[Prevalence of drusen in homes for the elderly]. / Prevalencia de drusas en una población institucionalizada anciana.

PURPOSE: To establish the prevalence of drusen in a population of over-65 year subjects residing in institutions. MATERIAL AND METHOD: A medical interview, ophthalmological examinations and midriatic retinography were performed in 392 older-than-65 year subjects living in homes for the elder (784 eyes). Each eye was reviewed by means of the Wissconsin Age-Related Maculopathy Grading System, in order to determine drusen frequency. RESULTS: Druses frequency totalled 33.3%. A great trend to symmetry was observed; bilateral in 23% of patients. The most frequent finding was multiple units (40 to 59 per eye), well defined soft drusen of 125 micrometer in size, which showed very little tendency to confluence. Twelve to 24% of macular area was affected by drusen. Subjects between ages of 65 to 74, presented the highest frequence. Drusen decreased with age from 75 years upwards. CONCLUSION: The observed drusen frequency found appear lower than those described in other studies outside our country, perhaps due to higher prevalence of media opacities. Midriatic retinography can be a good screening method for the detection of drusen.

Prevalencia de drusas en una población institucionalizada anciana / Prevalence of drusen in homes for the elderly

Objetivo: Establecer la prevalencia de drusas entre una población institucionalizada mayor de 65 años.Material y Métodos: Se realizó una anamnesis junto con una exploración oftalmoscópica a 392 personas institucionalizadas (784 ojos) mayores de 65 años, incluyendo retinografías midriáticas. Se valoró cada fondo de ojo por la clasificación internacional de Wisconsin, para determinar la frecuencia de drusas.Resultados: La frecuencia de drusas fue del 33,3 por ciento. Existe una gran tendencia hacia la simetría, siendo las drusas bilaterales en el 23 por ciento de los pacientes. El tipo de drusa más frecuente fue el de las drusas numerosas (40 a 59 por ojo), blandas bien definidas de 125 µm, con poca tendencia a confluir, y que afectaban del 12 al 24 por ciento del área macular. Se observó una mayor predisposición entre los 65 y 74 años, descendiendo su frecuencia en los pacientes de 75 o más años.Conclusión: La frecuencia de drusas detectada es menor a la presentada en otros estudios fuera de nuestro país, quizás debido a una mayor opacidad de los medios oculares. La retinografía midriática puede ser un buen método de screening para la detección de drusas (AU)

Optical coherence tomography evaluation of the corneal cap and stromal bed features after laser in situ keratomileusis for high myopia and astigmatism.

OBJECTIVE: To study the corneal microstructure by optical coherence tomography (OCT) after laser in situ keratomileusis (LASIK) for high myopia with and without astigmatism. DESIGN: Nonrandomized self-controlled comparative trial. PARTICIPANTS: Sixty-three consecutive LASIK eyes with spherical equivalent refraction between -6.0 and -17.0 diopters (D) and astigmatism between 0.0 and -5.0 D were prospectively recruited for examination. INTERVENTION: LASIK was performed with the Chiron Hansatome microkeratome (160-microm fixed plate) and Summit Apex Plus excimer laser using a 5.5/6.0/6.5-mm multizone pattern. Proper preoperative calculations were performed to ensure stromal beds thicker than 250 microm. MAIN OUTCOME MEASURES: OCT imaging and measurement of corneal thickness was performed preoperatively. In addition, corneal cap and stromal bed thickness measurements were performed 1 day, 1 month, and 3 months postoperatively. RESULTS: The average central corneal pachymetry was 538.9 +/- 26.2 microm preoperatively. Mean corneal cap thickness measured 124.8 +/- 18.5 microm 1-day postoperatively. Mean stromal bed thickness was 295.2 +/- 37.1 microm on the first postoperative day. Compared with the 1-day postoperative examination, the average stromal bed thickness increased significantly by 5.9 microm (P = 0.001) and 7.2 microm (P = 0.001) at the 1-month and 3-month postoperative examinations, respectively. Mean difference between actual (118.7 +/- 27.8 microm) and predicted (104.1 +/- 20.8 microm) central ablation depths was 14.6 +/- 16.7 microm (P = 0.0001). A weak but statistically significant positive association was found between preoperative refraction and the difference between expected and real ablation depth values (R = 0.26; P = 0.042). Posterior stromal beds were more than 250-microm thick in 58 eyes (89.9%) 1 day postoperatively. This safety requirement improved at the 1-month postoperative examination, when the partial regression accounted for slightly thicker stromal beds and only two cases (3.2%) exhibited posterior stromal tissue thinner than 250 microm. These two cases were seen only for corrections exceeding 12 D (P = 0.04). CONCLUSIONS: OCT appears to be a useful tool for the evaluation of both the qualitative and quantitative anatomic outcome of LASIK. Corrections of higher degrees of ametropia run a higher risk of producing a thinner than expected central cornea. Particularly, corrections greater than 12 D may lead eventually to stromal beds thinner than 250 microm, despite proper preoperative calculations. Because corneal flaps are usually thinner than expected with the microkeratome used herein, adequate posterior corneal stroma is preserved in most instances.