RESUMEN
Time-lapsed in vivo corneal confocal microscopy (IVCCM) has shown that corneal dendritic cells (DCs) migrate at approximately 1 µm/min in healthy humans. We have undertaken IVCCM of the whorl region to compare the density of rounded DCs, and DCs with (wDCs) and without (woDCs) dendrites and dynamics; trajectory (length travelled/time), displacement (distance from origin to endpoint/time) speeds and persistence ratio (displacement/trajectory) of woDCs in subjects with type 1 diabetes (T1D) (n = 20) and healthy controls (n = 10). Only the wDC density was higher (p = 0.02) in subjects with T1D compared to controls. There was no significant difference in cell dynamics between subjects with T1D and controls. woDC density correlated directly with HDL cholesterol (r = 0.59, p = 0.007) and inversely with triglycerides (r = −0.61, p = 0.005), whilst round-shaped cell density correlated inversely with HDL cholesterol (r = −0.54, p = 0.007). Displacement, trajectory, and persistency correlated significantly with eGFR (mL/min) (r = 0.74, p < 0.001; r = 0.48, p = 0.031; r = 0.58, p = 0.008, respectively). We show an increase in wDC density but no change in any other DC sub-type or alteration in cell dynamics in T1D. However, there were associations between DC density and lipid parameters and between DC dynamics and renal function. IVCCM provides evidence of a link between immune cell dynamics with lipid levels and renal function.
RESUMEN
PURPOSE: The purpose of this study was to establish an age-dependent normative range and factors affecting the migration rate of the corneal subbasal nerve plexus in a healthy control population. METHODS: Corneal nerve migration rate was measured in 60 healthy participants grouped by age: A, aged 20 to 39 years (n = 20); B, 40 to 59 years (n = 20); and C, 60 to 79 years (n = 20). Laser-scanning corneal confocal microscopy was performed on the right eye of all participants at baseline and again after 3 weeks. Fully automated software was used to montage the frames. Distinctive nerve landmarks were manually reidentified between the two montages, and a software program was developed to measure the migration of these landmark points to determine corneal nerve migration rate in micrometers per week (µm/wk). RESULTS: The mean ± SD age of all participants in the study was 47.5 ± 15.5 years; 62% of participants were male. The average corneal nerve migration rates of groups A, B, and C were 42.0 ± 14.0, 42.3 ± 15.5, and 42.0 ± 10.8 µm/wk, respectively (P = .99). There was no difference in corneal nerve migration rate between male (41.1 ± 13.5 µm/wk) and female (43.7 ± 13.2 µm/wk) participants (P = .47). There was no significant correlation between age (P = .97), smoking (P = .46), alcohol use (P = .61), and body mass index (P = .49, respectively) with corneal nerve migration rate. However, exercise frequency correlated significantly (P = .04) with corneal nerve migration rate. CONCLUSIONS: Corneal nerve migration rate varies in healthy individuals and is not affected by age, sex, or body mass index but is related to physical activity.
Asunto(s)
Córnea/inervación , Nervio Trigémino/fisiología , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Microscopía Confocal , Persona de Mediana Edad , Estudios Prospectivos , Programas Informáticos , Nervio Trigémino/diagnóstico por imagen , Adulto JovenRESUMEN
PURPOSE: To assess the repeatability of measuring the corneal nerve migration rate in individuals with and without neuropathy. METHODS: Wide-field montages of the subbasal corneal nerve plexus were generated at baseline and after 3 weeks for 14 participants. Montages were manually examined side by side to identify a referent landmark in the inferior whorl region (origin) and throughout each montage. A software program was developed to measure nerve migration of all identified points relative to the origin. Repeatability was determined by measurement of nerve migration for within observer (one researcher on 2 occasions, 5 days apart) and between observers (2 observers) within 4 different zones based on the distance from the origin and in the vertical section of the wide-field montage. The impact of images being montaged with fully automated software on repeatability was also investigated. RESULTS: The mean difference between observations 1 and 2 for observer 1 was 0.02 ± 1.3 µm/wk (P = 0.94), with an intraclass correlation coefficient (ICC) of 0.99 [95% confidence interval (CI) = 0.99-1.00], and the mean difference between observer 1 and 2 was 0.3 ± 1.2 µm/wk (P = 0.41), with an ICC of 0.99 (95% CI = 0.99-1.00). The mean difference between observations 1 (images montaged by semiautomated software) and 2 (images montaged by fully automated software) was 1.2 ± 4.9 µm/wk (P = 0.41), with an ICC of 0.96 (95% CI = 0.87-1.00). CONCLUSIONS: Measuring corneal nerve migration rate is highly repeatable for within and between observers and when using different methods of image montaging.
Asunto(s)
Córnea/inervación , Neuropatías Diabéticas/diagnóstico , Enfermedades del Nervio Trigémino/diagnóstico , Nervio Trigémino/patología , Adulto , Anciano , Neuropatías Diabéticas/fisiopatología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Microscopía Confocal , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Enfermedades del Nervio Trigémino/fisiopatologíaRESUMEN
PURPOSE: We have developed a novel technique to measure in vivo corneal nerve migration. METHODS: Wide-field montages of the subbasal corneal nerve plexus were generated at baseline and after 3 weeks. The 2 montages were manually examined side by side to identify a referent landmark in the inferior whorl region and 20 additional nerve landmarks throughout each montage. A software program was developed to measure nerve migration by quantifying the movement of the nerve landmarks relative to the inferior whorl landmark over the 3-week period. To illustrate the utility of this technique, nerve migration was measured in 2 individuals with diabetes (one with and the other without neuropathy) and a healthy control participant. RESULTS: The average nerve migration rate was calculated to be 18.4, 49.9, and 41.5 µm/wk for the diabetic individuals with and without neuropathy and the control participant, respectively. The number of landmarks for tracking nerve migration in the participants was 26, 21, and 20, and they were at an average distance of 1500, 1940, and 1461 µm, from the whorl, respectively. The rate of migration depended on the distance from the whorl; hence, linear equations were generated for each subject for comparison. CONCLUSIONS: This novel imaging technique allows rapid measurement of in vivo corneal nerve migration. The results indicate that diabetic neuropathy may be associated with reduced nerve migration; however, because of the high level of manual input required in this technique and the apparent complex characteristics of corneal nerve migration, repeatability and characterization studies are needed.