Decentration after Laser in Situ Keratomileusis(LASIK) and Photorefractive Keratectomy(PRK)

LASIK procedure was introduced recently for the correction of high myopia because of many complications in high-myopic PRK. The characteristic procedures such as hinged flap formation and stromal ablation may increase decentration. We evaluated the amount of decentration relative to the pupil center in 80 eyes of LASIK and 52 eyes of PRK using corneal topography(Corneal Analysis System: EyeSys Laboratories). All treatments were performed using excimer laser, Aesculap-Meditec, MEL 60-94 and corneal light reflex was used for centering. The vacuum ring was used for globe fixation. Mean amount of decentration in LASIK(0.65+/-0.42mm) was statisticallysignificantly increased compared with 0.49+/-0.29mm in PRK(p=0.01). Under -12D of attempted correction, mean amount of decentration in LASIK was 0.54+/-0.38mm which was not significantly different from 0.49+/-0.29mm in PRK(p=0.07). No correlation was observed between the magnitude of decentration and the frequency of loss of best cerrected visual acuity and night glare(p>0.05). The decentration more than 1mm was associated with increased amount of attempted correction (p=0.003) and low preoperative best corrected visual acuity(p=0.01). We considered that the differencee of the magnitude of decentration was attributed to some difference in procedures between LASIK and PRK. When vaccum ring is not used in other reports with other device, the decentration of LASIK was approximately twice as much as in PRK. The use of vacuum ring for the maintenance of globe may be effective in LASIK in which patients self fixation during ablation is more difficult than in PRK because the ablation time is longer and the ablation is performed on the stroma after flap formation.

The Effects of Epikeratoplasty & Laser in Situ Keratomileusis(LASIK) for Correction of High Myopia

In order to compare the clinical results of Epikeratoplasty (EPK) with Laser in situ keratomileusis(LASIK) to be corrected of high myopia above -9 diopters, the effect of the procedure on 74 patients following EKP and 63 patients following LASIK who were followed up at least 1 year were analyzed retrospectively. Postoperative mean uncorrected visual acuity was reached 0.56 until 3 month in EKP group and 0.53 until 1 month in LASIK group. LASIK group recovered and stabilized more rapidly than EKP guoup(p<0.01). Also LASIK group had more rapid recovery in keratometryp(p<0.01) and mean refractive error than EKP group(p<0.01). But there was no significant difference between two groups in uncorrected visual acuity(p=0.62), keratometry(p=0.41) and mean refractive error(p=0.32) at postoperative 1 year. LASIK seems to have more rapid and effective visual recovery than EKP for high myopia treatment.

Long Term Follow-Up of Epikeratophakia in the Pediatric Aphakia

We performed 3 cases of epikeratoplasties on two pediatric aphakic patients who were intolerable to contact lenses & spectacles. These epikeratoplasties were performed in accordance with the Kaufman-McDonald Epikeratophakia Method using the commercially available frozen and dried Kerato-Lens (Allergan Medical Optics), the lenticule of which was rehydrated at the time of surgery. The cataract extractions were performed at 3 months after birth on both eyes of the congenital cataract & at 18 months after birth on the traumatic cataract that had developed at 14 months after birth. The epikeratoplasties for the eyes with congenital cataract were performed at 24 months on the right eye and at 16 months after birth on the left eye respectively. The epikeratoplasty for the traumatic cataract eye was performed at 28 months after birth. The 3 grafts have remained successful over the follow-up period of 4 to 6 years. The right eye of congenital cataract case had myopic shift of 3.75D and best corrected visual acuity of 0.2 during 5-year of follow-up period and the other left eye had myopic shift of 4.75 D and best corrected visual acuity of 0.7 during 6-year of follow-up period. The traumatic cataract case had myopic shift of 1.0 D and best corrected visual acuity of 0.05 during 4-year of follow up period. In view of this, it is considered that the epikeratoplasty is of an effective treatment in correcting the refractive error in the pediatirc aphakia patients who intolerable to contact lens and in whom difficulty exists in determining whether an intraocular lens implantation is appropriate or not.

Sequential Bronchoalveolar Lavage in a Patient with Pulmonary Alveolar proteinosis: A case report / 대한마취과학회지

Bronchopulmonary lavage using a double-lumen endotracheal tube is an accepted modality for treatment of pulmonary alveolar proteinosis which characterized by filling of alveolar space with periodic acid-schiff positive proteinaceous material. Massive bronchopulmonary lavage is not without hazard. Improper positioning and inadequate cuff inflation of the endotracheal tube may lead drowning. So correct placement of double-lumen endotracheal tube and confirming complete seperation of the two lungs is important to prevent drowning. And periods of tidal drainage are accompanied with reperfusion to the non-ventilated lung and cause potentially dangerous levels of hypoxemia. One must investigate maneuvers to minimize perfusion to non-ventilated lung and to maximize gas exchange during unilateral lung lavage. The distribution of pulmonary blood flow during unilateral lung lavage can be manipulated by nonocclusive inflation of an ipsilateral pulmonary artery balloon. We report a case of sequential bronchoalveolar lavage in a patient with pulmonary alveolar proteinosis performed safely with pulmonary arterial catherter insertion.