ABSTRACT
BACKGROUND: Precise IOL calculation in post-refractive surgery patients is still a challenge for the cataract surgeon. The purpose of this study is to test whether adding Orbscan II values into the double-K method improves IOL calculation in this group of patients. METHODS: A prospective study with 43 eyes previously submitted to refractive surgery that underwent cataract extraction. IOL calculation was performed with double-K method. Post-K value was derived from Orbscan total-mean power map. The average corneal curvature of the general population (43.8D) was used as the pre-K value. Refraction results 30 days after surgery were compared with refraction that would be obtained if we used: (1) post-K values from keratometry, (2) post-K values from topography, and (3) pre-K values from Orbscan total-mean power. Anterior chamber depth measures obtained with the IOL Master and Orbscan II were compared. RESULTS: Mean postoperative spherical equivalent (SE) was -0.25 ± 1.10 D in eyes submitted to radial keratotomy , -1.04 ± 1.42 D in eyes previously submitted to myopic Lasik, and +0.05 ± 1.76 D in those submitted to hyperopic surgeries. Had we inputted post-K values derived from keratometer and from topography, we would have obtained significantly higher postoperative refractive errors in eyes previously submitted to myopic refractive surgery (p < 0.05). Refractions using pre-K derived from the central 8 mm Orbscan instead of 43.8 D were similar in all studied groups (p > 0.05). Anterior chamber depth measured with IOL Master or Orbscan were similar. CONCLUSIONS: Orbscan measurements used as the post-K values into the double-K method provide a precise IOL calculation, especially in post myopic refractive surgery patients.
Subject(s)
Cataract Extraction , Corneal Topography/methods , Lenses, Intraocular , Optics and Photonics , Refractive Surgical Procedures , Aged , Humans , Hyperopia/surgery , Keratomileusis, Laser In Situ , Keratotomy, Radial , Middle Aged , Myopia/surgery , Photorefractive Keratectomy , Prospective Studies , Refraction, Ocular/physiologyABSTRACT
PURPOSE: To assess the outcome of Ferrara intracorneal ring segments for keratoconus. SETTING: Private practice and university hospital, Porto Alegre, Brazil. METHODS: In this retrospective noncomparative interventional case series, 51 keratoconus eyes of 47 patients that had Ferrara intracorneal ring segment implantation were reviewed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal curvature, corneal astigmatism, surface regularity index, surface asymmetry index, and complications were analyzed. RESULTS: At a mean follow-up of 13.0 months +/- 8.7 (SD), the BSCVA improved in 86.4% of eyes, was unchanged in 1.9%, and worsened in 11.7%. The UCVA improved in 86.4% of eyes, was unchanged in 7.8%, and worsened in 5.8%. The mean spherical equivalent (SE) was reduced from -6.08 +/- 5.01 diopters (D) to -4.55 +/- 5.71 D and the mean refractive astigmatism, from -3.82 +/- 2.13 D to -2.16 +/- 2.07 D. The mean central corneal curvature was reduced from 48.76 +/- 3.97 D to 43.17 +/- 4.79 D. Eyes with central keratoconus had statistically significantly better results than eyes with inferior keratoconus in topographic astigmatism, SE, and refraction cylinder. Penetrating keratoplasty was avoided in 38 eyes (74.5%) during the follow-up. Intracorneal ring segment decentration occurred in 2 eyes (3.9%), segment extrusion in 10 eyes (19.6%), bacterial keratitis in 1 eye (1.9%) with segment extrusion, and a disciform keratitis in 1 eye (1.9%). CONCLUSION: Implantation of Ferrara intracorneal ring segments in patients with keratoconus was a safe and reversible procedure that led to stable results and avoided or delayed PKP in many cases.
Subject(s)
Biocompatible Materials , Corneal Stroma/surgery , Keratoconus/surgery , Polymethyl Methacrylate , Prostheses and Implants , Prosthesis Implantation , Astigmatism , Corneal Topography , Humans , Intraoperative Complications , Postoperative Complications , Retrospective Studies , Safety , Visual AcuityABSTRACT
OBJETIVO: Apresentar 10 casos de subluxação de cristalino, secundários a trauma ou a síndrome de Marfan, discutindo o tratamento e os resultados obtidos. MÉTODOS: Foram estudados 10 olhos de 9 pacientes, 6 casos secundários a trauma contuso e 4 casos a síndrome de Marfan. A idade média foi de 48,9 ± 18,2 anos, com tempo de seguimento de 34,6 ± 11,6 meses (12 a 62 meses). Os pacientes foram submetidos à facectomia intracapsular (1 caso), extracapsular com capsulorrexe (1 caso), facoemulsificação sem LIO (1 caso), e facoemulsificação com implante de LIO (7 casos). Anéis expansores capsulares foram utilizados em 7 olhos. RESULTADOS: Houve melhora da acuidade visual em todos os casos durante o seguimento, exceto em um, em que houve descolamento de retina, 20 dias após o procedimento. CONCLUSAO: A facectomia com implante de LIO em pacientes com cristalino subluxado é procedimento viável, principalmente com a facoemulsificação e o uso do anel expansor capsular, podendo melhorar bastante a acuidade visual e a qualidade de vida desses pacientes.
Subject(s)
Humans , Male , Female , Child , Adult , Middle Aged , Cataract Extraction/methods , Lens Implantation, Intraocular , Lens Subluxation/surgery , Eye Injuries , Phacoemulsification/methods , Retrospective Studies , Marfan Syndrome/complications , Lens Subluxation/etiologyABSTRACT
Achados experimentais envolvendo óxido nítrico (NO) sugerem que tal gás tem papel fisiológico na modulaçäo da atividade do sistema nervoso central de mamíferos. Apesar de sua meia-vida curta, o NO parece ser capaz de funcionar como transmissor em sinapses químicas, atuando, graças a sua capacidade de difusäo intercelular, em neurônios pré-sinápticos e pós-sinápticos. No presente artigo säo revisadas a localizaçäo da enzima de formaçäo do óxido nítrico e as açöes conhecidas que o NO tem na modulaçäo da atividade nervosa encefálica
