Applications of SMILE-extracted lenticules in ophthalmology

AIM:To review recent innovations,challenges,and applications of small incision lenticule extraction(SMILE)extracted lenticule for treating ocular disorders.METHODS:A literature review was performed in the PubMed database,which was last updated on 30 December 2021.There was no limit regarding language.The authors evaluated the reference lists of the collected papers to find any relevant research.RESULTS:Due to the simplicity and accuracy of modern femtosecond lasers and the extensive development of SMILE surgery,many healthy human corneal stromal lenticules were extracted during surgery,motivating some professionals to investigate the SMILE lenticule reusability in different ocular disorders.In addition,new approaches had been developed to preserve,modify,and bioengineer the corneal stroma,leading to the optimal use of discarded byproducts such as lenticules from SMILE surgery.The lenticules can be effectively re-implanted into the autologous or allogenic corneas of human subjects to treat refractive errors,corneal ectasia,and corneal perforation and serve as a patch graft for glaucoma drainage devices with better cosmetic outcomes.CONCLUSION:SMILE-extracted lenticules could be a viable alternative to human donor corneal tissue.

Prevalence of retinal pathologies in people over 60 years:the Tehran Geriatrics Eye Study

AIM:To determine the prevalence of some retinal pathologies in people over 60y and their association with demographic and ocular factors.METHODS:A cross-sectional study was conducted in Tehran using multistage cluster sampling.After selecting subjects aged 60 and over,optometric,and ophthalmic examinations were done.For retinal examination,a 90 D lens was used and indirect ophthalmoscopy was performed after instilling tropicamide drops.Biometry was done using the IOL Master for all participants.RESULTS:Of 3791 people that were invited through cluster sampling,3310 participated in the study(response rate=82%).The prevalence of retinal pigmented epithelium(RPE)change,drusen,geographic atrophy(GA),hypertensive retinopathy(HTR),nonproliferative diabetic retinopathy(NPDR),proliferative diabetic retinopathy(PDR),choroidal neovascularization(CNV),central retinal artery occlusion(CRAO),myopic retinopathy(MR),branch retinal vein occlusion(BRVO),and central retinal vein occlusion(CRVO)was 27.42%,11.08%,4.52%,3.03%,4.05%,0.54%,0.82%,0.39%,0.20%,0.49%,and 0.19%,respectively.After removing the effect of age,the odds of NPDR were 1.68 times higher in women compared to men(P=0.014).After removing the effect of sex,the odds of drusen,RPE change,GA,CNV,BRVO,and CRVO increased with age.CONCLUSION:There is a higher prevalence of RPE change,drusen,GA,CNV and a lower prevalence of MR and CRAO in the elderly population of Tehran aged over 60y compared to global average values.Considering the correlation of most of the diseases with age and their effects on vision,attention should be paid to these diseases and the related screening programs to prevent vision impairment.

Epidemiological aspect of retinoblastoma in the world: a review of recent advance studies

·AIM: To collect and present updated evidence about epidemiological aspects of retinoblastoma(Rb) in the world.·METHODS: A comprehensive search without the time and language restrictions was conducted in international databases, including MEDLINE, Scopus, Web of Science, and Pub Med. The search keywords were “retinoblastoma” OR “retinal Neuroblastoma” OR “retinal glioma” OR “retinoblastoma eye cancer” OR “retinal glioblastoma”.·RESULTS: The worldwide incidence of Rb is 1 in 16 000-28 000 live births, but was higher in developing compared to developed countries. Several attempts for improving early detection and treatment had increased the Rb survival rate from 5% to 90% in developed countries over the past decade, but its survival was lower in developing countries(about 40% in low-income countries) and the majority of mortalities occurred in developing countries. The etiology of Rb could be viewed as genetics in the heritable form and environmental and lifestyle factors in the sporadic form. Some environmental risk factors such as in vitro fertilization;insect sprays;father’s occupational exposure to oil mists in metal working, and poor living conditions might play a role in the occurrence of the disease. Although ethnicity might affect Rb incidence, sex has no documented effect and the best treatment approaches were now ophthalmic artery chemosurgery and intravitreal chemotherapy.·CONCLUSION: Determining the role of genetics and environmental factors helps to accurately predict the prognosis and identify the mechanism of the disease, which can reduce the risk of tumor development.

Auto-refraction versus subjective refraction in different phakic and pseudophakic conditions:the Tehran Geriatric Eye Study(TGES)

AIM:To compare the subjective refraction data with non-cycloplegic auto-refraction findings in the geriatric population above 60 years of age according to the different crystalline lens conditions.METHODS:This report is a part of the Tehran Geriatric Eye Study(TGES)that was conducted from January 2019 to January 2020 on elderly population 60 years of age and above in Tehran.The samples were selected by multistage stratified random cluster sampling.Of 3791 individual invitees,3310(response rate:87.3%)participated in this study.All study participants underwent non-cycloplegic autorefraction(auto-refractometer/keratometer Nidek ARK-510)and subjective refraction.RESULTS:Regarding the sphere,eyes with mixed cataract had the worst limits of agreement(LoA:-1.24 to 0.87)and the best agreement was related to the pseudophakic eyes(LoA:-0.83 to 0.54).The highest(0.27±0.31 D)and lowest(0.21±0.27 D)differences between the two methods regarding the cylinder power were observed in eyes with cortical cataract and normal eyes,respectively.The worst LoA between the two methods in measuring the cylinder power was related to the eyes with mixed cataract(LoA:-0.44 to 0.96).Regarding the J0(horizontal/vertical components of astigmatism),the mean values of J0 obtained by auto-refraction were tended more toward against the rule direction in all crystalline lens conditions,and the two methods had the greatest difference in cortical cataract cases(0.05±0.17 D).Regarding the J45(oblique components of astigmatism),the lowest(0±0.11 D)and highest(-0.01±0.12 D)differences were observed in normal eyes and eyes with cortical cataract,respectively.CONCLUSION:The auto-refractometer/keratometer Nidek ARK-510 results in the elderly with different phakic and pseudophakic conditions do not correspond well with subjective refraction findings.This discrepancy in spherical findings is more pronounced in individuals with mixed cataract than in other cases.

Axial length and anterior chamber indices in elderly population: Tehran Geriatric Eye Study

AIM:To determine the normative distribution of axial length(AL),anterior chamber depth(ACD),anterior chamber volume(ACV),anterior chamber angle(ACA),and some of their associated factors in subjects aged 60 and over.METHODS:In this cross-sectional study,160 clusters were sampled using multi-stage cluster sampling in Tehran,Iran.After a preliminary interview,the participants underwent optometric examinations including visual acuity and refraction measurement followed by slit lamp biomicroscopy.Finally,ocular imaging was done using the Pentacam AXL to measure AL,ACD,ACV,and ACA.RESULTS:A total of 4519 eyes of 2436 participants were evaluated,of whom 58.0%(n=1412)were female.The mean age of the subjects was 67.32±6.05y(range:60-95y).The mean AL,ACD,ACV,and ACA was 23.22 mm(23.18-23.27 mm),2.61 mm(2.59-2.62 mm),126.56 mm3(125.08-128.04 mm3),and 30.61°(30.3°-30.92°),respectively.In the multivariable model,after adjusting for the effect of both eyes,the longest and shortest AL was seen in myopic and hyperopic subjects,respectively.AL,ACD,ACV and ACA were significantly larger in men compared to women(P<0.001).Except ACA,other evaluated parameters showed an inverse correlation with age(P<0.001),however,this correlation was insignificant for AL(P=0.623).CONCLUSION:Normative value of AL,and other biometric parameters are specific for each ethnicity,age and sex group.Any alteration in these parameters and their effect on refraction should be considered in this age group,especially in case of cataract surgery.

The prevalence of red-green color vision deficiency and its related factors in an elderly population above 60 years of age

AIM:To determine the prevalence of red-green(RG)color vision deficiency(CVD)in an elderly population and its related factors.METHODS:This report is a part of the Tehran Geriatric Eye Study:a cross-sectional population-based study that was conducted on the elderly population(≥60y)of Tehran,Iran using multi-stage stratified random cluster sampling.All study participants underwent complete ocular examination,including the measurement of uncorrected and bestcorrected visual acuity,objective and subjective refraction,and slit-lamp biomicroscopy.The color vision was tested using Ishihara plates with the near optical correction in place.RESULTS:Of the 3791 invitees,3310 participated in the study.The data of 2164 individuals were analyzed after applying the exclusion criteria.The prevalence of R-G CVD was 3.73%(95%CI:2.37%–5.09%)in the whole sample;the prevalence of protanomaly,protanopia,and deuteranopia was 1.51%,1.76%,and 0.45%,respectively.The prevalence of R-G CVD was significantly higher in males than in females.The prevalence of RG CVD increased with advancing age from 2.91%in the age group 60–64y to 5.8%in the age group≥80y(P=0.070).According to the multiple logistic regression model,male sex,and glaucoma were significantly related to RG CVD.Older age and hypertension also had a marginally significant relationship with RG CVD.CONCLUSION:Changes in color vision occur in the elderly due to the aging process and some physiological and pathological factors.Since the change in visual perception may affect the person’s performance,this aspect of the visual system’s function should also be taken into consideration in the examinations of the elderly.

Receded near point of convergence as a predictor of mild cognitive impairment in the general geriatric population:results from a population-based study

AIM:To investigate the relationship between near point of convergence(NPC)and mild cognitive impairment(MCI)in the general elderly population.METHODS:The present report is a part of the Tehran Geriatric Eye Study(TGES):a population-based crosssectional study conducted on individuals 60 years of age and above living in Tehran,Iran using the multi-stage stratified random cluster sampling method.Cognitive status was assessed using the Persian version of the Mini-Mental State Examination(MMSE).All study participants underwent complete ocular examination including measurement of uncorrected and best-corrected visual acuity,objective and subjective refraction,cover testing,NPC measurement,and slit-lamp biomicroscopy.RESULTS:The data of 1190 individuals were analyzed for this report.The mean age of the participants analyzed was 66.82±5.42(60-92y)and 728(61.2%)of them were female.Patients with MCI had a significantly more receded NPC compared to subjects with normal cognitive status(10.89±3.58 vs 7.76±2.71 cm,P<0.001).In the multivariable logistic regression model and in the presence of confounding variables,a receded NPC was statistically significantly associated with an increased risk of MCI(odds ratio:1.334,95%confidence interval:1.263 to 1.410,P<0.001).According to receiver operating characteristic(ROC)analysis,a cut point NPC>8.5 cm(area under the curve:0.764,P<0.001)could predict the presence of MCI with a sensitivity and specificity of 70.9%and 69.5%,respectively.CONCLUSION:A receded NPC can be clinically proposed as a predictor of MCI in older adults.It is recommended that elderly with a receded NPC>8.50 cm undergo detailed cognitive screening for a definite diagnosis of MCI.In this case,the necessary interventions can be carried out to slow down MCI progression to dementia.

Distribution and associated factors of intraocular pressure in the older population:Tehran Geriatric Eye Study

AIM:To determine the distribution and associated factors of intraocular pressure(IOP) in an Iranian elderly population 60 years of age and above.METHODS:The present report is part of the Tehran Geriatric Eye study(TGES),a population-based cross-sectional study that was conducted on the residents of Tehran 60 years of age and above.The sampling was performed using multistage stratified random cluster sampling methods from 22 districts of Tehran,Iran.Demographic and history information,blood samples,and blood pressure were collected from all participants.Ocular examinations included measurement of uncorrected and best-corrected visual acuity,objective and subjective refraction,and slit-lamp biomicroscopy.The IOP was measured using Goldmann applanation tonometry(GAT).Corneal imaging and ocular biometry were performed using Pentacam AXL.RESULTS:The data of 3892 eyes of 2124 individuals were analyzed for this report.The mean age of the study participants was 66.49±5.31y(range:60 to 95y).The mean IOP was 15.2 mm Hg(95%CI:15.1 to 15.4),15.3 mm Hg(95%CI:15.1 to 15.5) and 15.1 mm Hg(95%CI:15.0 to 15.3) in all participants,males,and females,respectively.Of the study participants,1.3% had an IOP of ≥20 mm Hg.The mean IOP increased from 15.1 mm Hg in the age group 60-64y to 16.3 mm Hg in the age group ≥80y.According to the final multiple GEE model,the IOP was statistically significantly higher in men than in women.All the studied age groups,except for the 75-79-year-old age group,had significantly higher IOP compared to the 60-64-year-old age group.The IOP was significantly higher in underweight compared to other body mass index groups.Moreover,the IOP had a statistically significant direct relationship with the mean corneal power(mean CP),central corneal thickness(CCT),and systolic blood pressure.CONCLUSION:The present study presents the distribution of IOP in an Iranian elderly population.A higher IOP(within the range 14 to 17 mm Hg) is significantly associated with older age,male sex,high systolic blood pressure,increased mean CP,and CCT.These factors should be considered in the clinical interpretation of IOP.

Residual refractive errors in pseudophakic eyes and related factors:a population-based study

AIM: To determine residual refractive error after cataract surgery in pseudophakic eyes and its relationship with age, sex, and axial length(AL).METHODS: In this population-based cross-sectional study, the sampling was performed on individuals aged 60y and above in Tehran, Iran using a multi-stage stratified random cluster sampling method. Pseudophakic eyes with a best-corrected visual acuity of 20/32 or better were analyzed and their refractive results were reported.RESULTS: The mean spherical equivalent(SE) refraction was-0.34±0.97 diopters(D) and the mean absolute SE was 0.72±0.74 D with a median of 0.5 D. Moreover, 32.68%(n=546, 95%CI: 30.27%-35.08%), 53.67%(n=900, 95%CI: 51.23%-56.1%), 68.99%(n=1157, 95%CI: 66.96%-71.02%), and 79.73%(n=1337, 95%CI: 77.69%-81.76%) of the eyes had a residual SE within ±0.25, ±0.50, ±0.75, and ±1.00 D of emmetropia, respectively. According to the multiple logistic regression model, increasing age was associated with a statistically significant decrease in predictability for all cut points. Moreover, the predictability based on all cut points was significantly lower in individuals with an AL longer than 24.5 mm than in those with an AL between 22 to 24.5 mm.CONCLUSION: Based on the results, the accuracy of intraocular lens(IOL) power calculation is lower for those who underwent cataract surgery during the last 5y in Tehran, Iran. Among the most important influential factors, the choice of IOL or it's power disproportionate to eye conditions and age can be mentioned.

Smartphones,tele-ophthalmology,and VISION 2020

Telemedicine is an emerging field in recent medical achievements with rapid development. The ＂smartphone＂ availability has increased in both developed and developing counffies even among people in rural and remotes areas. Telebased services can be used for screening ophthalmic diseases and also monitoring patients with known diseases. Electronic ophthalmologic records of the patients including captured images by smartphones from anterior and posterior segments of the eye will be evaluated by ophthalmologists, and if patients require further evaluations, they will be referred to experts in the relevant field. Eye diseases such as cataract, glaucoma, age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity are the most common causes of blindness in many countries and beneficial use of teleophthalmology with smartphones will be a good way to achieve the aim of VISION 2020 all over the world. Numerous studies have shown that teleophthalmology is similar to the conventional eye care system in clinical outcomes and even provides more patient satisfaction as it saves time and cost, This review explains how teleophthalmology helps to improve patient outcomes through smartphones.

Evaluation of corneal topographic,tomographic and biomechanical indices for detecting clinical and subclinical keratoconus:a comprehensive three-device study

AIM:To evaluate the diagnostic ability of topographic and tomographic indices with Pentacam and Sirius as well as biomechanical parameters with Corvis ST for the detection of clinical and subclinical forms of keratoconus(KCN).METHODS:In this prospective diagnostic test study,70 patients with clinical KCN,79 patients with abnormal findings in topography and tomography maps with no evidence on clinical examination(subclinical KCN),and 68 normal control subjects were enrolled.The accuracy of topographic,tomographic,and biomechanical parameters was evaluated using the area under the receiver operating characteristic curve(AUC)and cross-validation analysis.The Delong method was used for comparing AUCs.RESULTS:In distinguishing KCN from normal,all parameters showed statistically significant differences between the two groups(P<0.001).Indices with the perfect diagnostic ability(AUC≥0.999)were Sirius KCN vertex of back(KVb),Pentacam random forest index(PRFI),Pentacam index of height decentration(IHD),and Corvis integrated tomographic/biomechanical index(TBI).In distinguishing subclinical KCN from normal,Sirius symmetry index of back(SIb;AUC=0.908),Pentacam inferior-superior difference(IS)value(AUC=0.862),PRFI(AUC=0.847),and Corvis TBI(AUC=0.820)performed best.There were no significant differences between the highest AUCs within keratoconic groups(De Long,P>0.05).CONCLUSION:In clinical KCN,all topographic,tomographic,and biomechanical indices have acceptable outcomes in terms of sensitivity and specificity.However,in differentiating subclinical forms of KCN from normal corneas,curvature-based parameters(SIb and IS value)followed by integrated indices(PRFI and TBI)are the most powerful tools for early detection of KCN.

Correlation of semi-quantitative findings of endolymphatic hydrops in MRI with the audiometric findings in patients with Meniere's disease

Purpose:To investigate the correlation between vestibular hydrops(VH),cochlearhydrops(CH),vestibular aqueduct non-visibility(VANV),and visually increased perilymphatic enhancement(VIPE)with the findings of pure-tone audiometry(PTA)in Meniere’s disease(MD)patients.Methods:In this cross-sectional study,53 ears belonging to 48 patients were divided into two groups and evaluated.In group“MD patients,”there were 24 ears of 19 patients diagnosed with the definite MD(14 patients with unilateral and 5 patients withbilateral involvements).The“control group”consisted of 29 non-symptomatic ears belonging to patients diagnosed with unilateral sudden sensory-neural hearing loss or unilateral schwannoma.All the patients underwent 2 sessions of temporal bone MRI using the same 3T system:an unenhanced axial T1,T2,and 3D-FLAIR MRI,an intravenous gadoliniumenhanced axial T1 fat-sat,and 4 h after the injection,an axial 3D-T2 cube and 3D-FLAIR session.VH,CH,VANV,and VIPE were assessed.Subsequently,the correlation between EH indices and PTA findings(in three frequency domains of low,middle,and high)were evaluated,and the predictive value of MRI was calculated.Results:VH was significantly correlated with the hearing threshold in the low,middle,and highfrequency domains.CH was also correlated with the hearing threshold in the low and middle domains.Contrarily,VIPE was not associated with hearing thresholds,and VANV was only correlated with the hearing threshold in low frequencies.Conclusion:The grade of VH,CH,and VANV were significantly correlated with the hearing thresholds in PTA.

Corneal biomechanics after rigid gas permeable contact lens wear in keratoconus eyes

Background:Evaluation of corneal biomechanical properties 3 months after using rigid gas permeable(RGP)contact lenses in keratoconus.Methods:In this prospective trial study,cases were 32 keratoconic eyes with no history of RGP lens wear.All eyes were examined with the Ocular Response Analyzer(ORA)and the Corneal Visualization Scheimpflug Technology(CORVIS-ST)to measure corneal hysteresis(CH),corneal resistance factor(CRF),deformation amplitude(DA),applanation velocity(AV)1 and 2,applanation length(AL)1 and 2,and peak distance before and 3 months after fitting aspheric RGP lenses.The effect of the correlation between contralateral eyes and maximum keratometry were controlled for in the analysis.Results were compared using repeated measures analysis of covariance.Results:At 3 months,neither the increases in mean CH(0.14±2.77 mm Hg,P=0.789),CRF(0.41±4.35 mm Hg,P=0.612),AV1(0.03±0.17 m/s,P=0.301),AV2(0.11±0.59 m/s,P=0.299),AL1(0.44±1.56 m/s,P=0.118),AL2(1.16±5.06 m/s,P=0.211),and peak distance(0.19±1.29 m/s,P=0.409),nor the decrease in mean DA(0.03±0.17 mm,P=0.402)was statistically significant.Conclusions:Results in our series of patients indicated that 3 months of RGP lens wear had no significant impact on corneal biomechanics,and perhaps non progression of keratoconus.Therefore,RGP lenses can be regarded safe and appropriate in keratoconic patients.

Comparison of anterior segment measurements using rotating Scheimpflug imaging and partial coherence interferometry

AIM:To compare central corneal thickness(CCT) and anterior chamber depth(ACD) measurements using rotating Scheimpflug imaging and partial coherence interferometry.·METHODS:As part of the first phase of Shahroud Eye Cohort Study with 5 190 subjects of 40 to 64 years of age,CCT and ACD were measured using Scheimpflug imaging with the Pentacam(Oculus,Inc.,Lynnwood,WA,USA) and partial coherence interferometry with the Allegro BioGraph(Wavelight,Erlangen,Germany).·RESULTS:After applying exclusion criteria,we had data of 4 387 subjects with a mean age of 50.7±6.2 years.Mean CCT with Pentacam and BioGraph were 528.6 ±33.2μm and 525.6 ±32μm respectively;the difference was statistically significant(P 【0.001),but the correlation was high(R=0.920).Mean ACD measurements using Pentacam and BioGraph were 2.68 ±0.35mm and 2.62 ±0.33mm respectively;the inter-device difference was significant(P 【0.001) with high correlation(R=0.944).The 95% limits of agreements between devices were-22.65μm to28.61μm and-0.16mm to 0.29mm for CCT and ACD measurements,respectively.·CONCLUSION:For both CCT and ACD,the BioGraph gave significantly lower values than the Pentacam(P 【0.05).Despite the high inter-device correlation,the 95%limits of agreements were wide,and this may limit their interchangeability in measuring the CCT and ACD.

Distribution of intraocular pressure and its determinants in an Iranian adult population

AIMTo determine the distribution of intraocular pressure (IOP) and its determinants in an Iranian population.METHODSIn a cross-sectional survey, random cluster sampling was conducted from the 40-64 years old population of Shahroud, in the north of Iran. All participants had optometry and ophthalmic exams. IOP was determined using the Goldmann tonometry method and biometric components were measured.RESULTSOf the 6311 people selected for the study, 5190 (82.2%) participated. The mean age of the participants was 50.9&#x000b1;6.2y and 58.7% of them were female. Mean IOP was 12.87&#x000b1;2.27 mm Hg. In this study 0.3% of the participants had an IOP higher than 21 mm Hg. The multiple linear regression model revealed that sex (Coef=-0.30; 95% CI: -0.43 to -0.17), diabetes (Coef=0.43; 95% CI: 0.19 to 0.67), high systolic blood pressure (Coef=0.02; 95% CI: 0.01 to 0.02), high body mass index (BMI) (Coef=0.03; 95% CI: 0.01 to 0.04), higher education (Coef=0.02, 95% CI: 0.01 to 0.04), thicker central corneal thickness (Coef=0.01; 95% CI: 0.01 to 0.02), and myopic shift in spherical equivalent (Coef=-0.14; 95% CI: -0.18 to -0.10) significantly correlated with high IOP.CONCLUSIONThe IOP in this 40-64 years old population is low overall. In the north of Iran, average IOP is statistically significantly correlated with female sex, diabetes, higher BMI, systolic blood pressure, higher education, thicker cornea, and myopic refractive error.

Subclinical inflammatory response after accelerated corneal cross-linking

Background:To evaluate the inflammatory response after accelerated collagen cross-linking(CXL)in eyes with keratoconus.Methods:Consecutive eyes with keratoconus undergoing CXL surgery were included in this nonrandomized interventional study.Aqueous flare was measured pre-and post-operatively with a laser flare photometer at 1 week,1,3 and 6 months after CXL.Results:Sixty eyes of 60 patients were entered into the study.Before CXL,the mean flare value was4.5 photons per millisecond(ph/ms).The flare values observed at week 1(7.1 ph/ms;P=0.008),month 1(6.5 ph/ms;P=0.04),month 3(6.7 ph/ms;P=0.004)and month 6(6.7 ph/ms;P=0.004)were significantly higher compared to baseline.Flare values were not significantly different from week 1 up to 6 months after CXL(P=0.930).No statistically significant correlation was detected between the amount of inflammation and keratometric indices.Conclusions:Accelerated CXL in patients with keratoconus may cause a subclinical inflammatory response which is evident as slight but rather long-lasting rise of aqueous flare.

PACK-CXL vs.antimicrobial therapy for bacterial,fungal,and mixed infectious keratitis:a prospective randomized phase 3 trial

Background:Infectious keratitis is a major cause of global blindness.We tested whether standalone photoactivated chromophore corneal cross-linking(PACK-CXL)may be an efective frst-line treatment in early to moderate infectious keratitis,compared with standard antimicrobial treatment.Methods:This is a randomized,controlled,multinational phase 3 clinical trial.Participants in fve centers in Egypt,India,Iran,Israel,and China,aged≥18 years,with infectious keratitis of presumed bacterial,fungal,or mixed origin,were randomly assigned(1:1)to PACK-CXL,or antimicrobial therapy.Outcomes measures included healing,defned as time to re-epithelialization of the corneal epithelial defect in the absence of infammatory activity in the anterior chamber and clearance of stromal infltrates.Treatment success was defned as the complete resolution of signs of infection.Results:Between July 21,2016,and March 4,2020,participants were randomly assigned to receive PACK-CXL(n=18)or antimicrobial therapy per American Academy of Ophthalmology(AAO)guidelines(n=21).No participants were lost to follow-up.Four eyes were excluded from the epithelialization time analysis due to treatment failure:two in the antimicrobial therapy group,and two in the PACK-CXL group.Success rates were 88.9%(16/18 patients)in the PACK-CXL group and 90.5%(19/21 patients)in the medication group.There was no signifcant diference in time to complete corneal re-epithelialization(P=0.828)between both treatment groups.Conclusions:PACK-CXL may be an alternative to antimicrobial drugs for frst-line and standalone treatment of early to moderate infectious keratitis of bacterial or fungal origin.

Tomography-based definition of keratoconus for Down syndrome patients

Background:To assess the diagnostic ability of Pentacam HR(Oculus Optikgeräte,GmbH,Wetzlar,Germany)tomographic indices in discriminating keratoconus(KC)and KC suspect(KCS)in 10-to 30-year-old patients with Down syndrome(DS).Methods:In this study,DS patients were enrolled through special needs schools,the National Down Syndrome Society,and relevant non-profit organizations.Diagnoses were made independently by two experienced specialists.Forty Pentacam indices related to corneal thickness,volume,density,keratometry,power,shape,aberration,and elevation were extracted.For each index,the accuracy for KC and KCS diagnosis was evaluated using discriminant analysis and the area under receiver operating characteristic curve(AUROC).From each enrolled case,data from only one eye was entered in the analyses.Results:Analyses were performed on data from 25 KC,46 KCS,and 154 non-ectatic DS eyes.The best discriminants for KC were anterior higher order aberrations(HOA)(cutoff>0.643,AUROC=0.879),posterior vertical coma(cutoff>0.0702μm,AUROC=0.875),anterior vertical coma(cutoff>0.4124μm,AUROC=0.868),and total HOA(cutoff>0.608,AUROC=0.867).The difference between AUROCs were not statistically significant(all P>0.05).For KCS,the best discriminants were minimum corneal thickness(cutoff≤480.0μm,AUROC=0.775),corneal volume(cutoff≤55.3μm,AUROC=0.727)and Belin Ambrosio display-total deviation(BAD-D)(cutoff>2.23,AUROC=0.718)with no significant difference between AUROCs(all P>0.05).Conclusions:In this sample of DS patients,best KC discriminators were HOA and coma which showed good diagnostic ability.For KCS,best predictors were minimum corneal thickness,corneal volume,and BAD-D with relatively good diagnostic ability.Defining a new set of KC diagnostic criteria for DS patients is suggested.

Tomography-based definition of keratoconus for Down syndromepatients

Background:To assess the diagnostic ability of Pentacam HR(Oculus Optikgerate,GmbH,Wetzlar,Germany)tomographic indices in discriminating keratoconus(KC)and KC suspect(KCS)in 10-to 30-year-old patients with Down syndrome(DS).Methods:In this study,DS patients were enrolled through special needs schools,the National Down Syndrome Society,and relevant non-profit organizations.Diagnoses were made independently by two experienced specialists.Forty Pentacam indices related to corneal thickness,volume,density,keratometry,power,shape,aberration,and elevation were extracted.For each index,the accuracy for KC and KCS diagnosis was evaluated using discriminant analysis and the area under receiver operating characteristic curve(AUROC).From each enrolled case,data from onlyoneeyewas entered intheanalyses.Results:Analyses were performed on data from 25 KC,46 KCS,and 154 non-ectatic DS eyes.The best discriminants for KC were anterior higher-order aberrations(HOA)(cutoff>0.643μm,AUROC=0.879),posterior vertical coma(cutoff>0.0702μm,AUROC=0.875),anterior vertical coma(cutoff>0.4124μm,AUROC=0.868),and total HOA(cutoff>0.608μm,AUROC=0.867).The difference between AUROCs were not statistically significant(all P>0.05).For KCS,the best discriminants were minimum corneal thickness(cutoff≤480.0μm,AUROC=0.775),corneal volume(cutoff≤55.3μm,AUROC=0.727)and Belin Ambrosio display-total deviation(BAD-D)(cutoff>2.23,AUROC=0.718)with no significant difference between AUROCs(all P>0.05).Conclusions:In this sample of DS patients,the best KC discriminators were HOA and coma which showed good diagnostic ability.For KCS,the best predictors were minimum corneal thickness,corneal volume,and BAD-D with relatively good diagnostic ability.Defining a new set of KC diagnostic criteria for DS patients is suggested.