Foveal Research Articles

Effects of local foveal photoreceptor defect on visual acuity

[Objective] To observe the effects of local macular foveal photoreceptor defects on visual acuity.[Methods] Thirty-one patients (31 eyes) with photoreceptor defect in macular fovea (case group)diagnosed by spectral domain optical coherence tomography (SD-OCT) and 30 patients (30 eyes) age-and diopter-matched normal subjects (control group) were enrolled in this study.There were 22 eyes with full photoreceptor defects and 9 eyes with outer segment defects in case group.All subjects were examined for best corrected visual acuity (BCVA),slit-lamp microscopy,direct ophthalmoscope and SD-OCT.Independent sample t-test was used to compare central foveal thickness (CFT) between case group and control group.Difference of logMAR BCVA,CFT,maximum width and height of photoreceptor defects,defected area and residual retinal thickness in macular between patients with full photoreceptor defects and outer segment defects were also compared.[Results] The CFT of case group and control group were (225.32± 19.70),(240.02 ± 10.70) μm,the difference was not statistically significant (t =-1.96,P＞0.05).In full photoreceptor defects and outer segment defects patients,the mean logMAR BCVA were 0.22±0.31,0.32±0.43; the mean CFT were (224.09± 20.57),(228.33± 18.17) μm; the maximum width of photoreceptor defects were (131.32± 108.18),(143.22±66.93) μm; the mean defected area were (0.022±0.054),(0.019±0.019) mm2 ; the mean maximum height of photoreceptor defects were (77.41±6.62),(44.89 ± 4.26) μm; the mean residual retinal thickness were (87.00 ± 20.31 ),( 128.33 ±23.54) μm respectively.There was no statistical significance between full photoreceptor defects and outer segment defects patients in the mean logMAR BCVA,CFT,maximum width of photoreceptor defects and defected area (t=-0.76,-0.538,-0.305,0.166; P＞0.05),but there were significant difference in mean maximum width of photoreceptor defects and residual retinal thickness (t =12.72,-4.91; P＜0.05).[Conclusion]s The local photoreceptor defects in macular fovea can lead to decrease of visual acuity.The wider the photoreceptor defects,the worse the visual acuity. Key words: Photoreceptors; /injuries; Vision, low; Fovea centralis; Tomography, optical coherence; Diagnostic imaging

Spectral domain optical coherence tomography features of acute Vogt-Koyanagi-Harada before and after treatment

[Objective] To observe the spectral domain optical coherence tomography (SD-OCT)features of acute Vogt Koyanagi-Harada (VKH) eyes before and after treatment.[Methods] Twenty-eight patients (56 eyes) with acute VKH diagnosed by slit-lamp microscopy,B mode ultrasound and fundus fluorescein angiography (FFA) were enrolled in this study.All the patients were treated with steroid after diagnosis.SD-OCT was performed in all the patients before and after treatment.The follow-up was ranged from 12 to 32 weeks with a mean of (21.30±8.53) weeks.The foveal retinal detachment height,inner and outer segments (IS/OS) of photoreceptors,and the changes in retinal structure within the vascular arcades before and after treatment were comparatively analyzed.[Results] OCT examination results showed that before treatment,all eyes had retinal neural epithelial detachment.The average neural epithelial detachment height in the fovea was (635.44±340.04) μm.Forty-three eyes (76.8％) had different types of subretinal exudates; 41 eyes (73.2％) had strong granular reflection in the subretinal space.Twenty-two eyes (39.3％) had paraforveal outer nuclear layer (ONL) thickening with finger-like protrusions attached with membrane-like structure.Thirty-three eyes (58.9％) had wavy lines of the retinal pigment epithelium(RPE).After the treatment,these exudates dissolved within one week and RPE line became straight.Theretina reattached after (2.33±0.82) weeks.In most patients external limiting membrane and IS/OS became intact after (5.01 ± 6.71) weeks and (11.40 ± 7.89) weeks respectively.However,at the end of follow-up,46 eyes (82.1％) still had focal areas of IS/OS defect and 11 eyes (19.6％) had focal ONL thinning.[Conclusion]s Before the treatment,the OCT features of acute VKH are serous retinal detachment at fovea,different types of subretinal exudates and wavy RPE.After the treatment,the OCT features of acute VKH are exudates dissolving,straight RPE line and early recovery of external limiting membrane. Key words: Uveomeningoencephalitic syndrome; Tomography, optical coherence; Diagnostic imaging

Transpupillary thermotherapy for circumscribed choroidal hemangiomas

To study the effects of transpupillary thermotherapy (TTT) on circumscribed choroidal hemangiomas (CCH). It was a retrospective cases series study. One hundred and fourteen cases (114 eyes) in out-patient department were enrolled in the study with 80 male cases and 34 female cases. The age ranged from 16 to 71 yrs with an average at 44 years. Single eye was affected in all cases. Indirect ophthalmoscope, fundus fluorescein angiography (FFA), ultrasound (B) were used for the examination. Treatment was delivered via slit lamp by using an 810 nm diode laser (Irises) with spots or composed spots (larger tumor) covering the whole tumor. If the tumor was located or partly located in the fovea, laser spot should be avoided in the fovea and papillo-macular bundle. The laser power should be lesser (light gray color) in parafovea area. Routine laser spot (gray-white color) was used in perifovea area. A width of 200 µm out of disk border should not be placed by laser spot in paradisk tumor cases. The visual acuity (VA) ≥ 0.5 of pre-and post-treatment was 17 eyes (14.9%) and 27 eyes (23.7%), respectively. Pre-treatment, the retinal detachment extended in the inferior part in 27 cases (23.7%) except on the tumor surface. The tumor was located at macular area in 67 cases (58.8%), around the disc in 35 cases (30.7%), at the temporal arcuate in 12 cases (10.5%). In our cases, VA maintenance with fluid absorption was noted in 76 cases (66.7%) after the treatment. VA improvement with fluid absorption in 28 case (24.6%). Both VA maintenance and improvement (rate of efficiency) with fluid absorption were 91.2%. Fluid non-absorption or VA decline was regarded as unsuccessful in 10 cases (8.8%). The average thickness of 32 cases tumor pre- and post-treatment was (3.90 ± 1.15) mm and (2.41 ± 1.30) mm. Twenty seven cases were followed up for ≥ 1 year (mean 22.8 months) with rate of efficiency at 81.5%. The complications (9 eyes, 7.9%) contained minor macular hemorrhage in 2 eyes, macular pucker in 3 eyes, macular edema and cystoid macular edema in 2 eyes, retinal branch occlusion in 1 eye, and arcuate scotoma in 1 eye. The treatment of TTT on CCH, whether the tumor located around-disc or in foveal area with exudative fluid could get successful in the majority of cases. TTT is one of the treatments worth doing owing to fewer complications, less expenses and easy-doing with definite and persistent effect.

Photodynamic therapy for treatment of chronic or recurrent central serous chorioretinopathy

To evaluate the effect of Spectral HRA + OCT-guided photodynamic therapy with half-dose verteporfin in the treatment of chronic or recurrent central serous chorioretinopathy. It was a retrospective case series. Twenty eyes of 18 patients with chronic or recurrent central serous chorioretinopathy were included. PDT was applied with half-dose verteporfin (3 mg/m(2)) on the site of active area shown on Spectral HRA + OCT (defined as focal or diffuse retinal pigment epithelial leakage, choroidal hyperpermeability, or pigment epithelial detachment located within the neurosensory detachment), and patients were observed to determine the anatomic and functional outcomes. Statistical analysis was performed using SAS (version 9.2). A P value of 0.05 was considered statistically significant. Comparisons of pre- and post-treatment best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were performed using a paired t test. The relationship between BCVA and CFT post-treatment was analyzed by linear correlation analysis. Comparisons of the BCVA of eyes with and without the integrity of photoreceptor IS-OS and/or external limiting membrane at the last follow-up visit were performed using two sample t test. The median CSC duration was 4.5 months (ranged 1 month to 2 years). The median follow-up period after PDT was 8 months (ranged 6 to 20 months). The mean BCVA before PDT was 0.35 ± 0.16 (ranged 0.05 to 0.6), at 3 months after PDT was 0.72 ± 0.32 (ranged 0.1 to 1.5) and at the last follow-up visit was 0.78 ± 0.29 (ranged 0.3 to 1.5) (t = 6.444, 6.883, P < 0.05). Fifteen eyes (75.0%) had improved vision, and 5 eyes (25.0%) had stable vision. The mean CFT was reduced from (369.0 ± 120.9) µm before PDT to (193.3 ± 30.6) µm 1 month after PDT, (194.9 ± 28.3) µm 3 month after PDT and (190.6 ± 33.7) µm at the last follow-up visit (t = -6.836, -6.826, -7.316; P < 0.05). At the last follow-up visit BCVA was not correlated with CFT (r = 0.166, P > 0.05), but BCVA of the eyes with the integrity of photoreceptor IS-OS and/or external limiting membrane was better than that of without (t = -3.53, P < 0.05). Subretinal fluid disappeared in all eyes 1 month after PDT and there was no recurrence during the follow-up. Spectral HRA + OCT-guided photodynamic therapy with half-dose of verteporfin seems effective and safe for the treatment of chronic or recurrent central serous chorioretinopathy.

A comparative study of macular thickness and function before and after idiopathic macular epiretinal membrane surgery

To compare the thickness and functional changes of the macula after idiopathic macular epiretinal membrane (IEM) surgery. A retrospective study. Thirty-seven patients (37 eyes) received surgical treatment of IEM. All patients received standard three-port vitrectomy as well as epiretinal membrane peeling. The best corrected visual acuity (BCVA, LogMAR) were recorded and optical coherence tomography (OCT) were used to evaluate central foveal thickness (CFT). Microperimetry (MP)-1 was used for the mean sensitivity (MS) of central 10° macula area. SPSS13.0 was used for statistical analysis. Rank and testing methods were used to compare the preoperative and postoperative BCVA, paired t testing method was used to compare the preoperative and postoperative CFT and MS values. Correlation analysis was used to study the BCVA, CFT, and MS. Pearson correlation analysis was applied to analyze measurement data and Spearman rank correlation analysis was used to analyze rating data. Postoperatively, the BCVA (0.1 - 0.7, median 0.4) was significantly better (Z = -4.97, P < 0.05) than the preoperative one (0.3 - 1.3, median 0.7). The CFT (246.2 ± 60.4) µm was significantly thinner (t = 15.86, P < 0.05) than the preoperative one (482.2 ± 101.8)µm. The MS of central 10° macula area (18.6 ± 1.8) dB was significantly higher (t = -9.20, P < 0.05) than the preoperative one (14.1 ± 3.4) dB. Thicker preoperative CFT was associated with a lower preoperative BCVA (r(s) = 0.91, P < 0.05), a lower MS of central 10° macula area (r = -0.82, P < 0.05) and a lower postoperative BCVA level (r(s) = 0.63, P < 0.05). But with a significant postoperative CFT reduce (r = 0.81, P < 0.05) and a significant postoperative BCVA increase (r(s) = 0.71, P < 0.05). Vitrectomy combined with macular epiretinal membrane removal can effectively promote the recovery of macular thickness and function in patients with IEM. Examination and analysis of preoperative CFT, BCVA and MS of macula area may help to predict the recovery of CFT and function objectively in patients of IEM.

Therapeutic effects of intravitreal injection of bevacizumab on exudative age-related macular degeneration and non-responders analysis

Objective To observe the effect of intravitreal bevacizumab (IVB) for exudative agerelated macular degeneration (eAMD),and analyze the reasons for treatment failure.Methods Eighteen eyes of 17 patients with eAMD who have been diagnosed by fundus fluorescein angiography (FFA),indocyanine green angiography (ICGA) and optical coherence tomography (OCT) were enrolled in this openlabel,single treatment group and prospective study.The patients received the first IVB treatment after diagnosis,and received the 2nd,3rd,4th,5th and 6th IVB treatment at 6,12,24,36,48 weeks after the first injection.The examinations of best corrected visual acuity (BCVA),intraocular pressure,slit lamp microscope,fundus photography,FFA,ICGA and OCT were performed before and after treatment.Nonresponders were defined as patients who had BCVA loss more than 5 letters at week 52 compared with BCVA before treatment.The therapeutic effects of IVB for eAMD were observed.The central macular thickness (CMT),maximum retinal thickness (MRT) and morphological changes of FFA,ICGA and OCT before and after treatment were comparative analyzed.Results Of the 18 eyes,12 eyes (66.67％) were effective to IVB,6 eyes (33.33％) were non-responders.The average CMT and MRT of non-responders were 506.83,635.33 μm before treatment,which decreased to 446.17,563.67 μtm at 52 weeks.They were reduced by 60.67 and 71.67 μtm respectively,but there was no statistically significant differences (t =-1.572,-0.943; P=0.116,0.345).FFA and ICGA examination found that the CNV lesions of 3 nonresponder eyes located in the foveal region,and became scars after the 6th treatment.The other 3 nonresponder eyes developed CNV repeatedly during the treatments,and after the 6th injections of bevacizumab the lesions were under control with less fluorescein leakage and macular retinal edema.Conclusion IVB treatment is effectivefor some eAMD patients,but is ineffective for patients with extensive expanded CNV and foveal CNV. Key words: Macular degeneration/therapy; Choroidal neovascularization/therapy; Antibodies; monoclonal/therapeutic use; Medical futility

Clinical observation of photodynamic therapy for choroidal neovascularization secondary to pathological myopia

Objective To observe the efficacy of photodynamic therapy (PDT) for choroidal neovascularization (CNV) secondary to pathological myopia (PM).Methods Sixty-six patients (73 eyes)with CNV secondary to PM who had undergone PDT were enrolled in this study.PDT was performed according to the standard treatment.The patients received the examinations of best corrected visual acuity (BCVA),ophthalmoscopy,fundus fluorescein angiography (FFA) and/or indocyanine green angiography (ICGA),and optical coherence tomography (OCT) before and after the treatment.Vision results were converted into logMAR records and compared before and after the treatment.The complete records of FFA were found in 52 eyes.FFA findings,treatment effects,were judged as well,moderate or poor according to the CNV leakage or bleeding,and CNV expanding or shrinking.The complete records of OCT were found in 11 eyes.CNV regional edema and foveal thickness were analyzed based on OCT examination.Results The mean logMAR BCVA after PDT treatment was 0.74 ± 0.51 with no significant difference compared with before treatment (t=1.11,P=0.27).There were 18 eyes (24.7％) with improved vision,43 eyes (58.9 ％ ) with stable vision,and 12 eyes (16.4 ％ ) with decreased vision.In 52 eyes with FFA findings,39 eyes (75.0％) with well effect,9 eyes (17.1％) with moderate effect,and 4 eyes (7.7％) with poor effect.OCT showed that after treatment the CNV regional edema subsided in most of eyes,and there were 7 (63.64％) with decreased foveal thickness,2 (18.18％) with stable thickness,and 2 (18.18％) with increased thickness.Conclusions PDT is an effective treatment for CNV secondary to PM.It may improve or stabilize the visual acuity. Key words: Choroidal neovascularization/therapy; Photochemotherapy; Myopia; degenerative/complications

Correlation between RS1 gene mutation genotypes and phenotypes in X-linked retinoschisis

Objective To investigate the correlation between mutation genotypes and phenotypes of X-linked retinoschisis (XLRS) patients. Methods33 male XLRS patients, 26 female carriers and 100normal subjects were enrolled in this study. All 33 XLRS patients were bilateral, which included 18 patients from 8 families and 15 sporadic patients. Among 66 XLRS eyes, there are microcystis-like foveal splitting in 49 eyes (74.2％), lamellar macular splitting in 43 eyes (65.2％), peripheral splitting in 32 eyes (48. 5％),retinal detachment in 17 eyes (25.8％), and vitreous hemorrhage in 8 eyes (13. 6％). Electroretinogram was performed on 42 eyes which showed decreased amplitude of b-wave. The 6 exons of RS1 gene were amplified by polymerase chain reaction and then directly sequenced. The correlation analysis was performed between mutation genotypes and phenotypes. Results There were 19 RS1 gene mutations including 6 novel mutations (p. Gly70Cys, p. Trp112Arg, p. Arg156Trp, p. His207ProfsX56, p. Arg209AlafsX28, p.Cys223Tyr). There was no correlation between mutation genotypes and phenotypes (X2 =0. 731, 3. 438,0. 820, 3. 208, 1. 992; P＞0. 05). ConclusionsRS1 gene mutation is a major cause of XLRS. The RS1 mutation genotype is not correlated with phenotype, so that the prognosis cannot be predicted by the genotypes. Key words: Retinoschisis/congenital; Retinoschisis/genetics; Genes; Mutation;

Clinical observation of vitrectomy for treatment of diffuse nontraditional diabetic macular edema

To evaluate the efficacy of vitrectomy combined with internal limiting membrane (ILM) peeling in the treatment of diffuse nontraditional diabetic macular edema. It was a retrospective case series study. Clinical records of 21 consecutive patients (21 eyes) with diffuse diabetic macular edema without macular traction were reviewed. All patients underwent pars plana vitrectomy with internal limiting membrane peeling. Main outcome measurements included pre- and postoperative optical coherence tomography (OCT) and visual acuity. Postoperative follow-up ranged from 12 to 24 months (mean, 16.3 months). Mean preoperative foveal thickness significantly decreased from (406 ± 59) µm to (291 ± 67) µm at 1 months after surgery (t = 9.26, P < 0.01), and further decreased to (280 ± 77) µm at 12 months (t = 9.46, P < 0.01). No differences in visual acuity between preoperative and postoperative were found during follow-up periods. The final best-corrected visual acuity improved in 8 (38.1%) of the 21 eyes, remained unchanged in 11 eyes (52.4%), and decreased in 2 eyes (9.5%). Pars plana vitrectomy with internal limiting membrane peeling appears to be beneficial in eyes with diffuse nontraditional diabetic macular edema in retinal thickness but visual acuity outcomes showed only minimal improvement as compared to the baseline.

Transthyretin is a potential Serum biomarker of high myopia

Objective To observe the abnormal expression of transthyretin in serum and vitreous of high myopia patients.Methods 116 patients(50 males and 66 females)with high myopia,diagnosed by retinoscopic reflex,slit-lamp microscope,indirect ophthalmoscope and Iol-Master,were enrolled.The patients had an average age of(49.7±12.3)years and average diopter of(-10±4.2)D.The control group had 86 healthy individuals(42 males and 44 females)with an average age of(48.5±10.5)years.According to the findings of indirect ophthalmoscope and optical coherence tomography(OCT)examination,the patients were classified as foveal detachment,macular hole,choroidal neovascularization,epimacular membrane.retinal scar and no significant pathological changes.2 ml peripheral blood samples were taken from all the subjects.The vitreous samples of high myopia patients with foveal detachment and macular hole (20 patients.20 eyes)were collected before pars plana vitrectomy.LTQ-MASS was performed on 16 serum samples of patients and 16 control serum samples.Western blot and enzyme linked immunosorbent assay (ELISA)were used to detect serum transthyretin expression in high myopia groups(n=100)and control group(n=80).Vitreous samples(n=20)and corresponding serum samples were further analyzed by ELlSA.Meanwhile,the relationship between visual acuity after surgery and transthyretin expression level in vitreous were analyzed.Results LTQ-MASS detected 4 proteins differentially expressed in the serum of patients and control group,transthyretin was the most significantly increased protein in high myopia patients.Western blot validated that serum transthyretin of high myopia group was much higher than that of the control group(t=3.68,P＜0.05).High myopia patients with macular hole and macular detachment had much higher serum and vitreous transthyretin than that of control group(F=9.28,P＜0.01).Patients with higher vitreous transthyretin had better postoperative visual acuity.Conclusions The transthyretin level increases significantly in serum and vitreous of high myopia patients,and it correlated with ocular pathologies and visual outcomes. Key words: Myopia,Degenerative/complications; Prealbumin; Proteomics; Serum

Correlation between visual acuity and foveal retinal thickness in anterior uveitic patients

Correlation between visual acuity and foveal retinal thickness in anterior uveitic patients

Comparison of central macular thickness (CMT) measurement between time domain and spectral domain (SD) optical coherence tomography (OCT) and reproducibility of SD OCT in active neovascular AMD

Purpose: To evaluate the reproducibility of Cirrus-SD OCT measurements and to compare central macular thickness (CMT) measurements between TD-Stratus and SD-Cirrus OCT in patients with active exudative AMD. Methods: Consecutive case series of patients with active exudative AMD seen in the Medical Retina Department. Patients underwent 1 scan with Stratus (macular thickness map protocol) and 5 scans with Cirrus (Macular Cube protocol) at the same visit by the same experienced examiner. To be included, patients best-corrected visual acuity (BCVA) had to be >20/200 while all scans had to be of sufficient quality, well-centered and at least one Cirrus scan with CMT >300 microns. The repeatability of the SD Cirrus was estimated by using all 5 CMT measurements and the mean of the Cirrus measurements was compared with the CMT obtained by TD Stratus. Results: Cirrus OCT demonstrated high intraobserver repeatability at the central foveal region (ICC 96%). The mean of the CMT measurements was 321microns for Stratus and 387 microns for Cirrus. The average difference was 65m (SD=30). The coefficient of concordance between Stratus and Cirrus CMT measurements was rho=0,749 with a high precision and a moderate accuracy. The equation of the line of regression between Stratus and meanCirrus is given by the following: M_stratus = 0,848 x m_cirrus - 4,496 (1).Conclusions: The Cirrus macular cube protocol allows reproducible CMT measurements in patients with active exudative AMD. In cases of upgrading from TD to SD use and vice versa, there is the possibility to predict the measurements by using the equation (1). These real life data and conclusions can help in improving our clinical management of patients with neovascular AMD.

Photoreceptor layer thickness measurement in normal and glaucomatous eyes with spectral domain OCT

Background Glaucoma is primarily characterized by the damage of retinal ganglion cells in the inner layer.Whether the outer retinal layers are involved is controversial.Although the functional abnormality of the outer retinal layers have been determined,structural studies present difierent outcomes.Objective This study measured and compared photoreceptor layer thickness between normal and glaucomatous eyes using spectral domain optical coherence tomography(OCT). Methods A case-control study was designed.The macular area of 38 eyes from 38 normal volunteers and 48 primary open-angle glaucomatous eyes(POAG)were imaged by spectral domain OCT(SD OCT).The outer nuclear layer(ONL)and inner and outer segments(IS/OS)layer thicknesses in fovea and parafovea(1.5 mm from the fovea) were measured by a single masked observer using an image analysis software (SigmaScan Pro version 5.0).Retinal nerve fiber layer(RNFL)thicknesses of the 86 eyes were measured by Stratus OCT.The photoreceptor layer thicknesses between normal and glaucomatous eyes were compared.The correlation of photoreceptor with RNFL thicknesses was evaluated with linear and non-linear regression models. Results The outer nuclear layer(ONL)thickness in the fovea in normal and glaucomatous eyes were 96.7±10.7μm and 103.7±13.3 μm,respectively,with a significant difference(P=0.011).The inner and outer segments(IS/OS)layer thicknesses in the fovea in the two groups were 59.3±5.5 μm and 59.5±5.5μm,respectively,without significant difference(P=0.890).The outer nuclear layer(ONL)thicknesses in the parafovea in normal and glaucomatous eyes were 70.9±14.0μm and 68.7 ±10.7μm,respectively,(P=0.410).The inner and outer segments(IS/OS)layer thicknesses in the parafovea in the two groups were 45.2±6.4 μm and 43.6±5.5μm,respectively(P=0.228).The relationship between ONL and RNFL thickness was best described with a second order polynomial regression model assoeiation(Y=-0.019X2+2.73X+10.34,R2=0.211,P=0.005). Conclusion The foveal ONL thickness is increased in glaucomatous eyes.The alteration of foveal ON L thickness is associated with the severity of the disease. Key words: Glaucoma; Photoreceptor; Optical coherence tomography

Optical coherence tomography of macular edema in retinal vein occlusion

Objective To observe the images characteristics of optic coherence tomography (OCT) on macular edema in retinal vein occlusion (RVO), and to explore the application value of Fourier-domain (FD)OCT in RVO macular edema. Methods The clinical data of 91 RVO patients (92 eyes) were retrospectively analyzed. All patients received examinations of best corrected visual acuity (BCVA), direct or indirect ophthalmoscope, slit lamp ophthalmoscope, and 60 patients (60 eyes)also underwent fundus fluorescein angiography. There were 35 patients (35 eyes) with central retinal vein occlusion (CRVO) and 56 patients (57 eyes) with branch retinal vein occlusion (BRVO). The type and involved layer of macular edema, and subtle structure changes of the outer retina were observed through the horizontal and vertical scanning lines through the foveal under the model of 5 Line Raster. The foveal thickness (FT), height of serous retinal detachment, width and height of foveal cystoid spaces and thickness of foveal photoreceptor layer were measure manually. The central fovea thickness (CFT), volume (V) and average thickness (AT) were collected from the OCT readings. Further analysis was focused on different type of the edema, characteristics of OCT images and the relationship between the different type of the edema and vision. Results The manifestation of macular edema was variable by OCT scanning, and can be categorized into diffuse edema (sponge-like thickening of the retina with reduced reflectivity) 12 patients ( 12 eyes, 13.0% ), cystoid edema (multi-cyst-like space in the neuro-retina separated by tissue column) 21 patients (21 eyes, 22.8%) and serous retinal detachment (separation of neuro-retina and retinal pigment epithelium by space with low reflectivity) 37 patients (37 eyes, 40. 2%) and mixed edema(mix of the above several edema form) 58 patients (59 eyes, 64.1 %). The edema can happen at different layers of the neuro-retina, including outer nuclear layer/outer plexiform layer (ONL/OPL) in 92 patients (92 eyes, 100. 0%), inner nuclear layer (INL) in 68 patients (68 eyes, 74.2%) and ganglion cell layer (GCL) in 23 patients (23 eyes, 25.0%).Statistic analysis revealed that BCVA was related to the integrity of IS/OS (r=3. 778 6, P=0. 000), ELM (r=4.462 2, P= 0. 000 ) and FT (r=-0.4513, P=0. 000 ), but not related to CFT (r=0.269 7, P=0.121), V(r=0.0528, P= 0. 054 ) and AT (r=0.0608, P=0.075). Conclusion he manifestation of macular edema associated with RVO is variable. FD-OCT can demonstrate its fine details, and some changes are related to visual acuity. Therefore, the value of quantitative analysis in these patients needs further confirmation. Key words: Macular edema/diagnosis; Retinal vein occlusion/diagnosis; Tomography, optical coherence

Image features of spectral-domain optical coherence tomography of high myopia with retinoschisis

Objective To observe the image features of high myopia with retinoschisis by spectraldomain optical coherence tomography (SD-OCT). Methods The clinical data of eight patients (eight eyes)of high myopia with retinoschisis were retrospective analyzed. All patients were diagnosed by SD-OCT (Topcon 3D OCT-1000), had no macular holes and underwent vitrectomy including internal limiting membrane (ILM) peeling and gas tamponade. All patients also underwent visual acuity, refraction,pre-mirror fundus examination and A/B-mode ultrasound examination. Visual acuity and SD-OCT were followed up at one, three and six months after surgery. Before surgery, pre-mirror fundus examination revealed shallow foveal detachment in 3/8 eyes, posterior scleral staphyloma in 7/8 eyes. SD-OCT showed concave arc stripes in 7/8 eyes, and outer retinoschisis in 8/8 eyes, middle or inner retinoschisis in 5/8 eyes and foveal detachment in 5/8 eyes. Results Six months after surgery, posterior retinoschisis disappeared in six eyes, foveal detachment still presented in one eye and parafoveal hole occurred in one eye. The corrected visual acuity improved from the 0. 15 to 0. 8 in one eye which had a restored continuous inner segment/outer segmen (IS/OS) line by SD-OCT. The corxected visual acuity improved from 0. 01 to 0. 1 in one eye, from 0. 05 to 0. 15 in one eye, not changed in five eyes. There was no continuous IS/OS line in those patients by SD-OCT. Conclusions SD-OCT shows a variety of morphological features of myopic retinoschisis which could be cured anatomically and functionally by vitrectomy combined ILM peeling. The continuity of IS/OS layer from SD-OCT could help to interpret the vision recovery after the operation. Key words: Retinoschisis/diagnosis; Myopia, degenerative/complications; Tomography, optical coherence

Multifocal electroretinogram findings of different types of diabetic macular edema

Background It is very important for us to understand retinal function change in the patient with diabetic mellitus in clinic. At present,the study about diabetic mellitus associated with macular edema includes fundus fluorescense angiography ( FFA) and multifocal electroretinogram ( mfERG) etc.. However, seldom research is performed in the mfERG findings for different types of diabetic macular edema. Objective This study aimed to investigate the mfERG change in different types of diabetic macular edema compared with normal population. Methods Fifty-seven eyes with diabetic macular edema from 40 patients and 35 eyes from age-and gender-matched normal subjects were enrolled in this study. The eyes with diabetic macular edema were assigned to local macular edema group (n=16) ,diffuse macular edema group (n = 22) and cystoid macular edema ( n = 17 ) based on the manifestation of FFA. MfERG was recorded in all the individuals. The informed consent was obtained from each subject prior to any the medical examination. Results In focal diabetic macular edema group,the response density of P1 wave was significantly attenuated in ring 1 , showing a statistical difference in comparison with controls (t =2. 170,P = 0.038) ,and the latencies of P1 and N1 waves showed obvious prolong in ring 4 and 5 (t = 2.519,P = 0. 017 ;t = 2. 451 ,P = 0. 020). In diffuse diabetic macular edema group,the response densities of P1 and N1 waves were declined in ring 1,3,5 and ring 1,3,4,5 respectively,and the latencies of P, in ring 3,4 were significantly delayed respectively in comparison with controls (all P < 0. 05 ). In cystoid diabetic macular edema group, the response densities of P1 and N1 waves were lowed from ring 1 through 5 respectively, and the latencies of P1 and N1 waves were significantly longer from ring 3 through 5 and ring 4 respectively with the statistically significant difference from controls (all P<0. 05). The visual function of fovea was badly damaged. Conclusion These studies indicate that the most serious damage of visual function is in foveal area in cystoid diabetic macular edema group, and is then parafoveal area of diffuse diabetic macular edema group and perifoveal area in focal diabetic macular edema group. The outcome of mfERG presents a good consistency with FFA findings in the patients with diabetic macular edema. Key words: Diabetes; Macular edema; Multifocal electroretinogram; Fundus fluorescein angiography

The neural mechanism of left hemiparalexia and left hemialexia in reading Chinese characters

Objective To investigate the underlying neural mechanism of left hemiparalexia and left hemialexia in reading Chinese characters. Methods A patient with reading disorders caused by brain infarctions at the left ventralis medialis occipitotemporal lobe and the splenium of the corpus callosum was studied. A series of neuropsychological tests, such as reading Chinese characters presented in the central foveal field or in the left and right half of the foveal field, were conducted with the patient, and neuroimaging techniques including high spatial resolution 3D-MRI and diffusion tensor tractography （DTT） were used to examine whether or not there were lesions of the neural pathway. Results The patient showed left hemiparalexia, which was characterized by making substitution or omission mistakes, mostly in the left parts of Chinese characters, and also left hemialexia（alexia for characters presented in left visual field）. 3D-MRI demonstrated infarctions in the left ventral mesial occipitotemporal area and in the left side of the splenium of the corpus callosum. The left lateral mid-fusiform cortex, which has been identified as the visual word form area（VWFA）, was almost intact. DTT indicated the major forceps fibers running through the splenium were all disconnected due to the infarction of the left splenium. Conclusion As a result of disruption of the splemium-major forceps pathway, visual character information in the left visual field which is initially projected to the right occipital cortex cannot be transferred from the right visual cortex to the left VWFA. This mechanism of left hemiparalexia and left hemialexia in reading Chinese characters is similar to that in reading English words. Key words: Left hemiparalexia; Left hemialexia; Corpus callosum; Visual word form area

Correlation between photoreceptor layer and visual acuity in eyes with persistent cystoid macular edema secondary to branch retinal vein occlusion

To study the correlation of visual acuity and photoreceptor in eyes with persistent cystoid macular edema associated with branch retinal vein occlusion (BRVO). It was a retrospective case series study.Medical records of 41 patients (41 eyes) with persistent cystoid macular edema secondary to BRVO diagnosed in Department of Ophthalmology, Peking Union Medical College Hospital from January 2008 to January 2010 were studied retrospectively. On the images obtained by spectral-domain OCT, the thickness of foveal neurosensory retina and photoreceptor layer that was beneath the foveal cystoid spaces, and the transverse length and height of foveal cystoid spaces were measured. The status of the junction between inner and outer segments of the photoreceptors (IS-OS) in the fovea was also assessed. The correlations between the parameters above and visual acuity were analyzed. The average foveal neurosensory thickness was (484.71 ± 131.86) µm, the photoreceptor layer thickness was (92.04 ± 45.53) µm and the size of foveal cavity was 772.59 µm × 362.17 µm. By the Spearman's rank correlation analysis, among the parameters above, only photoreceptor layer thickness showed correlation with logMAR visual acuity (r = -0.373, P = 0.016), while other parameters showed no correlation with logMAR visual acuity. Cases were classified as three groups according to the status of IS-OS layer: continuous group (8 cases), discontinuous group (19 cases) and interrupted group (14 cases). LogMAR visual acuity in these eyes with an interrupted IS-OS line in the fovea was significantly worse than that in eyes with a continuous or discontinuous IS-OS line (P = 0.030 and 0.003, respectively). There was no statistical difference between continuous and discontinuous group (P = 0.750). In patients with persistent cystoid macular edema associated with BRVO, the thickness of the foveal photoreceptor layer are positively associated with visual acuity, and the eyes without IS-OS layer have worse visual acuity than eyes with IS-OS layer.

Functional MRI for patients with visual pathway diseases

Objective To observe the results of function MRI and perimetry in patients with visual pathway diseases. Methods Three patients (6 eyes) with pituitary adenoma and craniopharyngioma diagnosed via pathological examination and three healthy volunteers aged from 24 to 30 were collected. The best corrected visual acuity was non-light perception-1. 0 in the 6 sick eyes and 1. 0 in the healthy eyes;all the involved individuals had no other ocular diseases except myopia and without any contraindications of MRI. Common tests including the best visual acuity, fundus test by direct or indirect ophthalmoscope, center static visual field tested by Octopus 101 perimeter, program 32, tendency oriented perimetry were performed. The visual stimulation subtended a field of view of about 12 degrees,consisted of high contrast and drifting checkerboards. MRI parameters: GE signa VH/i 3. 0T scanner. Functional data: GRE-EPI sequence, 20 slices lying perpendicular to the calcarine sulcus. Anatomical data was obtained using 3DSPGR sequence to acquire high resolution. The cortical surface was unfolded and then cut and inflated. Functional data was presented to the inflated surface and subsequently analyzed by AFNI software. Results In six eyes, three had temporal defects, two had upper temporal visual field defects, and the other one did not finish the visual field test. The retinotopic representations of health adults were obtained by using the phase-encoded visual stimulation. The Eccentricity coordinate maps showed that foveal representations lay in the occipital poles and the representations appeared further anterior as eccentricity increased. The polar angle coordinate maps showed that early retinotopically organized areas had a representation of visual field. The visual cortex beneath the calcarine sulcus matched with the upper visual field of the opposite side and which upon the calcarine sulcus matched with the under visual field of the opposite side. Less or no visual cortex response was revealed in the patients' function MRI or the response in injury side was vanished. The visual cortex response related with the visual field defects could not be induced in function MRI. Conclusion There is a good correlation between function MRI data and the results of perimetric evaluation. The function MRI can show the visual cortex response correlated with the visual field defects of the patients with visual pathway diseases. Key words: Optic neuritis/diagnosis; Pituitary neoplasms/diagnosis; Craniopharyngioma/diagnosis; Magnetic resonance imaging/utilization; Perimetry/utilization

The functional and morphological changes of macular after panretinal photocoagulation in the patients with diabetic retinopathy

Objective To observe the functional and morphological changes of macular after panretinal photocoagulation(PRP)in the patients with diabetic retinopathy(DR). Methods A total of 57 eyes of 34 patients with DR undergoing PRP were enrolled in this prospective and self-reflection study. Comparatively analyze the changes of the best visual acuity(BCVA), optical coherence tomography (OCT) and multi-focal electroretinography (mfERG) before PRP, 20 days, 3 months and more than 9 months after PRP. Statistical analyses were performed by wilcoxon, chi-square, Dunnett-t, LSD-t tests and spearman related analyses. The changes of macular function and foveal retinal thickness before and after PRP were comparatively analyzed. Results BCVA of all patients reduced at 9 months after PRP(P= 0. 022). The amplitude density of mfERG P1 of ring 2 decreased at 20 days after PRP(P= 0. 039), then recovered at 3 months and decreased again at 9 months(P=0. 014). The amplitude density of mfERG P1 of ring 3-5 decreased at 20 days, 3 months and more than 9 months after PRP(20 days: ring 3: P=0. 000, ring 4: P= 0. 001, ring 5:P=0.000; 3 months: ring 3:P=0. 000, ring 4. P=0. 006, ring 5: P=0.001; more than 9 months: ring 3: P=0. 000,ring 4: P=0.000, ring 5: P=0. 000). The amplitude density of mfERG P1 of ring 1 was significantly lower at 9 months after PRP(P=0. 050). The foveal retinal thickness increased at 20 days after PRP(P = 0. 007), then recovered at 3 months or later. Cystoid macular degeneration was found in 6 eyes(10. 5%) at 20 days after PRP. Conclusions After the treatment of PRP, there were some extend reduction of the macular function, a transient increase on foveal retinal thickness. Combined mfERG and OCT can be a comprehensively and objectively assessment of macular function and morphology. Key words: Diabetic retinopathy/therapy; Laser coagulation/methods; Laser coagulation/rehabilitation