Rasch validation of the Keratoconus End-Points Assessment Questionnaire in a Spanish population with keratoconus.

OBJECTIVE: To carry out a methodologically complete validation of the Spanish version of the Keratoconus End-Points Assessment Questionnaire (KEPAQ) in a Spanish population with keratoconus. METHODS: Analytical, prospective study, including patients with keratoconus without previous surgical history, in which a measurement of quality of life was performed using the KEPAQ questionnaire, a complete exploration of the anterior pole and a corneal elevation topography with the Galilei G6 topographer. The evaluation of the psychometric characteristics of the scale in the studied population was carried out using Rasch modeling. RESULTS: A total of 140 patients with keratoconus were included, with a median age of 26.0 years, the majority (57.6%) being men. For the KEPAQ-E subscale, the median score was 69.3, with a reliability of 0.85 and an eigenvalue of the first contrast of 2.34. For the KEPAQ-F, the median score was 56.4, with a reliability of 0.88 and an eigenvalue of 2.00. All infit and outfit parameters were within normal limits for both subscales. A significant evaluation was found between the evaluations of both subscales (rho = 0.696; p < 0.001). The evaluations of the subscales and various clinical and tomographic characteristics showed a significant classification between them (p value between 0.048 y 0.001). CONCLUSION: The KEPAQ is a psychometrically robust and valid scale to evaluate quality of life in the Spanish population with keratoconus. This questionnaire can be easily used for both clinical and research aims.

Translation and validation of the "Questionnaire for research on keratoconus results" (KORQ) in the Colombian population. / Traducción y validación del «Cuestionario para investigación de resultados en queratocono¼ (KORQ) en población colombiana.

OBJECTIVE: It is proposed to carry out a process of translation and adaptation of the "Questionnaire for Research on Keratoconus Results" (KORQ) into Spanish and its validation in a Spanish-speaking population, such as Colombia. This is intended to provide a tool for measuring and monitoring the commitment to quality of life of patients with this corneal ectasia. MATERIAL AND METHODS: A prospective analytical study was carried out, in which 200 subjects diagnosed with keratoconus completed a translated version of the KORQ questionnaire. The internal validity of the questionnaire was evaluated using Cronbach's Alpha, while its construction was evaluated by an Exploratory Factor Analysis, including a Parallel Horn Analysis for the selection of the number of underlying factors. Subsequently, 50 patients were re-selected to complete the questionnaire one week later. The repeatability of the questionnaire was measured by the Spearman test. RESULTS: The KORQ questionnaire in its Spanish version showed some internal validity in both sections. Both sections of the questionnaire showed an essentially unidimensional behaviour. The test-retest repeatability of the test was excellent (Spearman rho> 0.95). CONCLUSIONS: The translated version of the KORQ is valid in Colombian population.

Corneal collagen cross-linking. A review of its clinical applications. / Entrecruzamiento del colágeno corneal. Revisión de sus aplicaciones clínicas.

OBJECTIVE: To perform a literature review of the current clinical applications of corneal collagen cross-linking. METHODS: An exhaustive literature search was made, including the main biomedical databases, and encompassing all years since the introduction of cross-linking in ophthalmology practice. RESULTS: Corneal collagen cross-linking using UVA irradiation and riboflavin is a surgical technique that is currently being optimised, and is supported by a good amount of pre-clinical and clinical studies. These papers found show the beneficial effect of the surgery on preventing the progression of corneal ectasia, especially keratoconus, but also on pellucid marginal degeneration and keratectasia after refractive surgery. The effect of cross-linking on avoiding the occurrence of iatrogenic keratectasia when combined with a photo-ablative procedure is less clear to date. Additionally, it appears that cross-linking may have a considerable beneficial effect on controlling corneal infection caused by fungi, bacteria and amoebae. However, its effect on viral keratitis can be detrimental. The benefit on bullous keratopathy seems to be rather transient. CONCLUSIONS: Corneal collagen cross-linking may be used with relative safety and efficacy in patients with progressive keratoconus. Its use could also be considered in patients with other corneal ectasias or with corneal infections of non-viral origin. Currently, there is still a need for more studies as regards its effect on preventing iatrogenic keratectasia.

POEMS syndrome as an uncommon cause of papilledema.

BACKGROUND: Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is an uncommon condition related to a paraneoplastic syndrome secondary to an underlying plasma cell disorder. Among the myriad of manifestations of the disease, ocular signs and symptoms are relatively prevalent, affecting about half of all patients with the disease. OBJECTIVE: To report the ocular manifestations of POEMS syndrome. CASE: A 47-year-old lady diagnosed to have POEMS syndrome presented with painless progressive visual diminution. Her color vision was impaired. There was bilateral papilloedema. CONCLUSION: POEMS syndrome should be considered among the differential diagnoses of all patients with a bilateral papilledema in which no other cause can be readily elucidated.