Severity Of Keratoconus Research Articles

Repeatability and reliability of measurements obtained by the combined Scheimpflug and Placido-disk tomography in different stages of keratoconus.

The objective of this study is to evaluate the repeatability and reliability of corneal parameters in different stages of keratoconus patients using a combined Scheimpflug-Placido disc analysis system. In this prospective study, three consecutive measurements were performed by the same observer using Scheimpflug-Placido disc anterior segment analysis device in keratoconus patients. Flattest and steepest simulated keratometry and corneal volume, corneal aberrations, thinnest corneal thickness, symmetry index, keratoconus vertex and Baiocchi-Calossi-Versaci index were recorded. Keratoconic eyes were divided into four stages using the Amsler-Krumeich classification. Repeatability was evaluated using within the subject standard deviation, repeatability index (Ri) and coefficient of variation; reliability was evaluated by intraclass correlation coefficient (ICC). Pearson correlation coefficients were used to assess the correlation between the parameters evaluated. Two hundred sixty-one eyes of 261 keratoconus patients were included in the study. The repeatability for all corneal curvature parameters decreased as the keratoconus severity increased, and there is a positive correlation between keratometry of the apex and corneal curvature parameters (p < 0.05) except mean simulated keratometry. The corneal aberrations were repeatable in all keratoconus subgroups (Ri < 0.34 μm). There are also positive correlations between keratometry of apex and corneal aberrations (p < 0.05) except total high-order root mean square and spherical aberration. The reliability was excellent (ICC > 0.90) for all indices except keratoconus vertex back. The parameters used in the diagnosis and follow-up of keratoconus in the Sirius corneal tomography system may differ more than expected at stages 3 and 4 of the disease. Awareness of this situation may be helpful in planning follow-up and treatment.

Scheimpflug Densitometry in Keratoconus: A New Method of Visualizing the Cone.

To report an observation made while performing Scheimpflug densitometry analysis on the corneal region affected in keratoconus (KC) that seems to delineate the base of the cone. Scheimpflug densitometries of 20 healthy subjects and 90 patients with KC were examined. Corneal densitometry was analyzed using both "1-layer" and "2-layer" approaches. The first considers the corneal transparency layer by layer at different depths, whereas the second averages densitometry between 2 corneal layers selected by the examiner. Fixed layers, 120 μm depth, and endothelium were selected. Repeated same-day scans and longitudinal series of scans were also evaluated to see whether the findings evolved over time. Eighty-eight of 90 KC cases displayed a bright area on the densitometry map that corresponded to the cone location. The area's characteristics, such as its brightness, contrast, and the presence of a delimiting arc correlated with KC severity and was more noticeable in advanced cases. No similar marks were found in any of the normal subjects. The shape, location, and extent of the mark were consistent over consecutive measures taken on the same day. Changes over time were also seen in eyes with known clinical progression but was also seen in eyes considered clinically stable. The densitometry mark seems to correspond with the zone most affected by KC and could be a supplementary tool for documenting KC stage, alongside conventional parameters. Further studies are required to ascertain whether it could prove useful in KC detection, to determine progression, and to relate it to corneal biomechanical behavior.

Do Patients With Keratoconus Have Minimal Disease Knowledge?

To assess whether Swiss adult citizens diagnosed with keratoconus have the minimal knowledge that a corneal specialist would expect they should have. Experts defined the "minimal keratoconus knowledge" (MKK) with respect to definition, risk factors, symptoms, and possible treatment options of keratoconus. A survey was performed in 167 patients with keratoconus [mean age 38.8 years (SD 13.9), 77.7% male] in 5 specialized institutions. Of each participant, salient clinical characteristics, highest educational level, paramedical background, and specific health experience with keratoconus in the social surrounding were obtained. We calculated the proportion of MKK and examined whether patients with higher education and greater disease experience would perform better than those from other groups in multivariate analyses. No single citizen reached 100% MKK. The mean MKK was 35.2%, and the range was 0% to 76.2%. Participants with a university degree had only a moderately higher MKK [+8.7% (95% confidence interval: 4.4-13.0); P < 0.001]. Per age decile, the MKK declined by 3.1% (95% confidence interval: 1.2-4.9), P = 0.002. Disease duration, severity of keratoconus in Kmax values, and history of surgical treatment did not significantly increase MKK. Surprisingly, MKK was also lower in patients with a paramedical background [-6.3% (-14.1 to 1.4); P = 0.107]. This sample of Swiss patients with keratoconus did not know more than a third of the MKK. We found a little difference within various subgroups. There is a substantial mismatch between caregivers' expectations of patients' knowledge and patients' active knowledge regarding their condition. This may lead to an inefficient care delivery and misunderstandings.

Topographic screening reveals keratoconus to be extremely common in Down syndrome.

Keratoconus disproportionately affects people with Down syndrome (DS). This is the first study of its kind in Australasia. To investigate the prevalence of keratoconus in DS. Cross-sectional study. Athletes with DS attending 2017 New Zealand Special Olympics National Summer Games. Keratoconus was identified using corneal topography (TMS-4N, Tomey). Topography from both eyes was required to be included. Two independent quantitative criteria were used to indicate keratoconus. The first was keratoconus severity index ≥ 30%. The second, adapted from the literature, required at least four of eight topographic parameters to be abnormal. Data from the worse eye were analysed. Diagnosis in each group was subsequently confirmed qualitatively by three corneal fellowship-trained ophthalmologists. Those with a definitive diagnosis were grouped into Keratoconus Confirmed Group 1 (KCC1) and Keratoconus Confirmed Group 2 (KCC2), respectively. Keratoconus prevalence, severity, demographics. Of 110 athletes screened, N = 98 were included, mean age 30.0 ± 9.7 years. Using only topographic data, keratoconus was identified in 39 (39.8%) athletes by quantitative topographic criteria 1, and in 63 (64.3%) athletes by criteria 2. Keratoconus was confirmed by qualitative sub-specialist review in 30 (30.6%) (KCC1) and 38 (38.8%) (KCC2) athletes, respectively. Mean keratometry in groups KCC1 and KCC2 were 48.4 ± 3.2D and 48.2 ± 2.9D, respectively. Most were male (KCC1 63.3%, KCC2 76.3%) and of European ethnicity (KCC1 80%, KCC2 78.9%). We report keratoconus in 30.6% to 38.8% of athletes with DS; therefore, we believe keratoconus screening is indicated in DS for early management.

Safety and Efficacy of Scleral Lenses for Keratoconus.

SIGNIFICANCEThis study affirms the long-term safety and efficacy of scleral contact lens use in patients with keratoconus.PURPOSEThis study aimed to evaluate the safety and efficacy of contemporary scleral contact lenses in the visual rehabilitation of the keratoconic population.METHODSA retrospective study of keratoconic subjects examined between 2013 and 2018 was conducted. Subjects were included regardless of age, sex, pre-existing morbidity, or scleral lens design. Only eyes fit successfully with scleral contact lenses for ≥1 year were included. Exclusion criteria were prior corneal surgery, dystrophy, degeneration, and trauma.RESULTSA total of 157 eyes of 86 subjects met the study criteria. The mean Keratoconus Severity Score at initial fitting was 3.6 ± 1.0. Lenses were gas-permeable and nonfenestrated, with a mean overall diameter of 15.8 ± 0.6 mm and 70.1% toric scleral periphery. Physiological adverse events occurred in 9.6% of eyes, including microbial keratitis (0.6%), phlyctenulosis (0.6%), corneal abrasion (1.3%), contact lens–induced acute red eye (1.3%), corneal infiltrative events (1.3%), pingueculitis (1.3%), and hydrops (3.2%). Lens-related adverse events were documented in 55.4% of eyes. Adverse events related to surface issues included poor wetting in 1.9%, handling in 3.8%, reservoir fogging in 7.0%, lens intolerance in 7.6%, deposit in 8.9%, and broken lenses in 26.1% of eyes. The most common management strategies involved refits (54.0% of interventions), patient reeducation (29.5%), medical treatment (5.5%), surgical referral (6.8%), adjustment to wear time (2.5%), surface treatment (1.2%), and lens replacement (0.6%). Best-corrected distance logMAR visual acuity improved significantly from a mean of 0.50 in spectacles to a mean of 0.08 in scleral lenses (P < .0001). During the study period, 14.6% of eyes lost best-corrected scleral lens visual acuity, all from keratoconus progression.CONCLUSIONSConsistent with other groups, our study demonstrates excellent safety and efficacy of scleral contact lenses in subjects with keratoconus.

Posterior pole retinal thickness distribution pattern in keratoconus.

To evaluate the pattern of retinal thickness distribution in patients with keratoconus (KCN) and its correlation with disease severity. For this cross-sectional cohort study, the study subjects with documented keratoconus and normal eyes were prospectively enrolled. All subjects had anterior segment (Pentacam HR) and posterior segment (Spectralis) imaging. Posterior segment imaging by optical coherence tomography included the posterior pole asymmetry analysis map. Data were analyzed with multiple linear regression models and correlation tests to examine the mean and variance of the measured thickness of the retina and its distribution relative to the presence and severity of KCN. A total of 24 subjects with keratoconus (48 eyes) and 14 normal subjects (28 eyes) enrolled in this study. The posterior pole retinal thickness, both superior and inferior hemifields, as well as the overall retinal thickness in KCN patients was greater than the control group. There was a direct correlation between the overall retinal thickness of the posterior pole and the severity of KCN (R2 = 0.422, P < 0.001). However, the variability of the retinal thickness showed no difference between KCN-afflicted and healthy eyes. Although KCN is a disease of the anterior segment of the eye, we found an orderly increase in posterior pole retinal thickness that is correlated with the severity of disease in KCN eyes compared to control. These findings suggest that the retina may maintain some degree of plasticity to respond to the degraded optical system of the eye.

An analysis of factors associated with graft topographic outcomes after deep anterior lamellar keratoplasty.

To investigate the correlations between preoperative, operative, and postoperative factors and corneal graft topographic parameters after deep anterior lamellar keratoplasty (DALK) performed in keratoconus-affected eyes. This prospective, interventional study enrolled 44 eyes. Graft topographic parameters, including keratometric astigmatism and the surface regularity index (SRI), were assessed after complete suture removal. Univariate analyses were used to evaluate the effects of preoperative factors (donor quality, donor and recipient age, keratoconus severity), operative factors (graft size, donor button roundness, roundness and centration of the donor-recipient junction), and postoperative factors (time point of suture removal) on postoperative topographic parameters. The roundness of the donor-recipient junction after complete suture removal had a significant association with the roundness of the donor button after trephination (P = 0.04) and the amount of graft decentration relative to the limbus (P = 0.03). A significant correlation was found between the value of graft decentration relative to the limbus and postoperative keratometric astigmatism (P = 0.001) and between the roundness of the donor-recipient junction and the postoperative SRI (P = 0.02). The flat axis of the keratometric astigmatism and the longer axis of the graft lay in the direction of graft displacement. Other investigated factors had no significant association with postoperative topographic indices. Graft displacement relative to the limbus and roundness of the donor-recipient junction were the main predictors of graft astigmatism and regularity, respectively, after DALK. Noncircularity of the donor button after trephination could increase the graft surface irregularity indirectly by influencing the roundness of the surgical wound.

Logistic index for keratoconus detection and severity scoring (Logik)

PurposeTo develop an objective severity scoring system for keratoconus for the use in clinical practice. MethodsCorneal elevation and minimum thickness data of 812 subjects were retrospectively collected and divided into two groups: one control group with normal topography in both eyes (304 eyes), and one keratoconus group (508 eyes). Keratoconus cases ranged from suspect to moderate and had at least 1 examination in 1 of 2 recruiting centres. The elevation data were fitted to Zernike polynomial functions up to 8th order. An adapted machine learning algorithm was then applied to derive a platform-independent severity scoring and identification system for keratoconus. ResultsThe resulting logistic index for keratoconus (Logik) provided consistent and progressing scoring that reflected keratoconus severity. Moreover, the system provided an accurate classification of suspect keratoconus versus normal (sensitivity of 85.2%, specificity of 70.0%) when compared with Belin/Ambrosio Display Deviation (BAD_D) (sensitivity of 75.0%, specificity of 74.4%) and the Pentacam Topographical Keratoconus Classification (TKC) (sensitivity of 9.3%, specificity of 97.0%). Logik also showed better accuracy for grading keratoconus stages with an average accuracy of 99.9% versus (98.2%, 94.7%) with BAD_D and TKC respectively. ConclusionLogik is a reliable index to identify suspect keratoconus and to score the severity of the disease. It shows an agreement with existing approaches while achieving better performance.

Intraocular lens power calculation in eyes with keratoconus

The purpose was to review and document the methods used to calculate the power of the intraocular lens (IOL) to be implanted in cataract surgery in the specific scenario of eyes with keratoconus. This review included all scientific articles published in English that focused on the parameters and formulas used to calculate the power of the IOL to be implanted in eyes with keratoconus undergoing cataract surgery. There are few publications that show in detail how IOL power is calculated in these particular cases. If the keratometric value used was based on the standard refractive index (1.3375), it resulted in a postoperative refractive error with a tendency to hyperopia. The SRK/T formula yielded the best outcomes. The greater the severity of keratoconus the greater was the deviation of the postoperative refractive status from the target outcome.

Evaluation of vision-related quality of life in keratoconus patients, and associated impact of keratoconus severity indicators.

To evaluate vision-related quality of life in keratoconus patients and associated impact of keratoconus severity indicators using the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). This was a prospective cross-sectional study carried out from November 1, 2014, to April 30, 2015, in the corneal service of the Hôtel-Dieu hospital, Paris, France. A hundred and one keratoconus patients were consecutively enrolled. Participants completed a French-validated version of the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). Manifest refraction, maximum keratometry value, and corneal thinnest point were recorded. Associations between clinical and demographic factors, previous medical or surgical treatment, and NEI-VFQ-25 scale scores were evaluated. Vision-related quality of life was no better in patients managed with rigid gas permeable contact lens, collagen cross-linking, or intracorneal ring segment implantation, compared with untreated patients. In advanced keratoconus (stages II, III, and IV of Amsler-Krumeich classification), rigid gas permeable contact lens wearers had better general vision but more ocular pain. Distance-corrected visual acuity worse than 20/40, mean refractive cylinder > 2.5 diopters, and corneal thinnest point < 460μm in the better eye were associated with a lower vision-related quality of life. In multivariate analysis, only the uncorrected and distance-corrected visual acuity of the better eye remained significantly correlated with vision-related quality of life. Low distance-corrected visual acuity in the better eye was the strongest predictor of low vision-related quality of life.

The impact of catalase and glutathione peroxidase-1 genetic polymorphisms on their enzyme activities among Egyptian patients with keratoconus.

Elevated oxidative stress plays a significant role in pathophysiology of keratoconus (KC). Polymorphisms of the antioxidant enzymes as CAT and GPX-1 might alter their antioxidant enzyme capacities leading to increase in the oxidative damage induced KC. To analyze the impact of CAT rs7943316 A/T and GPX-1 rs1050450 C/T single nucleotide polymorphisms (SNPs) on the risk and severity of KC among a group of Egyptian population. CAT rs7943316 and GPX-1 rs1050450 SNPs were examined using polymerase chain reaction-restriction fragment length polymorphism in 100 control subjects and 150 KC patients [50 patients (KC stages 1&2), 50 patients (KC stage 3) and 50 patients (KC stage 4)]. Patients with TT genotype of CAT rs7943316 were at high risk of developing KC. T allele of GPX-1 rs1050450 was significantly associated with KC risk (P ˂0.001). The frequency of CAT TT genotype and T allele was significantly higher among severe stages of KC compared to mild and moderate stages. GPX-1 T allele frequency was significantly higher among severe stages of KC compared to mild and moderate stages. A very significant decrease in the antioxidant enzyme activities was observed in association with these SNPs. Age of the patients, CAT and GPX-1 SNPs as well as their enzyme activities were independent predictors of KC severity. Our study suggests that CAT (rs7943316) and GPX-1 (rs1050450) SNPs act as independent predictors for different grades of KC and that these SNPs might have a role in the pathogenesis of the disease.

Do visual performance and optical quality vary across different contact lens correction modalities in keratoconus?

PurposeWhile several advanced contact lens (CL) designs are commercially available for vision correction in keratoconus, their visual performance and optical quality, relative to each other and controls remains unclear. This prospective, crossover study tested the hypothesis that these CL designs would have a differential impact on visual performance and optical quality in subjects with advanced keratoconus, but not in early to moderate disease states. MethodsSpatial vision (logMAR acuity and contrast sensitivity), depth vision (stereoacuity) and optical quality (higher-order wavefront aberrations) were measured on 28 bilaterally mild to advanced keratoconics (age: 20–28yrs; 15 males), novice to CL wear, and in 10 age-matched controls using well-established psychophysical and aberrometry techniques. All data were collected on keratoconic subjects with their spectacles and with conventional RGP, Kerasoft®, Rose K2® and Scleral RGP® CL’s in randomized order, atleast a week apart from each other. ResultsAll outcome variables deteriorated with keratoconus severity and improved with CL wear, relative to spectacles (p < 0.05). This improvement was smaller for Kerasoft CL (p < 0.05) and higher but comparable for the other three CL designs (p = 0.3), across all disease severity. Visual functions and optical quality outcomes never reached control levels for any correction modality (p < 0.05). ConclusionVisual performance and optical quality in keratoconus does not appear to improve commensurately with the sophistication of CL design across disease severity. Non-visual factors like quality of CL fit, wearing comfort and cost may therefore drive the choice of CL dispensed in keratoconus more than the performance efficacy of these lenses.

Multicentre study: reliability and repeatability of Scheimpflug system measurement in keratoconus

PurposeTo assess the repeatability and reliability of the most important tomographic parameters for characterising keratoconus measured with a Pentacam HR (high resolution).MethodsOverall, 230 eyes in 158 patients with keratoconus were...

The impact of filaggrin genotype and atopic dermatitis on risk and severity of keratoconus

Abstract Background Filaggrin is a major structural protein in the skin barrier and null mutations in the filaggrin gene (FLG) increase the risk of developing atopic dermatitis (AD). Previous studies report an association between keratoconus (KC) and the presence of AD, and FLG mutated patients with concomitant AD may have a more severe KC. We investigated if FLG genotype and AD correlate to the frequency and severity of KC. Methods One hundred and eight patients were recruited and distributed in four groups based on KC and AD status. Patients with high myopia comprised the reference group. We used the topographical keratoconus classification (TKC), Kmax and central corneal thickness (CCT) to compare the groups and analyzed FLG mutation status by DNA sequencing. Results In total, 15 patients (14%) in our cohort harbored mutation in FLG. Nine of 49 patients (18%) with AD were FLG mutated whereas 6/59 (10%) without AD were carriers of FLG mutation (P = 0.22). There was no difference in Kmax between KC patients with and without AD (median Kmax 56.9 and 57.6, respectively – P = 0.81). Patients with FLG mutation had a median Kmax of 62.5 whereas FLG wild-type patients had a median Kmax of 56.9, P = 0.29. There was no difference in CCT between FLG mutated KC patients (median CCT 420 µm) and KC patients with FLG wild-type (median CCT 448 µm), P = 0.21. Conclusion In our cohort, the frequency of FLG mutations was low and genotype equally distributed between patients with and without AD and KC. There was no aggravation in KC severity parameters in FLG mutated patients compared to patients with FLG wild-type. Future studies powered to assess the synergistic influence of AD and FLG genotype may identify patients at risk of severe KC.

Assessment of corneal biomechanical changes after small incision lenticule extraction with Pentacam and Corvis ST

Objective: To investigate the application value of Pentacam combined with Corvis ST in evaluation of the changes of corneal biomechanics after femtosecond laser small incision lenticule extraction (SMILE) in Chinese myopia with an irregular cornea. Methods: The clinical records for 104 eyes of 57 patients who received SMILE in the Refractive Center of Beijing Tongren Hospital during January 2018 and May 2018 were collected. According to the keratoconus severity index (KSI), they were divided into two groups: regular corneal group (KSI<15%) and irregular corneal group (KSI: 15% to 25%). In both groups, the anterior corneal surface radius curvature was>7.25 mm (K<46.50 diopters), the posterior corneal surface radius curvature was>5.90 mm, the thinnest pachymetry was>490 μm, and best corrected visual acuity was ≥1.0. The vision, refraction, and corneal biomechanics before and after SMILE were assessed. The Topographic and Biomechanics Index (TBI) was analyzed by Pentacam combined with Corvis ST. Results: Before SMILE, the Corvis Biomechanical Index (CBI), TBI, and Belin/Ambrósio Deviation Normalized Index (BADD) of the irregular corneal group were significantly higher (t=-2.17, -6.78, -4.37, P<0.05) than the regular corneal group, while the stiffness parameter (SPA1) was significantly lower (t=2.58, P=0.011) compared to the regular corneal group (P<0.05). In the irregular group, the TBI was (0.28±0.2); the maximum value was 0.03, and the minimum value was 0.43. The CBI was (0.09±0.21); the maximum value was 0.00, and the minimum value was 0.54. The BADD was (1.33±0.47); the maximum value was 0.42, and the minimum value was 2.26. In the regular group, the TBI was (0.05±0.08); the maximum value was 0.00, and the minimum value was 0.20. The CBI was (0.01±0.03); the maximum value was 0.00, and the minimum value was 0.17. The BADD was (0.92±0.46); the maximum value was 0.00, and the minimum value was 1.64. There was no significant difference between two groups in age (t=0.20, P=0.508), central corneal thickness (t=1.64, P=0.104), biomechanical corrected IOP (t=0.73, P=0.468), max inverse radius (t=-0.24, P=0.815), spherical equivalent (t=-0.97, P=0.335), and best corrected visual acuity (t=0.21, P=0.833). After SMILE, the deformation amplitude in the irregular group was significantly higher at 1 month and 3 months (t=-3.13, -3.09, P<0.05). The irregular group had a significantly higher deformation amplitude ratio at 1 week, 1 month, and 1 year (t=-2.72, -3.39, -2.51, P<0.05). The SPA1 in the irregular group was significantly lower than the regular group at 1 week, 1 month, and 3 months (t=2.11, 2.73, 3.70, P=0.335, 0.010,<0.001). The changes of deformation amplitude (t=0.50, -1.10, -0.73, 2.12, P>0.05), max inverse radius (t=-1.52, -1.41, 0.01, -0.79, P>0.05), and SPA1(t=0.89, 0.90, 1.12, 0.90, P>0.05) after SMILE were similar between the irregular and regular groups, except that at 1 month after SIMILE, the deformation amplitude ratio changed more significantly in the irregular group (t=-3.01, P=0.003). Conclusions: The changes of corneal biomechanics in the groups of regular cornea and irregular cornea were stable with no significant difference during 1 year of post-SMILE. The diagnosis based on the corneal topography and corneal biomechanics is of certain significance for the screening of early keratoconus before keratorefractive surgery. (Chin J Ophthalmol, 2020, 56:103-109).

Prevalence of Astigmatism and Keratoconus in Egyptian Patients Evaluated by Schleimpflug Tomography: A Retrospective Cohort Study

Background: Scheimpflug camera uses various indices such as corneal thickness, detection of early and subclinical cases of keratoconus is challenging for the most refractive surgeon. However, corneal tomographic imaging is of great value in detecting such early changes. Purpose: To assess the pattern of refractive conditions implying corneal astigmatism, and KC, in an Egyptian population attending a major referral diagnostic eye center, ODLU, as assessed by Schleimpflug Imaging. Study Design: A retrospective, non-randomized, single-center, observational study. Patients and Methods: 501 recorded files for patients who were referred to ODLU for corneal tomography assessed by Scheimpflug imaging were retrieved by the serial selection, from January 2014 to June 2016 Results: 501 eyes, of 276 patients were analyzed, 50.7% males and 49.3% females, ranged from 5 to 80 years old, number of normal corneas was 39 eyes (7.8%), astigmatism 0.5D-1.5D was 120 eyes (24%), astigmatism >1.5D: 342 eyes (68.3%). The number of trauma/operated corneas( keratoplasty or LASIK) was 77 eyes(15.4%). The number of eyes with KC was 144 eyes (28.74%), The KC suspect corneas were 32 eyes (6.77%) Conclusion: The largest number of patients who were referred for corneal tomography had astigmatism more than 1.5 D, the number of keratoconus suspects was higher in females in the 20 to 40 years age group, however, the severity of keratoconus was more in males at the same age group.

Prevalence of Astigmatism and Keratoconus in Egyptian Patients Evaluated by Schleimpflug Tomography: A Retrospective Cohort Study

Background: Scheimpflug camera uses various indices such as corneal thickness, detection of early and subclinical cases of keratoconus is challenging for the most refractive surgeon. However, corneal tomographic imaging is of great value in detecting such early changes. Purpose: To assess the pattern of refractive conditions implying corneal astigmatism, and KC, in an Egyptian population attending a major referral diagnostic eye center, ODLU, as assessed by Schleimpflug Imaging. Study Design: A retrospective, non-randomized, single-center, observational study. Patients and Methods: 501 recorded files for patients who were referred to ODLU for corneal tomography assessed by Scheimpflug imaging were retrieved by the serial selection, from January 2014 to June 2016 Results: 501 eyes, of 276 patients were analyzed, 50.7% males and 49.3% females, ranged from 5 to 80 years old, number of normal corneas was 39 eyes (7.8%), astigmatism 0.5D-1.5D was 120 eyes (24%), astigmatism >1.5D: 342 eyes (68.3%). The number of trauma/operated corneas( keratoplasty or LASIK) was 77 eyes(15.4%). The number of eyes with KC was 144 eyes (28.74%), The KC suspect corneas were 32 eyes (6.77%) Conclusion: The largest number of patients who were referred for corneal tomography had astigmatism more than 1.5 D, the number of keratoconus suspects was higher in females in the 20 to 40 years age group, however, the severity of keratoconus was more in males at the same age group.

Level of awareness among non-medical students toward keratoconus, Abha,Saudi Arabia

Background: Keratoconus (KC) is a progressive, bilateral, asymmetric, ectatic disease that leads to progressive corneal thinning and protrusion, which results in progressive visual impairment and irregular astigmatism. Early detection plays a critical role in the management and prognosis. Awareness of the population at risk improves early screening and utilization of eye health care. The aim of the present study is to assess the awareness level among non-medical students toward KC, Abha city, Saudi Arabia. Materials and Methods: A cross-sectional study was conducted among the nonmedical students from January 2019 to May 2019 in the Southern Region of Saudi Arabia. A total of 393 nonmedical students were randomly selected through the university admission deanship records. Electronic consents were obtained from all participants. Close-ended questionnaires were circulated using the university official electronic mails. Results: A total of 374 females and 19 males were responded. Among those who had poor awareness, majority were female (95.7%) and belonged to the age group of 17–21 years (68.3%). Similar pattern was seen in the study participants with fair awareness. However, 57.1% of the study participants with good awareness belonged to the age group of 22–26 years. Conclusion: Visual impairment is a common condition among young population. Onset and severity of KC are diverse among countries. Early screening for the population at risk could hasten the appropriate medical intervention and reduce the burden of this condition. The level of awareness considered a key factor for a better utilization of the eye health care.

Accuracy of Intraocular Lens Formulas in Eyes With Keratoconus

To evaluate the refractive accuracy of currentintraocular lens (IOL) formulas in eyes with keratoconus. Retrospective case series. Preoperative optical biometry, Pentacam topography, and postoperative outcomes were collected from eyes with keratoconus that had uncomplicated cataract surgery between 2014 and 2018 at a single institution. Exclusion criteria include postoperative best-corrected spectacle visual acuity worse than 20/40, multifocal lens, prior ophthalmic surgeries, and prior ocular trauma. The Hoffer Q, SRK/T, Holladay I, Holladay II, Haigis, and Barrett Universal II formulas were analyzed in each eye stratified by keratoconus severity. A total of 73 eyes were included. All formulas had a positive mean predicted error ranging from 0.10 to 4.38 diopters (D). The Barrett Universal II formula had the lowest median absolute error for stage I (n= 46, 0.445 D) and II (n= 22, 0.445 D) eyes, and the highest percentage of eyes with predicted error within ±0.50 D for both stage I (52%) and II (50%) eyes. In stage III eyes (n= 5), the Haigis formula had the lowest median predicated error (1.90 D) and the highest percentage of eyes with predicted error within ±0.50 D (40%). Corneal power measured by optical biometers was higher than measurements by Pentacam keratometry. All formulas tend to have a hyperopic surprise. The Barrett Universal II formula was the most accurate for mild to moderate disease. Pentacam keratometry may help avoid hyperopic outcomes.

The Association Between Interleukin 1 Beta Promoter Polymorphisms And Keratoconus Incidence And Severity In An Egyptian Population.

PurposeIn the present study, we investigated whether interleukin 1 beta (IL1B) promoter polymorphisms are associated with keratoconus in an Egyptian population and their association with disease severity.MethodsA total of 95 Egyptian keratoconus patients and 126 Egyptian healthy controls were enrolled in the study. Two IL1B single nucleotide polymorphisms (SNPs) (rs1143627 and rs16944) were genotyped using Taqman real-time PCR to compare haplotype, genotype, and allele frequencies between cases and controls (primary outcome) and their association with disease severity (secondary outcome).ResultsStatistically significant association was observed for rs1143627 and rs16944; the T allele of rs1143627 and the G allele of rs16944 were associated with an increased risk of keratoconus (p < 0.001, odds ratio = 3.313, 4.770, respectively). The TT genotype of rs1143627 and the GG genotype of rs16944 were strongly associated with an increased risk of keratoconus (p < 0.001, odds ratio = 5.631, 11.478, respectively). The G allele of rs16944 was associated with an increased curvature of the flattest corneal meridian Kf in keratoconus (p = 0.041). The GG genotype of rs16944 was associated with an increased curvature of the flattest corneal meridian Kf, steepest corneal meridian Ks and average corneal curvature Kavg in keratoconus (p = 0.01, 0.046, 0.023, respectively).ConclusionIL1B is suspected to play a crucial role, both in development and severity of keratoconus in Egyptian population.