1.Clinical features and research progress in autosomal recessive Best disease
Chinese Journal of Ocular Fundus Diseases 2020;36(1):70-74
Autosomal recessive Best disease (ARB) is a rare clinical fundus disease caused by BEST1 mutation.The critical features of ARB are the presence of multifocal subretinal yellowish lesions,which corresponding to the hyperfluorescent spots on FAF,scattered over the posterior pole of the retina,absent of typical vitelliform lesions in the macula.Imaging of OCT is often manifested as subretinal or intraretinal fluid,and cystoid macular edema,and hypereflective focus at RPE level.EOG shows an absent or severely reduced light rise (decreased value of Arden),which often accompanied by reduction and delay of the rod and cone ERG.Some patients with ARB show hyperopia,short axial length and shallow anterior chambers,with a corresponding high incidence of angle-closure glaucoma.Though there isn't any effective therapeutic methods of ARB at present,prevention and treatment for its complications such as angle-closure glaucoma and choroidal neovascularization should be considered.Present study about ARB mainly focus on some retrospective cases,and ARB is often misdiagnosed with Best vitelliform macular dystrophy,central serous chorioretinopathy and other fundus diseases in clinic.A detailed understanding of the clinical features and genetic characteristics of ARB might be helpful in clinical diagnosis and treatment.Research with larger sample size are expected to further investigate the different stages of ARB and its developing process,the potential pathological mechanism,the relationship between genotype and phenotype,so as to improve the understanding of the disease.
2.Peripheral retinal fluorescence features of ultra-wide fundus fluorescein angiography in normal fundus eyes
Xiaoling WANG ; Changzheng CHEN ; Amin XU ; Zuohuizi YI ; Lu HE ; Juejun LIU ; Hongmei ZHENG
Chinese Journal of Experimental Ophthalmology 2021;39(7):609-613
Objective:To analyze the peripheral retinal fluorescence characteristics of normal fundus on ultra-wide field fluorescein angiography (UWFA) images.Methods:A cross-sectional study was conducted.Ninety-five patients (190 eyes) who underwent normal UWFA in Renmin Hospital of Wuhan University from July 2016 to January 2019 were enrolled.There were 94 (49.47%) male eyes and 96 (50.53%) female eyes.Among them, there were 72 (37.89%) mild cataract eyes, 60 (31.58%) moderate and low myopia eyes and 58 (30.53%) subjective blurred vision eyes.The peripheral retinal fluorescence characteristics were divided into vascular-associated feature or non-vascular feature according to whether the retinal vessel involved or not.The subjects were divided into ≤40 years old group and >40 years old group, and the differences in various features between the two groups were compared and analyzed.The study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2019-K037). Written informed consent was obtained from each patient prior to any examination.Results:Four non-vascular and five vascular-associated fluorescence features were found in normal peripheral retina.Non-vascular features contained glass hyperfluorescence in 158 (83.16%) eyes, far peripheral retina with mottled florescent band in 82 (43.16%) eyes, granular ground hyperfluorescence in 24 (12.63%) eyes and local mottled fluorescence in 21 (11.05%) eyes.Vascular-associated fluorescence features included peripheral avascular area in 92 (48.42%) eyes, vessels passing through the ora serrata in 66 (34.74%) eyes, microaneurysm in 60 (31.58%) eyes, slight leakage within 10 minutes after angiography in 56 (29.47%) eyes and angiotelectasis in 30 (15.79%) eyes.There were 19.61% (20/102) of eyes with peripheral retinal vessels passing through the ora serrata and 43.10% (44/102) of eyes with microaneurysm and 19.61% (20/102) of eyes with angiotelectasis in >40 years old group, and there were 52.27% (46/88), 18.23% (16/88) and 11.36% (10/88) correspondingly in ≤40 years old group, and the differences were statistically significant ( χ2=22.235, 10.451, 9.259; all at P<0.01). Conclusions:UWFA reveals four non-vascular and five vascular-associated fluorescence characteristics of normal fundus and age might be associated with the distribution of microaneurysm and angiotelectasis.
3.Characteristics of multicolor imaging in the acute central serous chorioretinopathy
Lu HE ; Changzheng CHEN ; Zuohuizi YI ; Xiaoling WANG ; Amin XU ; Juejun LIU
Chinese Journal of Experimental Ophthalmology 2021;39(11):997-1002
Objective:To investigate the features of multicolor imaging in the macular region of central serous chorioretinopathy (CSC) patients.Methods:A cross-sectional study was conducted.Thirty-four acute CSC patients (34 eyes) treated in Renmin Hospital of Wuhan University from August 2017 to January 2018 were enrolled.Among the 34 subjects, there were 21 males (21 eyes) and 13 females (13 eyes). The subjects were 26 to 61 years old, with an average age of (37.41±9.35) years.The course of the disease was 5 to 45 days, with an average course of (12.00±2.29) days.All the subjects were examined by color fundus photography, fluorescein angiography (FFA), indocyanine green angiography (ICGA), multicolor imaging, spectral-domain optical coherence tomography (SD-OCT). The image features of each patient were compared and analyzed.The diagnostic accordance rate for leakage point and serous retinal neuroepithelial detachment of multicolor imaging and color fundus photography was calculated according to FFA/ICGA and OCT.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2019-K037).Results:The serous retinal detachment region showed green light reflection area with clear boundary in 33 eyes (97.06%) in the standard as well as blue and green enhanced multicolor image, with not clear boundary in 1 eye (2.94%). The serous retinal detachment region showed weakly reflective area in 17 eyes (50%) in blue reflectance image, showed weak reflection with clear boundary in 32 eyes (94.11%) in green reflectance image, showed weakly reflection with clear boundary in 33 eyes (97.06%) in infrared reflectance image.The fluorescein leakage point in FFA image was found micro retinal pigment epithelium detachment (PED) in 19 eyes (55.88%), rough light band of retinal pigment epithelium (RPE) in 12 eyes (35.29%), and large PED in 3 eyes (8.82%) in SD-OCT image.The RPE leakage showed red mottled changes in the area of neuroepithelial detachment in 29 eyes (85.29%) in the standard as well as blue and green enhanced multicolor images, presented strong reflection spots in blue reflectance images in 2 eyes (5.88%), showed strong reflective spots in green reflectance in 5 eyes (14.70%), showed strong reflection spot in the weakly reflective area in 33 eyes (97.06%) in infrared reflectance images.Taking FFA/ICGA and OCT as the gold standard, the diagnostic accordance rate of standard multicolor, blue and green enhanced multicolor and infrared reflectance images for serous retinal neuroepithelial detachment and leakage points was higher than that of color fundus photography, and the differences were statistically significant (all at P<0.05). Conclusions:Standard multicolor, blue and green enhanced multicolor and infrared reflectance images can reflect the leakage point and retinal neuroepithelial detachment of acute CSC.Green reflectance image can show serous retinal neuroepithelial detachment of acute CSC.Multicolor imaging can be used as the auxiliary diagnosis method of acute CSC.
4.Application of multispectral fundus imaging in central serous chorioretinopathy
Lu HE ; Changzheng CHEN ; Zuohuizi YI ; Xiaoling WANG ; Amin XU ; Juejun LIU
Chinese Journal of Experimental Ophthalmology 2021;39(12):1075-1079
Objective:To explore the application of multispectral fundus imaging (MSI) in central serous chorioretinopathy (CSC).Methods:A diagnostic test study was conducted.Eighty-five eyes from 69 patients with macular diseases were enrolled in Renmin Hospital of Wuhan University from September 2017 to May 2018.There were 62 males (77 eyes) and 7 females (8 eyes) among the 69 patients with an average age of (48.0±11.2) years.The patients were divided into CSC group (45 cases, 61 eyes) and non-CSC group (24 cases, 24 eyes) according to whether suffering from CSC or not.Color fundus photography, fundus fluorescein angiography (FFA), indocyanine green angiography, spectral domain-optical coherence tomography and MSI were performed in the two groups and the images were collected.With FFA as the gold standard, the sensitivity, specificity, false positive rate, false negative rate, positive predictive value and negative predictive value of MSI in the diagnosis of CSC were calculated.Kappa consistency test was used to evaluate the consistency of MSI and FFA in diagnosing CSC, and to evaluate the diagnostic value of MSI in CSC.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2019-K037). Written informed consent was obtained from each subject prior to any medical examination.Results:The sensitivity, specicity, false positive rate, false negative rate, positive predictive value and negative predictive value of MSI for identifying CSC were 88.5%, 91.7%, 8.3%, 11.5%, 96.4% and 75.9%, respectively.The Kappa coefficient of agreement was 0.754.There was no significant difference in the identification of CSC between MSI and FFA ( χ2=1.780, P=0.180). Hyper-reflective signals corresponding to the leakage points were better detected with MSI images at 620-850 nm wavelength.The clear boundary of serous neuroepithelial detachment area was better detected with MSI images at 590-810 nm wavelength.The retinal pigment epithelium damage was better detected with MSI images at 660-850 nm wavelength. Conclusions:There is a good consistency between MSI and FFA.MSI can be an effective noninvasive inspection method for CSC.
5.Evaluation of choroidal vascularity index and subfoveal choroidal thickness in eyes with chronic central serous chorioretinopathy and their normal fellow eyes
Gongpeng SUN ; Zuohuizi YI ; Juejun LIU ; Changzheng CHEN
Chinese Journal of Experimental Ophthalmology 2023;41(2):160-165
Objective:To observe the choroidal vascular changes of chronic central serous chorioretinopathy (cCSC), and analyze their correlations with central macular thickness (CMT).Methods:A cross-sectional study was adopted.Seventy-six eyes of 38 patients with monocular cCSC who were treated in Renmin Hospital of Wuhan University from March 2018 to December 2019 were enrolled, and 30 eyes of 30 normal control matched with age, gender, and spherical equivalent (SE) were included.Choroidal images of all subjects, and the CMT, subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), total choroidal area (TCA), choroidal stromal area (SA), and choroidal luminal area (LA) were measured by Heidelberg enhanced depth imaging optical coherence tomography.The differences in SFCT, LA, SA, TCA, CMT and CVI between the cCSC eye, fellow eye and normal eye, as well as the correlation between SFCT and CVI, SFCT and CMT, and CVI and CMT were analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2020-K234).Results:The CVI and the SFCT of the cCSC eyes, fellow eyes and normal eyes were (71.67±5.60)% and 483.82(409.01, 550.87)μm, (68.33±3.85)% and 444.66(351.25, 505.15)μm, (64.70±1.88)% and 373.46(327.98, 405.48)μm, respectively.The CMT, SFCT, TCA, LA, CVI in cCSC eyes were significantly higher than those in the contralateral eyes and normal control eyes, while SFCT, TCA, LA, CVI in the contralateral eyes were higher than those in normal control eyes (all at P<0.05). Pairwise comparison among the three groups showed no significant difference in SA (all at P>0.05). Correlation analysis showed that in cCSC eyes, SFCT was strongly positively correlated with CVI ( rs=0.703, P<0.001), and there was no correlation between CMT and SFCT ( rs=0.181, P=0.278), or CMT and CVI ( r=0.231, P=0.164). Conclusions:The SFCT and CVI are higher in cCSC and the fellow eyes compared with normal eyes, and the choroidal vessels are significantly dilated in cCSC patients.The SFCT and CVI of the cCSC eye are slightly higher in comparison with the fellow eye.CMT is not correlated with SFCT or CVI in cCSC eyes.
6.Changes of blood flow density in patients with idiopathic choroidal neovascularization treated with anti-vascular endothelial growth factor
Juejun LIU ; Changzheng CHEN ; Zuohuizi YI ; Xiaoling WANG ; Amin XU ; Lu HE
Chinese Journal of Ocular Fundus Diseases 2019;35(1):31-35
Objective To assess changes of blood flow density of idiopathic choroidal neovascularization (ICNV) treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF).Methods Retrospective case analysis.Sixteen eyes of 16 patients with ICNV diagnosed with FFA and OCT were included in this study.Among them,12 were female and 4 were male.The mean age was 33.94±9.83 years.The mean course of diseases was 5.13 ±4.44 weeks.The BCVA,indirect ophthalmoscope,OCT and OCT angiography (OCTA) were performed at the first diagnosis in all patients.The BCVA was converted to logMAR.The macular fovea retinal thickness (CMT) was measured by OCT,and the selected area of CNV (CSA) and flow area of CNV (CFA) were measured by OCTA.The mean logMAR BCVA,CMT,CSA and CFA were 0.336±0.163,268.500±57.927 μm,0.651 ±0.521 mm2,0.327±0.278 mm2,respectively.All patients were treated with intravitreal ranibizumab (IVR,10 mg/ml,0.05 ml).Follow-up results including the BCVA,fundus color photography,OCT and OCTA were obtained 1 month after treatment.To compare the changes ofBCVA,CMT,CSA,CFA of ICNV treated with anti-VEGF.Pearson method was used to analyze the correlation between logMAR BCVA and CMT,CSA and CFA before and after the treatment.Results One month after treatment,the average logMAR BCVA,CMT,CSA and CFA were 0.176±0.111,232.500± 18.910 μm,0.420±0.439 mm2,0.215 ± 0.274 mm2.The mean logMAR BCVA (t=5.471,P< 0.001),CMT (t=2.527,P=0.023),CSA (t=4.039,P=0.001),CFA (t=4.214,P=0.001) significantly decreased at 1 month after injection compared to baseline,and the difference had statistical significance.The results of correlation analysis showed that the post-logMAR BCVA was moderately positively correlated with pre-CSA and post-CSA (r=0.553,0.560;P=0.026,0.024),and strongly correlated with pre-CFA and post-CFA (r=0.669,0.606;P=0.005,0.013),but not correlated with preCMT and post-CMT (r=0.553,0.560;P=0.026,0.024).Conclusion The blood flow density of ICNV measured by OCTA were significantly decreased in the treatment of anti-VEGF drugs.
7.The blood perfusion changes of peripapillary and macular vessels in patients with nonarteritic anterior ischemic optic neuropathy
Juejun LIU ; Changzheng CHEN ; Lu LI ; Zuohuizi YI ; Hongmei ZHENG
Chinese Journal of Ocular Fundus Diseases 2019;35(3):219-225
Objective To observe the blood perfusion changes ofperipapillary and macular vessels in patients with nonarteritic anterior ischaemic optic neuropathy (NAION).Methods Retrospective cohort study.Thirty-six eyes (19 affected eyes and 17 fellow eyes) of 19 patients with NAION diagnosed in People's Hospital of Wuhan University from November 2017 to January 2019 were included in this study.There were 1 0 males and 9 females,with the mean age of 55.05 ± 7.11 years.Forty eyes of 20 normal subjects matched with NAION patients were included as controls.BCVA,fundus color photography,SD-OCT and OCT angiography were performed in normal controls and repeated in NAION affected eyes at 1-2 weeks,1-2 months,3-5 months intervals.OCT quantitative measurements:average retinal nerve fiber layer thickness (aRNFL) of the disc and its superior values (sRNFL) and the inferior values (iRNFL),average ganglion cell complex thickness (aGCC) in macular region and its superior values (sGCC) and the inferior values (iGCC).OCTA quantitative measurements:average radial peripapillary capillary density (aRPC) and its superior values (sRPC) and the inferior values (iRPC),average vascular density of superficial retina (aSVD) in macular region and its superior values (sSVD) and the inferior values (iSVD),average vascular density of deep layer retina (aDVD),areas of foveal avascular zone (FAZ).The differences of OCT and OCTA quantitative measurements between NAION eyes and the fellow eyes and normal controls were comparatively analyzed.Independent sample t test,paired sample t test or nonparametric rank sum test were performed for comparison among three groups.Pearson or Spearman correlation analysis were used to analyze the correlation between RNFL and RPC,GCC and SVD,RNFL and GCC,RPC and SVD.Results At baseline,the aRNFL,aRPC and aDVD of NAION patients were significantly higher than those of normal controls.Compared with the fellow eyes,the aRNFL increased significantly and the aRPC decreased significantly in NAION affected eyes.The overall differences of aRNFL,aRPC,aGCC and aSVD at four intervals within NAION affected eyes were statistically significant (P<0.05).The average sRNFL,sRPC,sGCC and sSVD at 1-2 months interval were significantly lower than the average iRNFL,iRPC,iGCC and iSVD (P<0.05).Correlation analysis:at 1-2 months interval,aGCC was positively correlated with aSVD (r=0.482,P=0.037);at 3-5 months interval,aRNFL was positively correlated with aRPC (r=0.631,P=0.037).Conclusion There is a sectorial reduction of vascular density of peripapillary RPC and macular SVD with the disease progression of NAION.
8.Image characteristics and quantitative analysis of multicolor imaging in eyes with cystoid macular edema
Lu HE ; Changzheng CHEN ; Zuohuizi YI ; Xiaoling WANG ; Amin XU ; Juejun LIU
Chinese Journal of Ocular Fundus Diseases 2020;36(1):25-28
Objective To observe the imaging features of cystoid macular edema (CME) in multicolor imaging (MC),and to evaluate the value of MC in the diagnosis of CME.Methods Descriptive case series study.From August 2017 to June 2018,42 eyes of 37 patients with CME diagnosed in the people's Hospital of Wuhan University were included in the study.Among them,there were 24 males and 13 females,with an average age of 48.51 ± 10.29 years.There were 14 eyes with diabetic retinopathy,14 eyes with central retinal vein occlusion,8 eyes with branch retinal vein occlusion,4 eyes with uveitis,and 2 eyes with Eales disease.The macular color fundus photography (CFP) was performed with Visucam 200 non-mydriatic fundus camera of Zeiss company in Germany.MC,frequnce domainoptical OCT (SD-OCT) and FFA were examined by Spectralis HRA2 + OCT of Heidelberg company in Germany.According to the MC standard method,five images,including 488 nm blue reflection (BR),515 nm green reflection (GR),820 nm infrared reflection (IR) imaging and standard MC and blue-green enhancement (BG),were obtained at the same time.Compared with SD-OCT,CFP and MC images were scored.Friedman M test and Wilcoxon signed rank test were used for statistical analysis.Results The standard MC and BG images showed blue-green uplift area or petal-shaped appearance,surrounded by green reflection areas with clear boundaries.BR image can be seen in the low reflexes area.On the GR image,there were patches or cystic low reflection areas,surrounded by a slightly high reflection.On the IR image,patches or cystoid high reflexes can be seen,surrounded by low reflection dark areas with clear boundaries.The average scores of CFP,standard MC,GB,IR,GR and BR were 1.20± 0.94,3.05± 0.99,2.90± 1.04,2.55± 1.27,2.00± 0.94,0.51 ± 0.85 respectively,and the differences were statistically significant (χ2=151.61,P=0.000).The score of CFP were significantly lower than that of standard MC (Z=-5.421),BG (Z=-5.354),IR (Z=-4.714),GR (Z=-4.438) and higher than that of BR (Z=-3.435).The differences were statistically significant (P=0.000,0.000,0.000,0.000,0.001).Conclusions The quality of MC imaging is better than that of CFP.Combined with SD-OCT,it can be used as an assistant method to diagnose CME.
9.The macular vascular density in hypertensive patients without obvious hypertensive retinopathy
Ning MA ; Wei LI ; Juejun LIU ; Tao HE ; Yiqiao XING
Chinese Journal of Ocular Fundus Diseases 2020;36(5):358-361
Objective:To observe the changes of macular vascular density of hypertensive patients without obvious hypertensive retinopathy (HRP).Methods:Twenty-three patients (hypertension group) diagnosed as grade 2 or grade 3 essential hypertension in Cardiology Department of Renmin Hospital of Wuhan University from January to April 2019 were enrolled in the study. Among them, there were 13 males and 10 females. The mean age was 61.6 ± 5.6 years, and the mean BCVA was 0.74 ± 0.16. The course of hypertension was more than 7 years; Keith Wagener (K-W) grade was 0 or 1. Fifteen age-matched people without hypertension were selected as the control group, among which included 8 males and 7 females. Their average age was 59.7 ± 4.4 years and the average BCVA was 0.79 ± 0.17, the K-W grades were 0. There was no significant difference ( P=0.265, 1.000, 0.563) between the two groups in age ( t=1.739), sex ratio ( χ2=0.036) or BCVA ( t=0.585). All subjects were examined by BCVA, fundus photography and OCTA. OCTA scanned the macular area in the range of 3 mm × 3 mm. The software automatically divided the image into two concentric circles with the macular fovea as the center, which are the inner ring with a diameter of 1 mm (foveal area) and the outer ring with a diameter of 1-3 mm. The blood flow density of the whole, temporal, upper, nasal and lower capillary layers within 3 mm of the macular area, and foveal avascular zone (FAZ) area, central foveal retinal thickness (CFT) were measured. Results:Significant differences were observed in the vascular densities of total, temporal, nasal and inferior area of maculas ( t=2.188, 2.472, 5.105, 2.734; P=0.037, 0.020, 0.000, 0.010) between the two groups, while no significant differences were evidenced in foveal vascular densities and superior vascular densities ( t=0.575, 0.140; P=0.570, 0.889). There was no significant difference in FAZ area or CFT between the two groups ( t=0.367, 0.753; P=0.714, 0.457). Macular arches were intact in all hypertension patients. Conclusions:The vascular densities of total, temporal, nasal and inferior area of maculas in the hypertension patients without HRP decreased. The area of FAZ did not expand, and the structures of macular arch ring were normal.
10.The changes of choriocapillaris blood flow in chronic central serous chorioretinopathy before and after photodynamic therapy
Juejun LIU ; Changzheng CHEN ; Yishuang XU ; Hongmei ZHENG ; Lu HE
Chinese Journal of Ocular Fundus Diseases 2019;35(4):358-363
Objective To quantitatively analyze the changes ofchoroidal capillaries in chronic central serous chorioretinopathy (CCSC) before and after half-dose photodynamic therapy (PDT).Methods A retrospective cohort study.Nineteen patients (21 eyes) with CCSC were enrolled in this study from November 2017 to September 2018 in People's Hospital of Wuhan University.Among them,there were 14 males (15 eyes) and 5 females (6 eyes),with diseases course over than 6 months.All patients underwent half-dose PDT.Twenty normal subjects (40 eyes) matched with age and sex in CCSC group were taken as controls.The subfoveal choroidal thickness (SFCT) was measured by Heidelberg depth enhanced imaging-OCT before and after PDT treatment in CCSC patients and in normal subjects.Spectral-domain OCT (Retina map) and Angio-OCT angiography (3 mm × 3 mm) were arranged for all subjects at the same time.Macular fovea retinal thickness (CMT) was recorded under OCT-Retina map mode,and Angio-OCT 3 mm × 3 mm choroidal capillary images were binarized using Image J software,and calculating the area ratio of low pixel area as flow signal void (FSV).BCVA,spectral-domain OCT and Angio-OCT were performed 1 week and 1,3 months after PDT with the same equipment and methods before PDT.The changes of CMT,SFCT,FSV and BCVA in CCSC patients before and after PDT treatment were compared.Pearson correlation analysis was used to analyze the correlation between FSV and SFCT,age.Results The average CMT,SFCT and FSV in CCSC patients increased significantly compared with the controls (P<0.05).The average SFCT and FSV in CCSC patients 3 months after treatment were higher and the average CMT decreased compared with the controls (P=0.000,0.000,0.000).Comparison before and after PDT in CCSC patients:there were significant differences in average CMT,SFCT and FSV before and after PDT (P=0.000,0.000,0.000).Post Hoc multiple comparisons showed that the average CMT (P=0.000,0.000,0.000,0.000,0.000) and FSV (P=0.010,0.000,0.000,0.001,0.000) decreased significantly in all time points except for 1 month and 3 months after treatment,so as the average FSV (P=0.788,0.702).The average SFCT decreased 1 month and 3 months after treatment compared with the baseline (P=0.024,0.008),and there was no significant difference between before treatment and 1 week after treatment (P=0.162),and between 1 month and 3 months after treatment (P=0.687).The correlation analysis showed that there was no correlation between FSV and age in CCSC patients (r=0.052,P=0.822),but there was a correlation between FSV and age in controls (r=0.716,P=0.000).Conclusion Quantitative analysis of OCTA showes the degree of choriocapillary ischemia in the form of FSV in CCSC patients decreased after PDT treatment,however,which is still higher than normal controls.