Elena Basli

Epiretinal membrane recurrence: incidence, characteristics, evolution, and preventive and risk factors.

Background: To evaluate the incidence, evolution, clinical characteristics, possible risk factors or preventive factors, and visual outcomes of epiretinal membrane (ERM) recurrence. Methods: Retrospective study of 440 consecutive patients (440 eyes) who underwent pars plana vitrectomy for ERM. The internal limiting membrane (ILM) was peeled in 266 cases, with the help of indocyanine green in 27 cases and brilliant blue in 45 cases. Cases of symptomatic ERM recurrence were reoperated. Results: The incidence of ERM recurrence was 5% (22/440), and 2% of the patients were reoperated (9/440). Epiretinal membrane recurrence was symptomatic in 9 cases (41%) and asymptomatic in 13 cases (59%). ILM peeling was the only factor preventing ERM recurrence (adjusted odds ratio = 0.33, P = 0.026). The use of staining dyes did not prevent recurrence (adjusted odds ratio = 0.35, P = 0.338). In the case of ERM reproliferation, the absence of ILM peeling, the existence of ERM on the fellow eye, and poor visual acuity before surgery seemed to be associated with a high risk of symptomatic recurrence and reoperation. The mean duration for follow-up was 3.5 ± 1.7 years. Conclusion: ILM peeling not only reduces the likelihood of reproliferation of ERM but also seems to improve the visual prognosis of recurrent ERMs. The use of dyes did not reduce the rate of recurrence compared with when ILM was peeled without dyes.

Human epithelial cell cultures from superficial limbal explants

The volatile anesthetic sevoflurane is capable of inducing preconditioning and postconditioning effects in the brain. In this study, we investigated the effects of sevoflurane postconditioning on antioxidant and immunity indexes in cerebral ischemia reperfusion (CIR) rats. Rats were randomly assigned to five separate experimental groups I–V. In the sham group (I), rats were subjected to the same surgery procedures except for occlusion of the middle cerebral artery and exposed to 1.0 MAC sevoflurane 90 min after surgery for 30 min. IR control rats (group II) were subjected to middle cerebral artery occlusion (MCAO) for 90 min and exposed to O2 for 30 min at the beginning of reperfusion. Sevoflurane 0.5, 1.0 and 1.5 groups (III, IV, V) were all subjected to MCAO for 90 min, but at the beginning of reperfusion exposed to 0.5 MAC, 1.0 MAC or 1.5 MAC sevoflurane for 30 min, respectively. Results showed that sevoflurane postconditioning can decrease serum tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nitric oxide (NO), nitric oxide synthase (NOS) and increase serum interleukin-10 (IL-10) levels in cerebral ischemia reperfusion rats. In addition, sevoflurane postconditioning can still decrease blood lipid, malondialdehyde (MDA) levels, infarct volume and increase antioxidant enzymes activities, normal pyramidal neurons density in cerebral ischemia reperfusion rats. It can be concluded that sevoflurane postconditioning may decrease blood and brain oxidative injury and enhance immunity indexes in cerebral ischemia reperfusion rats.

New test for the diagnosis of bacterial endophthalmitis

Background: Diagnosis of bacterial endophthalmitis (BE) often fails due to: (1) insufficient volumes of vitreous fluid (VF) and aqueous humour (AH); (2) lack of sensitivity of culture; (3) antibiotic treatments; (4) polymerase chain reaction (PCR) cross-contamination; and (5) limitations on the interpretation of the real-time PCR melting curve. We developed a fast real-time (f-real-t) PCR to improve the performance of the laboratory diagnosis of BE. Methods: The following samples were processed after adding an internal control: phosphate buffered saline (PBS); VF, AH and cell suspensions spiked with Bacteria (Bac); VF and AH from patients with endophthalmitis; and VF and AH from non-infective patients. DNA was extracted (MagNA Pure®) and added to four tubes containing selected primers and probes for the identification and quantification of all Bac and eight genera by f-real-t PCR. Diagnostic performances based on direct microscopic examination, culture and f-real-t PCR were compared. Results: The f-real-t PCR detected at least 0.01 colony-forming units (CFU) of Bac/μl with no cross-reactivity with fungi. Correlation with culture-positive results was 100%. Sixty per cent of BE samples tested culture-positive, but f-real-t PCR tested positive for 90%. Samples from non-infective cases were negative. Conclusion: The f-real-t PCR detected and quantified Bac, Staphylococci, Streptococci, Haemophilus, Pseudomonas, Enterobacteria, Acinetobacter, Propionibacteriacae and Corynebacteria in one run. Cultures required several hours to days (with a non-negligible number of false-negative results) and the f-real-t PCR was completed in 90 min. The f-real-t PCR is presented as a new tool for the diagnosis of BE: its usefulness requires validation with larger series of samples.

Donor tissue selection for anterior lamellar keratoplasty.

Purpose: To assess the influence of donor characteristics on the outcome of anterior lamellar keratoplasty (ALK) and to evaluate whether corneal donor tissue considered unsuitable for penetrating or posterior lamellar keratoplasty due to poor endothelial condition may be safely used for ALK. Methods: Institutional setting. One hundred sixty-six consecutive ALK (166 patients) performed for optical indication in eyes with corneal diseases not involving the corneal endothelium. The main outcome measures were graft survival, early (0–12 months postoperatively) and late (after 12 months) annual endothelial cell loss, and postoperative logarithm of the minimum angle of resolution visual acuity. Results: The average and extreme values of donor tissue characteristics were: donor age, 70.6 years (range, 28–88 years); organ culture time, 20.9 days (range, 12–35 days); graft endothelial cell density before transplantation, 2047 cells per millimeters (range, 100–3300 cells/mm2); and deswelling time, 2.0 days (range, 1–4 days). The average follow-up time of patients was 48.1 ± 24.8 months (mean ± SD). None of the donor characteristics significantly influenced graft survival or postoperative endothelial cell loss (early and late phase). Donor age >80 years was associated with lower postoperative visual acuity at all postoperative points in time (P < 0.05). At 3 years, the mean logarithm of the minimum angle of resolution visual acuity was 0.44 (20/55) for grafts from donors older than 80 years and 0.25 (20/35) for younger donors. This result was shown to be significant both in univariate and in multivariate analysis. Conclusions: Grafts from elderly donors should be discarded before ALK. Conversely, donor tissue with poor endothelial cell density (<2000 cells/mm2) is suitable for ALK.

Conventional and Iontophoresis Corneal Cross-Linking for Keratoconus: Efficacy and Assessment by Optical Coherence Tomography and Confocal Microscopy

Purpose: To compare the efficacy, safety, and microstructural corneal changes during 2 years after conventional corneal collagen cross-linking (C-CXL) and transepithelial corneal CXL by iontophoresis (I-CXL) for keratoconus. Methods: Eighty eyes of 80 patients with progressive keratoconus were treated by C-CXL (n = 40) or I-CXL (n = 40). Patients were investigated before surgery and 1, 3, 6, 12, and 24 months after treatment. We measured central corneal thickness and maximal simulated keratometry values (Kmax) and performed specular microscopy and in vivo confocal microscopy at each time point. The demarcation line was assessed 1 month after treatment. Results: Kmax remained stable after I-CXL during the entire study period (P = 0.56), whereas the average keratometry increased by 0.2 diopter (50.9 ± 5.6–51.1 ± 5.2). Kmax significantly decreased 1 (P = 0.02) to 2 years (P < 0.01) after C-CXL, with an average decrease of 1.1 diopters (49.9 ± 4.5–48.8 ± 4.2). The failure rate of I-CXL was 20% and that of C-CXL 7.5%. The demarcation line was superficially visible in 35% of cases after I-CXL compared with 95% of cases after C-CXL. Endothelial cell density and central corneal thickness remained stable during the entire study period. The change in Kmax 2 years after C-CXL and I-CXL and the preoperative Kmax were negatively correlated (r2 = 0.14, P = 0.013, and r2 = 0.17, P = 0.007, respectively). Conclusions: I-CXL halted progression of keratoconus less efficiently than did C-CXL after 2 years of follow-up. Longer prospective studies are still needed to ensure I-CXL efficacy.

Original articleAnatomic Predictive Factors of Acute Corneal Hydrops in Keratoconus: An Optical Coherence Tomography Study

PURPOSE To define the optical coherence tomography (OCT) corneal changes predisposing to acute corneal hydrops among patients with advanced keratoconus. DESIGN Retrospective cohort study. PARTICIPANTS A total of 191 advanced keratoconic eyes from 191 patients with advanced keratoconus cases were studied. METHODS Data collected from patients with advanced keratoconus cases were studied during a minimum period of 24 months of follow-up. High-resolution Fourier-domain corneal OCT (5 μm of axial resolution) and corneal topography were performed every 4 months during the follow-up. Several anatomic features at the keratoconus cone were analyzed with OCT, including epithelial and stromal thicknesses, the aspect of Bowmans layer, the presence of Vogts striae, and stromal opacities. A comparative analysis between anatomic corneal features in eyes that developed corneal hydrops and those that did not develop this complication during the follow-up was performed. MAIN OUTCOME MEASURES Evaluation of anatomic corneal changes at risk of developing a corneal hydrops on the basis of OCT findings. RESULTS Eleven cases of corneal hydrops (5.8%) occurred in our series during a mean follow-up of 30 months (24-36 months). All of these patients were male and younger (23.7±5.9 years) than patients with no acute keratoconus (32.7±11.3 years). Increased epithelial thickening with stromal thinning at the conus and the presence of anterior hyperreflectives at the Bowmans layer level were significantly associated with corneal hydrops, whereas the presence of corneal scarring was a preventive factor. At the healing stage, a pan-stromal scar occurs, with a significant stromal thickening and cornea flattening. CONCLUSIONS Increased epithelial thickening, stromal thinning at the keratoconus cone, anterior hyperreflectives at the Bowmans layer level, and the absence of stromal scarring are associated with a high risk of developing corneal hydrops. These aspects should be taken into account by the clinician in the evaluation of keratoconus eyes and in the planning of corneal keratoplasty.

New combined technique of deep intrastromal arcuate keratotomy overlayed by LASIK flap for treatment of high astigmatism.

Purpose: The aim of this study was to describe a novel technique combining deep intrastromal arcuate keratotomy and superficial lamellar keratotomy followed by excimer photoablation for the management of high naturally occurring or postkeratoplasty astigmatism. Methods: In this retrospective case series, the first step was deep intrastromal arcuate keratotomy and superficial lamellar keratotomy performed at 100-&mgr;m depth by femtosecond laser. Manual incisions were made for flap elevation. The second step, after 1 month, consisted of reopening the flap and using an excimer laser to correct residual ametropia. Results: Nine eyes series were studied. The mean preoperative refractive cylinder correction was 6.11 ± 2.54 diopters (D). The mean postoperative refractive cylinder correction was 2.85 ± 1.31 D. The mean correction index was 1.07 ± 0.28 D. The mean best-corrected visual acuity improved from 20/40 to 20/22 after the 2 steps. The median follow-up was 11 (range, 9–17) months. No complications were observed and postoperative outcome was satisfactory. Conclusions: Permitting correction of a broader range of high astigmatism with good accuracy, this combined approach minimizes excision of corneal stromal tissue and postoperative complications.

Increased Reaction after Cross-linking in Keratoconus Melanoderm Patients

Corneal collagen cross-linking (CXL) using riboflavin and ultraviolet-A is an etiopathogenetic and innovative therapy for keratoconus. Histological changes after CXL have been well described on confocal microscopic images. Early postoperative findings include keratocyte apoptosis and anterior stromal edema. At the third month postoperatively, the stromal edema disappears and is followed by keratocyte population recovery and increase in stromal fiber density. On optical coherence tomography (OCT) images, only the corneal stromal demarcation line that corresponds to the transition zone between the cross-linked anterior corneal stroma and the untreated posterior corneal stroma has been recently described, indicating the transition zone between cross-linked anterior corneal stroma and untreated posterior corneal stroma. This line is clearly visible 1 month after corneal cross-linking, indicating probably the efficiency of the procedure. Melanoderm patients are considered at high risk for excessive scaring reaction after surgery. To the best of our knowledge, stromal reaction after CXL in this group of patients has not been evaluated. In this brief report, we describe aspects of increased stromal reaction observed in 4 eyes of 3 melanoderm patients who underwent CXL for evolutive keratoconus. These patients underwent cross-linking between January 2010 and May 2011 at the Quinze-Vingts National Ophthalmology Hospital (Paris, France). During the same period, 116 patients were scheduled to have CXL. Fourteen patients among them were melanoderm. Patients with pigmented skin and iris coloration were considered melanoderm patients regardless of their ethnicity. Progression of keratoconus was defined as an increase in the maximum K-value by more than 1.0–1.5 diopters (D) and a corresponding change (1.0–1.5 D) in the refractive cylinder in the previous 6–12 months. Patients received standard UVA–riboflavin 0.1% CXL treatment. After a 9-mm-diameter corneal epithelium abrasion, photosensitizing riboflavine (0.1% in 20% dextran T500 solution) solution was applied on the cornea every 3 min for 30 min. The central cornea was irradiated using UVA 365-nm light (8.0-mm diameter, 3.0-mW/cm irradiance) for 30 min (UV-X system, IROC AG, Zurich, Switzerland). Riboflavin eyedrops were applied every 5 min during the UVA exposure. After the riboflavin–UVA treatment, a therapeutic soft contact lens was applied for 3 days. Topical dexamethasone and tobramycin were given 4 times daily and gradually tapered over 1 month. Postoperatively patients were examined 1 week and 1, 3, and 6 months after the CXL treatment. The patient workup included the best spectacle-corrected visual acuity (BSCVA), slit-lamp examination, corneal topography (Orbscan IIz, B&L, Rochester, NY, USA), anterior spectral-domain OCT (AS-OCT) (RTVue, Optovue, Fremont, CA), specular microscopy (Noncon Robo SP-9000, Konan Medical, Hyogo, Japan), and in vivo laser scanning confocal microscopy (Heidelberg Retinal Tomograph II with Rostock Cornea Module, Heidelberg, Germany). The mean age of patients was 26 years (ranging from 24 to 27 years). There were 2 females and 1 male.