Laser photocoagulation spot-size errors stemming from the refractive state of the surgeon's eye.

نویسندگان

  • E Z Blumenthal
  • C N Serpetopoulos
چکیده

PURPOSE Meaningful errors in photocoagulation spot size may result from several factors. In this article we discuss one major factor, namely, fluctuations in the surgeon's accommodative state, coupled with an inaccurate setting of the slit-lamp oculars. DESIGN Experimental study. METHODS We analyzed and tested the optics of slit-lamp mounted lasers. Varying the ocular setting is correlated with measurements of the actual spot size obtained with each system. MAIN OUTCOME MEASURE The spot size obtained. RESULTS Three distinct, but related, phenomena that may lead to spot size errors are defined: (1) focusing the laser spot as opposed to focusing the retinal image; (2) instrument misalignment; (3) inadvertent accommodation. CONCLUSION The ocular setting must be meticulously calibrated to produce a true spot-sized burn. At the 50 microm setting, each diopter of induced accommodation, or erroneous ocular setting, almost doubles the actual spot size obtained. With large (500 microm) spot size settings, the defocused delivery system is more prone to spot-size errors in contrast with parfocal lasers.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effects of Laser Physical Parameters on Lesion Size in Retinal Photocoagulation Surgery: Clinical OCT and Experimental Study

Introduction: The aim of the present study was to determine burn intensity in retinal laser photocoagulation based on laser parameters; wavelength, power, beam size and pulse duration, using Optical Coherence Tomography (OCT), fundus camera, physical eye model and computer simulation in a clinical study.Materials and Methods: Participants were 10 adult patients between 50-80 years with prolifer...

متن کامل

Effects of Laser Physical Parameters on Lesion Size in Retinal Photocoagulation Surgery: Clinical OCT and Experimental Study

Introduction The aim of the present study was to determine burn intensity in retinal laser photocoagulation based on laser parameters; wavelength, power, beam size and pulse duration, using Optical Coherence Tomography (OCT), fundus camera, physical eye model and computer simulation in a clinical study. Materials and Methods Participants were 10 adult patients between 50-80 years with prolife...

متن کامل

Refractive Error and Anterior Segment Parametric Changes in Patients with Posterior Capsular Opacification after Nd: YAG Laser Posterior Capsulotomy

Background and Objective: Cataract is one of the most common causes of blindness in the world, and posterior capsular opacification (PCO) is the most common complication after cataract surgery. Nd: YAG laser posterior capsulotomy is a standard method for the treatment of PCO. The aim of this study was to investigate the effects of Yas laser capsulotomy on anterior segment parameters and lenticu...

متن کامل

Percutaneous laser photocoagulation of osteoid osteoma: Assessment of treatment in nine cases

ABSTRACT Background: Osteoid osteoma is a benign bony neoplasm and its classic treatment is surgery. In the r ecent decades percutaneous laser therapy was suggested to be replaced by surgery. In this study we have reviewed the results of the first applications of interstitial laser photocoagulation (ILP) for treatment of osteoid osteoma in Iranian patients. Materials and Methods: In this case s...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Ophthalmology

دوره 107 2  شماره 

صفحات  -

تاریخ انتشار 2000