Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia

●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical trial was conducted.Totally 98 eyes(74 patients)who underwent femtosecond laser-assisted cataract surgery(FLACS)with trifocal IOLs were enrolled in the study and followed up for 2y after surgery:46 eyes(33 patients)with capsular tension ring implantation in the long axial lengths(AL)group(26<AL<29 mm)and 52 eyes(41 patients)in the normal AL group(22<AL<24.5 mm).Postoperative outcomes about effectivity and safety,including the subjective and objective visual quality,and postoperative complications were assessed.●RESULTS:Uncorrected distance visual acuity at 5 m and uncorrected intermediate visual acuity at 60 and 80 cm in the long AL group were significantly worse than those in the normal AL group at 3mo postoperatively(P<0.05).The differences in reading speed,spectacle independence and potential visual complaints between the two groups were not statistically significant(P>0.05).The dysfunctional lens index and total modulation transfer function(MTF)average height were similar between the two groups.The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group(P<0.05).The total satisfaction score in the long AL group(91.32±2.76)was slightly higher than that in the normal AL group(90.36±3.47),but there was no difference(P=0.136).A statistically negative correlation was found between corrected distance visual acuity(CDVA)and dysfunctional lens index(r=-0.382,P=0.009),and between CDVA and the total MTF average height(r=-0.374,P=0.01).But there was no significant correlation between CDVA and total satisfaction score(r=0.059,P=0.696).Postoperative complications mainly presented as posterior capsular opacity(PCO),retinal detachment and cystoid macular edema.There was no difference in the incidence of fundus disease(6.5%vs 3.8%,P=0.663)or PCO(17.4%vs 7.7%,P=0.217)between the two groups at two years.●CONCLUSION:The utilization of trifocal IOL and capsular tension ring implantation is beneficial for cataract patients with axial high myopia undergoing FLACS.This approach not only ensures excellent subjective feelings and objective visual quality,but also does not increase the incidence of postoperative complications.

Early changes in corneal densitometry after FS-LASIK combined with accelerated corneal cross-linking for correction of high myopia

AIM:To observe the effects of femtosecond laserassisted excimer laser in situ keratomileusis combined with accelerated corneal cross-linking(FS-LASIK Xtra)on corneal densitometry after correcting for high myopia.METHODS:In this prospectively study,130 patients underwent FS-LASIK or FS-LASIK Xtra for high myopia.Their right eyes were selected for inclusion in the study,of which 65 cases of 65 eyes in the FS-LASIK group,65 patients with 65 eyes in the FS-LASIK Xtra group.Patients were evaluated for corneal densitometry at 1,3,and 6mo postoperatively using Pentacam Scheimpflug imaging.RESULTS:Preoperative differences in corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups in different ranges were not statistically significant(P>0.05).Layer-by-layer analysis revealed statistically significant differences in the anterior(120μm),central,and total layer corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups at 1 and 3mo postoperatively(all P<0.05),the FS-LASIK Xtra group is higher than that of the FS-LASIK group.Analysis of different diameter ranges showed statistically significant differences between the FS-LASIK group and the FS-LASIK Xtra group at 1mo postoperatively in the ranges of 0–2,2–6,and 6–10 mm(both P<0.05);At 3mo postoperatively,the FS-LASIK Xtra group is higher than that of the FS-LASIK group in the ranges of 0–2 and 2–6 mm(P<0.05).At 6mo postoperatively,there were no statistically significant differences in corneal densitometry between the FS-LASIK group and the FS-LASIK Xtra group in different diameter ranges(all P>0.05).CONCLUSION:There is an increase in internal corneal densitometry during the early postoperative period after FS-LASIK Xtra for correction of high myopia.However,the densitometry values decreased to the level of conventional FS-LASIK at 6mo after surgery,with the most significant changes observed in the superficial central zone.

Rhegmatogenous retinal detachment in highly myopic eyes with implantable collamer lens

AIM:To investigate the clinical characteristics,treatment methods and outcomes of rhegmatogenous retinal detachment(RRD)in highly myopic eyes with implantable collamer lens(ICL).METHODS:High myopia patients who received treatment for nontraumatic RRD after ICL implantation surgery at the Retinal Department of Zhongshan Ophthalmic Center from Jan 2018 to Dec 2022 were reviewed.Comprehensive ophthalmologic examinations including visual acuity measurement and digital fundus photography were performed in each patient.RESULTS:A total of nine RRD eyes from nine patients who received V4c-ICL implantation were included.The mean time from ICL implantation surgery to the diagnosis of RRD was 32.44±22.56mo(range,1-60mo).At the initial visit for RRD,giant retinal tear(GRT),horseshoe tear,simple round hole,and horseshoe tear combined with round hole were detected in 3,3,2,and 1 eye(s),respectively,with maculaoff in eyes.Eight patients received surgical treatment,and one patient was treated by retinal laser photocoagulation alone.The ICL was preserved in 7 eyes.At the last followup,the mean best corrected visual acuity(BCVA)improved significantly from 1.76±1.06 logMAR at presentation to 0.81±1.01 logMAR(P=0.035),and no case of recurrent retinal detachment was found.CONCLUSION:The morphological presentation of retinal breaks is diverse in this study.The ICL can be preserved in most cases during the course of retinal detachment repair surgery in our data,companied with acceptable visual and anatomical outcomes.

Clinical Effect Analysis of Posterior Chamber Intraocular Lens Implantation for Correcting High Myopia and Astigmatism

Objective:To explore the corrective effect of posterior chamber intraocular lens implantation with phakic eyes in the treatment of high myopia and astigmatism.Methods:From May 2023,the hospital began to collect the case data of diagnosis and treatment of high myopia and astigmatism.By May 2024,310 cases were included,all of which were treated with posterior chamber intraocular lens implantation.The visual acuity,astigmatism and axial position of the intraocular lens were observed before and after treatment.Results:At different time points after the operation,the patient’s vision was significantly improved compared with that before the operation(P<0.05),and the vision level was equal to or greater than the best-corrected vision before the operation.At different time points after the operation,the average rotation of the intraocular lens was less than 5 degrees.Astigmatism was significantly lower than that before the operation(P<0.05).After the operation,the intraocular pressure increased in 11 cases,accounting for 3.55%,with no adverse complications such as lens turbidity,glare and obvious halo occurring.Conclusion:The posterior chamber intraocular lens implantation with phakic eyes has an ideal correction effect in the treatment of high myopia and astigmatism,which can effectively improve the vision level of patients and reduce the degree of astigmatism,and has high effectiveness and safety.

Retinoschisis at Macular Area in Highly Myopic Eye by Optic Coherence Tomography

Purpose:To improve our understanding of macular schisis in highly myopic eyes. Methods:From 2002.6-2003.12, the highly myopic eyes(>6D) which has macular schisis found by OCT at our hospital were included in the study. Each eye then received further examinations including visual acuity,refractive error and ultra-sonography. Then the results were analyzed to find the characteristic of the entity. Results:During that period, OCT found macular schisis in 38 highly myopic eyes from 36 patients. Their vision was low, and their average axial length and refractive error were 29.6mm and -10.5D respectively. The appearance and the area of the schisis are different among the eyes. But the schisis can be largely divided into two types: inner and outer schisis. They can exit independently or concurrently in the same eye. And the schisis was often accompanied by other macular findings, like retinal detachment, macular hole. Conclusion:Macular schisis in highly myopic eyes is not uncommon in the clinic. OCT is useful in its diagnosis.

Long-term vision-threatening complications of phakic intraocular lens implantation for high myopia

AIMTo report the long-term vision-threatening complications in patients who underwent phakic intraocular lens (pIOLs) implantation for high myopia.

Accuracy of axial length measurements from immersion B-scan ultrasonography in highly myopic eyes

AIM:To evaluate the accuracy of axial length(AL)measurements obtained from immersion B-scan ultrasonography(immersion B-scan)for intraocular lens(IOL)power calculation in patients with high myopia and cataracts.METHODS:Immersion B-scan,contact A-scan ultrasonography(contact A-scan),and the IOLMaster were used to preoperatively measure the AL in 102 eyes from 102 patients who underwent phacoemulsification and IOL implantation.Patients were divided into two groups according to the AL:one containing patients with22 mm≤AL【26 mm(group A)and the other containing patients with AL≥26 mm(group B).The mean error(ME)was calculated from the difference between the AL measurement methods predicted refractive error and the actual postoperative refractive error.RESULTS:Ingroup A,ALs measured byimmersion Bscan(23.48±1.15)didn’t differ significantly from those measured by the IOLMaster(23.52±1.17)or from those by contact A-scan(23.38±1.20).In the same group,the standard deviation(SD)of the mean error(ME)of immersion B-scan(-0.090±0.397 D)didn’t differ significantly from those of IOLMaster(-0.095±0.411 D)and contact A-scan(-0.099±0.425 D).In group B,ALs measured by immersion B-scan(27.97±2.21 mm)didn’t differ significantly from those of the IOLMaster(27.86±2.18 mm),but longer than those measured by Contact A-scan(27.75±2.23 mm,P=0.009).In the same group,the standard deviation(SD)of the mean error(ME)of immersion B-scan(-0.635±0.157 D)didn’t differ significantly from those of the IOLMaster(-0.679±0.359 D),but differed significantly from those of contact A-scan(-0.953±1.713 D,P=0.028).CONCLUSION:ImmersionB-scanexhibitsmeasurement accuracy comparable to that of the IOLMaster,and is thus a good alternative in measuring AL in eyes with high myopia when the IOLMaster can’t be used,and it is more accurate than the contact A-scan.

Diagnostic ability of ganglion cell complex thickness to detect glaucoma in high myopia eyes by Fourier domain optical coherence tomography

AIM：To evaluate the ability of macular ganglion cell complex（GCC） thickness using Fourier domain optical coherence tomography（FD-OCT） to detect glaucoma in highly myopic eyes.METHODS：Cross-sectional study.A total of 114 participants,consecutively were enrolled.Macular GCC thickness and peripapillary retinal nerve fiber layer（RNFL） thickness were obtained with RTVue FD-OCT.Receiver operating characteristics curves were constructed for each measurement parameter,and areas under the curves（AUCs） were compared.RESULTS：Both the average GCC and average RNFL thickness showed negative correlations with axial length（rGCC=-0.404,P=0.001;rRNFL=-0.561,P〈0.001）.The largest AUCs from GCC,and RNFL parameters were 0.968 [global loss volume（GLV）],and 0.855（average RNFL）,respectively.GLV was significantly better for detecting high myopic glaucoma than average RNFL（P〈0.001）.CONCLUSION：Macular GCC thickness has higher diagnostic power than peripapillary RNFL thickness to discriminate glaucoma patients from non-glaucoma subjects in high myopia.

Comparison axial length measurements from three biometric instruments in high myopia

AIM： To compare the axial lengths （ALs） measured with Lenstar, IOLMaster and A-scan contact ultrasound （Ultrasound） in normal and high myopia （HM）. METHODS： Eighty-four normal eyes and 49 HM eyes were included. Three consecutive measurements were performed on each eye in the following order： Lenstar, IOLMaster, and Ultrasound. The repeatabilities of the AL measurements for each instrument were assessed by calculating the pooled coefficients of variation （CVs） of 18 eyes in each group. Comparisons between the HM and normal groups were made with independent sample t-tests. The inter-device agreements were evaluated with Bland-Altman analyses and paired two-tailed t-tests. RESULTS： For normal group, the CVs of the AL measurements taken with the Lenstar, IOLMaster and Ultrasound were 0.001%, 0.01% and 0.14%, respectively. The corresponding CVs for the HM group were 0.005%, 0.02% and 0.15%, respectively. There was significant difference between the Lenstar and the IOLMaster in normal group （P=0.031） but not in HM group （n=0.100）. In the two groups, the Lenstar and the IOLMaster produced higher values than did the Ultrasound （all P〈 0.001）. All three instruments exhibited good agreement in terms of AL values. For the intraocular lens （IOL） power calculation using SRK II formula, the Lenstar and the IOLMaster showed 0.5 D higher than Ultrasound in both groups （all P〈0.001）. No significant difference existed between the Lenstar and the IOLMaster for the IOL power calculation in both normal （n=0.474） and HM group （P= 0.103）. CONCLUSION： The three devices exhibited excellent intra-visit repeatabilities in the AL measurements. The AL and IOL power difference between partial coherence interferometry and ultrasound instruments should be noticed.

The association of lumican polymorphisms and high myopia in a Southern Chinese population

AIM：To investigate the correlation between lumican（LUM）gene and high myopia in a Southern Chinese population.METHODS：The study comprised of 95 high myopia patients with a spherical equivalent≤-6.5 diopters（D）.The control group recruited 95 individuals with a spherical equivalent ranging from-0.5 D to＋0.5 D.Direct sequencing was used to detect the single nucleotide polymorphisms（SNPs）of LUM gene in coding region.Genotype distributions were tested for Hardy-Weinberg disequilibrium.Genotypic and allelic frequencies were analyzed through Chi-square test or Fisher’s exact test.RESULTS：We identified 3 SNPs of the LUM gene：LUM c.32（rs577456426）,LUM c.507（rs17853500）and LUM c.849（rs181915277）.Among the three SNPs,the genotype and allele frequencies of rs17853500 showed a significant difference between patients and control subjects（P〈0.05）.However,there were no significant differences in rs181915277and rs577456426 between the two groups（P〉0.05）.CONCLUSION：LUM c.507 polymorphism may be a risk factor for the pathogenesis of high myopia in the Southern Chinese population.

High myopia as a risk factor in primary open angle glaucoma

Glaucoma, one of the leading causes of irreversible blindness in the adult population worldwide, is a progressive optic neuropathy. Primary open angle glaucoma (POAG) is the most commonly reported type of glaucoma in population based prevalence studies worldwide. Elevated intraocular pressure is a well-known major risk factor for POAG. In addition, there is growing evidence that other risk factors like age, gender, race, refractive error, heredity and systemic factors may play a role in glaucoma pathogenesis. Many studies found that high myopia has been associated with POAG, however, direct and convincing evidences are still lacking. The aim of this review is to summarize the evidences implicating high myopia as a risk factor in the pathogenesis of POAG.

Association between lumican gene-1554 T/C polymorphism and high myopia in Asian population:a meta-analysis

AIMTo investigate the association between lumican gene -1554 T/C polymorphism and high myopia susceptibility.

Measurements of the parapapillary atrophy area and other fundus morphological features in high myopia with or without posterior staphyloma and myopic traction maculopathy

AIM:To investigate the affecting factors of parapapillary gamma and delta zones and other fundus morphological features in high myopia.METHODS:Seventy high myopia patients were included in this retrospective observational study and 47 patients were female.Patients were divided into three groups:no posterior staphyloma(no PS),PS with myopic traction maculopathy(PS with MTM),and PS without MTM using 3-dimensional magnetic resonance imaging and optical coherence tomography.MTM patients were fur ther classified into three types[epiretinal membrane,macular hole,and macular retinoschisis(MRS)].Diameters of the gamma and delta zones were measured among other morphometric variables using fundus photographs.RESULTS:Of the 70 individuals(127 eyes),the mean age was 57.46±13.56y.In univariate analysis,morphological features changed most dramatically in PS with MTM patients,who had the largest gamma zone diameters,the largest disk-fovea distance(DFD)and disk-fovea angle,and the smallest angle kappa and vertical distance of temporal arterial arcade.However,their horizontal delta zone diameter was smaller than in the patients with PS yet without MTM.In multivariate analysis,with axial length(AL)and age adjusted,the horizontal diameter in the delta zone of the PS without MTM group was still significantly larger than in the PS with MTM group(P=0.024).Comparing the three subtypes of MTM patients,the diameters of the gamma zone and DFD in MRS group were the largest.CONCLUSION:The characteristics of the gamma and delta zones change inconsistently in different stages of high myopia.These changes may be associated with anatomical changes caused by local traction.Factors such as PS,AL and age play an important role.These findings may provide a hint about the pathogenesis of traction in high myopia.

Genetic association of COL1A1 polymorphisms with high myopia in Asian population: a Meta-analysis

AIM: To comprehensively evaluate the potential association of COL1A1 polymorphisms with high myopia by a systematic review and Meta-analysis. METHODS: All association studies on COL1A1 and high myopia reported up to June 10, 2014 in PubMed, Embase, Web of Science, and the Chinese Biomedical Database were retrieved. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were analyzed for single-nucleotide polymorphisms (SNPs) using fixed- and random - effects models according to between-study heterogeneity. Publication bias analyses were conducted by Eggers test. RESULTS: A total of four studies from reported papers were included in this analysis. The Meta-analyses for COL1A1 rs2075555, composed of 2304 high myopia patients and 2272 controls, failed to detect any significant association with high myopia. A total of 971 cases and 649 controls were tested for COL1A1 rs2269336. The association of COL1A1 rs2269336 with high myopia was observed in recessive model (CC vs CG+GG, P = 0.03) and in heterozygous model (CG vsGG, P = 0.04), but not in other models. CONCLUSION: This Meta-analysis shows that COL fill rs2269336 (CC vs CG +GG) affects individual susceptibility to high myopia, whereas there is no association detected between SNPs rs2075555 and high myopia. Given the limited sample size, further investigations including more ethnic groups are required to validate the association.

Five-year results of refractive outcomes and visionrelated quality of life after SMILE for the correction of high myopia

AIM:To evaluate the long-term visual,refractive outcomes and vision-related quality of life after small incision lenticule extraction(SMILE)for the correction of high myopia.METHODS:Thirty patients(60 eyes)with high myopia who underwent SMILE more than 5y were selected as the SMILE group.Another 30 high myopia patients(60 eyes)who had worn corrective spectacles for more than 5y were selected as the control group.In SMILE group,the postoperative follow-up time were 3,6 mo,1 and 5y.Uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),spherical equivalent(SE),and ocular axial length(AL)were analyzed.The Chinese version of the National Eye Institute Visual Function Questionnaire-25(CHI-NEI-VFQ-25)was used to evaluate the vision-related quality of life in the SMILE group and the control group.RESULTS:In SMILE group,the mean preoperative SE was-7.29±0.87 D(range-6.00 to-9.125 D).At 5-year follow up,the efficacy index and safety index of SMILE were 1.09±0.18 and 1.19±0.12,respectively.Five years postoperatively,44 eyes(73%)obtained a visual acuity of 20/20 or better.There were no eyes with CDVA loss of one or more Snellen lines.Forty-nine eyes(82%)and 57 eyes(95%)were within±0.50 and±1.00 D of attempted correction at 5-year follow-up,respectively.Forty-eight eyes(80%)had astigmatism<0.50 D at 5-year followup.The postoperative mean SE values at 3,6 mo,1,and 5y were 0.11±0.44,0.07±0.45,-0.02±0.41,and-0.15±0.46 D,respectively.No significant change was observed in the ocular AL from before operation to 5y postoperatively(26.08±0.96 mm vs 26.01±0.94 mm,P=0.068).Compared to the control group,the SMILE group showed a significantly higher total score on the CHI-NEI-VFQ-25(90.14 vs 81.43,P<0.001).CONCLUSION:In the present study,in a long-term follow-up we demonstrate that correcting high myopia with SMILE is safe,effective,and predictable.Vision-related quality of life after SMILE is better in the SMILE group than in the control group who wore corrective spectacles.

Macular Bruch's membrane defects and other myopic lesions in high myopia

AIM: To compare the ocular fundus features of highly myopic eyes with and without macular Bruch’s membrane(BM) defects and investigate the associations between macular BM defects and other myopic lesions.METHODS: This retrospective, observational case series included 262 eyes(139 patients) with high myopia(HM) refractive error ≥-6.0 diopters(D) or axial length ≥26.5 mm from March 2019 to December 2019.The patients underwent a comprehensive ophthalmic examination, including sweptsource optical coherence tomography(SS-OCT).The features of macular BM defects and other ocular fundus lesions were examined in OCT images.RESULTS: Totally 51 eyes(19.5%) were detected with macular BM defects, which were characterized by a lack of BM, retinal pigment epithelium(RPE), and an almost complete loss of photoreceptors or choriocapillaris.Eyes with macular BM defects had worse best-corrected visual acuity(BCVA) than those without(P<0.001).Dome-shaped macula(DSM, P=0.042), retinal cysts(P=0.006), choroidal neovascularization(CNV, P<0.001), choroidal defects and abnormality(P=0.003), scleral defects(P=0.015), scleral deformation(P=0.005), posterior staphyloma(P=0.011), and perforating vessels(P<0.001) occurred more frequently in eyes with macular BM defects.In multivariate analysis, the presence of macular BM defects remained the significant association with presence of DSM(P=0.013), scleral defects(P=0.015), posterior staphyloma(P=0.001), perforating vessels(P<0.001) and CNV(P=0.004).CONCLUSION: Macular BM defects has a prevalence of approximately 20% in HM and it has tight association with other myopic fundus lesions.BM might be crucial in the pathogenesis of myopic fundus lesions due to its biomechanical function.A comprehensive understanding of BM’s role is useful for further researches about myopic lesions.

Trends in research related to high myopia from 2010 to 2019:a bibliometric and knowledge mapping analysis

AIM:To evaluate the global trends in and explore hotspots of high myopia(HM)research.METHODS:This bibliometric analysis was used to reveal the publication trends in HM research field based on the Web of Science Core Collection(WoSCC).VOSviewer version 1.6.13 software was used to analyze the data and construct a knowledge map including the yearly publication number,journals,countries,international collaborations,authors,research hotspots,and intellectual base in HM.RESULTS:The search engine found 3544 peer-reviewed publications on HM between 2010 and 2019,and the yearly research output substantially elevated over the past decade.China is the top publishing country,and Sun Yatsen University was the most active academic institution.Jonas JB is the top publishing scientist,and Investigative Ophthalmology and Visual Science(IOVS)was the most productive journal.The highest cited references mainly focused on epidemiology and management.The keywords formed 6 clusters:1)refractive surgery;2)etiology and clinical characteristics;3)the mechanism of eye growth;4)management for myopic maculopathy;5)vitrectomy surgical treatment;6)myopia-associated glaucoma-like optic neuropathy.CONCLUSION:The evaluation of development trends based on the data extracted from WoSCC can provide valuable information and guidance for ophthalmologists and public health researchers to improve management procedures in HM field.

Visual quality after implantation of trifocal intraocular lenses in highly myopic eyes with different axial lengths

AIM:To analyze postoperative clinical results after implantation of trifocal intraocular lenses(IOLs)in highly myopic eyes with different axial lengths(ALs).METHODS:This retrospective study describes 61 eyes of 44 patients that were implanted with trifocal diffractive IOLs(AT LISA tri 839 MP).Twenty-one eyes(15 patients)were included in the AL<26 mm group,19 eyes(13 patients)in the AL≥26 mm and<28 mm group,and 21 eyes(16 patients)in the AL≥28 mm group.Postoperative outcomes,including corrected and uncorrected distance visual acuity(UDVA),intermediate and near visual acuity at 167 cd/m2 luminance,depth of focus at 85 cd/m2 luminance,and objective optical quality parameters assessed using the Optical Quality Analysis System(OQAS),were compared among the groups at 3 mo.RESULTS:There were no significant differences in the mean UDVA,uncorrected intermediate visual acuity,uncorrected near visual acuity,corrected distance visual acuity,distance-corrected intermediate visual acuity,and distance-corrected near visual acuity(DCNVA)among the three groups(P>0.05).Better near and intermediate visual acuity(from-1.5 D to-3.0 D)were noted on the defocus curve of the AL<26 mm group(P<0.01 vs AL≥28 mm group).Significantly higher objective scatter index(OSI)values and lower modulation transfer function(MTF)cut-off values,Strehl ratio(SR),and OQAS values(OVs)were observed in the AL≥28 mm group(P<0.01 vs AL<26 mm group).All OQAS parameters had statistically significant correlations with DCNVA and visual acuity at the vergence of-2.5 D(P<0.05 to P<0.01).CONCLUSION:Implantation of trifocal IOLs provides good short-term visual and refractive outcomes in highly myopic eyes with different ALs.However,the near vision decreases in the extremely myopic eyes at lower luminance,which is associated with the lower objective optical quality in these eyes.

Abnormal resting-state functional network centrality in patients with high myopia： evidence from a voxel-wise degree centrality analysis

AIM： To investigate the functional networks underlying the brain-activity changes of patients with high myopia using the voxel-wise degree centrality（DC） method.METHODS： In total, 38 patients with high myopia（HM）（17 males and 21 females）, whose binocular refractive diopter were-6.00 to-7.00 D, and 38 healthy controls（17 males and 21 females）, closely matched in age, sex, and education levels, participated in the study. Spontaneous brain activities were evaluated using the voxel-wise DC method. The receiver operating characteristic curve was measured to distinguish patients with HM from healthy controls. Correlation analysis was used to explore the relationship between the observed mean DC values of the different brain areas and the behavioral performance.RESULTS： Compared with healthy controls, HM patients had significantly decreased DC values in the right inferior frontal gyrus/insula, right middle frontal gyrus, and right supramarginal/inferior parietal lobule（P〈0.05）. In contrast, HM patients had significantly increased DC values in the right cerebellum posterior lobe, left precentral gyrus/postcentral gyrus, and right middle cingulate gyrus（P〈0.05）. However, no relationship was found between the observed mean DC values of the different brain areas and the behavioral performance（P〉0.05）.CONCLUSION： HM is associated with abnormalities in many brain regions, which may indicate the neural mechanisms of HM. The altered DC values may be used as a useful biomarker for the brain activity changes in HM patients.

Clinical outcomes of transepithelial photorefractive keratectomy versus femtosecond laser assisted keratomileusis for correction of high myopia in South Egyptian population

AIM: To evaluate the safety and efficacy of transepithelial photorefractive keratectomy(t-PRK) with adjuvant mitomycin C(MMC) versus femtosecond laser assisted keratomileusis(Femto-LASIK) in correction of high myopia.METHODS: Prospective randomized comparative study including 156 eyes of 156 patients with high myopia and a spherical equivalent refraction(SER) <-6.00 D. They were divided randomly into two groups: Group A included 72 eyes treated with t-PRK with adjuvant MMC and Group B included 84 eyes treated with Femto-LASIK. Visual acuity, SER, corneal topography, pachymetry and keratometry were assessed for 12 mo postoperatively.RESULTS: The preoperative mean SER was-8.86±1.81 and-9.25±1.70 D in t-PRK MMC group and Femto-LASIK respectively(P=0.99) which improved to-0.65±0.43 D and-0.69±0.50 D at 12 mo follow up. Mean SER remained stable during the 12 mo of follow-up, with no statistically significant difference between the two groups(P=0.64). In t-PRK MMC group, only six eyes needed retreatment after six months of follow up. And two eyes showed haze(one reversible haze grade 2, while the other had dense irreversible haze grade 4).CONCLUSION: t-PRK MMC provides safe and satisfactory visual outcomes and acceptable risk as Femto-LASIK in patients with high myopia.