David Díaz Valle

Corneal cross linking and infectious keratitis: a systematic review with a meta-analysis of reported cases

BackgroundCollagen cross linking (CXL) of the cornea has been developed recently as a new treatment for multidrug-resistant infectious keratitis. The aim of this study is to summarize the previously published data and evaluate the effectiveness of this treatment.ResultsThe search identified 12 articles. The number of eyes was 104. The infectious keratitis was associated with bacteria in 58 eyes (57f%): Gram-positive bacteria in 44 (43%; 4 of which were infected with Mycobacterium (3.6%)) and Gram-negative bacteria in 14 eyes (13%), fungus in 13 eyes (12%), and Acanthamoeba in 7 eyes (7%). In 26 eyes (25%), the microbiological culture was negative or not performed. The mean time of re-epithelization after CXL was 20.7±28.1 days (minimum of 3, maximum of 145). Sixteen eyes underwent deep or lamellar keratoplasty. The pooled analysis suggested that CXL has a favorable effect on the block of corneal melting in 85% (95%; CI 0.77, 0.91) of eyes.ConclusionAlthough randomized controlled trials are needed, the available evidence supports the use of CXL in the treatment of infectious keratitis.

Blood-aqueous barrier permeability determination in HLA B27-positive acute anterior uveitis patients

The blood-aqueous barrier (BAB) permeability was studied by fluorophotometry in 17 healthy control subjects and in 27 eyes from 27 patients with HLA-B27-positive acute anterior uveitis (HLA-B27 AAU). Twenty of these patients had an associated spondyloarthropathy. BAB permeability was studied during the ocular inflammatory crisis and in the disease-free periods in the same patients. Anterior chamber fluorophotometric scans were performed before and 30 minutes after the intravenous injection of 14 mg/kg of sodium fluorescein. The diffusion coefficient (Kd) was obtained from the ratio between the fluorescein concentration in the anterior chamber and the NPBF. Data were analyzed using the Students t test and analysis of variance. A statistically significant difference (P < 0.001) was found between the Kd of active HLA-B27 AAU (61.4±16.8×10−4 min−1) and the Kd of inactive HLA-B27 AAU (4.8±1.6×10−4 min−1). No statistically significant differences were found between the Kd of inactive HLA-B27 AAU and the Kd of the control subjects (4.3±1.0×10−4min−1). We also failed to detect significant differences between patients with and without spondyloarthropathy either during the acute attack or during the disease-free period. On the basis of these results we conclude that the permeability of the BAB remains intact in inactive HLA-B27-positive AAU. The parallel fluorophotometric behaviour of HLA-B27-positive AAU with spondyloarthropathy and without spondyloarthropathy suggests that both share a common pathogenetic mechanism.

Glaukos(®) trabecular stent used to treat steroid-induced glaucoma.

Purpose This case report illustrates the efficacy of the Glaukos trabecular bypass (Glaukos i-stent, Glaukos Corporation, Laguna Hills, California, USA) used for intraocular pressure (IOP) control in a patient with glaucoma induced by the steroid treatment of post–laser-assisted in situ keratomileusis (LASIK) bilateral anterior uveitis. Methods A 35-year-old woman who had undergone LASIK 5 months previously presented with blurred vision in both eyes. Examination revealed bilateral anterior uveitis and diffuse lamellar keratitis (DLK) requiring steroid treatment. In response to treatment, inflammation improved but the patient had increased IOP that was difficult to control. The course of pressure elevation was more aggressive in the left eye despite the gradual discontinuation of steroids. We therefore decided to place 2 trabecular i-stents in the left eye. Results This solution achieved good pressure control with no associated complications after 1 year follow-up. Conclusions This trabecular bypass seems a safe and effective therapeutic option for IOP control when there is a poor response to conventional treatment in this type of secondary glaucoma.

Deep anterior lamellar keratoplasty versus penetrating keratoplasty in corneas showing a high or low graft rejection risk

Purpose: To compare visual, topographic and topometric outcomes in patients subjected to deep anterior lamellar keratoplasty or penetrating keratoplasty showing a high or low risk of graft rejection. Setting: Complejo Hospitalario La Mancha Centro, Ciudad Real, Spain. Materials and methods: Data were reviewed for consecutive patients with a corneal stroma disease undergoing deep anterior lamellar keratoplasty or penetrating keratoplasty over the period 2009–2015 at our centre by the same surgeon. The outcome measures examined were 2-year follow-up best-corrected visual acuity, refractive error, topographic astigmatism, intraocular pressure, endothelial cell density and central corneal thickness. Results: Of 115 eyes enrolled, 46 underwent deep anterior lamellar keratoplasty (15 low risk, 31 high risk) and 69 penetrating keratoplasty (23 low risk, 46 high risk). Mean postoperative best-corrected visual acuity (logMAR) in the low- and high-risk groups, respectively, were 0.31 and 0.26 for deep anterior lamellar keratoplasty (p = 0.32) and 0.40 and 0.51 for penetrating keratoplasty (p = 0.28). The values for the high-risk deep anterior lamellar keratoplasty versus high-risk penetrating keratoplasty patients were 0.26 and 0.51, respectively (p = 0.004). Mean postoperative spherical equivalents were −2.60 D for low-risk deep anterior lamellar keratoplasty versus −2.29 D for high-risk deep anterior lamellar keratoplasty (p = 0.19), and −0.41 D for low-risk penetrating keratoplasty versus −0.13 D for high-risk penetrating keratoplasty (p = 0.51). Conclusion: Final best-corrected visual acuity and visual acuity gains were better for deep anterior lamellar keratoplasty, mainly in corneas with a high rejection risk. Despite a better corneal thickness recorded in the deep anterior lamellar keratoplasty group, the other variables examined were comparable. Deep anterior lamellar keratoplasty emerged as an effective alternative to penetrating keratoplasty for patients with a disease affecting the corneal stroma.