Objective To investigate the refractive shift after combined surgery （phacoemulsification, intraocular lens implantation and vitrectomy） by comparing the difference between the predictive and postoperative refractive power.Methods The clinical data of 44 patients (48 eyes) underwent combined surgery (combined group) and 30 patients (50 eyes) underwent cataract surgery (cataract group) were retrospective analyzed. Combined group was further divided into two sub-groups by the kind of tamponade: balanced salt solution group and gas group. Before surgery, axial length and corneal curvature were measured, and the predictive spherical equivalent (PSE) was calculated. Axial length, corneal curvature and actual spherical equivalent (ASE) were measured in six months after surgery. The differences between PSE and ASE were compared between combined group and cataract group, balanced salt solution group and gas group.Results In combined group,the mean PSE was (-0.10plusmn;0.42) D and ASE was（-1.00plusmn;1.10） D, and the difference was significant（t=6.687, P＜0.05）. Patients underwent combined surgery showed a statistically significant myopic shift compared with those underwent simple cataract surgery （t=-3.792,P＜0.05）, the refractive shift of balanced salt solution group and gas group were (-0.76plusmn;0.89） and （-1.19plusmn;0.94） D respectively, and there was no significant difference（t=-1.530,P＞0.05）.Conclusion Combined surgery of phacoemulsification and vitrectomy tends to shift the actual refractive status to myopia.
Objective To investigate the characteristic of the multifocal visual evoked potentials(MVEP)and the visual function across the visual field in anisometropic amblyopes and isometropic amblyopes. Methods MVEP from 32 anisometropic amblyopic eyes and 31 control eyes were tested. Results In anisometropic amblyopic eyes,the latencies of MVEP were significantly prolonged．The amplitudes of MVEP were significantly attenuated in the central region of the visual field,and these phenomena gradually reduced with the increase of the eccentricity． Conclusion The visual function of anisometropic amblyopic eyes is reduced more significantly in the central region than in the peripheral region of the visual field. (Chin J Ocul Fundus Dis,20000,16:27-29)
ObjectiveTo investigate the potential effect of hyperopia status on subfoveal choroidal thickness (SFCT) in silicone oil (SO)-filled eyes.MethodsThis self-comparative study was conducted in Department of Ophthalmology, Central Theater Command General Hospital. The 50 patients (100 eyes) were collected with unilateral macula-on rhegmatogenous retinal detachment from January 2019 to July 2019, who successfully underwent pars plana vitrectomy (PPV) and SO tamponade. Retinal reattachment was observed after surgery in all patients. One month after PPV, the affected eye was wore soft, contact lenses for 24 hours to correct refractive error (RE), depending on its optometry value. The SFCT of the affected eyes was measured using OCT before and after lenses wear. The fellow eyes also received OCT examination at the same time. T test was used to compare SFCT between SO-filled eyes and fellow eyes.ResultsThe mean RE of the SO-filled eyes was +6.38±1.12 D. The mean SFCT of SO-filled eyes (247.12±17.63 μm) was significantly thinner than that of the fellow eyes (276.32.55±17.63 μm) (P＜0.001). The SFCT of the SO-filled eyes was significantly thinner than fellow eyes, and the difference was statistically significant (t=－3.95, P＜0.001). After lenses wear, the mean SFCT of the SO-filled eyes increased to 276.32±24.86 μm. Compared with before lenses wear, the difference was statistically significant (t=－4.30, P＜0.001). Compared with the fellow eye, the difference was not statistically significant (t=0.05, P＞0.05).ConclusionSFCT reduction in the SO-filled eyes may be due to the hyperopia status caused by SO, which can be reserved by RE correction.
ObjectiveTo observe the changes in refractive status of eyes with idiopathic macular hole (IMH) after vitrectomy and phacoemulsification and IOL implantation (combined surgery).MethodsA retrospective clinical study. From January 2016 to June 2019, 51patients (56 eyes) of IMH who underwent combined surgery at the Tianjin Medical University Eye Hospital. were included in the study. Among them, there were 17 males and 34 females with the average age of 66.79±4.33 years. All the affected eyes underwent BCVA, retinoscopy and axial length (AL) measurement. The IOL power was calculated according to the SRK-T formula and the refractive power (predicted value) was predicted. The average BCVA of the affected eye was 0.20±0.13. The average anterior chamber depth was 2.89±0.28 mm. The average △corneal astigmatism was 0.73±0.43 D, the average AL was 22.92±0.70 mm, the average predicted refractive power was 0.10±0.66 D. All the affected eyes underwent standard transciliary flat part three-channel 25G combined surgery. Six months after the operation, the actual value (actual value) of the diopter after the operation was measured with the same equipment and method before the operation. Paired t test was used to compare the difference between the predicted value and the actual value.ResultsSix months after the operation, the actual value of the refractive power was -0.19±0.64 D. Compared with the pre-operative refractive power, the difference was not statistically significant (t=1.665, P=0.102). The difference between the actual value and the predicted value was －0.33±0.81 D.ConclusionsThe refractive status of the IMH eye undergoes myopia drift after combined surgery. The preoperative IOL power budget can be appropriately reserved for +0.3 D hyperopia.
Purpose To study the refractive state of silicone oil tamponade eyes. Methods To calculate the theoretical refractive state of eyes with silicone oil based on clinical visual optics and to perform retinoscopy on 48 silicone oil filled eyes with pars plana vitrectomy (PPV) and 45 ones with PPV plus lens ectomy with retinal reposition, and then study theoretical and experimental differences of diopter in silicone oil filled eyes. Results Postoperative diopter of the former increases (+6.26plusmn;1.20)D than preoperative diopter, while that of the latter is (+11.40plusmn;2.22)D. Conclusion Hyperopic changes are found in silicone oil tamponade eyes, and the experimental values are lower than the theoretical ones. This may be helpful in predicting the change of diopter of silicone oil tamponade eyes. (Chin J Ocul Fundus Dis, 2001,17:102-104)
ObjectiveTo explore the distribution of choroidal thickness and its influence factors in university students.MethodsA cross-sectional study. A total of 896 eyes of 896 college students were included in the study. Among them, there were 350 males (350 eyes) and 546 females (546 eyes). All the eyes were right eyes. The average age was 19.18 ± 1.36 years old. According to the spherical equivalent refraction (SER), the eyes were divided into non-myopia group, low myopia group, moderate myopia group and high myopia group, which were 59, 251, 356 and 230 eyes, respectively. The subfoveal ChT (SFCT) was measured using a swept-frequency source optical coherence tomography scanner. According to the ETDRS, the choroid within 6 mm of the fovea was divided into three concentric circles centered on the fovea of the macula, which were the central area with a diameter of 1 mm, the inner ring area of 1-3 mm and the outer ring area of 3-6 mm. The outer ring area of 3-6 mm has a total of 9 zones. The inner ring and outer ring 4 regions were superior, inferior, nasal and temporal, respectively. The distribution characteristics of ChT in different regions, genders and diopter groups were observed. Bivariate correlation analysis were used to analyze the correlation of ChT and SER, axial length (AL).ResultsThe average SFCT of 896 eyes was 221.28±67.35 μm. The mean SFCT of males and females were 227.20±69.38 and 217.50±65.80 μm, respectively. The difference of SFCT between different genders was statistically significant (t=2.075, P=0.038). Compared with the central region ChT, there was no significant difference in ChT between the outer ring and the outer region (t=0.086, P=0.932). The difference of ChT in other regions was statistically significant (t=-21.973, -5.818, 36.328, -3.065, -18.017, -10.595, 57.007; P＜0.001, ＜0.001, ＜0.001, ＜0.002, ＜0.001, ＜0.001, ＜0.001). In the horizontal direction, ChT gradually thickens from nasal to temporal (F=2 251.558, P＜0.001); in the vertical direction, ChT gradually decreases from superior to the central, but have a little increased from central to inner inferior, then decreased to outer inferior again (F=45.425, P＜0.05). Correlation analysis showed that SFCT was negatively correlated with AL (r=0.478, P＜0.01) and a negative correlation with axial length (r=−0.395, P＜0.01), and positively correlated with SER (r=0.478, P＜0.01). SFCT decreased by 12.29 μm for every in myopic refractive error of 1 D, or by 20.14 μm for every increase in AL of 1 mm.ConclusionsChT is changed by different location. The horizontal direction is gradually thickened from nasal to temporal. The vertical direction is thicker than the center. The inferior inner ring area is thicker than the outer ring area. Gender, SER and AL are the influencing factors of SFCT.
Objective To verify the changes of optics and refraction of the eyes after retinal detachment surgery with the tamponade of silicone oil in vitreous cavity. Methods The optical calculation was taken as the following by using the parameter of Gullstrand model eye:（1）The refraction of silicone filled eye in non-accommodative status;（2）The refraction of silicone filled eye in non-accommodative status;（3）The aniseikonia analysis when one eye filled with the silicone oil;（4）The IOL power re-calculation． Results （1） Compa red with the normal eye,the eye filled with silicone oil is moved toward high hyperopia of +9．19 D;（2）When corrected,the accommodation amplitude reduced 1.42 D induced by filling silicone oil. Conclusion When eye filled with silicone oil,the change of refractive power tends to be highly hyperopic,the amplitude of accommodation decreased,and the regular IOL power calculation formula is no longer available. (Chin J Ocul Fundus Dis，2000，16：139-212)
Purpose To investigate the influence of ametropia on stereopsis and its mechanism by using the disparity evoked potential testing. Methods A new set of static random dot stereograms was utilized as a stimulation to elicit the disparity evoked potentials in 21 ametropes and 40 stereo normal subjects. Rezults The P250 wave,which was related to stereoscopic stimulation in ametropes,was recorded in both the ametropes and emetropic stereo normal persons in this series,and the characteristic changes of P250 wave with increasing visual disparity in ametropes were similar to those in normal subjects.The differences of mean amplitudes and latencies of P250 waves between myopes and hyperopes were not significant. Conclusion Ametropia in full correction dose not significanly affect the function of stereopsis. (Chin J Ocul Fundus Dis,1998,14:225-227)