Straatsma syndrome / Síndrome de Straatsma

Abstract The presence of retinal myelinated nerve fibers is not a rare finding during routine examinations, and it is usually a benign and isolated finding. However, in some rare cases, it can be associated with other ophthalmological conditions. We describe a case of a patient with the triad myelin nerve fibers, myopia and ambliopia, which configures the Straatsma Syndrome.

Resumo A presença de fibras de mielina é um achado comum durante exames oftalmológicos de rotina. Na maior parte das vezes, tem caráter beningno e é um achado isolado. No entanto, em alguns raros casos, a presença de mielinização pode estar associada a outras condições oftalmológicas. Descrevemos um caso de paciente com a tríade presença de fibras nervosas retinianas mielinizadas, miopia, e ambliopia, configurando a síndrome de Straatsma.

Straatsma syndrome: two case reports / Síndrome de Straatsma: dois relatos de caso

Abstract This article reports two cases of Straatsma Syndrome, a rare disease, emphasizing its clinical features that inclued myopia, strabismus and amblyopia associated with persistent myelinated fibers in the retina. Ophthalmic examination, color retinography and optical coherence tomography were performed.

Resumo Este artigo relata dois casos de síndrome de Straatsma, uma doença rara, enfatizando suas características clínicas que incluem miopia, estrabismo e ambliopia associada a persistência de fibras de mielina na retina. Foram realizados exame oftalmológico, retinografia e tomografia de coerência óptica.

Correlations between the deformation parameters measured by Corvis ST and corneal morphology parameters in myopic patients / 中华实验眼科杂志

Background The novel dynamic biomechanical device Corvis ST can measure a variety of corneal deformation parameters and record the dynamic process of cornea deformation.Understanding various corneal deformation parameters is of important clinical significance for morphological and functional prediction for myopic eyes in corneal refractive surgery.However,the range and meaning of corneal deformation parameters in myopic eyes are still unknown.Objective This study was to establish the range of corneal defamation parameters by Corvis ST and explore its clinical significance in myopic eyes.Methods A descriptive study was designed under the approval of Ethic Committee of Tianjin Eye Hospital and informed consent of patients.This study protocol complied with Helsinki Declaration.Four hundred and seventy-seven eyes of 257 myopic patients who were going to receive corneal refractive surgery were included in Tianjin Eye Hospital from June 2014 to January 2015.The corneal deformation parameters including the first applanation time (1st A-time),first applanation lengh (1 st A-length),first applanation velocity (1 st A-velocity),second applanation time (2nd A-time),second applanation length (2nd A-length),second applanation velocity (2nd A-velocity),highest concavity time (HC-time),highest concavity deformation amplitude (HC-DA),highest concavity peak distance (HC-PD),highest concavity radius (HC-R),non-contact intraocular pressure (IOPnct) and the central corneal thickness (CCTst) were measured by Corvis ST.Corneal structural parameters including CCT and corneal curvature were measured by 3-D anterior segment analysis system (Pentacam),and corneal biomechanical parameters including corneal resistance factor (CRF),corneal hysteresis (CH),intraocular pressure mimic Goldmann (IOPg) and intraocular pressure of corneal compensation (IOPcc) were measured by Ocular Response Analyzer (ORA).The distributions of the data were tested with the Shapiro-Wilk test and 95％ confidence intervals (CI) were calculated.The correlations of the variables were evaluated by Pearson correlation coefficient and Spearman rank correlation coefficient.Multiple linear regression was used to analyze the changes of 1st A-time,2nd A-time and HC-DA with corneal morphology and biomechanical parameters.Resnlts Only 1st A-time,2ndA-time,HC-time,HC-DA,CCTst and IOPnct showed the normality distribution in corneal deformation parameters.The positive correlations were found between 1st A-time,1st A-length,2nd A-length,2nd A-velocity,HC-R with CCT (r=0.338,rs=0.129,rs=0.282,rs =0.374,r=0.306,all at P＜0.01),while 1st A-velocity,2nd A-time,HC-D and HC-PD showed the negative correlations with CCT (rs =-0.235,r=-0.130,r=-0.259,r=-0.226,all at P＜0.01).CRF and CH showed positive correlations with 1st A-time,2nd A-length,2nd A-velocity,HC-time,HC-R and negative correlations with HC-PD,△A-length (all at P＜0.05).1st A-time,2nd A-time and HC-DA changed with CRF and IOPcc with the regression formations of 1st A-time =6.185+0.066CRF+0.034IOPec (F=300.123,P =0.000),2nd A-time=23.397-0.074IOPec-0.044CRF (F=227.979,P=0.000) and HC-DA =1.523-0.017IOPcc-0.017CRF (F=152.662,P=0.000).The CCTst,IOPst and IOPnct values by Corvis ST were significantly lower than CCT by Pentacam ([548.23±26.31] μm,IOPg ([15.02±2.72]mmHg and ([16.02-±2.56]mmHg) by ORA respectively (t =11.00,2.919,6.815,all at P ＜ 0.01).Conclusions The corneal deformation parameters by Corvis ST can quantitatively describe corneal biomechanical properties in myopic eyes.Both IOP and the corneal steep curvature of the 3 mm center area (K2) affect the deformation response of cornea.The reliability of Corvis ST in the measurement of CCT and IOP remains to be further studied.

Roles of intraocular pressure in different degree of myopia and axial elongation in children / 中华实验眼科杂志

Background The development and progression of myopic eyes is biomechanical and dominated by axial elongation.The biomechanics change of stretching of the fundus and sclera appears to reduce its thickness and elastic modulus,which make eyeballs more susceptible to the distending forces of intraocular pressure (IOP).Objective This study was to analyz the axial length (AL) and IOP changes in different degree of myopia and investigate the roles of IOP in myopia development and AL elongation.Methods A prospective cases-controlled study was performed under the informed consent of patients and custodian.Four hundred and twenty-eight eyes of 428 children aged 4-14 years were enrolled in Affilicated Second Hospital of Zhengzhou University from February to December 2014.The patients were divided into 4 groups based on the refractive status.Ninety-three eyes of 93 patients were in the hyperopic-emmetropia group with the spherical equivalent (SE) of (1.81±2.32) D,192 eyes of 192 patients were in mild myopia group with the SE of (-1.43±0.74)D,83 eyes of 83 patients were in the moderate myopia group with the SE of (-4.09±0.89) D and 60 eyes of 60 patients were in the high myopia group with the SE of (-8.02±2.61) D.AL was measured by IOL Master system,IOP was measured by iCare tomnometer,and the central corneal thickness (CCT) was measured by OCT.The corrected IOP was calculated based on IOPcorrection =IOPGAT+(544-CCT)/37.03.The correlations between IOP ion and AL or diopter were analyzed.Results The AL values were (22.44±1.32) mm,(23.89±1.09) mm,(25.05±0.89) mm and (26.47±1.20) mm in the hyperopic-emmetropia group,mild myopia group,moderate myopia group and the high myopia group,showing a significant difference among the four groups (F =177.336,P =0.000).The IOP ion values were (15.24 ±2.73) mmHg,(17.51 ±2.98) mmHg,(17.94 ±2.34) mmHg and (18.49 ± 2.90) mmHg in the hyperopic-emmetropia group,mild myopia group,moderate myopia group and the high myopia group,with a significant difference among the four groups (F =22.104,P =0.000).The IOP tion values were significantly lower in the hyperopic-emmetropia group than that in the mild myopia group,moderate myopia group and high myopia group (all at P＜0.05),and the mean IOP tion value in the high myopia group was significantly higher than that in the mild myopia group (P =0.018).The IOP tion was negatively correlated with diopter (r =-0.384,P＜0.01) and positively correlated with AL (r =0.377,P＜0.01).Conclusions As the increase of myopic diopter and elongation of AL,IOPcorrection is considerably elevated in childhood.IOP tion rising in childhood probably promotes the progression of myopia and elongation of AL.

Association analysis of accommodative microfluctuations and wavefront aberration in emmetropia and myopia in teenagers / 中华实验眼科杂志

Background When focusing on a target,the accommodative system exhibits small variations in power within a range,termed microfluctuations.Exploring the correlation between the characters of microfluctuations and the aberrations of the eyes through a critical period-teenager can deepen the understanding of the onset and development of myopia.Objective This study was to investigate the correlation between accommodative microfluctuations and wavefront aberrations of human eyes,and to explore the role of accommodative microfiuctuations in the development of myopia.Methods A cross-sectional study was designed and performed.Fifty-four teenagers aged from 12 to 15 years were enrolled in this study in Eye Hospital,Wenzhou Medical University from 2010 to 2011,including 19 emmetropic subjects,18 incipient myopic subjects and 17 progressive myopic subjects,who were chosen based on the refractive changes for the last two years.The accommodative response and microfluctuations were measured by WAM-5500 infrared autorefractor with RSVP at 25,33 and 50 cm respectively,each RSVP distance was tested for 5 minutes.The accommodative values were divided into low frequency component (LFC) (0-0.6 Hz),middle frequency component(MFC) (0.6-0.9 Hz) and high frequency component (HFC) (1.0-1.4 Hz) after Fourier spectrum analysis.The wavefront aberrations of the whole eye and corneal were recorded by i-Trace aberrometer and Humphrey corneal topography.The differences of accommodative response,microfluctuations and aberrations were evaluated and compared among the emmetropic group,incipient myopic group and progressive myopic group.The correlations of accommodation and aberrations were analyzed.This study followed Declaration of Helsinki,and informed consent was obtained from each subject.Results Under the 25 cm and 33 cm reading distance,the accommodative response values were (2.78 ± 0.35) D and (2.19 ± 0.27) D in the emmetropic group,which were significantly higher than (2.44±0.33) D and (1.89±0.35)D in the progressive myopic group (P=0.002,0.003).LFC,MFC and HFC were remarkably increased as the reading distance decreased (Fdistance =8.480,14.270,21.400;all at P ＜0.01).A significant difference was seen in LFC among different reading distances (Fgroup =4.115,P＜0.05),and the LFCs in the progressive myopic group were considerably higher than those in the emmetropic group in the 25,33 and 50 cm reading distances (P=0.044,0.038,0.032).No significant differences were found in MFC and HFC among the three groups (Fgroup =0.859,0.682;both at P＞0.05).Under the 25 cm and 33 cm reading distances,significant positive correlations were found between LFC and corneal coma,intraocular coma,whole ocular aberrations or intraocular higher order aberrations (all at P＜0.05),however,no significant correlations were seen between MFC or HFC and wavefront aberrations (all at P＞0.05).Conclusions In teenagers,the accommodative response of emmetropia is much stronger than that of progressive myopia,and the accommodative microfluctuation in emmetropia and incipient myopia is much less than that in progressive myopia.These shifts are possibly associated with the variability,and microfluctuations of accommodation is greater in progressive myopes than emmetropes.There are certain correlations between wavefront aberrations and accommodative microfluctuations.The refractive group differences in the accommodative microfluctuations may be related to differences in the wavefront between myopes and emmetropes.Under near reading distance,LFC is correlated with higher order aberrations.

Expressions of complement factors C1q and C3 in retina with negative lens-defocused myopia in guinea pigs / 中华实验眼科杂志

Background High myopia is seriously harmful to visual function.To explore the mechanism of high myopia is significant for the prevention and treatment.Complement proteins C1q and C3 have emerged as critical mediators of synaptic refinement and plasticity,however,their effects in retina on myopia remain elusive.Objective This study was to investigate the expressions of complement factors C1q and C3 in the retina with negative lensdefocused myopia in guinea pigs.Methods The use and care of animals complied with the application of Peking Union Medical College Hospital Iaboratory Animal Welfare Ethics Committee.Twelve 3-day-old pigmented guinea pigs were assigned randomly to the lens-defocused group and the normal control group.The left eyes were covered by -10 D PMMA lens for 4 weeks as the defocused eye group,and the right eyes were covered using 0 D PMMA lens in the same way as the fellow control eye group.The right eyes of the normal guinea pigs were used as the normal control eye group.The refractive diopter of guinea pigs was examined by retinoscopy.The animals were sacrificed at the fourth week and the expressions of complement C1q and C3 in the retinas of guinea pigs were detected by Western blot.Results The diptors were (-1.21±0.71)D,(+2.46±0.75)D and (+1.75±0.50)Din the defocused eye group,normal eye group and the fellow eye group at the fourth week,showing a significant difference among the groups (F=51.55,P=0.69),and diopters were insignificantly different between the normal eye group and fellow eye group (q =2.62,P=0.08).However,the diopters of the defocused eye group were significantly higher than those of the fellow eye group (q =10.92,P＜0.01).The expressions of C1q and C3 proteins in the retinas were significantly different among the defocused eye group,fellow eye group and normal eye group (C1 q:F=8.810,P =0.003;C3:F =14.490,P＜0.001),and expression levels of C1q and C3 proteins in the defocused eye group were significant higher than those of the fellow eye group (C1q:q=4.14,P=0.01 ;C3:q=4.71,P=0.005) ;while no significant differences were found between the fellow eye group and the normal eye group (C1q:q =1.61,P =0.27; C3:q =2.82,P =0.070).Conclusions The expression levels of C1q and C3 up-regulate in the retinas with lens-defocused myopic animal model.Excessive complement activation in retinas may be involved in the development of myopia.