Objective To investigate the clinical characteristics of prepapillary and preretinal vascular loops. Methods The clinical manifestation, results of the fundus fluorescein angiography, and the prognosis of 20 cases(24 eyes) with prepapillary and preretinal vascual loops were analyzed retrospectively. Results 66.7% of prepapillary and preretinal vascular loops were involved in one eye, and 95.8% of vascular loops were located within one optic disc diameter. There were different configuration types of the vascular loops. Among 20 cases(24 eyes) of the vascular loops, 70.8%(17 eyes) were arterial, 12.5%(3 eyes) were venous, and 16.7%(4 eyes) were both arterial and venous. 62.5% of eyes with prepapillary and preretinal vascular loops were associated with other congenital and developmental anomalies of retinal vascular vessels. Conclusion Most PRVL are arterial and superior to the optic disc. The serious distortion of the vascular loops may result in disturbance of blood flow in artery and retinal hemorrhage, which cause visual loss. (Chin J Ocul Fundus Dis, 1999, 15: 9-11)
ObjectiveTo evaluate the effect of form deprivation myopia on optic nerve head and retinal morphology in guinea pigs using optical coherence tomography (OCT). MethodsTwenty guinea pigs aged from 4 to 5 weeks were chosen and randomly divided into the experimental group and control group, with 10 guinea pigs in each group. Form deprivation myopia was established for the right eyes of guinea pigs in experimental group for 4 weeks. The guinea pigs of control group were not intervened. Before and 4 weeks after form deprivation, refraction was measured by retinoscopy after cycloplegia; the axial length was measured by A-scan ultrasound; retinal nerve fiber layer (RNFL) thickness, optic nerve head and retinal morphology of guinea pigs were analyzed using OCT. ResultsBefore form deprivation, there were no statistically significant differences in spherical equivalent, axial length, RNFL thickness, disc edge area, optic disc area, average cup disc ratio, vertical cup disc ratio, cup volume, retinal thickness, or retinal volume between the experimental group and control group of guinea pig (P > 0.05). After 4 weeks of form deprivation, RNFL thickness of (64.9±17.7) μm in guinea pigs in experimental group was thinner compared to (97.9±25.1) μm in control group (t=-2.845, P=0.015). Retinal thickness of (142.7±3.4) μm in guinea pigs in experimental group was thicker compared to (138.4±3.5) μm in control group (t=2.338, P=0.038). There were no significant differences in disc edge area, optic disc area, average cup disc ratio, vertical cup disc ratio, cup volume or retinal volume between groups (P > 0.05). There were statistically significant differences in spherical equivalent, axial length, RNFL thickness, vertical cup to disc ratio cup volume, and retinal thickness between after and before form deprivation in the right eye of guinea pigs in the experimental groups (t=46.001, -50.119, 5.385, 3.447, -2.814, -8.911; P < 0.05), while there were no statistically significant differences in disc edge area, optic disc area, average cup disc ratio, or retinal volume (P > 0.05). ConclusionForm deprivation myopia has an effect on RNFL and retinal thickness.
ObjectiveTo observe the macular choroidal and retinal pigment epithelium (RPE) thickness in tilted disc syndrome (TDS). MethodsThis is a descriptive study. Thirty eyes of 22 TDS patients (TDS group) and 30 eyes of 15 normal subjects (control group) were analyzed. Among TDS group, there were 8 males (11 eyes) and 14 females (19 eyes), the average age was (9.00±2.78) years old. The best corrected visual acuity (BCVA) was 0.3-1.0, and the average spherical equivalent degree was (-3.44±2.22) DS. Among the control group, there were 8 males (16 eyes) and 7 females (14 eyes), the average age was (9.33±1.11) years old. The best corrected visual acuity (BCVA)≥1.0, and the average spherical equivalent degree was (-3.18±1.13)DS. The difference of the spherical equivalent degree between two groups was not statistically significant (t=-1.648, P=0.110). Enhanced depth imaging techniques of frequency-domain optical coherence tomography was used to measure the thickness of choroid and RPE at totally 17 sites. There sites included subfoveal, 4 sites each (500, 1000, 1500 and 2000 μm from the fovea) at the horizontal (nasal/temple) and vertical (superior/inferior) directions. ResultsThe subfoveal choroidal thickness was (235.53±51.77) μm and (273.45±60.3) μm in TDS patients and control respectively, the difference was significant(t=-2.612,P=0.011). The difference of the choroidal thickness of the other 8 horizontal sites (F=24.180) and 8 vertical sites (F=23.390) in TDS group was statistically significant (P=0.000). The TDS choroidal thickness of all horizontal sites except nasal 1000 μm site was thinner than corresponding sites of the control group (P<0.05). The TDS choroidal thickness of the subfoveal site and 4 inferior vertical sites was thinner than corresponding sites of the control group (P<0.05). The subfoveal RPE thickness was (32.56±5.00) μm and (36.58±3.60) μm in TDS patients and control respectively, the difference was significant(t=-3.567,P=0.001). The subfoveal RPE thickness was the thickest among other 16 sites in both groups, and the TDS RPE thickness of all sites was thinner than control group, the difference was statistically significant (P<0.05). ConclusionThe choroidal and RPE thickness of TDS patient was thinner than normal subjects.
Optic disc drusen (ODD) is an acellular deposit located in front of the cribriform of the optic disc. ODD has been much underdiagnosed due to few obvious clinical symptoms. These clinical symptoms are easily confused with optic disc edema caused by systemic high-risk diseases. The current mainstream view is that optic nerve fiber axon metabolism is disordered, leading to intracellular mitochondrial calcification. After axon chronic disintegration, calcified mitochondria continuously release outside the cell, resulting in a much higher concentration of extracellular calcium than inside the cell. The continuous deposit and accumulation of extracellular calcification fuse to small calcified corpuscles, which lead to ODD formation. OCT enhanced deep imaging can detect ODD sensitively, and its image feature is a weak reflection core completely or partially surrounded by a strong reflection edge. ODD is one of the common causes for optic disc crowding. During adolescence, the accumulating calcified bodies buried in the deep optic disc gradually extrude and migrate to the superficial optic disc, which turn into superficial ODD. As a consequence, part of these ODD patients rapidly progress during adolescence and generally become stable in adulthood with anterior ischemic optic neuropathy, or other vascular complications.
ObjectiveTo compare the choroidal thickness (CT) of macular and peripapillary area among malignant glaucoma(MG), chronic primary angle-closure glaucoma (CPACG) and normal control eyes. And to investigate the correlation between CT and MG. Methods Sixteen subjects (32 eyes) with MG, 31 (31 eyes) with CPACG and 32 (32 eyes) normal controls were collected. MG eyes and the fellow non-MG eyes were included in the MG group. CT of all subjects was measured in the fovea, 1mm and 3mm to the fovea and peripapillary area using enhanced-depth imaging technique of optical coherence tomography (OCT-EDI). The average of CT in fovea by horizontal and vertical macular scan was defined as the average CT in fovea. The average of temporal, superior, nasal and inferior CT in 1 mm and 3 mm to the fovea were measured respectively. The average of temporal, superior, nasal and inferior CT was defined as the average CT in peripapillary area. The differences of CT among MG, CPACG and normal controls were compared. And the differences of CT between MG eyes and the fellow non-MG eyes were compared. ResultsAfter eliminating the influence of age, the average CT of MG in the fovea, 1mm and 3mm to the fovea was significantly thicker than that of CPACG and normal controls (P < 0.05). And the average CT of CPACG in the fovea, 1mm and 3mm to the fovea was significantly thicker than that of normal controls (P < 0.05). In peripapillary area, the temporal, superior and inferior CT of MG was significantly thicker than that of CPACG and normal controls (P < 0.05). There was no significant difference of CT in peripapillary area between CPACG and normal controls (P > 0.05). In the fovea, 1mm and 3mm to the fovea and peripapillary area, there was no significant difference of CT between MG eye and the fellow non-MG eye in MG group (t=－1.029~－0.130, P > 0.05). ConclusionsThe choroid thickness of macular and peripapillary area in MG eyes is thicker than that of CPACG and the normal controls. An increased CT of macular and peripapillary area may be one of the risk factors for MG.