Adaptación cultural y validación del cuestionario Ocular Surface Disease Index en una población chilena / Validation of the Ocular Surface Disease Index Questionnaire for Chilean patients

Background: Ocular Surface Disease Index (OSDI) is the most commonly used questionnaire worldwide to detect dry eye disease. Although it is massively used in clinical practice in Chile, its use has not been validated yet in the country. Aim: To develop a cultural adaptation and to validate the OSDI questionnaire for the Chilean population. Material and Methods: For cultural adaptation, a translation, retro-translation and an expert panel review was carried out. The resulting questionnaire was applied to a pilot group of twelve participants and their comments were considered for the final questionnaire version. The final questionnaire was applied to a non-random sample of 200 patients aged 53 ± 17 years (75% women). Internal consistency and construct validity were evaluated by Cronbach's alpha and exploratory factor analysis respectively. Results: According to the OSDI score, 81% of respondents had dry eye (55% severe). Reliability was 0.91 and factor analysis resulted in three factors explaining 75.4% of the total variance. Conclusions: The OSDI questionnaire version obtained in this study demonstrated excellent internal consistency values and adequate construct validity making it applicable to clinical practice and dry eye research.

Treatment of recurrent corneal erosion by extended-wear bandage contact lens.

PURPOSE: To assess the efficacy of using a bandage contact lens (BCL) for 3 months for recurrent corneal erosions (RCE) to facilitate epithelial adhesion. METHODS: Retrospective study of patients presented to the Casey Eye Institute (Portland, OR) with RCE after failing at least 6 weeks of medical lubrication therapy. Subjects were treated with an extended-wear BCL for 3 months and then followed for approximately 1 year. The main outcome measure was recurrence of RCE. Best-corrected visual acuity was measured before and after BCL therapy. RESULTS: From the 12 patients studied, 9 (75%) had no recurrence of RCE after approximately 1 year of follow-up. Three subjects had subjective complaints of recurrent erosion during the follow-up period with 1 of these 3 subjects having objective findings of a recurrent erosion. CONCLUSIONS: Three-month BCL treatment is a safe and effective medical therapy with a relatively low recurrence rate of RCE.

Femtosecond-assisted deep anterior lamellar keratoplasty using big-bubble technique in a cornea with 16 radial keratotomy incisions.

PURPOSE: To report on a patient with uncorrectable fluctuating astigmatism from multiple previous radial keratotomy (RK) procedures who successfully underwent a femtosecond laser-assisted deep anterior lamellar keratoplasty (DALK) with big-bubble technique. METHODS: A 60-year-old woman with a history of multiple RK procedures with 16 radial incisions and 4 Ruiz-style cuts had fluctuating corneal astigmatism with preoperative best contact lens-corrected visual acuity of 20/80. RESULTS: Intraoperatively, a femtosecond laser-assisted zigzag pattern DALK was performed. Descemet baring was successfully achieved using the big-bubble technique without air escaping from the radial incisions, likely related to precise depth of base of posterior side cut made by laser. Postoperative best-corrected visual acuity is 20/25 with 1.3 diopter of astigmatism at 5 months. CONCLUSIONS: To our knowledge, this is the first report to use this technique in a cornea with RK incisions. Femtosecond lasers may promote the success of DALK in challenging corneas.

Comparison of femtosecond laser-assisted keratoplasty versus conventional penetrating keratoplasty.

PURPOSE: To compare postoperative outcomes for femtosecond laser-assisted keratoplasty (FLAK) with conventional penetrating keratoplasty (PK). DESIGN: Retrospective, comparative surgical series. PARTICIPANTS: Fifty consecutive patients who underwent FLAK and 50 case-controlled patients that had PK at the Casey Eye Institute (Oregon Health & Science University, Portland, OR). METHODS: Data was collected for 50 consecutive cases that underwent zigzag incision FLAK and was compared with 50 subjects that had conventional blade trephine incision PK with similar age, diagnosis and concurrent ocular morbidities over a 2-year follow-up period. MAIN OUTCOME MEASURES: Topographic astigmatism, best spectacle-corrected visual acuity, uncorrected visual acuity, pinhole visual acuity, and the timing of selective suture removal (or adjustment) over various follow-up intervals up to 2 years postoperatively. RESULTS: Significantly lower topographic astigmatism was achieved in the FLAK group over the PK group in the 4- to 6-month follow-up period (P = 0.0324), which correlated well with significant earlier selective suture removal that occurred in that same group over both the 2- to 3-month (P = 0.0025) and 4- to 6-month (P = 0.0236) follow-up periods. This difference in astigmatism was no longer present at any other follow-up period up to 24 months postoperatively. The subset analysis of patients with keratoconus or post-LASIK ectasia did not show any difference in either astigmatism or visual acuity at any time. CONCLUSIONS: Compared with PKP, FLAK had significant improvement in astigmatism before but not after the 6 month postoperative follow-up period. Earlier suture removal was noted in the FLAK group. No significant improvement in best spectacle-corrected visual acuity was noted at any time point. There were no complications or difficulties with trephination in the FLAK procedure across a wide range of corneal pathologies.

The effect of active site mutations in the oxaloacetate decarboxylase and pyruvate kinase-like activities of Anaerobiospirillum succiniciproducens phosphoenolpyruvate carboxykinase.

Anaerobiospirillum succiniciproducens His225Gln, Asp262Asn, Asp263Asn, and Thr249Asn phosphoenolpyruvate carboxykinases were analyzed for their oxaloacetate decarboxylase, and pyruvate kinase-like activities. The His225Gln and Asp263Asn enzymes showed increased Km values for Mn2+ and PEP compared with the native enzyme, suggesting a role of His225 and Asp263 in Mn2+ and PEP binding. No mayor alterations in Km values for oxaloacetate were detected for the varied enzymes. Alterations of His225, Asp262, Asp263, or Thr249, however, did not affect the Vmax of the secondary activities as much as they affected the Vmax for the main reaction. The results presented in this communication suggest different rate-limiting steps for the primary reaction and the secondary activities.