European Journal of Implant and Refractive Surgery最新文献

OBJECTIVE: To compare the degradation properties of nylon and polyester (Mersilene) sutures using scanning electron microscopy (SEM). STUDY DESIGN: Sutures which were removed on clinical grounds for the correction of astigmatism at 6 and 12 months postoperatively following routine extracapsular cataract extraction were studied under SEM. RESULTS: Progressive disintegration of nylon sutures over the study period. Mersilene appeared to maintain its structural integrity. CONCLUSIONS: SEM confirms clinical studies that Mersilene sutures remain intact and so are less likely to cause late complications when left in situ.

OBJECTIVES: The thermal side-effects during phacoemulsification were measured with a special temperature sensor during 8 s of continuous phacoemulsification. Over 500 measurements were performed in a constructed model of the anterior chamber and in enucleated eyes of pigs. SETTING: Department of Ophthalmology, General Hospital Barmbek, Hamburg, Germany. MAIN OUTCOME MEASURES: The influences of the anterior chamber volume, phacoemulsification power, pulse rate, hardness of the lens, viscoelastic material and insufficient or interrupted irrigation and/or aspiration were examined. RESULTS: With uninterrupted aspiration and irrigation, the temperature of the irrigation fluid was measured after 1–2 s in the anterior chamber. At the phaco sleeve, however a temperature increase was detected. Without irrigation, temperatures of more than 100 °C developed at the phaco sleeve. During pulse mode and with reduced power, temperature increase was reduced by half. CONCLUSIONS: The main risk factor for phacoburns is the interruption of irrigation. Application of viscoelastic material, reduced anterior chamber volume, very small tunnel incision, hard nuclei and high ultrasonic power without pulse are further important risk factors.

Videokeratoscopy has proved an invaluable clinical tool in allowing a better understanding of corneal topography and how this varies in the general population. Its value is significant in the area of refractive surgery and in the diagnosis and monitoring of some corneal disorders. A further potential application of videokeratoscopy is in the area of contact lens fitting and after care, and some systems already include a contact lens module in their software. The software can show the contact lens to cornea fitting relationship in a number of ways and can store and present both clinical information and contact lens data which is helpful to the practitioner. This article reviews the means by which the systems may help the clinician working in the area of contact lens fitting and follow-up care.

OBJECTIVE: (1) To present a new, inexpensive technique for manual cataract extraction using a new irrigation-aspiration cannula (Beirouty) and to report the results of this technique. (2) To compare the results of this technique with phacoemulsification and other techniques of smallincision surgery. STUDY DESIGN: A prospective analysis of patients who had cataract extraction by the manual nucleosuction technique (MNT) since December, 1992, performed by 1 surgeon (Z.A.YB.). SETTING: General Ophthalmic Unit, Stobhill NHS Trust, Glasgow, U.K. PATIENTS: Forty-nine patients (63 eyes), aged 11–85 years, with suitable cataracts. MAIN OUTCOME MEASURES: To determine perioperative complications, best corrected Suellen visual acuity, astigmatic shift, induced astigmatism and time to final refraction. RESULTS: There were no cases of posterior capsular tears and / or vitreous loss. Best corrected visual acuity was 6/9 or better in 85% of eyes. Astigmatic shift was negligible. Surgical re-intervention was required in 1 eye for slight wound dehiscence. All patients received their spectacles at 6–8 weeks. CONCLUSIONS: MNT is a safe and easy technique to learn. The results are very favourable when compared to other techniques of cataract surgery through a small incision. This procedure is performed with standard cataract instruments.

OBJECTIVE: To compare visual function in the Alcon Iogel 2000s/sm (poly HEMA) and Alcon MZ30BD all polymethymethacrylate (PMMA) posterior chamber intraocular lenses. STUDY DESIGN: Over a 4-month period all patients with 1 of the above lenses were assessed. Patients with coexistent pathology were excluded. All remaining patients had uncomplicated phacoemulsification performed by a single surgeon. SETTING: Lions Eye Institute, Perth, Western Australia. PATIENTS: Forty-eight eyes of 43 patients were examined, 25 poly HEMA and 23 PMMA lenses. OUTCOME MEASURES: Visual acuity, contrast sensitivity and glare. RESULTS: Poly HEMA lenses were significantly better than PMMA lenses, visual acuity P = 0.0001, contrast sensitivity P = 0.004 and glare P = 0.019. CONCLUSIONS: The poly HEMA lens performed better than the PMMA lens for all tests of visual function. However modulation transfer function and optical design are similar for both lenses. This result may reflect another in vivo property of the poly HEMA lens. However it would require a larger controlled trial to confirm any differences.