Isabelle Goemaere

Anatomic 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.

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.

Dystrophie de Cogan révélée après chirurgie réfractive de type Lasik

A 48-year-old woman with no significant past history underwent bilateral simultaneous laser in situ keratomileusis for correction of her myopia. On the tenth postoperative day, the patient complained of visual decrease and photophobia. Slit lamp exam showed corneal epithelial irregularities. Confocal microscopy was performed and revealed a characteristic appearance of epithelial basement membrane dystrophy (EBMD). The patient was successfully treated with artificial tears and autologous serum eyedrops. EBMD may be missed before LASIK surgery, even after a careful pre-operative examination. Exacerbation of EBMD after LASIK surgery is rare. It should be considered when unexplained corneal epithelial defects or irregularities occur following LASIK. Confocal microscopy is very useful to confirm the diagnosis.

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.