Corneal densitometry after photorefractive keratectomy, laser-assisted in situ keratomileusis, and small-incision lenticule extraction.

PurposeThe aim of this study was to gain greater insight into the corneal densitometry changes occurring as a result of refractive surgery and to compare these changes across three widely used surgical techniques, namely, photorefractive keratectomy (PRK), laser-assisted in situ keratomileusis with a femtosecond laser (LASIK-FS), or ReLEx small-incision lenticule extraction (ReLEx SMILE).Patients and methodsThree hundred and thirty-six patients (184 male and 152 female patients) participated in this study. They were split into three groups according to the refractive surgery technique they had undergone: LASIK-FS (74 patients), PRK (153 patients), and ReLEx SMILE (109 patients). All participants underwent an exhaustive eye examination both before and after surgery. Pre- and postoperative corneal densitometry was measured using an Oculus Pentacam system.ResultsThe mean postoperative total corneal densitometry values were 16.53±1.94 for the LASIK-FS group, 15.53±1.65 for PRK, and 16.10±1.54 for ReLEx SMILE. When corneal densitometry was analyzed for specific corneal areas, the values corresponding to the 0-2, 2-6, and 6-10 mm annuli were similar across the three surgical techniques. The only region in which differences were found was the peripheral area (P<0.05), but these variations across techniques were not statistically significant.ConclusionsCorneal densitometry can be used as an objective metric to assess corneal response to refractive surgery, and to monitor patients over time. Corneal densitometry was not negatively affected by any of the refractive surgical procedures under evaluation.

Agreement and clinical comparison between a new swept-source optical coherence tomography-based optical biometer and an optical low-coherence reflectometry biometer.

PurposeTo compare measurements taken using a swept-source optical coherence tomography-based optical biometer (IOLmaster 700) and an optical low-coherence reflectometry biometer (Lenstar 900), and to determine the clinical impacts of differences in their measurements on intraocular lens (IOL) power predictions.MethodsEighty eyes of 80 patients scheduled to undergo cataract surgery were examined with both biometers. The measurements made using each device were axial length (AL), central corneal thickness (CCT), aqueous depth (AQD), lens thickness (LT), mean keratometry (MK), white-to-white distance (WTW), and pupil diameter (PD). Holladay 2 and SRK/T formulas were used to calculate IOL power. Differences in measurement between the two biometers were determined using the paired t-test. Agreement was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots.ResultsMean patient age was 76.3±6.8 years (range 59-89). Using the Lenstar, AL and PD could not be measured in 12.5 and 5.25% of eyes, respectively, while IOLMaster 700 took all measurements in all eyes. The variables CCT, AQD, LT, and MK varied significantly between the two biometers. According to ICCs, correlation between measurements made with both devices was excellent except for WTW and PD. Using the SRK/T formula, IOL power prediction based on the data from the two devices were statistically different, but differences were not clinically significant.ConclusionsNo clinically relevant differences were detected between the biometers in terms of their measurements and IOL power predictions. Using the IOLMaster 700, it was easier to obtain biometric measurements in eyes with less transparent ocular media or longer AL.

Effect of pharmacological pupil dilation on measurements and iol power calculation made using the new swept-source optical coherence tomography-based optical biometer.

PURPOSE: To determine whether pupil dilation affects biometric measurements and intraocular lens (IOL) power calculation made using the new swept-source optical coherence tomography-based optical biometer (IOLMaster 700©; Carl Zeiss Meditec, Jena, Germany). PROCEDURES: Eighty-one eyes of 81 patients evaluated for cataract surgery were prospectively examined using the IOLMaster 700© before and after pupil dilation with tropicamide 1%. The measurements made were: axial length (AL), central corneal thickness (CCT), aqueous chamber depth (ACD), lens thickness (LT), mean keratometry (MK), white-to-white distance (WTW) and pupil diameter (PD). Holladay II and SRK/T formulas were used to calculate IOL power. Agreement between measurement modes (with and without dilation) was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots. RESULTS: Mean patient age was 75.17±7.54 years (range: 57-92). Of the variables determined, CCT, ACD, LT and WTW varied significantly according to pupil dilation. Excellent intraobserver correlation was observed between measurements made before and after pupil dilation. Mean IOL power calculation using the Holladay 2 and SRK/T formulas were unmodified by pupil dilation. CONCLUSIONS: The use of pupil dilation produces statistical yet not clinically significant differences in some IOLMaster 700© measurements. However, it does not affect mean IOL power calculation.

"Dry Lake" technique for the treatment of hypertrophic bleb following XEN(®) Gel Stent placement.

CASE REPORT: The case of a patient with previous uncomplicated XEN(®) drainage glaucoma surgery is described, who presented with hypertrophic bleb and mechanical ectropion. Treatment consisted of the «Dry Lake¼ procedure to drain the hypertrophic bleb following blockage with viscoelastic of the ab-interno stent and bleb sealing with a tissue adhesive. DISCUSSION: Proposals for the management of this type of bleb include therapeutic strategies, sutures or even autologous blood. The use of Tissucol(®), already described in glaucoma surgery, may be appropriate to treat this complication of XEN(®) placement.

Determinacion de niveles de vitamina D y su relacion con la densidad mineral osea (DMO) en mujeres perimenopausicas / Vitamin D and Bone mineral density of perimenopause women

Objetivos. Conocer en nuestro medio los niveles de vitamina D en mujeres durante el climaterio y su diferencia en los casos de osteopenia / osteoporosis confirmados por osteodensitometría. Muestra. Se tomaron 27 pacientes que consultaron por síndrome climaterio a la Clínica de Climaterio del Instituto Materno Infantil (IMI) de Bogotá durante 1999: 3 osteoporóticas, 12 osteopénicas y 12 normales por osteodensitometría de acuerdo a los parámetros establecidos por la Asociación Internacional de Osteoporosis.Metodología. Se utilizó la técnica de radioinmunoanálisis para la determinación cuantitativa de 1,25 (OH)2D2 en plasma humano, utilizando el kit Gamma b1, 25 dihydroxyvitamin de la casa IDS, por medio de inmunoextracción. Sensibilidad - 2 Desviaciones estándar de 10 replicas del calibrador cero (5 pmol/L). Valor de referencia 46- 110 pmol/L. Estos datos se compararon con la Densidad Mineral Osea (DM0) medida por densitometría a nivel de columna lumbar (L4) y fémur, considerando como osteoporosis un T-score de -2.5. Para el cálculo de la muestra se utilizó la prueba de T (22 grados de libertad), asumiendo igualdad de varianzas. Resultados: El promedio para el grupo es 81.7 +18.9 pmol/L. El 68 por ciento de la muestra se encuentra entre 62.7 y 100.6 pmol/L dentro del promedio de lo esperado. El promedio de las mujeres normales es de 100.4 + 13.56 pmol/L y las osteopénicas de 66.96 + 9.5 pmol/L estos valores representan una disminución del 33 por ciento cuando se comparan las mujeres normales frente a las osteopénicas. Existe una diferencia significativa p< 0.001 entre las de DM0 normales y las osteopénicas