Otman Sandali

Long-term Results of Deep Anterior Lamellar versus Penetrating Keratoplasty

OBJECTIVE To compare deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in eyes with corneal diseases not involving the corneal endothelium (keratoconus, scars after infectious keratitis, stromal dystrophies, and trauma). DESIGN Retrospective, comparative case series. PARTICIPANTS One hundred forty-two consecutive DALK (DALK group; big-bubble technique or manual lamellar dissection using a slitlamp) and 142 matched PK (PK group). METHODS Three models were used to describe the postoperative outcomes of the endothelial cell density. A joint regression model was used to predict long-term graft survival. Visual acuity, ultrasound pachymetry, specular microscopy, and optical coherence tomography (OCT) findings were recorded. MAIN OUTCOME MEASURES Postoperative endothelial cell loss and long-term predicted graft survival. RESULTS The average 5-year postoperative endothelial cell loss was -22.3% in the DALK group and -50.1% in the PK group (P<0.0001). The early- and late-phase annual rates of endothelial cell loss were -8.3% and -3.9% per year, respectively, in the DALK group and -15.2% and -7.8% per year in the PK group (P<0.001; biphasic linear model). The median predicted graft survival was 49.0 years in the DALK group and 17.3 years in the PK group (P<0.0001). The average visual acuity was lower in the manual dissection subgroup compared with the PK group (average difference, 1.0 to 1.8 line) and with the big-bubble subgroup (average difference, 2.2 to 2.5 lines). The average central corneal thickness at 12 months was 536 μm in the PK group, 523 μm in the big-bubble subgroup, and 562 μm in the manual dissection subgroup (P<0.001). The average thickness of the residual recipient stroma measured by OCT was 87±26 μm in the manual dissection subgroup. No correlation was found between this figure and logarithm of the minimal angle of resolution at any postoperative time point (P>0.05). CONCLUSIONS Long-term, model-predicted graft survival and endothelial densities are higher after DALK than after PK. The big-bubble technique gives better results than manual dissection and PK. Compared with PK, manual dissection provides higher survival of both the corneal endothelium and graft, but lower visual acuity.

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.

Corneal epithelial thickness mapping using Fourier-domain optical coherence tomography for detection of form fruste keratoconus

Purpose To determine whether optical coherence tomography (OCT) epithelial mapping can improve the detection of form fruste keratoconus. Setting French National Eye Hospital, Paris 6 Pierre & Marie Curie University, Paris, France. Design Retrospective comparative study. Methods Eyes with normal corneas, form fruste keratoconus, moderate keratoconus, or severe keratoconus were assessed using Fourier‐domain OCT (RTVue 5.5), scanning‐slit corneal topography (Orbscan IIz), and rotating Scheimpflug camera (Pentacam Comprehensive Eye Scanner). Several parameters provided by the software or derived from elevation maps, OCT pachymetric maps, and OCT epithelium parameters were evaluated and compared between the 4 groups. Results The study involved 145 eyes. There were no significant differences in the keratometry (K) value, inferior–superior value, keratoconus index, central K index, and topographic keratoconus classification indices between the form fruste keratoconus group and the control group (P > .05). Form fruste keratoconic corneas had less epithelial thickness in the thinnest corneal zone than normal corneas, and greater epithelial thickness in the thinnest corneal zone than keratoconic corneas (P < .005). The epithelial thickness in the thinnest corneal zone in form fruste corneas was located inferiorly (P < .005) and corresponded with the zone of minimum epithelial thickness and maximum posterior elevation (P < .005). The receiver operating characteristic curve analysis showed good overall predictive accuracy of the epithelial thickness in the thinnest corneal zone, with a 52 &mgr;m threshold value for discriminating form fruste keratoconic corneas from normal corneas. Conclusions The epithelial thickness in the thinnest corneal zone and its location provided by the OCT epithelial mapping might be useful for the early diagnosis of form fruste keratoconus. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

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.

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.

Récidive d’une membrane épirétinienne idiopathique dite « vasocentrique » : particularités cliniques et chirurgicales

The vasocentric epiretinal membranes (ERM) are idiopathic ERM centered on retinal blood vessels, described mainly in young patients. We report a case of a 70-year-old patient who presented with a decrease in visual acuity secondary to a vasocentric epiretinal membrane. A successful vitrectomy and ERM removal were performed. Four years after surgery, a contractile ERM centered on the superior temporal blood vessel occurred and was associated with retinal distortions at the posterior pole. The second surgery combined removal of the recurrent ERM, which was adherent to the temporal vessels, and peeling of the internal limiting membrane in the macular area. Although there was visual recovery, the patient is still suffering from metamorphopsia 2 years after surgery. The vasocentric ERM have a poor visual outcome and a high risk of recurrence in comparison with other ERM disorders. This case report describes the main clinical and surgical characteristics of this type of membrane.

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.

Infectious Keratitis in Severe Limbal Stem Cell Deficiency: Characteristics and Risk Factors

Purpose: To evaluate the incidence, clinical and microbiological characteristics and risk factors of infectious keratitis in patients with limbal stem cell deficiency (LSCD). Methods: Retrospective comparative case series of 35 patients with severe LSCD. Results: The mean follow-up time was 46 months. Infectious keratitis were mainly caused by Gram positive bacteria (94%). Only 7 infections (37%) healed under fortified adapted antibiotics. In 8 cases (42%), amniotic membrane transplantation was required and in 4 cases (21%) «à chaud» keratoplasty was performed. Significant risk factors associated with infectious keratitis were: soft contact lens extended wear, history of persistent epithelial defects, number of quadrants of corneal vascularization, re-epithelialization time after amniotic membrane or corneal transplantation, and use of corticosteroid or cyclosporin eye drops. Conclusion: Infectious keratitis in LSCD is frequent and severe. The restoration of the epithelial barrier integrity and a careful use of therapeutic contact lenses may help to prevent infection.