eye group (F=5.552, P=0.270). The results of multiple linear regression analysis revealed that the CCD-1.0, CCD-1.5, and CCD-3.0 showed a linear correlation with the area of FAZ (β=－0.494, －0.527, －0.566; P=0.015, 0.009, 0.010) and CRT (β=－0.322, －0.466, －0.342; P=0.026, 0.002, 0.028). CCD-1.0 and CCD-1.5 showed a linear correlation with the vessel density of DCP (β=0.277, 0.275; P=0.047, 0.045). ConclusionBoth retinal and choroidal microvasculature are abnormal in resting eyes with PU, and macular circulation disorders may be present in the unaffected fellow eye.
Purpose
To investigate the relationship between the changes of the thickness of retina in macula and the abnormalities in multifocal electroretinog rams (mERG) in diabetic retinopathy.
Methods
mERG and optical coherence tomography (OCT) examination were performed in 38 patients (60 eyes) with DR (phase Ⅲ～Ⅳ). The data were processed with software SPSS and line relation analysis was done.
Results
The response densities of N1, P1 and N2 in central 5deg; area was significantly negative related to the thickness of neuroretina in macular fovea (correlation efficient -0.252～-0.266，Plt;0.05). The response density of N2 in central 10deg; area was also significantly negative related to the thickness of neuroretina in macular fovea (correlation efficient -0. 332，P=0.01).There was no significant relationship between the latencies of N1 in central 5deg;, 10deg; area and the thickness of macula, whereares the latenc ies of P1 and N2 in central 5deg; were negatively related to the thickness of retinal pigment epithelium in the macular fovea (correlation efficient-0.271～ - 0.322，Plt;0.05).
Conclusion
The changes of the thickness of neuroretina in macula may affect the local retinal function in macula, which may be revealed by the reduction of response densities in mERG in patients with diabetic retinopathy.
(Chin J Ocul Fundus Dis, 2001,17:257-259)
Idiopathic macular membrane (iERM) is a fibrocellular membrane that forms on the inner surface of the retina. In its early stages, symptoms of iERM are usually not apparent. However, advanced iERM can cause different degrees of visual impairment and effect the quality of life of patients. Current studies suggest that iERM may be associated with posterior vitreous detachment (PVD), age, sex, race and/or ethnicity, poor lifestyle, refractive error, diabetes, hypercholesterolemia, and cardiovascular disease. The most well-established risk factors for iERM are age and PVD. The pathogenesis of iERM is extremely complex. Various cell types, such as Müller cells, Hyalocytes and myofibroblasts, nerve growth factor, interleukin-6, transforming growth factor β, vascular endothelial growth factor and other cytokines and growth factors, as well as a variety of genes and proteins are directly or indirectly involved in the formation of iERM, however, their exact role remains a mystery. In the future, further studies at the molecular level and gene level are needed to provide greater help for the clinical diagnosis and treatment of iERM.
With the popularity and development of artificial intelligence (AI), disease screening systems based on AI algorithms are gradually emerging in the medical field. Such systems can be used for primary screening of diseases to relieve the pressure on primary health care. In recent years, AI algorithms have demonstrated good performance in the analysis and identification of lesion signs in the macular region of fundus color photography, and a screening system for fundus lesion signs applicable to primary screening is bound to emerge in the future. Therefore, to standardize the design and clinical application of the macular region lesion sign screening systems based on AI algorithms, the Ocular Fundus Diseases Group of Chinese Ophthalmological Society, in collaboration with relevant experts, has developed this guideline after investigating issues, discussing production evidence, and holding guideline workshops. This guideline aims to establish uniform standards for the definition of the macular region and lesion signs, AI adoption scenarios, algorithm model construction, datasets establishment and labeling, architecture and functions design, and image data acquisition for the screening system to guide the implementation of the screening work.
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)
Objective
To analyze the correlation of foveal avascular zone (FAZ) size with visual acuity and metamorphopsia in idiopathic macular epiretinal membrane (IMEM) eyes.
Methods
This is a cross-sectional study, including 43 patients (43 eyes) with IMEM (IMEM group) and 35 health subjects (35 eyes) as control group. The best corrected visual acuity (BCVA) was measured using the international standard visual acuity chart, and the results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. The severity of metamorphopsia was measured using M-charts. The FAZ areas were estimated with optical coherence tomography angiography (OCTA) in both the superficial and deep capillary plexus layers. The central macular thickness (CMT) was assessed with spectral-domain optical coherence tomography. There was no difference of logMAR BCVA and CMT between two groups (Z=?7.379, ?7.560; P＜0.001). The differences of FAZ areas between the two groups were analyzed. The correlative analysis was performed to investigate the relationship between FAZ areas and visual acuity as well as metamorphopsia.
Results
The FAZ area in superficial and deep capillary plexus in IMEM group were smaller than those in control group (t=?30.316, ?27.606; P＜0.001). In IMEM group, the mean M-score was 0.41±0.32; the horizontal and vertical M-score were 0.49±0.40 and 0.32±0.29, respectively. The horizontal M-score was higher than vertical M-score with the significant difference (Z=?2.000, P=0.046). In IMEM group, the FAZ area in superficial capillary plexus correlated inversely with metamorphopsia (r=?0.709, P＜0.001); the FAZ area in deep capillary plexus correlated inversely with metamorphopsia and BCVA (r=?0.533, ?0.838; P＜0.001).
Conclusions
The FAZ areas are significantly decreased in IMEM eyes compared with normal eyes. Both superficial and deep FAZ areas are correlated with metamorphopsia, and deep FAZ area is also correlated with BCVA.
Idiopathic parafoveal telangiectasis (IPT) is a retinal vascular disease which is characterized by foveal and parafoveal telangiectasia. The main clinical manifestations are retinal telangiectasis, reduced retinal transparency, retinal venular dilatation, yellow exudation, retinal pigment epithelial lesions, retinal hemorrhage, macular atrophy, macular hole or lamellar hole, subretinal neovascularization and retinal detachment. According to the clinical characteristics and features of fluorescein angiography, IPT can be divided into 3 types and 6 subtypes. Laser photocoagulation, photodynamic therapy, and intravitreal injection of glucocorticoid or anti-vascular endothelial growth factor drugs, can reduce the macular edema and neovascularization. However, due to the unclear etiology of IPT, the existing treatment measures are not specific for its etiology. We need to work hard to understand further the clinical features and pathogenesis of IPT and search the targeted treatments based on its pathogenesis mechanism.
Objective To observe the distribution of macular thickness and its relationship with axial length, gender, refraction status and race in six-year-old children. Methods 1543 six-year-old children from 34 schools in Sydney were randomly selected. The thickness of center macula（CM）, inner macula（IM）and outer macula（OM）were measured by optical coherence tomography（OCT）, the differences of macular thickness between different genders and races were comparatively analyzed. The axial length and refraction status of all children were measured by IOL Master and autorefractor RK-F1 respectively. Results The CM, IM and OM thickness of all those six-year-old children were normally distributed，on average they were 193.6, 264.3 and 236.9 mu;m respectively,the differences were statistically significant（t=0.40,0.08,0.20;P＜0.05）. The CM,IM and OM average thickness was 194.2,264.9,229.0 mu;m for boys and 189.3,262.5,231.5 mu;m for girls respectively. CM and IM thickness of boys were thicker than those in girls（t=0.15,0.11;P＜0.05）. The CM,IM and OM average thickness was 196.0,265.2,237.5 mu;m for White kids,186.0,262.3,236.5 mu;m for East Asia kids and 19.4,263.7,233.8 mu;m for Central East kids respectively. The CM and IM thickness of White and Central East children were significantly thicker than East Asia children (t=0.12,0.15;Plt;0.05）. There was no difference between these three races in OM thickness（t=0.16,P=0.6）. The IM and OM were thinner with longer axial length (Plt;0.05). The CM,IM and OM thickness was thicker with higher hyperopic degrees (Plt;0.05). Conclusions Macular thickness was normally distributed in six-year-old children and was significantly affected by gender, race, axial length and refraction status.
ObjectiveTo observe the effect of epinephrine in intraocular irrigation solution on retinal vascular caliber and macular thickness.
MethodsA prospective control study. 32 eyes of 32 patients with macular hole who underwent vitrectomy were enrolled in this study. The patients including 14 males (14 eyes) and 27 females (18 eyes), with the average age of (64.0±4.5)years. Uncorrected visual acuity, corrected visual acuity, slit lamp biomicroscopy, indirect ophthalmoscopy, fundus color photography and optical coherence tomography were performed in all patients. Retinal vascular caliber located in 0.5-1.0 disc diameter from optic disk was measured from digital fundus photographs and summarized as central retinal artery (CRAE) and vein (CRVE) equivalents in all eyes at baseline and at the 1 month, 3 months follow-up visit. The macular thickness is the distance from retinal interface of inner plexiform layer to retinal pigment epithelium layer. The macula was divided into inner ring ( < 3 mm) and outer ring (3-6 mm) according to the distance from the fovea. The patients were divided into experiment group (include epinephrine in intraocular irrigation solution, 1:1000) and control group (without epinephrine in intraocular irrigation solution), 16 eyes in each group. The difference of CRAE and CRVE between two groups was not significant (P > 0.05). The difference of macular thickness between inner ring and outer ring was not significant (P > 0.05). The average follow-up was 3.5 months. CRAE, CRVE and macular thickness in inner ring and outer ring before and 1 month, 3 months after surgery were comparatively analyzed.
ResultsThe differences of CRAE and CRVE before and 1, 3 months after surgery both in experiment group (tCRAE=0.322, 0.148; tCRVE=0.317, 0.005) and control group (tCRAE=0.226, 0.137; tCRVE=0.284, 0.151) were not significant (P > 0.05). The differences of CRAE (t=0.624, 0.424) and CRVE (t=0.015, 0.041) between experiment group and control group also were not significant (P > 0.05). The differences of macular thickness in inner ring and outer ring before and 1, 3 months after surgery both in experiment group (tinner=0.322, 0.148;touter=0.317, 0.005) and control group (tinner=0.226, 0.137;touter=0.284, 0.151) were not significant (P > 0.05). The differences of macular thickness in inner ring (t=1.568, 0.373) and outer ring (t=-1.697, 0.536) between experiment group and control group also were not significant (P > 0.05).
ConclusionEpinephrine (1:1000) in intraocular irrigation solution has no effect on retinal vascular caliber and macular thickness in patients with macular hole.
