Assessment of large-diameter and small-diameter SoftK specialty contact lenses for early-stage keratoconus.

INTRODUCTION: Soft contact lenses may be a good alternative for early-stage keratoconus (KC) patients who do not tolerate rigid gas permeable (RGP) lenses due to ocular discomfort or complications. This prospective study compared outcomes obtained after 2 weeks of wearing two types of soft silicone hydrogel contact lenses for keratoconus that varied in their diameter and central thickness (cc). METHODS: Patients with Amsler-Krumeich grades I or II KC were fitted with small-diameter (14.2 or 14.8 mm) SoftK (SD-SoftK, cc = 0.48 mm) and large-diameter (17 mm) SoftK (LD-SoftK, cc = 0.60 mm) lenses, each worn for 2 weeks in a crossover design. Low (10%;10VA) and high (100%;100VA) contrast visual acuity, contrast sensitivity (CS, Pelli-Robson), higher order aberrations (HOAs, Visionix Vx130), the number of trial lens modifications during fitting and the subjectively preferred lens were compared using Friedman tests with post-hoc analysis. RESULTS: Forty eyes (N = 20, 10 males, mean age: 39.0 ± 9.9 years, range: 23-55 years) were examined. Their habitual median (interquartile1, interquartile3) 10VA (LogMAR), 100VA (LogMAR) and CS (LogCS) were 0.52 (0.30, 0.50), 0.14 (0.10, 0.15) and 1.35 (1.35, 1.50), respectively. For the SD-SoftK condition, the values were 0.23 (0.17, 0.30), 0.02 (0.00, 0.05) and 1.50 (1.50, 1.65), respectively. For the LD-SoftK condition, the respective values were 0.36 (0.27, 0.44), 0.09 (0.05, 0.13) and 1.50 (1.50, 1.60). SD-SoftK lenses significantly improved 10VA compared with habitual and LD-SoftK. SD-SoftK also significantly improved CS compared with habitual, but not LD-SoftK. LD-SoftK significantly improved spherical aberration compared with uncorrected (0.03 ± 0.10 µ vs. 0.07 ± 0.13 µ) but not SD-SoftK (0.04 ± 0.07 µ). Both lenses required a mean of 1.5 modifications prior to final lens fitting. Fewer adverse events were seen with SD-SoftK (N = 3) compared with LD-SoftK (N = 8), and 75% of participants preferred SD-SoftK lenses. CONCLUSION: SD-SoftK lenses were preferred by 75% of subjects, were associated with fewer adverse events and significantly improved 10VA compared with LD-SoftK lenses. SD-SoftK lenses also significantly improved CS compared with the habitual correction, but this did not differ significantly from the LD-SoftK lenses.

Factors Associated With Receipt of Crosslinking for Keratoconus.

PURPOSE: The aim of this study was to identify factors associated with receipt of standard fluence epithelium-off crosslinking (CXL) for keratoconus (KCN). METHODS: This retrospective, cross-sectional study reviewed electronic health records of treatment-naive patients with KCN seen at the Wilmer Eye Institute between January 2017 and September 2020. Tomographic data were derived from Pentacam (Oculus, Wetzlar, Germany) devices. Multivariable population-average model using generalized estimating equations adjusting for age, sex, race, national area deprivation index, vision correction method, and disease severity was used to identify factors associated with receipt of CXL. RESULTS: From 583 patients with KCN, 97 (16.6%) underwent CXL for KCN. Patients who received CXL in at least 1 eye were significantly younger (mean 24.0 ± 7.8 years) than patients who had never undergone CXL (33.4 ± 9.3 years) ( P < 0.001). In multivariable analysis, Black patients had 63% lower odds of receiving CXL for KCN (OR: 0.37, 95% CI, 0.18-0.79) versus White patients, and older age was protective against receipt of CXL (OR: 0.89 per 1-year increase, 95% CI, 0.86-0.93). Comparison of characteristics by race demonstrated that Black patients presented with significantly worse vision, higher keratometric indices (K1, K2, and Kmax), and thinner corneal pachymetry at baseline versus White or Asian patients. CONCLUSIONS: In this clinical cohort of patients with KCN from a tertiary referral center, Black patients were less likely to receive CXL presumably because of more advanced disease at presentation. Earlier active population screening may be indicated to identify and treat these patients before they become ineligible for treatment and develop irreversible vision loss. Such strategies may improve health equity in KCN management.

Assessment of Health Disparities and Barriers to Accessing Keratoconus and Crosslinking at a Tertiary Referral Center.

PURPOSE: The aim of this study was to determine the barriers to accessing the crosslinking service in Auckland, New Zealand. METHODS: This was a prospective 1-year study of patients at Auckland District Health Board. Studied parameters included age, sex, body mass index, ethnicity, New Zealand Deprivation (NZDep; an area-based measure of socioeconomic status, 1 = low deprivation-10 = high deprivation) score of residence, disease severity (maximum keratometry and thinnest corneal thickness), attendance, distance travelled, car ownership, employment status, and visual outcomes. Statistical analysis was performed using independent t tests, Pearson correlation, independent samples ANOVA, MANCOVA, and binomial logistic regression. RESULTS: Four hundred fifty-four patients with keratoconus were analyzed and had a mean age of 24.1 ± 0.8 years, mean body mass index of 33.0 ± 9.7 kg/m 2 , and 43% were female. Pacific Peoples consisted 40.2% of the population; Maori 27.2%; Europeans 21.2%; Asian 9.9%; and Middle Eastern, Latin American, and African (MELAA) 1.3%. The mean distance travelled was 12.5 ± 9.5 km, NZDep score was 6.8 ± 2.6, and attendance was 69.0 ± 42.5%. The lowest attendance was observed in Pacific Peoples (58.9%) and the highest was in Asians (90%) ( P = 0.019). The mean worst-eye visual acuity at attendance was 0.75 ± 0.47 logMAR (6/35). Unemployment was associated with worse best-eye visual acuity at FSA ( P = 0.01) and follow-up ( P < 0.05). Maori and Pacific Peoples had the highest NZDep ( P < 0.001), were younger at presentation ( P = 0.019), had higher disease severity ( P < 0.001), and worse visual acuity ( P < 0.001). CONCLUSIONS: Poor attendance was seen in this cohort. Pacific Peoples and Maori presented younger with worse disease severity and visual acuity but also had the highest nonattendance. These results suggest that deprivation, factors associated with ethnicity, and unemployment are potential barriers to attendance.

A Comprehensive Wavefront Assessment of Keratoconus Using an Integrated Scheimpflug Corneal Tomographer/Hartmann-Shack Wavefront Aberrometer.

OBJECTIVES: To characterize higher-order aberrations (HOAs) in different severities of keratoconus (KC) from the anterior and posterior corneal surfaces and whole eye using an integrated Scheimpflug corneal tomographer/Hartmann-Shack wavefront aberrometer. METHODS: This study included eyes with clinical KC, topographic KC (no clinical signs), fellow eyes with very asymmetric ectasia with normal topography and no clinical signs (VAE-NT), and control eyes. Corneal and ocular wavefront aberrations were obtained using an integrated Scheimpflug tomographer/Hartmann-Shack wavefront aberrometer. The diagnostic capability of distinguishing VAE-NT from the control was also tested. RESULTS: This study included 68 eyes with clinical KC, 44 with topographic KC, 26 with VAE-NT, and 45 controls. Clinical KC had significantly greater total HOAs and coma from the anterior and posterior corneal surfaces and whole eye than the other groups ( P <0.05). Although topographic KC had significantly greater values in all wavefront parameters than the control ( P <0.05), ocular and corneal HOAs did not differ between the VAE-NT and control groups. The coma from the anterior cornea in topographic KC was significantly greater than that in VAE-NT ( P <0.05); the coma from the posterior cornea and whole eye did not differ. Total HOAs from the anterior corneal surface exhibited the highest area under the receiver operating characteristic curve value of 0.774 (sensitivity, 73%; specificity, 78%). CONCLUSION: A comprehensive wavefront assessment can be used to quantitatively evaluate corneal and ocular HOAs across various severity of KC. Total HOAs from the anterior corneal surface exhibited the potential ability in distinguishing VAE-NT from the control eyes.

Enhanced morphological assessment based on interocular asymmetry analysis for keratoconus detection.

PURPOSE: To clarify the interocular asymmetry of corneal morphological descriptors and evaluate its discriminant ability of keratoconus (KC). METHODS: This retrospective study recruited 344 normal participants and 290 KC patients, randomized to training and validation datasets. Interocular correlation and agreement were evaluated on 44 corneal morphological descriptors derived from Schiempflug tomography. Logistic regression models were constructed using binocular data and of which diagnostic performance was evaluated using the area under receiver operating characteristics curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI). RESULTS: Interocular agreement of corneal descriptors is better in the normal than in KC except for dimensions of cornea and anterior chamber. The interocular asymmetry increases along with the severity of KC. Interocular asymmetry in maximum anterior keratometry, mean anterior keratometry and higher-order aberrations of anterior surface show high AUC above 0.950. Binocular logistic regression index reaches an AUC of 0.963 with high specificity (95.2%) and brings gain to monocular parameters in distinguishing the normal eyes from KC (NRI = 0.080 (0.042 ~ 0.118), P < 0.001) and IDI = 0.071 (0.049 ~ 0.092), P < 0.001). Interocular asymmetry benefits even more in subclinical keratoconus (SKC) detection reflected by NRI (0.4784 (0.2703-0.6865), P < 0.001) and IDI (0.2680 (0.1495-0.3866), P < 0.001) measures. CONCLUSION: Interocular asymmetry is a well-characterized feature of KC and related to the severity. It is feasible to apply the interocular asymmetry in diagnosis of KC and SKC as a replenishment of monocular parameters and in progression tracking.

Prevalence and Economic Burden of Keratoconus in the United States.

PURPOSE: To assess the prevalence and economic burden of keratoconus in the United States. DESIGN: Retrospective cohort study. METHODS: Patients enrolled in Medicaid and Children's Health Insurance Program (CHIP) who were diagnosed with keratoconus between 2016 and 2019 were included. The data reported to the Centers for Disease Control and Prevention (CDC) Vision and Eye Health Surveillance System (VEHSS) were analyzed. The crude prevalence rates (national and statewise) were obtained from the database and extrapolated to estimate the keratoconus case count in the United States. The keratoconus prevalence was compared between male and female individuals using the Mann-Whitney test, whereas Brown-Forsythe 1-way analysis of variance was used to compare prevalence between age and racial groups. The Dunnett T3 multiple comparison test was used for intergroup comparison. Finally, the economic burden of keratoconus was assessed by inflation-adjusted direct costs to patients and total cases in the country. RESULTS: In the cohort of 69,502,000 patients enrolled for Medicaid and CHIP, the national prevalence of keratoconus was computed to be 0.04% in 2019 and had increased from 0.03% in 2016. The highest prevalence of keratoconus was observed in patients 18 to 39 years of age, followed by patients 40 to 64 years of age; comparable prevalence rates were observed in these age groups in the Black population. The prevalence was moderately higher in female compared to male individuals; however, significantly higher keratoconus prevalence was observed in Black female individuals compared to male individuals. A significantly high prevalence of keratoconus was observed in the Black population, followed by Hispanic population. In 2019, the average inflation-adjusted lifetime cost of keratoconus treatment was USD 28,766.69, with a cumulative economic burden of USD 3.8 billion. CONCLUSIONS: In the United States, keratoconus is most prevalent in individuals 18 to 39 years of age. The keratoconus prevalence is higher in the Black population, specifically female individuals, and the diagnosis is often delayed in these patients.

Real-world socioeconomic determinants of corneal crosslinking in a national cohort.

PURPOSE: To characterize recent socioeconomic trends in patients with keratoconus/corneal ectasias undergoing corneal crosslinking (CXL). SETTING: A deidentified administrative medical claims database comprised commercial and Medicare Advantage health claims from across the United States. DESIGN: Population-based retrospective cohort study. METHODS: This study identified 552 patients with keratoconus/corneal ectasia who underwent CXL and 2723 matched controls who did not undergo CXL based on Current Procedural Terminology coding from a U.S. national insurance claims database from 2016 to 2020. For each patient, characteristics, including sex, race, age, household net worth, education level, insurance plan type, and geographic region, were extracted. Multivariate logistic regression was conducted to determine the odds of undergoing crosslinking. RESULTS: Age 30 years or older (odds ratio [OR], 0.34, P < .001) was associated with decreased likelihood of undergoing CXL. Sex, race, education, and patient income were not associated with odds of undergoing CXL. Patients with health maintenance organization insurance had lower odds of undergoing CXL (OR, 0.64, P = .047). Geographically, patients on the east coast (OR, 0.37, P < .001) and Lower Midwest (OR, 0.31, P < .001) had statistically lower odds of undergoing crosslinking. CONCLUSIONS: This is the first study to identify socioeconomic determinants of CXL, and it highlights that geographic location and insurance type may limit accessibility to patients.

Racial Variation in Visual Impairment of Patients With Keratoconus at Presentation.

PURPOSE: This study aimed to investigate racial disparities in the severity of keratoconus (KCN) at presentation, their intersection with socioeconomic variables, and other factors associated with visual impairment. METHODS: This retrospective cohort study examined medical records of 1989 patients (3978 treatment-naive eyes) with a diagnosis of KCN seen at Wilmer Eye Institute between 2013 and 2020. A multivariable regression model adjusting for age, sex, race, insurance type, KCN family history, atopy, smoking status, and vision correction method examined factors associated with visual impairment, defined as a best available visual acuity of worse than 20/40 in the better eye. RESULTS: Demographically, Asian patients were the youngest (33.4 ± 14.0 years) ( P < 0.001), and Black patients had the highest median area deprivation index (ADI) of 37.0 [interquartile range (IQR): 21.0-60.5] ( P < 0.001). Multivariable analysis showed a higher risk of visual impairment for Black (OR 2.25, 95% CI, 1.71-2.95) versus White patients. Medicaid (OR 2.59, 95% CI, 1.75-3.83) and Medicare (OR 2.48, 95% CI, 1.51-4.07) were also associated with a higher odds of visual impairment compared with private insurance, and active smokers were more likely to have visual impairment than those with no prior smoking history (OR 2.17, 95% CI, 1.42-3.30). Eyes of Black patients had the highest maximum keratometry (Kmax) (56.0 ± 11.0D) ( P = 0.003) and the lowest thinnest pachymetry (463.2 ± 62.5 µm) ( P = 0.006) compared with eyes of other races. CONCLUSIONS: Black race, government-funded insurance, and active smoking were significantly associated with increased odds of visual impairment in adjusted analyses. Black race was also associated with higher Kmax and lower thinnest pachymetry, suggesting that Black patients have more severe disease at presentation.

Observation and assessment of the immediate use of a silicon hydrogel contact lens after transepithelial corneal cross linking: a prospective study.

BACKGROUND: Transepithelial corneal crosslinking (CXL) is a novel surgical approach for the treatment of keratoconus, which is a bilateral asymmetrical ophthalmological disease accompanied by progressive corneal ectasia. Silicon hydrogel (SiH) contact lenses have been extensively used in clinical ophthalmologic medicine, as a postoperative ophthalmological intervention. However, the ideal lens application duration after transepithelial CXL remains uncertain. Here, we aimed to investigate the effects and comfort of immediate corneal contact lens use after transepithelial CXL for keratoconus. METHODS: In this prospective study, 60 patients with keratoconus who underwent transepithelial CXL treatment were enrolled from September 2021 to January 2023 with a male:female ratio of 39:21, and an average age of 25.42 ± 5.47 years. The patients were divided randomly into two groups: group A contained 30 patients wearing silicone hydrogel contact lenses for 7 days postoperatively, and group B contained 30 patients wearing the same contact lenses for 3 days. Ten subjective ophthalmologic symptoms were surveyed by the patients, including pain, photophobia, foreign body sensation, tearing, burning, blurred vision, dry eyes, difficulty opening the eyes, astringency, and stinging. Ophthalmologic signs, including corneal edema and conjunctival congestion, were recorded by a single clinician on postoperative days 1, 3, and 7. RESULTS: Each surgical procedure was readily performed without complications, and both groups postoperative day 7 (P = 0.04), where group B scored (0.01 ± 0.41) lesser than group A (0.12 ± 0.29), whilst corneal edema in both groups recorded significantly different on postoperative days 5 and 7 (group A demonstrated the result of 0.17 ± 0.14 and 0.08 ± 0.11 for the respective days, whereas group B indicated 0.10 ± 0.13 and 0.03 ± 0.07 at the corresponding times). CONCLUSIONS: Immediate use of silicone hydrogel corneal lenses after transepithelial CXL effectively alleviates postoperative ocular distress, particularly with a three-day use period as the ideal duration.

A Clinical Decision Tree to Support Keratoconus Patients Considering Corneal Cross-Linking Combined with Refractive Treatment.

BACKGROUND: To develop a fast and frugal decision tree to identify keratoconus patients most likely to benefit visually from the combination of corneal cross-linking (CXL) with topography-guided photorefractive keratectomy ("CXL plus"). PATIENTS AND METHODS: The outcome of interest was an improvement in uncorrected distance visual acuity (UDVA) by at least two lines at the 12-month follow-up. Preoperative and 12-month follow-up data from patients who received CXL plus (n = 96) and CXL only (n = 96) were used in a recursive partitioning approach to construct a frugal tree with three variables (corneal thickness [>/< 430 um], patient interest in CXL plus [yes/no], and tomographic cylinder [ 3 D]). In addition, we estimated the probability of the outcome from a multivariate logistic regression model for each combination of variables used in the decision tree. RESULTS: In the complete sample, 101/192 (52.6%) patients improved by at least two lines at the 12-month follow-up. Patients affirmative in all three answers had a 75.6% (34/45) probability of gaining at least two lines of improvement in UDVA by CXL plus. The statistical model estimated a 66.0% probability for a successful outcome. CONCLUSION: A fast and frugal tree consisting of three variables can be used to select a patient group with a high likelihood to benefit from CXL plus. The tree is useful in the preoperative counseling of keratoconus patients contemplating the CXL plus option, an intervention that is not fully covered by many health insurances.

Morphological and functional assessment of the tear film and meibomian glands in keratoconus.

PURPOSE: To evaluate morphological and functional state of the meibomian glands (MG) in keratoconus patients. METHODS: One hundred eyes of 100 keratoconus patients and 100 eyes of 100 age-matched control subjects were included into this study. Ocular Surface Disease Index (OSDI) scores, non-invasive break up time (NIBUT), findings of meibography, staining with fluorescein of the ocular surface, tear film break-up time (TBUT), and Schirmer I test were documented in all patients' eyes and control eyes and were compared between the groups . RESULTS: The mean TBUT and NIBUT were significantly lower, corneal staining and OSDI scores were statistically greater in the keratoconus group (p < 0.05). The mean meiboscore, partial gland, gland dropout and gland thickening scores for upper/lower eyelids were significantly greater in keratoconus patients than controls (p < 0.05). The NIBUT measurements significantly correlated with MG loss in upper/lower eyelids (p < 0.05). The severity of keratoconus seemed to correlate with meiboscore, partial gland, gland thickening scores in upper/lower eyelids. CONCLUSION: Our data suggests that corneal ectasia in keratoconus is related with alterations in ocular surface, tear film function and MG morphology. Early screening and treatment of MG dysfunction may improve ocular surface quality and allow better disease management in keratoconus patients.

The ABCD grading system in assessment of corneal cross-linking effect in keratoconus with different cone locations.

PURPOSE: The aim of this study was to analyse the postoperative corneal cross-linking results of corneal parameters and the ABCD grading system, depending on the cone location. METHODS: Thirty eyes of 25 patients with keratoconus (KC), who received the corneal cross-linking (CXL) treatment, were included in this study. The exclusion criteria were: patients under 18 years of age, corneal pachymetry less than 400 µm, corneal scarring, history of ocular trauma, history of ocular surgery, and corneal pathology other than KC. Patients were examined at the baseline visit, and followed-up at three, six, and twelve months after the CXL. All patients underwent visual acuity and Scheimpflug tomography at all visits. Progression parameters, keratometries, and ABCD grading were compared between the visits. Patients were classified into two groups: central and paracentral cones group (within the central 5 mm corneal zone) and peripheral cones group (outside the central 5 mm corneal zone), based on X-Y coordinates of maximal keratometry (Kmax). RESULTS: Parameter A remained relatively stable throughout the follow-up period in both groups. Parameter B and parameter C showed a significant increase in both groups postoperatively. Parameter D showed stability at the 6-month post-CXL visit in the peripheral KC group, while the central and paracentral KC group showed improvement at the 12-month post-CXL visit. CONCLUSION: There was no significant difference in the postoperative response between different cone locations in the ABCD grading system, when classifying according to the Kmax, except an earlier recovery of the parameter D in peripherally located cones.

Socioeconomic Correlates of Keratoconus Severity and Progression.

PURPOSE: The purpose of this study was to investigate the social determinants of health for keratoconus. METHODS: In this retrospective cohort study of patients with keratoconus, the electronic health record was reviewed for keratometry, treatments received, clinical comorbidities, and social characteristics. Outcomes included severe keratoconus at presentation (steep keratometry ≥52 diopters), disease progression (≥0.75 diopters increase from the first to the most recent clinical visit), and corneal transplantation. Logistic regression was used to evaluate factors associated with severity at presentation and corneal transplantation. Cox proportional hazards modeling was used to evaluate progression. RESULTS: A total of 1038 patients with keratoconus were identified, 725 (70%) of whom had baseline imaging. Compared with commercially insured patients, Medicaid recipients were more likely to have severe keratoconus, independent of social and clinical confounders [odds ratio (OR) 1.94, 95% confidence interval (CI), 1.12-3.35, P = 0.017]. Male sex was independently associated with progression (hazard ratio = 1.38, 95% CI, 1.03-1.84, P = 0.030). Medicare and Medicaid recipients were more likely to require transplantation compared with commercially insured patients (OR 2.71, 95% CI, 1.65-4.46, P < 0.001 and OR 1.74, 95% CI, 1.08-2.80, P = 0.022, respectively). Other social determinants of health, including non-White race/ethnicity, limited English proficiency, and unemployment, were associated with the outcomes only in univariate analysis. Obstructive sleep apnea, atopy, body mass index, and tobacco use were not associated with any outcome. CONCLUSIONS: Socioeconomic factors were more consistent predictors of keratoconus severity and corneal transplantation compared with clinical factors that have received relatively greater attention in the keratoconus literature.

Optic disc and retinal vessel densities assessment by optical coherence tomography angiography in patients with keratoconus.

BACKGROUND: This study aimed to evaluate retinal and optic disc vascular changes in patients with keratoconus (KC) using optical coherence tomography angiography (OCTA). METHODS: Thirty-two eyes of 22 patients with KC and 24 eyes of 24 age- and sex-matched healthy controls were included in this study. Corneal topography and OCTA were performed. Quantitative vessel density of the macular superficial capillary plexus (SCP), macular deep capillary plexus (DCP), and radial peripapillary capillaries (RPC); choriocapillaris flow area; and choroidal thickness were compared between the KC and control groups. RESULTS: SCP and DCP vessel densities showed a significant reduction in the KC group compared to that in the control group (p < 0.001 and p < 0.001 in the whole image and parafovea, respectively). Choriocapillaris flow area was significantly higher in patients with KC than in the control group (p = 0.003). The foveal avascular zone area did not significantly differ between the two groups (p = 0.949). RPC inside disc vessel density was significantly decreased in the KC group compared to that in the control group (p < 0.001). CONCLUSION: This study revealed important macular, choroidal, and optic disc vessel densities changes in patients with KC. Macular whole vessel density and parafoveal vessel density of the SCP and DCP decreased, while choriocapillaris flow area increased in patients with KC.

Assessment of the corneal biomechanical features of granular corneal dystrophy type 2 using dynamic ultra-high-speed Scheimpflug imaging.

PURPOSE: To evaluate the corneal biomechanical features of eyes with granular corneal dystrophy type 2 (GCD2) by analyzing corneal biomechanical indices obtained using a Corvis ST (CST) dynamic ultra-high-speed Scheimpflug imaging device. METHODS: In this retrospective case-control study, 35 CST parameters were compared in normal eyes (control) and eyes of patients with GCD2 treated at Osaka University Hospital, Osaka, Japan. The parameters included the Corvis Biomechanical Index (CBI), which is important in differentiating eyes with keratoconus from normal eyes. We measured the deposition rates of lesions in the central 7-mm region of the eye and assessed the correlation between the deposition rate and the CBI. RESULTS: Twenty-one eyes with GCD2 and 23 control eyes were analyzed. Eyes with GCD2 showed significantly less corneal stiffness in 15 CST parameters than did control eyes. In particular, the CBI was remarkably higher in eyes with GCD2 than in control eyes (P = 0.000006). Additionally, the deposition rate and the CBI were positively correlated. CONCLUSIONS: GCD2 eyes had softer corneas than did control eyes in most biomechanical CST parameters, and one of the parameters (the CBI) was linked to the rate of deposited lesions. Since IOP may be underestimated in GCD2 eyes, management should be especially careful in GCD2 cases complicated by glaucoma.

Choroidal thickness assessment in keratoconus patients treated with cross-linking compared to healthy population.

PURPOSE: To analyze the choroidal thickness between patients with keratoconus undergoing cross-linking treatment and a healthy population, as well as to determine the factors that influence choroidal thickness. METHODS: This was an observational, analytical, case-control study that was conducted from February 2021 to June 2021. Choroidal thickness was measured at different locations, including the subfoveal, nasal (1000 µm), temporal (1000 µm), superior (1000 µm) and inferior (1000 µm) locations using a Spectral-domain optical coherence tomography with enhanced depth imaging, which allowed us to obtain horizontal and vertical B-scans centered on the fovea. RESULTS: This study included 21 patients with keratoconus (mean age, 21.86 ± 5.28 years) and 28 healthy patients (mean age, 24.21 ± 4.71 years). Choroidal thickness was significantly greater in patients with keratoconus than in healthy patients in each of the following measured locations: subfoveal (P < 0.001); nasal (1000 µm) (P < 0.001), temporal (1000 µm) (P < 0.001), superior (1000 µm) (P < 0.001) and inferior (1000 µm) (P < 0.001) locations. Variables such as age (ρ = - 0.09; P = 0.50) and refraction (ρ = 0.14; P = 0.34) were not found to be associated with choroidal thickness. In a stepwise multiple linear regression, the group was the single variable correlated with choroidal thickness (ß = 0.88; P < 0.001). CONCLUSION: Choroidal thickness is thicker in keratoconus patients treated with cross-linking than in the healthy population. This finding could be associated with inflammatory choroidal mechanisms in keratoconus patients, but more studies are needed. Age and refractive error do not seem to influence choroidal thickness.

Avaliação das aberrações de alta ordem em pacientes com ceratocone inicial / Assessment of high-order aberrations in patients with early keratoconus

RESUMO Objetivo Identificar alterações de aberrometria de alta ordem em diferentes graus de ceratocone. Métodos Estudo transversal, retrospectivo, observacional. Foram analisados 54 pacientes (108 olhos) diagnosticados com ceratocone pelo mesmo especialista em córnea por meio dos critérios ABCD de Belin/Ambrósio Enhanced Ectasia, utilizando-se o tomógrafo Pentacam® HR 70900 (Oculus Wetzlar, Alemanha). Além disso, foram feitas análises qualitativa e quantitativa das aberrações de alta ordem desses mesmos pacientes por meio do OPD-Scan III-NIDEK. Resultados Por meio da avaliação de ambos os olhos dos pacientes com os critérios de Belin-Ambrósio, constatou-se presença de ceratocone em 34 pacientes. Ademais, por meio da análise estatística, constatou-se relação direta entre a asfericidade posterior e o desenvolvimento do ceratocone, com p<0,001 (referência: p<0,05). Por meio da análise do OPD-Scan III-NIDEK, as principais aberrações de alta ordem encontradas nos pacientes com ceratocone foram coma, trefoil e aberração esférica. Conclusão O raio da curvatura posterior é a primeira variável a se alterar com o desenvolvimento do ceratocone, o que se faz perceptível na análise da asfericidade posterior por meio o Pentacam®. Além disso, a alteração da paquimetria e da asfericidade posterior influencia diretamente o desenvolvimento de aberrações de alta ordem em pacientes com ceratocone.

ABSTRACT Objective To identify higher order aberrometry changes in different degrees of keratoconus. Methods Cross-sectional, retrospective, observational study. Fifty-four patients (108 eyes) diagnosed with keratoconus by the same corneal specialist using the Belin/Ambrósio Enhanced Ectasia ABCD criteria were analyzed, using the Pentacam® HR 70900 tomograph (Oculus Wetzlar, Germany). In addition, qualitative and quantitative analysis of higher order aberrations in these patients was performed using the OPD-Scan III-NIDEK. Results Through the evaluation of both eyes of the patients according to the criteria of Benin Ambrósio, the presence of KCN was verified in 34 patients. Furthermore, through statistical analysis, a direct relationship was found between posterior asphericity and the development of KCN; p<0.001 (reference: p<0.05). Through the analysis of the OPD scan, the main higher order aberrations found in patients with KCN were Coma, Trefoil and Spherical Aberration (AE). Conclusion The posterior curvature radius is the first variable to change with the development of the KCN, which is noticeable in the analysis of posterior asphericity in Pentacam. In addition, alterations in pachymetry and posterior asphericity directly influence the development of higher order aberrations in patients with KCN.