The effect of bevacizumab versus ranibizumab in the treatment of corneal neovascularization: a preliminary study.

PURPOSE: To compare the short term effects of bevacizumab and ranibizumab injections on the regression of corneal neovascularization (NV). METHODS: Sixteen eyes of 16 patients with corneal NV were randomly assigned for an injection with 2.5 mg of bevacizumab (group 1, n = 8) or 1 mg of ranibizumab (group 2, n = 8) through subconjunctival and intrastromal routes. The patients were prospectively followed-up for one month after the injections. Corneal NV areas, as shown on corneal slit-lamp photographs stored in JPEG format, were calculated using Image J software before the injection, one week after the injection, and one month after the injection. The corneal NV areas were compared before and after the injections. RESULTS: Seven women and nine men, with an average age of 51 years, presented with corneal NV secondary to herpetic keratitis (7 cases), graft rejection (6), chemical burn (1), pemphigoid (1), and recurrent ulcer (1). In group I, the preoperative corneal NV area (8.75 ± 4.33%) was significantly decreased to 5.62 ± 3.86% one week after the injection and to 6.35 ± 3.02% one month after the injection (p = 0.012, 0.012, respectively). The corneal NV area in group 2 also exhibited a significant change, from 7.37 ± 4.33% to 6.72 ± 4.16% one week after the injection (p = 0.012). However, no significant change was observed one month after the injection. The mean decrease in corneal NV area one month after injection in group 1 (28.4 ± 9.01%) was significantly higher than in group 2 (4.51 ± 11.64%, p = 0.001). CONCLUSIONS: Bevacizumab injection resulted in a more effective and stable regression of corneal NV compared to the ranibizumab injection. The potency and dose of these two drugs for the regression of corneal NV require further investigation.

Corneal thickness measurement using Orbscan, Pentacam, Galilei, and ultrasound in normal and post-femtosecond laser in situ keratomileusis eyes.

PURPOSE: To compare corneal pachymetry assessment using slit scanning imaging (Orbscan), rotating Scheimpflug imaging (Pentacam), dual Scheimpflug system (Galilei), and ultrasound pachymetry in normal and post-femtosecond (FS) laser in situ keratomileusis (LASIK) eyes. METHODS: Sixty eyes of 60 patients were enrolled for this study, which consisted of 30 unoperated eyes (normal corneas) and 30 eyes after FS-LASIK (post-LASIK corneas). Central corneal thickness was measured sequentially using Orbscan II, Pentacam, Galilei, and ultrasound pachymetry, and the average value of measurements obtained by the 4 different methods were compared in each group. RESULTS: In normal corneas, corneal thickness measurements were not different by all 4 methods [P = 0.202, 1-way analysis of variance (ANOVA)]. In post-LASIK corneas, the measurement was significantly different among those achieved by 4 methods (P < 0.001, 1-way ANOVA). Orbscan measurement was thinner than those yielded by Galilei, Pentacam, or ultrasound pachymetry with average of 47.7, 38.5, and 34.4 µm, respectively (all P values < 0.001, 1-way ANOVA and the Tukey multiple comparisons test) in post-LASIK corneas. Orbscan, Pentacam, and Galilei measurements showed good agreement with ultrasound pachymetry data in both groups, except Orbscan data in post-LASIK corneas showed a statistically significant difference from ultrasound pachymetry measurements (P value = 0.001, 1-way ANOVA and the Tukey multiple comparisons test). CONCLUSIONS: Any of central corneal thicknesses obtained by all 4 measurement modalities might be acceptable before refractive surgery. However, in post-FS-LASIK eyes, measurements using Orbscan were thinner than those obtained with other modalities; in contrast, those with Pentacam or Galilei were comparable with ultrasound pachymetry.

Treatment of corneal opacity by planned lamellar keratectomy using the femtosecond laser.

PURPOSE: To report successful vision restoration after lamellar keratectomy using a femtosecond (FS) laser in a patient with superficial corneal opacity that developed after an episode of epidemic keratoconjunctivitis. METHODS: A 19-year-old girl with corneal opacity in the left eye was referred to our department for treatment. The opacity was principally located within the superficial anterior cornea. To remove the opacity with minimization of change in the keratometric value, we performed lamellar keratectomy with the aim of creating a 100-µm-thick flap, using an FS laser (IntraLase FS; AMO, Irvine, CA). RESULTS: Postoperatively, corneal opacity was removed and vision improved. Six months after surgery, the corneal surface was stable and smooth, and no corneal haze was observed. The keratometric value measured by corneal topography and manifest refraction showed no hyperopic shift postoperatively. CONCLUSIONS: This report indicates that the FS laser may be an effective surgical tool for the treatment of patients with corneal opacity and that hyperopic shift is not of concern.

The usefulness of the "double-needle" technique for combined cataract extraction and corneal transplantation.

The authors report using double-needle cataract extraction in the course of triple surgery and describe the usefulness of a double-needle technique. Before penetrating preparation of the recipient cornea, two straight double-arm 10-0 Prolene needles (Ethicon, Edinburgh, Scotland) were inserted in parallel on the recipient corneal bed transcorneally immediately anterior to the iris. The use of two needles stabilized the iris plane and offset positive vitreous pressure during triple surgery, continuous curvilinear capsulorrhexis, phacoemulsification, irrigation, and aspiration, allowing the safe implantation of an intraocular lens in the bag in an open-sky state. There were no procedural difficulties and no complications. This simple technique using double needles in triple surgery can be used effectively and may prevent forward movement of the lens-iris diaphragm, anterior capsular tearing, and rapid expulsion of the lens caused by positive vitreous pressure in the open-sky state.

Successful treatment of superficial corneal irregularity by lamellar keratectomy using the femtosecond laser.

The authors report successful vision restoration after cataract surgery using a femtosecond laser in a patient with superficial corneal irregularity. A 62-year-old man with corneal irregularity and a cataract in the left eye was referred for treatment. The superficial corneal opacity causing the irregularity was mainly located within the superficial anterior cornea. To acquire a stable keratometric value, which is important for accurate calculation of intraocular lens power, lamellar keratectomy using a femtosecond laser (IntraLase; AMO, Irvine, CA) was performed to smooth the cornea surface. Postoperatively, corneal smoothness was restored and a stable keratometric value was acquired. Vision was improved with the expected refraction after cataract surgery. The femtosecond laser may be an effective surgical tool for patients with superficial corneal irregularity and cataracts.

A new surgical technique: a femtosecond laser-assisted keratolimbal allograft procedure.

PURPOSE: To evaluate the feasibility of a femtosecond (FS) laser-assisted keratolimbal allograft (KLAL) technique. DESIGN: Interventional case series. METHODS: This study included 3 patients with extensive limbal stem cell deficiency. The donor cornea was dissected with an FS laser (IntraLase FS laser, 60 kHz) using a ring procedure, without outer side cutting for the limbal graft, after a penetrated dissection of the donor cornea prior to penetrating keratoplasty (PKP). The depth and width of the ring procedure were adjusted for each individual patient. Further extension to the periphery of the sclerocorneal tissue of the donor graft was performed with a diamond knife. In a case of KLAL alone, the unhealthy limbal tissue of the recipient was removed with the FS laser by the same method employed in donor preparation. One patient underwent KLAL alone, and 2 patients underwent KLAL combined with PKP. The patients were followed up for a maximum of 10 months. RESULTS: Limbal grafts were even and thin, as expected. The case with KLAL alone showed the fastest epithelization of the recipient cornea. The 2 cases of combined KLAL and PKP showed excellent approximation between recipient and donor tissue. The ocular surfaces have been stable for 8 months in case 1 and 10 months in cases 2 and 3. CONCLUSION: FS laser-assisted KLAL has potential advantages in terms of simplicity and speed as compared with conventional techniques.

A novel technique: eccentric lamellar keratolimbal allografting using a femtosecond laser.

PURPOSE: To report on a patient who received an eccentrically designed lamellar keratolimbal allograft prepared using a femtosecond (FS) laser to preserve peripheral curvature. METHODS: A 19-year-old woman, with a pseudopterygium on the left eye resulting from dermoid excision about 11 years earlier, received an eccentric lamellar keratolimbal allograft in a procedure involving FS laser use. Corneal flaps of depths 280 and 400 mum and diameters 6.5 and 6.6 mm were eccentrically created by FS laser treatment of the recipient and donor eyes, respectively, after removal of the pseudopterygium. After amniotic membrane transplantation, the eccentrically designed corneal flap was secured with 10-0 nylon sutures. RESULTS: Corneal flap creation was uneventful. Only minimal suturing was required for lamellar keratoplasty, and no complications occurred. Twelve months after surgery, a stable corneal surface was observed, with minimal scar formation at the graft margin and relatively good graft interface clarity. CONCLUSION: Eccentric lamellar keratolimbal allografting using an FS laser is an effective and time-saving surgical method to treat peripheral corneal abnormalities featuring corneal opacity.

The effect of femtosecond laser lamellar dissection at various depths on corneal endothelium in the recipient bed of the porcine eye.

BACKGROUND AND OBJECTIVE: To evaluate the effect of femtosecond laser lamellar dissection on corneal endothelium ultrastructure and viability. MATERIALS AND METHODS: Newly enucleated porcine eyes (N = 32) were used. The eyes were divided into four groups and a 7.5-mm diameter corneal lamellar dissection with the same size side cut at various depths was performed using a 60-kHz femtosecond laser with raster and spiral lamellar pattern. The endothelium was examined using scanning electron microscopy and light microscopy with Alizarin red staining. RESULTS: All four groups showed similar corneal endothelial cell morphology and viability at the center of the endothelium regardless of the lamellar cut pattern (P > .05). In groups 2 and 3, linear dotted endothelial cell damage or folding correlating with the side cut was observed. CONCLUSION: Using femtosecond lasers for stromal dissection and side cutting was safe for the central endothelium and caused only minimal damage to the peripheral endothelium, regardless of the laser emission pattern.

Femtosecond laser lamellar keratoplasty to aid visualization for cataract surgery.

PURPOSE: To describe a new surgical technique for a patient with cataract combined with corneal opacity. METHODS: This technique, femtosecond laser-assisted cataract surgery, was performed on a patient with a history of corneal opacity in both eyes from childhood. Because the patient had deep stromal corneal opacity, a corneal button 400-mum thick was made for lamellar keratoplasty while cataract surgery was performed simultaneously. RESULTS: Lifting of the flap and removal of the corneal button before cataract surgery was successful without any intraoperative complications. CONCLUSIONS: Femtosecond laser-assisted cataract surgery is a promising surgical procedure for a cataract patient with stromal corneal opacity.

The comparison of femtosecond laser-assisted penetrating keratoplasty with conventional surgery in terms of endothelial safety: ex vivo study using porcine eyes.

PURPOSE: To evaluate the effect of using femtosecond (FS) laser technology for penetrating keratoplasty (PK) in terms of corneal graft endothelial ultrastructure and viability in porcine eyes. METHODS: Thirty-two freshly enucleated porcine eyes were divided into 4 equal groups (n = 8): group 1, incomplete penetration using the FS laser (a 100 microm-depth from the endothelial side remained); group 2, complete penetration using the FS; group 3, trephination using a vacuum trephine until the aqueous humor appeared; group 4, no treatment (control group). For groups 1 and 2, side cuts were performed using a 60-kHz FS laser (IntraLase FS Laser, Abbot Medical Optics, Abbott Park, IL). Preoperative ultrasound pachymetry was used to make measurements at 5 positions. Scanning electron microscopy (SEM) was used to determine morphological changes, and light microscopy with Alizarin red staining was used to determine the amount of cell death. RESULTS: Preoperative corneal thicknesses were similar for all groups. All 4 groups showed similar corneal endothelial cell morphology and viability at the graft center (P = 0.15, Kruskal-Wallis test). At the graft border, endothelial cell damage was minor in group 1, moderate in group 2, and most severe and diffuse in group 3 (P = 0.009, Kruskal-Wallis test). CONCLUSIONS: FS laser use is safe for the endothelium at the graft center and has less harmful effects on the endothelium at the incision area than does conventional trephination. Therefore, FS laser-assisted corneal grafts with complete penetration seems to be the optimum choice for preserving endothelial cells during PK.

New surgical strategy for corneal tattooing using a femtosecond laser.

PURPOSE: The purpose of this study was to describe a new method of femtosecond (FS) laser-assisted corneal tattooing and to report the results of this method in a case series. METHODS: The study involved 6 eyes of 6 patients with total or partial corneal opacity. An FS laser was used for lamellar dissection and to make a side cut with a hinge, creating a corneal flap. Laser parameters were adjusted depending on ocular condition and the location of the corneal opacity. After lifting the corneal flap, further lamellar dissection with a diamond blade was performed up to the periphery of the limbal area. Using a cannula, dye was injected into the lamellar stromal bed and the space of the lamellar dissected pocket in the limbus, after which the flap was repositioned. RESULTS: The design and application of the FS laser for dissection and flap creation were successful in all cases. There were no significant complications other than an incomplete cut under band keratopathy in 1 eye. The cosmetic effects were satisfactory in all cases. No patient complained of pain for more than 1 day after surgery. CONCLUSIONS: The advantages of the FS laser-assisted corneal tattooing include a customized design, speed, decreased pain, reduced risk of perforation, and good wound healing. This procedure provides improvements over current corneal tattooing techniques, although it is relatively expensive.

Different epithelial cleavage planes produced by various epikeratomes in epithelial laser in situ keratomileusis.

PURPOSE: To determine the anatomic cleavage planes produced by various epikeratomes in epithelial laser in situ keratomileusis (epi-LASIK). SETTING: Department of Ophthalmology, IIsan Paik Hospital, Goyang, Korea. METHODS: Sixteen eyes (8 patients) were included in this study. Three epikeratomes, the Moria Epi-K, Centurion SES, and Amadeus II, were used to collect 4 epithelial flaps from 2 patients in the epi-LASIK procedure. Four epithelial flaps from 2 patients were also obtained by laser-assisted subepithelial keratectomy (LASEK). Immunohistochemical staining using monoclonal antibodies against integrin beta1, integrin beta4, laminin 5, and collagen type VII was performed. RESULTS: Immunohistochemical staining showed expression of integrin beta1 and integrin beta4 in all epithelial flaps. In epi-LASIK, the expression of laminin 5 and collagen type VII had a linear or dotted pattern that differed based on the epikeratome used. In the epithelial flaps obtained using LASEK, the expression of laminin 5 and collagen type VII had a dotted pattern. CONCLUSIONS: Each epikeratome yielded reproducible but different cleavage planes of corneal epithelium. The results suggest that further study is needed to elucidate the wound-healing process after epi-LASIK because different cleavage planes produced by different epikeratomes may influence the process.

Creation of an extremely thin flap using IntraLase femtosecond laser.

A 43-year-old woman had laser in situ keratomileusis (LASIK) using the IntraLase femtosecond laser (IntraLASIK) to create 110 microm flaps. Despite uneventful flap formation, the flaps in both eyes were extremely thin, making it difficult to lift them. The flap in the right eye resembled an epi-LASIK epithelial flap. It was lifted uneventfully. The flap in the left eye was stretched and torn on lifting, and the procedure was therefore postponed. After 6 months, the IntraLASIK surgical procedure was repeated in the left eye using a thicker and smaller flap than in the first procedure. Despite the improvements associated with using an IntraLase femtosecond laser, thinner-than-intended corneal flaps can occur. Early recognition of such a flap can prevent further complications.