1,721,013 research outputs found
Keratoconus : current and future state-of-the-art
Full text linkThis book provides a practical guide to the most recent advances in the diagnostic management of corneal ectasia. Clear, concise chapters address new standardized nomograms of treatment of early progressive ectasia, new epithelium on future crosslinking with and without oxygen supplement, customized protocols, laser assisted corneal regularization protocols and the new femtolaser assisted lamellar corneal transplant. Clinicians and surgeons seeking a go-to guide on the topic of corneal ectasia will find this book to be an essential resource for the latest developments and predicted future trends in the field. © The Editor(s) (if applicable) and The Author(s)
Anterior Acute Uveitis Report in a SARS-CoV-2 Patient Managed with Adjunctive Topical Antiseptic Prophylaxis Preventing 2019-nCoV Spread Through the Ocular Surface Route
No full textPurpose: To report the clinical-epidemiological association between acute anterior uveitis and acute bilateral follicular conjunctivitis in a 30-year-old female patient who had tested positive for the SARS-CoV-2 RT-PCR.Methods: A 30-year-old female visited emergency ophthalmology care at the Siena Crosslinking Centre, Italy, for a bilateral eye redness lasting two weeks, associated with unilateral photophobia and blurred vision in her right eye. She visited on the 23rd of March 2020 in the full pandemic period and presented chills and fever with a temperature of 39.0 degrees C, associated with complete loss of taste. Since eye examination findings, systemic symptoms and epidemiological criteria correlated with SARS-CoV-2 infection, she was referred to Siena University Hospital, Italy, for the SARS-CoV-2 nasopharyngeal buffer and haematological examinations for uveitis.Results: Eye examination revealed bilateral conjunctival hyperaemia with acute follicular conjunctivitis associated with right eye acute anterior uveitis characterized by diffuse pigmentary and whitish immune precipitates over the anterior capsule of the crystalline lens and initial anterior lens opacity explaining the blurred vision. Adjunctive prophylactic eye topical treatment, included in the acronym SHYPIO (0.02% sodium hypochlorite solution, 0.6% povidone iodine eye-drops and 10.50% ozonized oil eye-drops), was associated with conventional uveitis therapy to prevent the virus spread through the ocular surface route.Conclusion: Our report demonstrates that complicated acute anterior uveitis (iridocyclitis) with blurred vision could be associated with SARS-CoV-2 infection, being potentially sight-threatening for early complicated lens opacity. Ophthalmologists examining suspected or asymptomatic patients should be aware of the risk of 2019-nCoV infection
PACK-CXL: Corneal cross-linking in infectious keratitis
Full text linkBackground: Corneal cross-linking (CXL) using ultraviolet light-A (UV-A) and riboflavin is a technique developed in the 1990's to treat corneal ectatic disorders such as keratoconus. It soon became the new gold standard in multiple countries around the world to halt the progression of this disorder, with good long-term outcomes in keratometry reading and visual acuity. The original Dresden treatment protocol was also later on used to stabilize iatrogenic corneal ectasia appearing after laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). CXL efficiently strengthened the cornea but was also shown to kill most of the keratocytes within the corneal stroma, later on repopulated by those cells.Review: Ultraviolet-light has long been known for its microbicidal effect, and thus CXL postulated to be able to sterilize the cornea from infectious pathogens. This cytotoxic effect led to the first clinical trials using CXL to treat advanced infectious melting corneal keratitis. Patients treated with this technique showed, in the majority of cases, a stabilization of the melting process and were able to avoid emergent a chaud keratoplasty. Following those primary favorable results, CXL was used to treat beginning bacterial keratitis as a first-line treatment without any adjunctive antibiotics with positive results for most patients. In order to distinguish the use of CXL for infectious keratitis treatment from its use for corneal ectatic disorders, a new term was proposed at the 9th CXL congress in Dublin to rename its use in infections as photoactivated chromophore for infectious keratitis -corneal collagen cross-linking (PACK-CXL).Conclusion: PACK-CXL is now more frequently used to treat infections from various infectious origins. The original Dresden protocol is still used for this purpose. Careful modifications of this protocol could improve the efficiency of this technique in specific clinical situations regarding certain types of pathogens
Femtosecond-Laser Assisted Deep Anterior Lamellar Keratoplasty (F-DALK)
No full textDALK is a demanding procedure performed by comparably few surgeons. Femtosecond-laser assisted DALK (f-DALK) potentially shortens the learning curve for surgeons, which benefits patients by reducing the invasiveness of the procedure, improving the odds against complications and by maintaining patient’s own, healthy endothelial tissue. The key advantage in using the femtosecond laser for DALK is the higher rate of successful intraoperative preparation and thus, fewer conversions to penetrating keratoplasty
Chemically-Boosted Corneal Cross-Linking for the Treatment of Keratoconus through a Riboflavin 0.25% Optimized Solution with High Superoxide Anion Release
No full textThe purpose of this study was to evaluate the effectiveness and safety of a novel buffered riboflavin solution approved for corneal cross-linking (CXL) in progressive keratoconus and secondary corneal ectasia. Following the in vivo preclinical study performed on New Zealand rabbits comparing the novel 0.25% riboflavin solution (Safecross®) containing 1% hydroxypropyl methylcellulose (HPMC) with a 0.1% riboflavin solution containing 0.10% EDTA, accelerated epithelium-off CXL was performed on 10 patients (10 eyes treated, with the contralateral eye used as control) through UV-A at a power setting of 9 mW/cm2 with a total dose of 5.4 J/cm2. Re-epithelialization was evaluated in the postoperative 7 days by fluorescein dye test at biomicroscopy; endothelial cell count and morphology (ECD) were analyzed by specular microscopy at the 1st and 6th month of follow-up and demarcation line depth (DLD) measured by anterior segment optical coherence tomography (AS-OCT) one month after the treatment. We observed complete re-epithelization in all eyes between 72 and 96 h after surgery (88 h on average). ECD and morphology remained unchanged in all eyes. DLD was detected at a mean depth of 362 ± 50 µm, 20% over solutions with equivalent dosage. SafeCross® riboflavin solution chemically-boosted corneal cross-linking seems to optimize CXL oxidative reaction by higher superoxide anion release, improving DLD by a factor of 20%, without adverse events for corneal endothelium
Ultrathin Descemet stripping automated endothelial keratoplasty versus Descemet membrane endothelial keratoplasty: a fellow-eye comparison
Full text linkBackground To compare the visual outcome and patients' satisfaction after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) performed on fellow eyes of the same patients. Methods In this retrospective study, the records of 18 pseudophakic patients affected by Fuchs endothelial dystrophy who underwent DMEK in one eye and UT-DSAEK in the fellow eye were reviewed. Best corrected visual acuity (BCVA), corneal pachymetry, keratometry, corneal aberrations, photopic and mesopic contrast sensitivity, and endothelial cell counts measured 12 months after surgery in either eye were analyzed and compared. The results of a satisfaction questionnaire were also reviewed. Results Twelve months after surgery, BCVA was not significantly different in UT-DSAEK and DMEK eyes (0.10 +/- 0.04 and 0.07 +/- 0.07 logMAR, respectively); at both 4- and 6 mm optical zones total and posterior corneal higher order aberrations (HOAs), posterior astigmatism and total coma were significantly lower after DMEK; BCVA in both groups was significantly correlated mainly with anterior corneal aberrations; contrast sensitivity was higher after DMEK especially in mesopic conditions and at medium spatial frequencies; the endothelial cell density was similar, although slightly higher in the UT-DSAEK group (p = 0.10). The satisfaction questionnaire showed that although patients were highly satisfied from both procedures, more than half of them preferred DMEK and reported a more comfortable and quicker postoperative recovery. Conclusions DMEK and UT-DSAEK showed no evidence of difference in terms of postoperative BCVA, although DMEK had a better performance in terms of contrast sensitivity, posterior corneal aberrations and overall patient satisfaction
Slowing the Progression of Keratoconus - Turning to Corneal Crosslinking
No full textRiboflavin UV-A Corneal Crosslinking was developed in the 1990s to treat progressive keratoconus. Its indication was rapidly extended to iatrogenic corneal ectasias. Conventional 3mW/cm2 CXL represents the gold standard therapy in multiple Countries around the World to halt the progression of early stages corneal ectasia demonstrating good long-term visual results and low complications. Early diagnosis, slowing the progression of keratoconus turning to native corneal crosslinking spirit: stabilizing ectasia progression preventing corneal shape modification, is the key. Conventional and Accelerated CXL protocols demonstrated a medium-long term improvement in visual and topo-aberrometric parameters. New conservative approaches such as topography-guided CXL and CXL-plus corneal reshaping techniques are under investigation for patients with poor spectacles corrected visual acuity and contact lenses intolerance before keratoplasty
Factors predicting unsuccessful big bubble deep lamellar anterior keratoplasty.
No full textPURPOSE: To evaluate the role of corneal structural resistance as a surgical failure factor in deep lamellar keratoplasty (DLK).
METHOD: A total of 10 eyes of 10 patients underwent DLK at the Ophthalmic Hospital in Rome. The big bubble technique was performed for deep stromal dissection by air injection. Seven patients were affected by advanced keratoconus and corneal thinning ranging from 441 to 235 microm. Two patients were affected by central corneal opacity from herpetic keratitis, and one patient suffered from corneal leucoma caused by bacterial keratitis. Clinical follow-up comprising final astigmatism and visual acuity findings were evaluated with a minimum follow-up of 12 weeks.
RESULTS: DLK was successfully performed in eight eyes, five of which were affected by moderate to advanced keratoconus and three by post-infective corneal opacity. In these patients preoperative ultrasonic pachymetry ranged between 441 and 287 microm. In the remaining two patients a perforation of the Descemet's membrane (DM) occurred while attempting to separate it from the overlying stroma by the big bubble technique, requiring a penetrating keratoplasty (PK) to be performed. In both cases preoperative ultrasonic pachymetry was below 250 microm. Both perforations occurred at a different site than the needle site and at the operative time of the big-bubble injection.
DISCUSSION: An ultrastructurally weakened DM may suffer a loss of resistance to a stressing force, becoming unable to tolerate the big bubble technique, and thus being perforated. Since the weakening of the DM is related to end-stage keratoconus corneal thinning, the preoperative corneal thickness rather than the surgeon's ability can play a major role in surgical failure of DLK. Our study reveals a very high risk of perforation of the DM when pre-operative total pachymetry is below limit of 250 microm
Irido-corneal-endothelial syndrome: a confocal and anterior segment coherent tomography differential diagnosis
No full textEssential iris atrophy represents one of the phenotypic expressions of irido-corneal-endothelial syndrome (ICE-S). Despite some typical clinical features, differential diagnosis of the endothelial alteration at early stage of the disease is not easy also with a careful slit lamp examination, with different overlapping clinical aspects. We report differential diagnosis by in vivo confocal microscopy and anterior segment optical coherent tomography, between ICE-syndrome related endotheliopathy in a 62 year male patient and other pathologies involving corneal endothelium with different therapeutic and prognostic implications: Posterior polymorphous corneal dystrophy, cornea guttata and Fuch’s endothelial dystrophy. Even if the ICS-Syndrome is generally unilateral and non familial, a bilateral occurrence may be possible. The disease may progress leading to secondary glaucoma and corneal decompensation. In this contest, early diagnosis becomes fundamental to monitor corneal endothelial and stromal changes, IOP variation and pupil distortion in order to establish a correct therapeutic strategy. Differential analysis with posterior polymorphous corneal dystrophy, cornea guttata and Fuch’s endothelial dystrophy is necessary, especially in bilateral disease due to different prognosis and management of these pathologies. Indeed in this clinical case, despite the apparent absence of stromal modifications at biomicroscopic examination, in vivo confocal microscopy allowed us to detect the presence of a stromal sub-clinical edema, explaining patients visual fluctuations with a consequent customized therapeutic strategy and prognostic evaluation
Intraoperative OCT Pachymetric Mapping During Accelerated Pulsed High-Fluence Corneal Collagen Crosslinking With Dextran-Free Riboflavin
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