Search results for "Contact lens"
showing 9 items of 119 documents
Influence of the tear film on optical quality of the eye
1997
The optical quality of the tear film of the eye was tested by measuring the retinal image before and after the break-up time (BUT). An objective method was used based on the evaluation of the retinal image of a point test projected onto the fovea. The loss of an entire tear film would result in a decrease in the optical quality because of corneal irregularities and the formation of an irregular tear lens after the BUT. Our results confirm the expected loss both of non-contact lens wearers and contact lens wearers. Also, the fact that the optical deterioration found after the BUT is greater for contact lens wearers confirms that soft contact lens wear produces a disruption of the tears.
Dynamic in vitro dehydration patterns of unworn and worn silicone hydrogel contact lenses.
2008
Purpose: To evaluate the effect of wear on dynamic in vitro dehydration of silicone hydrogel (Si-Hi) contact lens (CL) using a previously described gravimetric procedure. Methods: Five different silicone hydrogel (Si-Hi) contact lenses (CL) were evaluated after being worn by patients under daily wear conditions for 15 days to 1 month. Lenses were conditioned and disinfected with a multipurpose solution after each day of wear. Lenses were left to dehydrate in an analytical balance under controlled conditions of temperature and relative humidity and the results compared with data from new lens samples of the same power and material. Several quantitative parameters were obtained and compared b…
Impact of the pupil size – central optical zone diameter relationship on visual performance in aspheric multifocal contact lenses
2020
Abstract Purpose To determine the impact of different central optical zone diameters (COZDs), obtained from pupil size, on the visual performance of presbyopic subjects fitted with centre-distance simultaneous-image multifocal contact lenses (SIMCLs). Methods Thirty-two presbyopic volunteers, between 45–58 years of age, participated in this prospective, controlled, double-blind study. Subjects were fitted with 5 centre-distance SIMCLs of variable COZD, determined from the measurement of pupil size under photopic light conditions and corresponding to 60, 70, 80, 90 and 100 % of pupil diameter. Subjects visual performance was evaluated through the measurement of distance, intermediate and nea…
Benefits and Side Effects of Bandage Soft Contact Lens Application after LASIK
2005
Purpose To evaluate benefits and side effects of bandage soft contact lens (BSCL) insertion after LASIK in relation to patients’ characteristics. Design Prospective, randomized, bicenter comparative investigational trial. Participants One hundred patients (200 eyes) with myopia and/or myopic astigmatism. Methods Each patient underwent consecutive (Marburg, Germany) or simultaneous (Mainz, Germany) bilateral LASIK. At the end of the procedure, the first treated eye received a drop of ofloxacin and dexamethasone, patch, and transparent protective shield for 2 to 4 hours. The fellow eye received in addition a BSCL, soaked in the same eyedrops for 20 to 24 hours. Main Outcome Measures Schirmer …
Lens implant selection with absence of capsular support.
2001
If contact lens or spectacle correction is not viable, little debate exists that the secondary placement of an intra-ocular lens (IOL) is the method of choice in the absence of capsular support. The choice of IOL mainly depends on the preoperative status of the eye (eg, aphakia in children) and the selected location for the implant. Theoretically, there are several IOL implantation approaches in cases without capsular support: an angle-supported anterior chamber (AC) IOL, an iris-fixated ACIOL, an iris-sutured or iris-fixated posterior chamber (PC) IOL and a transsclerally sutured PCIOL. No consensus exists, however, on the indications as well as on the relative safety and efficacy of these…
Transpupillary thermotherapy (TTT) for age-related macular degeneration (AMD) – Is it time to say good-bye?
2010
Abstract Purpose To evaluate the effectiveness of transpupillary thermotherapy (TTT) for the closure of classic and occult subfoveal choroidal neovascularization (CNV) and to discuss whether TTT is a useful treatment modality for age-related macular degeneration (AMD). Materials and methods The present paper is a retrospective review of the clinical results from a patient group which was treated with TTT in the University Eye Clinic in Mainz. From January 2000 to December 2002, a total of 20 eyes of 20 patients with subfoveal CNV (due to AMD in 16 eyes, due to pathologic myopia in 4 eyes) received TTT. The procedure was delivered using an infrared diode laser at 810 nm, equipped with a modi…
Proclear EP vs placebo: visual outcomes and symptoms of asthenopia in nonpresbyopes and early presbyopes
2011
Purpose: Over the past 20 years, many studies have reported the success of multifocal contact lenses (MFCLs) compared to monovision (MV), with only partial success being reported for MFCLs. Chronologically it appears there has been a gradual improvement in the performance of MFCLs. This study investigated whether this change in success is reflected in clinical practice. Method: Lens fit data collected from 2005 to 2009 by the International Contact Lens Prescribing Survey Consortium was reviewed for patients over 45 years old. A similar survey conducted from 1988 to 1989 was also reviewed and compared. Twelve published (Pubmed.gov) reports of clinical trials involving MFCLs and MV were revie…
Multifokālo kontaktlēcu lietotāju redzes asums un stereoredze
2018
Bakalaura darbs uzrakstīts uz 37 lapaspusēm, satur 10 zīmējumus, 5 tabulas un 18 literatūras avotus. Darba mērķis ir novērtēt redzes asumu un stereoredzi tuvumā un tālumā pacientiem koriģētiem ar brillēm un multifokālajām kontaktlēcām. Mūsu pētījumi parādīja, ka tāluma binokulārais redzes asums visiem pacientiem ir labs – virs 0,95. Tuvuma redzes asums pacientiem koriģētiem ar brillēm ir labāks un pacienti dod priekšroku brillēm. Tuvuma stereoredze noteikta ar Titmusa mušas testu un Titmusa apļu testu pacientiem koriģētiem ar brillēm un kontaktlēcām bija laba. Tāluma stereoredzes parametriem mēs redzam atšķirību, ar brillēm stereoredze ir labāka, bet rezultātu atšķirība nav statistiski būti…
IMI Prevention of Myopia and Its Progression
2021
The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy…