Topographic Progression of Keratoconus in the Korean Population

PURPOSE: To develop a criterion for determining the topographic progression of keratoconus and to analyze the prognostic factors of progression. METHODS: Medical records of 211 eyes of 128 patients who had been followed up for more than 2 years on three or more occasions were retrospectively reviewed. Topographic parameters, including simulated K, corneal astigmatism, irregular astigmatism at 3 and 5 mm, thinnest-point pachymetry, anterior and posterior elevation, and inferior minus superior index, were used to determine topographic progression. Topographic progression was determined by the greatest kappa value associated with progression to corneal graft surgery. Eyes were separated into progressed and non-progressed groups on the basis of topographic progression. The association of clinical factors with topographic progression, including demographic factors, contact lens use, corneal erosion, and atopic history at the time of diagnosis, was assessed by logistic regression. RESULTS: When topographic progression was defined as five or more progressed topographic parameters, the greatest kappa value (0.354) was obtained. Ninety-four of the 211 keratoconic eyes (44.5%) were identified as topographically progressed. Age at diagnosis was significantly different between the progressed and non-progressed groups (22.2 vs. 24.7 years, p = 0.014). Logistic regression revealed that younger age at diagnosis was a risk factor for topographic progression (odds ratio, 0.948; 95% confidence interval, 0.907 to 0.991; p = 0.010). CONCLUSIONS: We developed a criterion for evaluating topographic progression of keratoconus using diverse topographic indices. Younger age at diagnosis was associated with topographic progression of keratoconus.

Paraoxonase 1 status in keratoconus: a preliminary study of activity and polymorphism / Estatus de la paraoxonasa 1 en el queratocono: estudio preliminar de actividad y polimorfismo

OBJECTIVE: To determine the activity of paraoxonase 1 (PON1) in keratoconus in a Malaysian population in comparison with non-keratoconic subjects. METHODS: Clinical eye examinations were performed on patients with keratoconus and non-keratoconic subjects after questionnaires were completed. Blood samples were collected and subjected to spectrophotometry analysis of paraoxonase and diazoxonase activities for the determination of the status of PON1 of every individual. RESULTS: Of the 11 keratoconic patients and 55 non-keratoconic control samples collected, eight patients of Indian ethnicity were keratoconic (73%), whereas 33 non-Indians were non-keratoconic (60%; p = 0.047). Paraoxonase activity was lower in Indians compared to the non-Indians ie Malays and Chinese (p = 0.008). Keratoconic subjects had a lower paraoxonase activity compared to non-keratoconics (p = 0.038). CONCLUSIONS: The reduced paraoxonase activity in keratoconic patients suggests that the keratoconic corneas were more susceptible to oxidative stress. Reduced paraoxonase activity and keratoconus status appears to be associated with ethnicity.

OBJETIVO: Determinar la actividad de paraoxonasa 1 (Pon 1) en el queratocono en una población malaya, en comparación con sujetos no queratocónicos. MÉTODOS: Se realizaron exámenes clínicos oculares a pacientes con queratocono y a sujetos no queratocónicos luego que los mismos respondieran a los cuestionarios. Se recogieron muestras de sangre, que fueron entonces sometidas a análisis espectrofotométrico en relación con las actividades de la paraoxonasa y la diazoxonasa para la determinación del estatus de la paraoxonasa 1 de cada individuo. RESULTADOS: De los 11 pacientes queratocónicos y las 55 muestras de control no queratocónicas recogidas, 8 pacientes de etnicidad india fueron queratocónicos (73%), mientras que 33 no indios fueron no queratocónicos (60%; p = 0.047). La actividad de la paraoxonasa fue más baja en los indios en comparación con los no indios, es decir, los malayos y los chinos (p = 0.008). Los sujetos queratocónicos tenían una actividad de la paraoxonasa más baja, comparada con los no queratocónicos (p = 0.038). CONCLUSIONES: La actividad de la paraoxonasa reducida en los pacientes queratocónicos sugiere que las córneas queratocónicas son más susceptibles al estrés oxidativo. La actividad de la paraoxonasa reducida y el estatus del queratocono parecen estar asociados con la etnicidad.

Safety and efficacy of Intacs in Indian eyes with keratoconus: an initial report.

CONTEXT: In contact lens-intolerant keratoconus patients, intrastromal placement of Intacs is becoming a promising new modality of treatment. AIMS: To study the safety and efficacy of implantation of microthin corneal inserts (Intacs) in Asian-Indian keratoconus patients. SETTINGS AND DESIGN: Retrospective interventional case series, in the cornea and refractive surgery service, at a tertiary care eye hospital in South India, between May 2006 and July 2007. MATERIALS AND METHODS: Intacs (Addition Technology, USA) were successfully implanted by mechanically creating tunnels, in 12 eyes of 12 keratoconus patients, who were contact lens-intolerant. The patients (mean age 25.58 years, nine male and three female) had a minimum follow-up of six months. Five patients had severe keratoconus (mean K > 53 D) and nine had central cones. RESULTS: All patients improved or retained visual acuity. The uncorrected visual acuity (UCVA) improved from a mean value of 0.06, (SD +/- 0.08) to 0.19 postoperatively (SD+/- 0.15) ( P = 0.01). The change in mean best corrected visual acuity (BCVA) was from 0.51, (SD +/- 0.24), to 0.69, (SD +/-0.00) ( P = 0.01) postoperatively. The average central keratometry reading was 52.55 D. The change in mean K from 52.84 to 49.16 and 49.15 at one and six months respectively, was statistically significant. We did not have any major intra- or early postoperative complications. Eight of 12 eyes became contact lens-tolerant post-surgery. CONCLUSION: The procedure of Intacs implantation appears to be safe and effective in a small group of Indian population at an intermediate follow-up.