Comparison of the morphological and biomechanical characteristics of keratoconus, forme fruste keratoconus, and normal corneas.
Guo Li-Li,Tian Lei,Cao Kai,Li Yu-Xin,Li Na,Yang Wei-Qiang,Jie Ying
Seminars in ophthalmology
: To explore the feasibility of corneal morphological and biomechanical parameters for keratoconus and forme fruste keratoconus diagnosis.: This case-control study included a total of 517 eyes from 408 keratoconus patients (KC group), 83 eyes from 83 forme fruste keratoconus patients (FFKC group), and 158 eyes from 158 patients with normal corneas (NL group). All subjects underwent routine ophthalmologic examinations. Pentacam and Corneal Visualization Scheimpflug Technology (Corvis ST) were used to obtain corneal morphological and biomechanical parameters. Differences between groups were compared using receiver operating characteristic (ROC) curve analysis.: ROC analysis showed that all corneal morphological parameters and most biomechanical parameters distinguished KC from NL, with an area under the curve (AUC) greater than 0.80, of which Belin-Ambrósio enhanced ectasia total deviation index (BAD-D) and tomographic and biomechanical index (TBI) were most efficient. The AUC for distinguishing KC from NL of the BAD-D was 0.989 and the TBI was 0.993, which were not statistically significant (DeLong et al., = .232). The BAD-D cut-off point of 1.595 provided 95.9% sensitivity for distinguishing KC from NL with 100% specificity. The TBI cut-off point of 0.515 provided 96.7% sensitivity for distinguishing KC from NL with 100% specificity. The ability of other parameters to distinguish KC from NL was lower than that of BAD and TBI. Except for central astigmatism from the anterior corneal surface (AstigF), the AUC that distinguished FFKC from NL was 0.862. The AstigF cut-off point of 4.65 provided 73.5% sensitivity for distinguishing FFKC from NL with 99.3% specificity. Other parameters distinguished FFKC from NL with low efficiency. Among them, the AUC for distinguishing FFKC from NL of the TBI was 0.722, whose cut-off point of 0.273 provided 55.4% sensitivity for distinguishing KC from NL with 79.7% specificity.: BAD-D and TBI have the highest efficiency, sensitivity, and specificity for distinguishing KC from NL. Except for AstigF, other corneal morphological and biomechanical parameters have a relatively low ability to distinguish FFKC from NL.
10.1080/08820538.2021.1896752
Relationship between corneal biomechanical parameters and corneal sublayer thickness measured by Corvis ST and UHR-OCT in keratoconus and normal eyes.
Li Yong,Xu Zhiqiang,Liu Qiaoli,Wang Yuzhou,Lin Kan,Xia Jiahui,Chen Shihao,Hu Liang
Eye and vision (London, England)
BACKGROUND:To explore the relationship between corneal biomechanical parameters and corneal sublayer thickness using corneal visualization Scheimpflug technology (Corvis ST) and ultrahigh-resolution optical coherence tomography (UHR-OCT) in clinical and suspected keratoconus and normal eyes. METHODS:Cross-sectional prospective study. A total of 94 eyes of 70 participants were recruited. Twenty five eyes of 19 keratoconus patients, 52 eyes of 34 patients showing high risk of developing keratoconus according to the Belin/Ambrosio Enhanced Ectasia Display, and each eye of 17 normal subjects were enrolled. All participants underwent Corvis ST, Pentacam, and UHR-OCT examinations at the same time. Stiffness parameter A1 (SP-A1), deformation amplitude ratio (DA ratio), and other biomechanical parameters were recorded using Corvis ST. The vertical and horizontal thickness profiles of central 3 mm corneal epithelium, Bowman's layer, and stroma as measured by the perpendicular distance between the neighboring interfaces were generated using UHR-OCT. The flat keratometry and steep keratometry were obtained using Pentacam. Analysis of correlation was applied to explore the association between variables. RESULTS:Most of the biomechanical parameters and corneal sublayer thickness profiles showed statistical differences among three groups. A statistically significant linear relationship was noted between SP-A1 and DA ratio in all three groups. SP-A1 was found to be positively correlated with epithelial and Bowman's layer thickness in the keratoconus (KC) group, and with stromal thickness in all three groups. In the normal and suspected keratoconus (SKC) groups, only stromal thickness was included in the stepwise linear regression to predict SP-A1, whereas in the KC group, steep keratometry and Bowman's layer thickness were included. CONCLUSIONS:Significant and different correlations were noted between corneal stiffness and corneal sublayer thickness in different groups, indicating that corneal sublayers may play different roles in maintaining corneal biomechanical stability between keratoconus and normal eyes.
10.1186/s40662-020-00225-z
Changes in Anterior and Posterior Corneal Elevation in Patients With Allergic Conjunctivitis.
Wang Qian,Yu Fei,Feng Ziqing,Li Weihua,Li Naiyang,Du Xinyue,Zhao Xuan,Li Saiqun,Yuan Jin
Frontiers in medicine
To evaluate corneal elevation changes in patients with allergic conjunctivitis (AC) and to analyze their correlations with ocular allergy signs and corneal biomechanical alterations. Thirty patients (30 eyes) with AC and twenty normal subjects (20 eyes) were included in this prospective study. All participants underwent a complete ocular examination, including corneal tomography by Pentacam and corneal biomechanics evaluation by Corvis ST. AC patients were evaluated for their eye rubbing frequency and ocular allergic signs. The elevation at the thinnest location (TE) and the central location (CE), the elevation difference at the thinnest location (TED) and the central location (CED), and the mean value of elevation difference in the central 4 mm zoom (MED) of both the anterior and posterior corneal surface were significantly higher in the AC group than in the normal group ( < 0.05 for all). In AC patients, only anterior corneal elevation parameters were positively correlated with eye rubbing frequency and ocular allergy sign severity ( < 0.05 for all), while the tomography and biomechanical index (TBI) was positively correlated with the elevation parameters of both the anterior and posterior corneal surfaces ( < 0.05 for all). AC patients carry an increased risk of corneal ectasia. Posterior corneal elevation parameters are sensitive and reliable predictors of keratoconus (KC) risk in AC patients. https://clinicaltrials.gov/ct2/show/NCT04299399, identifier [NCT04299399].
10.3389/fmed.2021.788302
Prevalence and associated factors of keratoconus in Jerusalem: a cross-sectional study.
Millodot Michel,Shneor Einat,Albou Sophie,Atlani Esther,Gordon-Shaag Ariela
Ophthalmic epidemiology
PURPOSE:To determine the prevalence and associated factors for keratoconus in a college student population sample in Jerusalem. METHODS:Volunteers participated in this cross-sectional study. Videokeratography was performed on both eyes of each subject who also completed an anonymous questionnaire. Keratoconus was defined by cone apex ≥ 50D, inferior-superior dioptric difference ≥ 3.5 diopters, as well as positive results from the software indices KISA, KCI and KSI. The association between independent predictors and keratoconus was analyzed using multivariate logistic regression analysis. RESULTS:Of a total of 987 volunteers, 981 (mean age 24.4) were included. The prevalence of keratoconus among all subjects was 2.34% (95% confidence interval [CI] 1.4-3.3). It was significantly higher in men (4.91%, CI 2.6-7.3) than women (1.07%, CI 0.3-1.9) but not between Israeli Arabs (3.0%, CI 0.6-5.4) and Israeli Jews (2.2%, CI 1.2-3.3). Keratoconus was significantly associated with positive family history of the disease (Odds Ratio [OR] 17.1, CI 5.0-57.8, P<0.001), male gender (OR 5.4, CI 2.1-14.3, P=0.001) and atopy (OR 3.0, CI 1.2-7.6, P=0.02), but not with eye rubbing. CONCLUSIONS:The prevalence of keratoconus in Jerusalem was found to be much higher than that seen in other parts of the world, except India. This may be related to a combination of genetic and environmental factors. Positive family history, male gender and atopy were shown to be significant predictors. The results of this study signal a need for public health outreach and intervention for keratoconus.
10.3109/09286586.2011.560747
Corneal biomechanical changes in allergic conjunctivitis.
Wang Qian,Deng Yuqing,Li Saiqun,Du Xinyue,Zhao Xuan,Zhang Tingting,Yuan Jin
Eye and vision (London, England)
BACKGROUND:To explore corneal biomechanical changes, identify related factors and determine early indicators of keratoconus (KC) development risk in allergic conjunctivitis (AC) patients. METHODS:A total of 50 patients, including 20 eyes without AC and 30 eyes with AC were enrolled in this study. All patients underwent a complete ocular examination, including evaluations of clinical manifestations of AC, corneal tomography and densitometry by Pentacam, corneal biomechanics by Corvis ST, and corneal and epithelial thickness mapping by RTvue optical coherence tomography (OCT). RESULTS:The index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), index of height decentration (IHD) and Belin/Ambrosio enhanced ectasia total deviation index (BAD-D) were significantly higher in the AC group than in the non-allergic conjunctivitis (NAC) group (P < 0.05). The tomography and biomechanical index (TBI) was also significantly higher in the AC group (P = 0.04). The average epithelial thickness in the 2-7 mm annulus was significantly thinner in the AC group than in the NAC group (P < 0.05). The average densitometry of the total cornea and the anterior layer were higher in the AC group than in the NAC group (P < 0.001). The ISV, IVA, KI, IHD and BAD-D were significantly correlated with the TBI and changes in corneal epithelial thickness in AC patients (P < 0.05). The changes in epithelial thickness were closely related to the eye rubbing frequency and allergic sign scores (P < 0.05). CONCLUSIONS:AC patients should be advised to routinely undergo corneal tomographic and biomechanical measurements, and the TBI could be used as an indicator of KC development risk in AC patients. TRIAL REGISTRATION:Corneal Biomechanical Changes of Allergic Conjunctivitis, NCT04299399 . Registered March 3, 2020 - Retrospectively registered.
10.1186/s40662-021-00241-7
Sabatier Principle for Rationalizing Enzymatic Hydrolysis of a Synthetic Polyester.
JACS Au
Interfacial enzyme reactions are common in Nature and in industrial settings, including the enzymatic deconstruction of poly(ethylene terephthalate) (PET) waste. Kinetic descriptions of PET hydrolases are necessary for both comparative analyses, discussions of structure-function relations and rational optimization of technical processes. We investigated whether the Sabatier principle could be used for this purpose. Specifically, we compared the kinetics of two well-known PET hydrolases, leaf-branch compost cutinase (LCC) and a cutinase from the bacterium (TfC), when adding different concentrations of the surfactant cetyltrimethylammonium bromide (CTAB). We found that CTAB consistently lowered the strength of enzyme-PET interactions, while its effect on enzymatic turnover was strongly biphasic. Thus, at gradually increasing CTAB concentrations, turnover was initially promoted and subsequently suppressed. This correlation with maximal turnover at an intermediate binding strength was in accordance with the Sabatier principle. One consequence of these results was that both enzymes had too strong intrinsic interaction with PET for optimal turnover, especially TfC, which showed a 20-fold improvement of at the maximum. LCC on the other hand had an intrinsic substrate affinity closer to the Sabatier optimum, and the turnover rate was 5-fold improved at weakened substrate binding. Our results showed that the Sabatier principle may indeed rationalize enzymatic PET degradation and support process optimization. Finally, we suggest that future discovery efforts should consider enzymes with weakened substrate binding because strong adsorption seems to limit their catalytic performance.
10.1021/jacsau.2c00204
Effects of eye rubbing and breath holding on corneal biomechanical properties and intraocular pressure.
Liu Wan-Cherng,Lee Shui-Mei,Graham Andrew D,Lin Meng C
Cornea
PURPOSE:To determine whether corneal biomechanical properties and intraocular pressure (IOP) are affected by eye rubbing and breath holding. METHODS:Corneal hysteresis, corneal resistance factor, corneal compensated IOP (IOPcc), and Goldmann equivalent IOP (IOPg) were measured on both eyes of 40 subjects. Measurements were taken at baseline before eye rubbing (ER(0)) and before breath holding (BH(0)), immediately after 2 episodes of eye rubbing (ER(1) and ER(2)), and during 2 episodes of breath holding (BH(1) and BH(2)). RESULTS:Corneal hysteresis, corneal resistance factor, and IOPg were significantly lower after ER(1) compared with ER(0) and were significantly lower after ER(2) compared with ER(1). In contrast, IOPcc did not decrease significantly. There were no significant differences among BH(0), BH(1), and BH(2) in any of the 4 outcomes. CONCLUSIONS:Eye rubbing should be avoided before measurements of corneal biomechanical properties and IOPg. In contrast, breath holding during measurements is not likely to cause a significant change in IOPg and IOPcc or corneal biomechanical properties.
10.1097/ICO.0b013e3182032b21
Clinical characteristics and topographic findings of corneal ectasia in patients with symptomatic blepharitis.
Hung Kuo-Hsuan,Tan Hsin-Yuan,Chen Hung-Chi,Yeh Lung-Kun
Taiwan journal of ophthalmology
PURPOSE:The purpose of this study is to present characteristics and topographic findings of patients with corneal ectasia and symptomatic ocular demodicosis. MATERIALS AND METHODS:A retrospective, noncomparative study. Twenty-one patients with symptomatic ocular demodicosis and corneal ectasia since 2017 to 2019 were enrolled. Patients with dry eye syndrome and meibomian gland dysfunction were identified and treated. Demographic data, topography, and clinical data were collected. All patients underwent lash sampling to confirm mite infestation by direct visualization under the microscope. RESULTS:Twenty-one ectasia patients (36 eyes) were enrolled with male preponderance (M:F =18:3). Mean age (years) was 28.6 ± 8.12. Of the 21 cases reviewed, the average number of topography taken was 6.8 within 43.8 months of follow-up. Corneal ectasia was characterized by focal thinning area beside central cornea, with corresponding mean thickness of 487.1 μm and 518 μm, respectively. All ectasia patients were combined with blepharitis and associated symptoms, proven by direct microscopic examination. After treatment with eyelid cleanser (OCuSOFT® Lid Scrub® PLUS), warm compress, and improved daily hygiene, ocular demodicosis and topographic changes were controlled and even reversed. CONCLUSION:Our results indicated that ocular demodicosis may be potentially associated with corneal ectasia. blepharitis still remains an overlooked differential diagnosis in clinic; however, it may be one of the risk factors triggering eye rubbing. Comorbidity of lid infestation with eye rubbing may lead to corneal ectasia, even in elder patients with thick cornea. Therefore, meticulous examination and intensive treatment were highly recommended in this group of patients.
10.4103/tjo.tjo_45_20
A multivariate analysis and statistical model for predicting visual acuity and keratometry one year after cross-linking for keratoconus.
Wisse Robert P L,Godefrooij Daniël A,Soeters Nienke,Imhof Saskia M,Van der Lelij Allegonda
American journal of ophthalmology
PURPOSE:To investigate putative prognostic factors for predicting visual acuity and keratometry 1 year following corneal cross-linking (CXL) for treating keratoconus. DESIGN:Prospective cohort study. METHODS:This study included all consecutively treated keratoconus patients (102 eyes) in 1 academic treatment center, with minimal 1-year follow-up following CXL. Primary treatment outcomes were corrected distance visual acuity (logMAR CDVA) and maximum keratometry (K(max)). Univariable analyses were performed to determine correlations between baseline parameters and follow-up measurements. Correlating factors (P ≤ .20) were then entered into a multivariable linear regression analysis, and a model for predicting CDVA and K(max) was created. RESULTS:Atopic constitution, positive family history, and smoking were not independent factors affecting CXL outcomes. Multivariable analysis identified cone eccentricity as a major factor for predicting K(max) outcome (ß coefficient = 0.709, P = .02), whereas age, sex, and baseline keratometry were not independent contributors. Posttreatment visual acuity could be predicted based on pretreatment visual acuity (ß coefficient = -0.621, P < .01, R(2) = 0.45). Specifically, a low visual acuity predicts visual improvement. A prediction model for K(max) did not accurately estimate treatment outcomes (R(2) = 0.15). CONCLUSIONS:Our results confirm the role of cone eccentricity with respect to the improvement of corneal curvature following CXL. Visual acuity outcome can be predicted accurately based on pretreatment visual acuity. Age, sex, and K(max) are debated as independent factors for predicting the outcome of treating keratoconus with CXL.
10.1016/j.ajo.2013.11.001
Accelerated Corneal Cross-Linking: Efficacy, Risk of Progression, and Characteristics Affecting Outcomes. A Large, Single-Center Prospective Study.
Hatch Wendy,El-Defrawy Sherif,Ong Tone Stephan,Stein Raymond,Slomovic Allan R,Rootman David S,Rabinovitch Theodore,Kranemann Christoph,Chew Hall F,Chan Clara C,Bujak Matthew C,Cohen Ashley,Lebovic Gerald,Jin Yaping,Singal Neera
American journal of ophthalmology
PURPOSE:We examined the efficacy and preoperative characteristics that affect outcomes of accelerated (9 mW/cm for 10 minutes) corneal cross-linking (CXL). DESIGN:Prospective single-center observational cohort study. METHODS:We enrolled 612 eyes of 391 subjects with progressive keratoconus (n = 589), pellucid marginal degeneration (n = 11), and laser in situ keratomileusis-induced ectasia (n = 12). We evaluated best spectacle-corrected visual acuity (BSCVA), topography, refraction, endothelial cell density, corneal thickness, haze, intraocular pressure, and visual function before and 12 months after the CXL procedure. We tabulated the proportion of those with progression of maximum keratometry (Kmax). We included participant's race, age, sex, and the presence of preoperative apical scarring and environmental allergies in a multivariable linear regression model to determine the effect of these characteristics on outcomes. RESULTS:At 1 year there was no significant change in mean Kmax (n = 569). Progression of Kmax was higher in subgroups with a baseline Kmax >58 diopters (n = 191) and those 14-18 years of age (n = 53). Preoperative BSCVA, Kmax, refraction, corneal cylinder, coma, central corneal thickness, and vision function were statistically and clinically significant predictors of outcomes (P < .001). Preoperative apical scarring led to worsening haze (P = .0001), more astigmatism (P = .002), more central corneal thinning (P = .002), and was protective to the endothelium (P = .008). Race, age, and sex affected some outcomes. CONCLUSION:Mean Kmax was stable at 1 year after accelerated CXL. Younger patients and those with a higher preoperative Kmax need to be monitored closely for progression. Preoperative BSCVA, topography, refraction, CCT, and apical scarring were significant predictors of outcomes.
10.1016/j.ajo.2020.01.006
Effect of Corneal Cross-linking versus Standard Care on Keratoconus Progression in Young Patients: The KERALINK Randomized Controlled Trial.
Larkin Daniel F P,Chowdhury Kashfia,Burr Jennifer M,Raynor Mathew,Edwards Matthew,Tuft Stephen J,Bunce Catey,Caverly Emilia,Doré Caroline,
Ophthalmology
PURPOSE:To examine the efficacy and safety of corneal cross-linking (CXL) for stabilization of progressive keratoconus. DESIGN:Observer-masked, randomized, controlled, parallel-group superiority trial. PARTICIPANTS:Sixty participants 10 to 16 years of age with progressive keratoconus, one eye of each deemed the study eye. METHODS:The study eye was randomized to either CXL plus standard care or standard care alone, with spectacle or contact lens correction as necessary for vision. MAIN OUTCOME MEASURES:The primary outcome was steep keratometry (K2) in the study eye as a measure of the steepness of the cornea at 18 months. Secondary outcomes included keratoconus progression defined as a 1.5-diopter (D) increase in K2, visual acuity, keratoconus apex corneal thickness, and quality of life. RESULTS:Of 60 participants, 30 were randomized to CXL and standard care groups. Of these, 30 patients in the CXL group and 28 patients in the standard care group were analyzed. Mean K2 in the study eye 18 months after randomization was 49.7 D (standard deviation [SD], 3.8 D) in the CXL group and 53.4 D (SD, 5.8 D) in the standard care group. The adjusted mean difference in K2 in the study eye was -3.0 D (95% confidence interval [CI], -4.9 to -1.1 D; P = 0.002), favoring CXL. Adjusted differences between groups in uncorrected and corrected vision favored eyes receiving CXL: -0.31 logarithm of the minimum angle of resolution (logMAR; 95% CI, -0.50 to -0.11 logMAR; P = 0.002) and -0.51 logMAR (95% CI, -1.37 to 0.35 logMAR; P = 0.002). Keratoconus progression in the study eye occurred in 2 patients (7%) randomized to CXL compared with 12 patients (43%) randomized to standard care. The unadjusted odds ratio suggests that on average, patients in the CXL arm had 90% (odds ratio, 0.1; 95% CI, 0.02-0.48; P = 0.004) lower odds of experiencing progression compared with those receiving standard care. CONCLUSIONS:CXL arrests progression of keratoconus in the majority of young patients. CXL should be considered as a first-line treatment in progressive disease. If the arrest of keratoconus progression induced by CXL is sustained in longer follow-up, particular benefit may be derived from avoiding a later requirement for contact lens wear or corneal transplantation.
10.1016/j.ophtha.2021.04.019
Keratoconus detection using OCT corneal and epithelial thickness map parameters and patterns.
Journal of cataract and refractive surgery
PURPOSE:To detect keratoconus using optical coherence tomography (OCT) corneal map parameters and patterns. SETTING:Casey Eye Institute, Oregon Health and Science University, Portland, Oregon. DESIGN:Cross-sectional observational study. METHODS:A spectral-domain OCT was used to acquire corneal and epithelial thickness maps in normal, manifest keratoconic, subclinical keratoconic, and forme fruste keratoconic (FFK) eyes. A 2-step decision tree was designed. An eye will be classified as keratoconus if both decision tree conditions are met. First, at least 1 of the 4 quantitative corneal thickness (minimum, minimum-maximum, and superonasal-inferotemporal) and epithelial thickness (standard deviation) map parameters exceed cutoff values. Second, presence of both concentric thinning pattern on the epithelial thickness map and coincident thinning patterns on corneal and epithelial thickness maps by visual inspection. RESULTS:The study comprised 54 eyes from 29 normal participants, 91 manifest keratoconic eyes from 65 patients, 12 subclinical keratoconic eyes from 11 patients, and 19 FFK eyes from 19 patients. The decision tree correctly classified all normal eyes (100% specificity) and had good sensitivities for detecting manifest keratoconus (97.8%), subclinical keratoconus (100.0%), and FFK (73.7%). CONCLUSIONS:The 2-step decision tree provided a useful tool to detect keratoconus, including cases at early disease stages (subclinical keratoconus and FFK). OCT corneal and epithelial thickness map parameters and patterns can be used in conjunction with topography to improve keratoconus screening.
10.1097/j.jcrs.0000000000000498
Five-year results of a prospective, randomised, contralateral eye trial of corneal crosslinking for keratoconus.
Meyer Jay J,Jordan Charlotte A,Patel Dipika V,Gokul Akilesh,Dean Simon J,Ahmed Suheb,Subbiah Shanu,McGhee Charles N J
Clinical & experimental ophthalmology
BACKGROUND:Few studies have evaluated corneal crosslinking (CXL) in a prospective, randomised fashion. This study aimed to determine the efficacy and safety of CXL to reduce the progression of keratoconus. METHODS:Prospective, unmasked, randomised, contralateral eye controlled trial at a tertiary eye centre. PARTICIPANTS:Individuals with bilateral progressive keratoconus. One eye from each subject was randomised to CXL and the contralateral, untreated eye acted as the control. PRIMARY OUTCOME MEASURE:change in maximum keratometry. SECONDARY OUTCOME MEASURES:uncorrected distance visual acuity, spectacle corrected distance visual acuity, spherical equivalent refraction, simulated keratometry, corneal astigmatism, minimum pachymetry and complications. RESULTS:Thirty-eight individuals (mean age 21.1 ± 6.7 years) were enrolled with one eye treated with CXL. At 5 years, there was a mean decrease in maximum keratometry of treated eyes (-1.45 ± 2.25 D) compared to an increase among the controls (1.71 ± 2.46 D; p < 0.001). There were significant differences between the treated and control groups in the mean change of Steep SimK (-1.07 ± 1.22 vs. 0.96 ± 1.97 D; p < 0.001), Flat SimK (-0.61 ± 1.34 vs. 0.43 ± 1.12 D; p < 0.001), corneal astigmatism (-0.45 ± 1.31 vs. 0.63 ± 1.52 D; p < 0.01) and minimum pachymetry (-32.49 ± 26.32 vs. -13.57 ± 24.11 μm; p < 0.01). Complications included sterile infiltrates (n = 2), microbial keratitis (n = 1), persistent corneal haze/scarring at 5 years (n = 4) and loss of ≥2 lines of corrected distance visual acuity (n = 3). CONCLUSIONS:CXL is an effective and relatively safe intervention to halt or reduce the progression of keratoconus in the majority of eyes for at least 5 years.
10.1111/ceo.13959
Mini-Scleral Lenses Improve Vision-Related Quality of Life in Keratoconus.
Kreps Elke O,Pesudovs Konrad,Claerhout Ilse,Koppen Carina
Cornea
PURPOSE:To evaluate the effects of mini-scleral lenses on visual acuity (VA) and visual functioning in patients with keratoconus. METHODS:This prospective, interventional study examined the effects of mini-scleral lenses on VA and visual functioning in patients with keratoconus. Patients younger than 18 years or with a history of refractive surgery or corneal graft surgery were excluded. Patients were fitted with mini-Misa lenses, Senso mini-scleral lenses, or Zenlens mini-scleral lenses. Outcome measures were scleral lens-corrected VA and vision-related quality of life as assessed with the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-39). RESULTS:Eighty-nine eyes of 50 keratoconus patients were included in the study. Median baseline logarithm of the minimal angle of resolution VA with habitual correction was 0.22 (range 0.02-1.04). Mini-scleral lens fitting resulted in a statistically significant visual improvement (median 0; P < 0.0001). At the 6-month follow-up, 11 patients (22%) had abandoned mini-scleral lens wear, primarily because of difficulties with lens handling (7 patients). Of the 39 patients with continued wear, 33 patients (84.6%) wore their lenses for a daily average of 12 hours. NEI-VFQ scoring in these patients showed significantly improved results for both visual functioning and socioemotional scales after scleral lens fitting (P < 0.0001). CONCLUSIONS:Mini-scleral lenses significantly improve VA and visual functioning on NEI-VFQ in patients with keratoconus. Difficulties with lens insertion and removal are the principal reason for lens dropout.
10.1097/ICO.0000000000002518
Quality-of-Life Improvement After Scleral Lens Fitting in Patients With Keratoconus.
Eye & contact lens
OBJECTIVES:To assess the quality-of-life improvement after scleral lens fitting in patients with keratoconus. METHODS:We conducted a prospective observational study of all consecutive patients with keratoconus starting scleral lens fitting in 2019, from January 2 to December 27, at the Dijon University Hospital, France. Quality of life was assessed before and after wearing scleral lenses for 3 months through the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ 25) questionnaire. We investigated factors potentially influencing quality of life: final visual acuity, keratoconus stage, and maximum keratometry reading. RESULTS:In total, 41 eyes of 24 patients were successfully fitted with scleral lenses, 92.9% were 18 mm in diameter and 7.1% were 17 mm. The visual acuity improved by -0.4±0.3 logarithm of the minimum angle of resolution (P<0.001) after scleral lens fitting. Visual gain increased with keratometry and keratoconus severity (P<0.001; P<0.01). The NEI-VFQ 25 score increased by 19.5±19.1 points on average (P<0.001). No association was found between the factors under study and improvement in quality of life. CONCLUSION:Our study confirms the functional improvement in patients with keratoconus fitted with scleral lenses, especially in patients with more advanced disease. Moreover, it suggests a major role of these lenses in improving quality of life, independently of the severity of the disease and the visual gain.
10.1097/ICL.0000000000000821
Comparative analysis of the morphological and biomechanical properties of normal cornea and keratoconus at different stages.
Wu Ying,Guo Li-Li,Tian Lei,Xu Ze-Quan,Li Qian,Hu Jian,Huang Yi-Fei,Wang Li-Qiang
International ophthalmology
PURPOSE:To compare the morphological and biomechanical properties of normal cornea and keratoconus at different stages. METHODS:A total of 408 patients (517 eyes) with keratoconus were included in this study. According to the Topographic Keratoconus (TKC) grading method, keratoconus was divided into stage I (TKC = 1, 130 eyes), stage II (TKC = 1-2, 2, 164 eyes), stage III (TKC = 2-3, 3, 125 eyes) and stage IV (TKC = 3-4, 4, 98 eyes). A total of 158 normal subjects (158 eyes) were recruited as the normal group. The corneal morphological parameters and biomechanical parameters were obtained with Scheimpflug tomography (Pentacam) and corneal visualization Scheimpflug technology (Corvis ST), and the receiver operating characteristic (ROC) curves were drawn. RESULTS:Each corneal morphological and most biomechanical parameters of the keratoconic eyes were significantly different from those of the normal eyes in this study (p < 0.001). ROC curve demonstrated that most parameters in this study showed high efficiency in diagnosing keratoconus (the area under the ROC (AUC) was > 0.9), with the Belin-Ambrósio deviation (BAD-D) and Tomographic and Biomechanical Index (TBI) showing higher efficiency. The efficiency of BAD-D and TBI was high in differentiating keratoconus at different stages (AUC > 0.963). The comparison of ROC curves of keratoconus at different stages did not reveal statistically significant differences for TBI. CONCLUSION:BAD-D and TBI can effectively diagnose stage I keratoconus. Moreover, the efficiency of TBI is the same in diagnosing keratoconus at all stages, while the diagnostic efficiency of other parameters increases with the increase in keratoconus stages.
10.1007/s10792-021-01929-4
Influence of interleukin 17 A and 17 F polymorphisms in keratoconus.
Gomes Isabela Bronchtein,Ayo Christiane Maria,Lopes Alessandro Garcia,Kumano Laurie Sayuri,de Faria Junior Geraldo Magela,de Almeida Gildásio Castello,Castiglioni Lilian,de Mattos Luiz Carlos,Brandão Cinara Cássia
Molecular biology reports
BACKGROUND:Until a few years ago, keratoconus was defined as a noninflammatory degenerative disease. However, recent studies have shown that the altered balance between inflammatory cytokines, proteases, and protease inhibitors, as well as free radicals and oxidants, have a crucial role in the pathogenesis of this disease. The aim of this study is to investigate whether interleukin 17 A G197A (rs2275913) and interleukin 17 F T7488C (rs763780) polymorphisms are associated with keratoconus in patients from a population of the northwestern region of the State of São Paulo, Brazil. METHODS AND RESULTS:35 patients and 61 controls were enrolled. Genotyping of interleukin 17 A G197A and interleukin 17 F T7488C polymorphisms was carried out using the polymerase chain reaction-restriction fragment length polymorphism technique. Statistical analyses were conducted using the chi-square test, and an odds ratio with a 95% confidence interval was also calculated to evaluate the association between polymorphisms and disease. Evaluating interleukin 17 F T7488C, we found that the TT genotype is associated as a risk factor for keratoconus (P = 0.04; OR = 3.01; CI 1.11-8.14). As for evaluating interleukin 17 A G197A, the allele and genotype frequencies between patients and controls were compared and no statistically significant differences were found. CONCLUSIONS:Our data showed that the interleukin 17 F T7488C polymorphisms may exert an influence in keratoconus.
10.1007/s11033-021-06708-z
The Aotearoa Research Into Keratoconus Study: Geographic Distribution, Demographics, and Clinical Characteristics of Keratoconus in New Zealand.
Cornea
PURPOSE:To investigate the epidemiologic, demographic, and basic clinical characteristics of individuals with keratoconus managed by optometrists in New Zealand (NZ)/Aotearoa. METHODS:A prospective, longitudinal, nationwide, survey protocol was completed for every patient with keratoconus who underwent a consultation with participating optometrists in a 2-year period. Data for each patient included date of birth, sex, self-reported ethnicity, new or previous diagnosis, uncorrected (UCVA) and best-corrected visual acuity (BCVA), type of refractive correction required to obtain BCVA and keratometric readings obtained using keratometry or computerized topography. RESULTS:One thousand eight hundred sixty-nine cases were identified, with a mean age of 41.0 ± 15.7 years, 56.4% being men, and 87.3% with previous diagnosis. The distribution of cases was skewed toward Auckland (41.6%), Waikato (21.3%), Wellington (16.8%), and Bay of Plenty (13.3%). Self-reported ethnicities were predominantly NZ European (54.4%), Māori (24.7%), and Pacific Peoples (15.5%), disproportionate to the general population profile (74.0%, 14.9%, and 7.4% respectively). Most eyes (64.3%) were managed with rigid contact lenses (corneal lens in 34.2%). The mean K-mean was 49.0 ± 5.7 D. The mean UCVA was 6/42 and BCVA was 6/9. Māori and Pacific Peoples had both the highest K-mean and proportions of eyes graded stage IV on the Amsler-Krumeich scale. CONCLUSIONS:The results indicate that keratoconus is relatively common in NZ with at least 1869 patients managed by optometrists in 2 years. Most eyes had mild to moderate disease; however, Māori and Pacific Peoples seem to have greater disease severity. An ethnic predilection is apparent, with Māori and Pacific Peoples overrepresented relative to their population proportions, reinforcing a long-held clinical suspicion.
10.1097/ICO.0000000000002672