7 resultados para eye lens

em Universidad de Alicante


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Purpose To evaluate visual, optical, and quality of life (QoL) outcomes and intercorrelations after bilateral implantation of posterior chamber phakic intraocular lenses. Methods Twenty eyes with high to moderate myopia of 10 patients that underwent PRL implantation (Phakic Refractive Lens, Carl Zeiss Meditec AG) were examined. Refraction, visual acuity, photopic and low mesopic contrast sensitivity (CS) with and without glare, ocular aberrations, as well as QoL outcomes (National Eye Institute Refractive Error Quality of Life Instrument-42, NEI RQL-42) were evaluated at 12 months postoperatively. Results Significant improvement in uncorrected (UDVA) and best-corrected distance (CDVA) visual acuities were found postoperatively (p < 0.01), with significant reduction in spherical equivalent (p < 0.01). Low mesopic CS without glare was significantly better than measurements with glare for 1.5, 3, and 6 cycles/degree (p < 0.01). No significant correlations between higher order root mean square (RMS) with CDVA (r = −0.26, p = 0.27) and CS (r ≤ 0.45, p ≥ 0.05) were found. Postoperative binocular photopic CS for 12 cycles/degree and 18 cycles/degree correlated significantly with several RQL-42 scales. Glare index correlated significantly with CS measures and scotopic pupil size (r = −0.551, p = 0.04), but not with higher order RMS (r = −0.02, p = 0.94). Postoperative higher order RMS, postoperative primary coma and postoperative spherical aberration was significant higher for 5-mm pupil diameter (p < 0.01) compared with controls. Conclusions Correction of moderate to high myopia by means of PRL implantation had a positive impact on CS and QoL. The aberrometric increase induced by the surgery does not seem to limit CS and QoL. However, perception of glare is still a relevant disturbance in some cases possibly related to the limitation of the optical zone of the PRL.

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Implantation of phakic intraocular lenses (pIOLs) is a reversible refractive procedure, preserving the patient’s accommodative function with minimal induction of higher order aberrations compared with corneal photoablative procedures. Despite this, as an intraocular procedure, it has potential risks such as cataracts, chronic uveitis, pupil ovalization, corneal endothelial cell loss, pigmentary dispersion syndrome, pupillary block glaucoma, astigmatism, or endophthalmitis. Currently, only two models of posterior chamber pIOLs are commercially available, the implantable collammer lens (STAAR Surgical Co.) and the phakic refractive lens (PRL; Zeiss Meditec). The number of published reports on the latter is very low, and some concerns still remain about its long-term safety. The present article reviews the published literature on the outcomes after PRL implantation in order to provide a general overview and evaluate its real potential as a surgical refractive option.

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Purpose: To report the successful outcome obtained after fitting a new hybrid contact lens in a cornea with an area of donor-host misalignment and significant levels of irregular astigmatism after penetrating keratoplasty (PKP). Materials and methods: A 41-year-old female with bilateral asymmetric keratoconus underwent PKP in her left eye due to the advanced status of the disease. One year after surgery, the patient referred a poor visual acuity and quality in this eye. The fitting of different types of rigid gas permeable contact lenses was performed, but with an unsuccessful outcome due to contact lens stability problems and uncomfortable wear. Scheimpflug imaging evaluation revealed that a donor-host misalignment was present at the nasal area. Contact lens fitting with a reverse geometry hybrid contact lens (Clearkone, SynergEyes Carlsbad) was then fitted. Visual, refractive, and ocular aberrometric outcomes were evaluated during a 1-year period after the fitting. Results: Uncorrected distance visual acuity improved from a prefitting value of 20/200 to a best corrected postfitting value of 20/20. Prefitting manifest refraction was +5.00 sphere and -5.50 cylinder at 75°, with a corrected distance visual acuity of 20/30. Higher order root mean square (RMS) for a 5 mm pupil changed from a prefitting value of 6.83 µm to a postfitting value of 1.57 µm (5 mm pupil). The contact lens wearing was referred as comfortable, with no anterior segment alterations. Conclusion: The SynergEyes Clearkone contact lens seems to be another potentially useful option for the visual rehabilitation after PKP, especially in cases of donor-host misalignment.

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Purpose: To report a very successful outcome obtained with the fitting of a new-generation hybrid contact lens of reverse geometry in a thin cornea with extreme irregularity due to the presence of a central island after unsuccessful myopic excimer laser refractive surgery. Methods: A 32-year-old man attended to our clinic complaining of very poor vision in his right eye after bilateral laser in situ keratomileusis (treatment or surgery) for myopia correction and some additional retreatments afterward. After a comprehensive ocular evaluation, contact lens fitting with a reverse geometry hybrid contact lens (SynergEyes PS, SynergEyes, Carlsbad, CA) was proposed as a solution for this case. Visual, refractive, and ocular aberrometric outcomes with the contact lens were evaluated. Results: Distance visual acuity improved from a prefitting uncorrected value of 20/200 to a postfitting corrected value of 20/16. Prefitting manifest refraction was +6.00 sphere and −3.00 cylinder at 70°, with a corrected distance visual acuity of 20/40. Higher order root mean square for a 5-mm pupil changed from a prefitting value of 1.45 to 0.34 µm with the contact lens. The contact lens wearing was reported as comfortable, and the patient was very satisfied with this solution. Conclusions: The SynergEyes PS contact lens seems to be an excellent option for the visual rehabilitation of corneas with extreme irregularity after myopic excimer laser surgery, minimizing the level of higher order aberrations and providing an excellent visual outcome.

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We describe a case report of a patient that was implanted with a posterior chamber phakic intraocular lens (Phakic Refractive Lens, PRL) for the correction of moderate myopia and who developed postoperatively a fixed mydriasis compatible with an Urrets-Zavalia Syndrome (UZS). Specifically, a sudden acute increase of IOP in the left eye was observed in the immediate postoperative period. After IOP stabilization, the refractive result was good, but a fixed and mydriatic pupil appeared. This condition led the patient to experience visual discomfort, halos, and glare associated with high levels of higher-order aberrations in spite of the good visual result. A tinted-contact lens was fitted in order to minimize those symptoms. The UZS should be considered as a possible complication after implantation of posterior chamber phakic intraocular lenses.

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This case report reports the visual rehabilitation obtained with the fitting of a new design of full scleral contact lens (ICD 16.5 contact lens, Paragon Vision Sciences, distributed by Lenticon, Madrid, Spain) in a cornea with advanced keratoconus and previous implantation of intracorneal ring segment with a very limited effect. This eye had a refraction of –3.00 × 55° cylinder, providing a visual acuity of 0.5 LogMAR. The topographic pattern was very irregular with the presence of a significant central protrusion and a significant central corneal thinning. Some previous unsuccessful fittings have been performed with corneal and corneal-scleral lenses. A comfortable wearing was achieved with a fully scleral contact lens of 4600 μm of sagittal height, optical power of –11.25 D, and providing an apical clearance of 196 μm. A visual acuity of 0.0 LogMAR combined with a relevant aberrometric improvement was achieved with this contact lens. The patient was completely satisfied with the fitting. The result was maintained during 1 year after the fitting. Full scleral lenses are then able to provide comfortable wear and a significant increase in visual acuity combined with a significant improvement in the visual quality in eyes with advanced keratoconus.

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Purpose: To evaluate and characterize the clinical profile of young asymptomatic or minimally symptomatic patients without diagnosis of dry eye but showing signs compatible with dry eye syndrome (DES). Methods: Prospective study including a total of 50 consecutive subjects with ages ranging from 18 to 40 years that were identified as asymptomatic or minimally symptomatic by means of the Ocular Surface Disease Index (OSDI) (score of <22). In all patients, a complete battery of tests for the diagnosis of DES was performed including the evaluation of the tear film break-up time (TFBUT), the level of corneal and conjunctival staining, and the eyelid and Meibomian morphology. Results: The OSDI score was significantly higher in women than in men (median: 12.5 vs. 5.3, P=0.01). Low grades of ocular surface staining, dysfunction of Meibomian gland expression, and alteration of quality of Meibomian secretions were observed in 56%, 58%, and 84% of eyes, respectively. More eyes with some dysfunction of Meibomian gland expressibility had a TFBUT less than 5 sec (P=0.033). A statistically significant difference in the OSDI score was found between patients with and without systemic allergies (P=0.036) and between male and female (P=0.01). Likewise, the OSDI score was significantly higher in those women wearing contact lenses compared with those not wearing them (P=0.012). Conclusions: Asymptomatic or minimally symptomatic young subjects may present low grades of clinical signs compatible with DES, with a trend to more symptomatology in women and allergic patients. These outcomes should be confirmed in future studies with larger samples.