Intraobserver Repeatability Assessment of the S390L Firefly WDR Slitlamp in Patients With Dry Eye Disease: Objective, Automated, and Noninvasive Measures.

OBJECTIVES: To assess the intraobserver repeatability of automated, objective, and noninvasive measures obtained with the S390L Firefly WDR slitlamp. METHODS: This cross-sectional study included 50 eyes of patients with dry eye disease with a mean age of 55.06±12.96 years. Three consecutively repeated measures of the following variables were obtained: first noninvasive break-up time (F-NIBUT), average noninvasive break-up time (A-NIBUT), tear meniscus height, tear meniscus area (TMA), nasal ciliary hyperemia (NCIH), temporal ciliary hyperemia (TCIH), nasal conjunctival hyperemia (NCOH), temporal conjunctival hyperemia (TCOH), upper loss area meibomian gland (U-LAMG), lower loss area meibomian gland (L-LAMG), upper meibomian gland dysfunction grade (U-MGD grade), and lower meibomian gland dysfunction grade (L-MGD grade). Intraobserver repeatability was estimated with coefficient of variation (CoV), intrasubject standard deviation (SD) (S w ), and Bland-Altman plots. RESULTS: All variables showed no statistically significant differences in the repeated-measures analysis except for L-MGD grade ( P =0.045). F-NIBUT and A-NIBUT obtained the highest CoV with an average value of 0.48±0.41 [0.02-1.00] and 0.34±0.25 [0.02-1.00], respectively. The remaining variables showed CoVs between 0.04±0.11 [0.00-0.43] and 0.18±0.16 [0.00-0.75]. A-NIBUT, TMA, NCOH, and L-LAMG obtained an S w of 2.78s, 0.21 mm 2 , <0.001, and 4.11%, respectively. Bland-Altman plots showed a high level of agreement between pairs of repeated measures. CONCLUSION: The S390L Firefly WDR slitlamp has moderate intraobserver repeatability for F-NIBUT and A-NIBUT, which suggests that F-NIBUT and A-NIBUT are tests with high variability. The remaining variables show satisfactory intraobserver repeatability.

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.

Dry eye disease and tear film assessment through a novel non-invasive ocular surface analyzer: The OSA protocol.

We describe the role of OSA as a new instrument in the study of dry eye, and we recommend a protocol for conducting the tests as well as describe the advantages and disadvantages compared with other instruments. A comparison with other ocular surface devices (Tearscope Plus, Keratograph 5M, anterior-segment ocular coherence tomography, Easy Tear View-Plus, LipiView, IDRA, and LacryDiag) were presented due to manual or automatic procedure and objective or subjective measurements. The purpose of this study was to describe the OSA as new non-invasive dry eye disease diagnostic device. The OSA is a device that can provide accurate, non-invasive and easy-to-use parameters to specifically interpret distinct functions of the tear film. This OSA protocol proposed a lesser to higher non-invasive ocular surface dry eye disease tear film diagnostic methodology. A complete and exhaustive OSA and OSA Plus examination protocol was presented within the subjective questionnaire (Dry Eye Questionnaire 5, DEQ5), limbal and bulbar redness classification (within the Efron grade Scale, interferometry lipid layer thickness (LLT) (according to Guillon pattern), tear meniscus height (manually or automatic), first and mean non-invasive break up time (objective and automatic) and meibomian gland (MG) dysfunction grade and percentage (objective and automatic). The OSA and OSA Plus devices are novel and relevant dry eye disease diagnostic tools; however, the automatization and objectivity of the measurements can be increased in future software or device updates. The new non-invasive devices supposed represent a renewal in the dry eye disease diagnosis and introduce a tendency to replace the classic invasive techniques that supposed less reliability and reproducibility.

Tomographic and aberrometric assessment of first-time diagnosed paediatric keratoconus based on age ranges: a multicentre study.

PURPOSE: To describe paediatric keratoconus (KC) patients by tomographic and aberrometric characteristics at first diagnosis, in a multicentre study. METHODS: We included 278 eyes from 139 paediatric patients, with a first tomographic diagnosis (Pentacam® ) of KC prior to 18 years old. KC classification was based on the KC Index (≥ 1.07) and Topographic Keratoconus Classification (TKC ≥ 1). Patients were divided based on age ranges (14 and under and over 14 years) and gender. Statistical analysis was performed with SPSS statistics 25.0. ANOVA factor was carried out comparing to compare groups. RESULTS: 278 eyes were screened, and 230 eyes were diagnosed with paediatric KC. Mean age was 15.48 ± 2.33 (6 to 18) years. We found differences in terms of TKC (2.08 ± 0.89 and 2.38 ± 0.82, p < 0.05) and spherical aberration (-0.71 ± 0.97 and -1.07 ± 1.36, p < 0.05) among the 14 years old or under and above 14 years old groups, respectively. Overall, female paediatric KC patients presented a more severe TKC, Belin Ambrosio Display, maximum keratometry, asphericity and primary and secondary coma aberrations compared to male KC patients. We observed a correlation between CDVA and asphericity (r = 0.71, p < 0.01), as well as between CDVA and spherical aberration (r = 0.69, p < 0.01). CONCLUSION: Our findings revealed that the debut of KC is usually in a moderate to advanced stage in the paediatric population at first diagnosis, particularly in female patients. Corneal tomography should be systematically performed in children with recent onset of corneal astigmatism.

Could the percent tissue altered (PTA) index be considered as a unique factor in ectasia risk assessment?

PURPOSE: To evaluate the efficacy, safety, predictability and stability of the percent tissue altered (PTA) formula in post-LASIK (laser-assisted in situ keratomileusis) ectasia risk assessment. METHODS: One hundred and ninety-three eyes from 104 patients with low to moderate myopia that underwent femtosecond LASIK were included in this retrospective, observational and longitudinal study. Seventy-eight eyes were classified in the higher-PTA (> 40%) group and 115 eyes in the lower-PTA (< 40%) group. Spherical manifest refraction, cylinder manifest refraction, logMAR and Snellen previous corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), anterior face Baiocchi Calossi Versaci index (BCVf) and posterior face (BCVb), central corneal thickness (CCT), estimated residual stromal bed (RSB), spherical aberration (SA) and root mean square (RMS) were reported. All patients were followed up for 4 years. RESULTS: In the higher-PTA group, 97% of eyes reported UDVA 20/20 or better, and in the lower-PTA group, all eyes achieved 20/20 or better. No group reported decreased visual acuity. The higher-PTA group obtained 55% of eyes within ± 0.50 D and 90% within ± 1.00 D; and the lower-PTA group obtained 63% of eyes within ± 0.50 D and 90% within ± 1.00 D. Both groups showed a refraction correction of 0.50 D or more in 36% and 31% of eyes, in the higher-PTA and the lower-PTA groups, respectively. CONCLUSION: Percent tissue altered index should not be considered as a unique variable in post-LASIK ectasia risk assessment. Ectasia susceptibility screening should integrate tomography and biomechanical variables in order to help us to decide any refractive treatment choice and increasing refractive surgery safety.