1,721,068 research outputs found
Late corneal scarring after retinal detachment surgery, forty-two months after photorefractive keratectomy.
No full textA 42-year-old man had uneventful bilateral nonsimultaneous photorefractive keratectomy (PRK) for severe myopia. Thirty-nine months after the procedure, the patient presented with a retinal detachment (RD) in the right eye. Cerclage, vitrectomy, endolaser, and intravitreal silicone oil tamponade were performed, and the RD was successfully repaired. Three months after vitrectomy and 42 months after PRK, the patient complained of visual impairment in the right eye and photophobia. On slitlamp examination, marked reticular scarring of the central anterior cornea was observed. The occurrence of late-onset corneal haze highlights the need for special attention to patients who have vitrectomy after PRK
Parasurgical therapy for keratoconus by riboflavin-ultraviolet type A rays induced cross-linking of corneal collagen: preliminary refractive results in an Italian study
No full textPurpose: To assess the effectiveness of riboflavin-ultraviolet type A rays induced cross-linking of corneal collagen in reducing progression of keratoconus and in improving visual acuity in patients with progressive keratoconus. Setting: Department of Ophthalmology, Siena University, Siena, Italy. Methods: This was a second-phase prospective nonrandomized open study. Starting in September 2004, 10 eyes of 10 patients (mean age 31.4 years) with bilateral keratoconus were treated by combined riboflavin-ultraviolet type A rays (UVA) collagen cross-linking. Radiant energy was 3 mW/cm2 or 5.4 joule/cm2 for a 30-minute exposure at 1 cm from the corneal apex. A complete ophthalmologic examination (uncorrected visual acuity [UCVA], sphere spectacles corrected visual acuity (SSCVA), best spectacle-corrected visual acuity [BSCVA]) was performed. Patients had corneal computerized topographic examination, linear scan optical tomography, endothelial cell count, ultrasound pachometry, intraocular pressure (IOP) evaluation, and HRT II system confocal microscopy at 1, 2, 3, and 6 months. After treatment, eyes were medicated and dressed with a soft contact lens. Results: Comparative preoperative and postoperative results showed increases of 3.6 lines for UCVA (P = .0000112), 1.85 lines for SSCVA (P = .00065), and 1.66 lines for BSCVA (P = .00071). Topographic analysis showed a mean K reduction of 2.1 ± 0.13 diopters (D) in the central 3.0 mm. Statistical analysis of IOP and endothelial cell count did not show significant differences. Topo-aberrometric analysis findings of corneal symmetry showed a trend toward increasing corneal symmetry with a major reduction in asymmetry between vertical hemimeridians. Conclusions: Refractive results showed a reduction of about 2.5 D in the mean spherical equivalent, topographically confirmed by the reduction in mean K. Results of surface aberrometric analysis showed improvement in morphologic symmetry with a significant reduction in comatic aberrations. © 2006 ASCRS and ESCRS
Acute transient macular detachment after uneventful cataract surgery in a highly myopic eye
Full text linkPurpose: We report a case of a highly myopic patient who presented a serous macular detachment at 24 hours after uncomplicated cataract surgery. Observations: Surprisingly, after six days from surgery, a reabsorption of the detachment was noticed and the macular area returned to be anatomically normal without any surgical intervention. This early postoperative complication could be caused by changes in the vitreoretinal interface and ocular fluid dynamics or to a rupture of blood-retinal barriers due to postoperative inflammation. Conclusions and importance: Our case reports on the occurrence of an early transient macular detachment after uneventful cataract surgery in a highly myopic eye. This finding suggests the importance of an OCT-based control in the immediate postoperative hours
Trypan blue staining of the anterior capsule: the one-drop technique
No full textCapsule staining is usually a two- or three-stage procedure in which trypan blue is injected under air, a viscoelastic device, viscoelastic mixed with dye, or compartmentalized viscoelastic and balanced salt solution. In these techniques, the consequent irrigation of the anterior chamber with balanced salt solution may lead to a less stable anterior chamber, a decrease of pupil diameter, and damage of the corneal endothelium. A modification of current injection techniques for staining the anterior capsule under a dispersive viscoelastic device with 1 drop of trypan blue by an ordinary 27-gauge anterior chamber cannula is describe
Corneal crosslinking: riboflavin concentration in corneal stroma exposed with and without epithelium
No full textPURPOSE:
To evaluate intrastromal concentrations of riboflavin with and without epithelium to ensure the efficacy and safety of corneal crosslinking (CXL) by the standard and transepithelial procedures.
SETTING:
Department of Ophthalmology and Department of Pharmacology G. Segre, Siena University, Siena, Italy.
METHODS:
This study comprised keratoconic patients enrolled for penetrating keratoplasty (PKP) and warm-stored sclerocorneal rings unsuitable for transplantation. Half the PKP specimens were debrided, and half were left with the epithelium in situ. One of the latter and 1 debrided sample were not exposed to riboflavin (controls). Samples in both groups were soaked with 0.1% riboflavin-dextran 20% solution instilled every 2 minutes for 5, 15, and 30 minutes. Riboflavin concentrations were determined by high-performance liquid chromatography (HPLC).
RESULTS:
The study evaluated 14 PKP specimens and 16 sclerocorneal rings. Control samples did not show a riboflavin emission peak. In exposed samples with epithelium, the mean riboflavin concentration was 91.88 ng/g after 5 minutes of exposure, 95.60 ng/g after 15 minutes, and 94.92 ng/g after 30 minutes. In the debrided samples, the mean riboflavin concentration was 14.42 microg/g, 20.92 microg/g, and 24.06 microg/g, respectively. No differences were seen between the in vivo samples and the ex vivo samples.
CONCLUSIONS:
The HPLC quantitative study showed that stromal concentrations of riboflavin increased with exposure time only if the epithelium was removed. A theoretically safe and effective riboflavin concentration of 15 microg/g was obtained for ultraviolet A-induced CXL only after the epithelium was removed and after at least 10 minutes of riboflavin application every 2 minutes
Corneal collagen cross-linking to stop corneal ectasia exacerbated by radial keratotomy
No full textPURPOSE: To assess the efficacy of riboflavin ultraviolet A (UV-A) corneal collagen cross-linking in the management of keratoconic corneal ectasia exacerbated by radial keratotomy (RK).
METHODS: A patient with progressive corneal ectasia and hyperopic shift, occurring 10 years after RK performed in the left eye, was treated with riboflavin UV-A corneal collagen cross-linking according to the Siena protocol: Pilocarpin 0.1% drop (1 hour before), lidocaine 4% drops 15 minutes before, mechanical scraping of epithelium (9-mm-diameter area), preirradiation stromal soaking for 10 minutes in riboflavin 0.1%-dextrane 20% (Ricrolin; Sooft Italy) applied every 2 minutes, and 30 minutes of total exposure (6 steps of 5 minutes) to solid-state UV-A illuminator (Caporossi, Baiocchi, Mazzotta Vega X linker; CSO Opthalmics, Florence, Italy), energy delivered 3 mW/cm, and irradiated area 9 mm in diameter.
RESULTS: After the operation, uncorrected visual acuity and best spectacle-corrected visual acuity improved from 0.2 to 0.6 and from 0.3 to 0.8 Snellen lines, respectively, in a 12-month follow-up. Improved topographical K readings and corneal symmetry index were also recorded starting from the first postoperative month and continuing thereafter. No adverse effects were recorded after treatment.
CONCLUSIONS: Riboflavin UV-A-induced corneal cross-linking seems to be a promising surgical option in the management of unstable corneal ectasia exacerbated by RK, particularly in eyes with preexisting keratoconus. A large cohort and longer follow-up are needed to determine its long-term efficacy in this clinical settin
Manual deep lamellar keratoplasty: alternative methods and air-guided technique.
No full textPurpose. To describe the techniques proposed for performing deep lamellar keratoplasty
(DLK) and to evaluate the efficacy of a new, modified technique.
Methods. Fourteen eyes in 11 patients with keratoconus of moderate degree were
included. All patients underwent a DLK with manual dissection from a limbal side port
after an air bubble injection in the anterior chamber. All patients had complete
ophthalmologic examination 6 months after the suture removal, evaluating best corrected
visual acuity, corneal thickness, endothelial cell count, and topographic astigmatism.
Results. One case (7.1%) was converted to penetrating keratoplasty because of microperforation.
In the 13 successful cases, 10 eyes (71.4%) achieved 20/30 or better 6 months
after suture removal. Mean postoperative pachymetry was 628.39 (SD 57.34). Specular
microscopy 6 months after suture removal revealed average endothelial cell count of 2261
(SD 287/mm2).
Conclusions. Comparing this modified DLK technique with other methods proposed by
several authors, air-guided DLK seems to be safe and effective and, after a short learning
curve, can be performed with a low risk of conversion to penetrating keratoplasty
Keratoconus Therapeutic Guidelines based on staging: from CrossLinking to Penetrating Keratoplasty : Linee guida basate sullo staging del cheratocono: dal cross-link corneale alla cheratoplastica
No full textIl cheratocono rappresenta la più comune e frequente distrofia “ectasica” della cornea a carattere degenerativo. Generalmente la malattia ha esordio in età puberale, è bilaterale, asimmetrica ed è contraddistinta dalla presenza di una astigmatismo irregolare associato a riduzione dello spessore corneale. In circa il 20% dei casi il cheratocono evolutivo necessita di una cheratoplastica lamellare e/o perforante a seconda dello stadio e della compliance del paziente alle lenti corneali. I progressi tecnologici a servizio dell’Oftalmologia e l’uso quasi routinario della topografia e della pachimetria corneale in chirurgia rifrattiva hanno messo in luce una grande quantità di cheratoconi non ancora diagnosticati pertanto, nella nostra esperienza, l’incidenza della malattia è realmente ben superiore (1 caso su 450 pazienti) rispetto a quella riportata in letteratura (1 caso su 2000). Il cheratocono in Italia ed in Europea è la prima causa di trapianto corneale e ciò desta non poche preoccupazioni in particolare per l’impatto sociale e sanitario dovuto al coinvolgimento di pazienti sempre più giovani. Alla luce delle nuove possibilità terapeutiche ad “indirizzo patogenetico” come il Crosslinking corneale, oggi non si può accettare né una diagnosi tardiva né una scelta terapeutica non adeguatamente ponderata la quale deve essere basata sulla corretta stadiazione clinico-strumentale della malattia, sulla sua evolutività, sulla compliance alle lenti a contatto, sull’età del paziente e sulla sua qualità di vita.
La moderna terapia del cheratocono è diretta in tre direzioni principali: prevenzione o rallentamento della progressione in fase rifrattiva; correzione o riduzione del difetto rifrattivo e delle aberrazioni; sostituzione della cornea ectasica in fase avanzata in pazienti non suscettibili di miglioramento contattologico. Questa Review si propone di descrivere le attuali possibilità terapeutiche del cheratocono basate sullo stadio della malattia fornendo utili e pratiche linee guida basate sulla osservazione e sul trattamento di migliaia di casi da parte degli Autori.Keratoconus is one of the most frequently encountered types of ectatic dystrophic degeneration of the cornea. It generally has its onset in adolescence, is bilateral, asymmetric and characterized by irregular astigmatism associated with thinning of the cornea. In approximately 20% of cases keratocornus requires lamellar and/or perforating keratoplasty, depending on the stage of the condition and the patient’s compliance with contact lenses. Technical advances in ophthalmology and widespread use of corneal topography and pachymetry in refractive surgery have revealed a considerable number of undiagnosed cases of keratoconus. In our experience, its real incidence is far higher (1 in 450 patients) than that reported in the literature (1 in 2000 patients). In Italy and elsewhere in Europe, keratoconus is the primary reason for corneal transplantation and has raised concern about its social and medical impact owing to the increasing number of younger patients seeking treatment. Advanced pathogenetic-based therapeutic options such as corneal crosslinking now permit prompt diagnosis and adequate treatment based on correct clinico-diagnostic staging of the condition, its natural history, compliance with contact lenses, patient age and quality of life. There are three basic approaches to treatment: prevention or slowing down of progression during the refractive stage; correction or reduction of the refractive defect of aberrations; replacement of the ectatic cornea in the advanced stage in keratocornus recalcitrant to lens treatment. This review article describes current therapies according to the stage of the disease and provides useful practical guidelines derived from observation and treatment of thousands of cases from the authors’ clinical series
Transepithelial corneal collagen crosslinking for progressive keratoconus: 24-month clinical results
No full textPurpose: To assess the clinical results of transepithelial collagen crosslinking (CXL) in patients 26 years and younger with progressive keratoconus suitable for epithelium-off (epi-off) CXL. Setting: Department of Ophthalmology, Siena University Hospital, Siena, Italy. Design: Prospective case series. Methods: The study included 26 eyes (26 patients) treated by transepithelial (epithelium-on) CXL. The mean age was 22 years (range 11 to 26 years) (10 younger than 18 years; 16 between 19 years and 26 years). Preoperative and postoperative examinations included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, simulated maximum keratometry (K), coma and spherical aberration, and corneal optical coherence tomography optical pachymetry. The solution for transepithelial CXL (Ricrolin TE) comprised riboflavin 0.1%, dextran 15.0%, trometamol (Tris), and ethylenediaminetetraacetic acid. Ultraviolet-A treatment was performed with the Caporossi Baiocchi Mazzotta X Linker Vega at 3 mW/cm2. Results: After relative improvement in the first 3 to 6 months, the UDVA and CDVA gradually returned to baseline preoperative values. After 12 months of stability, the simulated maximum K value worsened at 24 months. Coma aberration showed no statistically significant change. Spherical aberration increased at 24 months. Pachymetry showed a progressive, statistically significant decrease at 24 months. Fifty percent of pediatric patients were retreated with epi-off CXL due to significant deterioration of all parameters after 12 months of follow-up. Conclusions: Functional results after transepithelial CXL showed keratoconus instability, in particular in pediatric patients 18 years old and younger; there was also functional regression in patients between 19 years and 26 years old after 24 months of follow-up. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. © 2013 ASCRS and ESCRS
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