Simultaneous conventional photorefractive keratectomy and corneal collagen cross-linking for pellucid marginal corneal degeneration.

PURPOSE: To present the results after simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking for pellucid marginal corneal degeneration. METHODS: In this prospective, interventional case series, 6 patients (8 eyes) with pellucid marginal corneal degeneration were enrolled. All patients underwent simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking; corneal epithelium was removed by transepithelial phototherapeutic keratectomy during treatment (Cretan protocol plus conventional photorefractive keratectomy). Visual and refractive outcomes were evaluated along with endothelial cell density preoperatively and at 1, 3, 6, and 12 months postoperatively. RESULTS: No intraoperative or postoperative complications were observed in any of the patients. LogMAR mean uncorrected distance visual acuity improved significantly from 1.05 ± 0.33 preoperatively to 0.41 ± 0.27 (P = .018) at 12 months postoperatively. Mean corrected distance visual acuity did not change significantly (P > .05) postoperatively. Mean spherical equivalent improved significantly from -3.52 ± 2.29 diopters preoperatively to -1.57 ± 1.76 diopters (P = .028) at last follow-up. Mean corneal astigmatism was significantly reduced from -6.83 ± 2.33 diopters preoperatively to -4.71 ± 1.89 diopters (P = .018) at the last follow-up. No endothelial cell density alterations were observed throughout the follow-up period (P > .05). CONCLUSIONS: Simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking seems to be an effective, safe, and promising treatment for the management of pellucid marginal corneal degeneration.

Topography-guided transepithelial PRK after intracorneal ring segments implantation and corneal collagen CXL in a three-step procedure for keratoconus.

PURPOSE: To present the results of topography-guided transepithelial photorefractive keratectomy (PRK) after intracorneal ring segments implantation followed by corneal collagen cross-linking (CXL) for keratoconus. METHODS: In this prospective case series, 10 patients (16 eyes) with progressive keratoconus were included. All patients underwent topography-guided transepithelial PRK after Keraring intracorneal ring segments (Mediphacos Ltda) implantation, followed by CXL treatment. The follow-up period was 6 months after the last procedure for all patients. Time interval between both intracorneal ring segments implantation and CXL and between CXL and topography-guided transepithelial PRK was 6 months. RESULTS: LogMAR mean uncorrected distance visual acuity and mean corrected distance visual acuity were significantly improved (P<.05) from 1.14±0.36 and 0.75±0.24 preoperatively to 0.25±0.13 and 0.13±0.06 after the completion of the three-step procedure, respectively. Mean spherical equivalent refraction was significantly reduced (P<.05) from -5.66±5.63 diopters (D) preoperatively to -0.98±2.21 D after the three-step procedure. Mean steep and flat keratometry values were significantly reduced (P<.05) from 54.65±5.80 D and 47.80±3.97 D preoperatively to 45.99±3.12 D and 44.69±3.19 D after the three-step procedure, respectively. CONCLUSIONS: Combined topography-guided transepithelial PRK with intracorneal ring segments implantation and CXL in a three-step procedure seems to be an effective, promising treatment sequence offering patients a functional visual acuity and ceasing progression of the ectatic disorder. A longer follow-up and larger case series are necessary to thoroughly evaluate safety, stability, and efficacy of this innovative procedure.

Femtosecond laser technology in corneal refractive surgery: a review.

PURPOSE: To discuss current applications and advantages of femtosecond laser technology over traditional manual techniques and related unique complications in corneal refractive surgical procedures, including LASIK flap creation, intracorneal ring segment implantation, astigmatic keratotomy, presbyopic treatments, and intrastromal lenticule procedures. METHODS: Literature review. RESULTS: From its first clinical use in 2001 for LASIK flap creation, femtosecond lasers have steadily made a place as the dominant flap-making technology worldwide. Newer applications are being evaluated and are increasing in their frequency of use. CONCLUSIONS: Femtosecond laser technology is rapidly becoming a heavily utilized tool in corneal refractive surgical procedures due to its reproducibility, safety, precision, and versatility.

Efficacy of Topical Nepafenac 0.3% in the Management of Postoperative Cystoid Macular Edema.

PURPOSE: To assess the effect of twice-daily nepafenac ophthalmic suspension 0.3% on postoperative cystoid-macular-edema (CME). PATIENTS AND METHODS: In this prospective, clinic-based, non-randomized case-series, 21 patients (21 eyes) were enrolled with either acute or chronic postoperative CME after cataract extraction. Patients were treated with twice-daily nepafenac 0.3% drops, and followed for at least a 4-month period. Best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT)-derived central retinal thickness (CRT) were measured. RESULTS: From 21 patients, eight presented with acute postoperative CME and 13 with chronic CME. Mean follow-up was 4.82±1.24 months. No adverse events were reported during the study. Baseline BCVA was 0.49±0.36 logMAR and improved to 0.36±0.42 logMAR at the last follow-up visit (P<0.005). CRT decreased from 450.40±90.74 µm at baseline to 354.60±81.49 µm (P<0.05), following treatment. CONCLUSION: Our outcomes strongly suggest that administrating nepafenac 0.3% drops on a twice-daily regimen could be a promising alternative for the management of postoperative CME. Additional studies are necessary to further validate our results.

Femtosecond Laser-Assisted Intra-Corneal Drug Delivery.

PURPOSE: To present a case of fungal keratitis that was successfully treated with direct intrastromal medication delivery through a corneal incision created with the femtosecond laser. METHODS: A 71-year-old female patient with recurrent episodes of an unresponsive, deep stromal keratitis for six months' duration, resistant to various therapeutic approaches, was referred to our institute. The 150 kHz Intralase iFS laser (Abbott Medical Optics Inc., Santa Ana, CA) was used to create a corneal pocket in an attempt to permit drug delivery directly into the corneal abscess. RESULTS: Five days after the intrastromal injections, the clinical condition was improved. Two years after the procedure, the cornea is stable and free of any clinical signs or symptoms of recurrence. CONCLUSIONS: In this case report, an alternative application of femtosecond laser technology is presented, performing intrastromal drug delivery through a corneal incision for the treatment of fungal keratitis.

Corneal stroma demarcation line after standard and high-intensity collagen crosslinking determined with anterior segment optical coherence tomography.

PURPOSE: To use anterior segment optical coherence tomography (AS-OCT) to compare corneal stroma demarcation line depth after corneal collagen crosslinking (CXL) with 2 treatment protocols. SETTING: Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece. DESIGN: Prospective comparative interventional case series. METHODS: Corneal collagen crosslinking was performed in all eyes using the same ultraviolet-A (UVA) irradiation device (CCL-365). Eyes were treated for 30 minutes with 3 mW/cm(2) according to the standard Dresden protocol (Group 1) or for 10 minutes with 9 mW/cm(2) of UVA irradiation intensity (Group 2). One month postoperatively, 2 independent observers measured the corneal stroma demarcation line using AS-OCT. RESULTS: Sixteen patients (21 eyes) were enrolled. Group 1 comprised 7 patients (9 eyes) and Group 2, 9 patients (12 eyes). The mean corneal stroma demarcation line depth was 350.78 µm ± 49.34 (SD) (range 256.5 to 410 µm) in Group 1 and 288.46 ± 42.37 µm (range 238.5 to 353.5 µm) in Group 2; the corneal stroma demarcation line was statistically significantly deeper in Group 1 than in Group 2 (P=.0058, t test for unpaired data). CONCLUSION: The corneal stroma demarcation line was significantly deeper after a 30-minute CXL treatment than after a 10-minute CXL procedure with high-intensity UVA irradiation.

Correlation of the corneal collagen cross-linking demarcation line using confocal microscopy and anterior segment optical coherence tomography in keratoconic patients.

PURPOSE: To evaluate and compare the depth of the corneal stromal demarcation line after corneal collagen cross-linking (CXL) using 2 different methods: confocal microscopy and anterior segment optical coherence tomography (AS OCT). DESIGN: Prospective, comparative, interventional case series. METHODS: Seventeen patients (18 eyes) with progressive keratoconus were enrolled. All patients underwent uneventful CXL treatment according to the Dresden protocol. One month after surgery, corneal stromal demarcation line depth was measured in all patients by 2 independent observers using confocal microscopy and AS OCT. RESULTS: Mean corneal stromal demarcation line depth measured using confocal microscopy by the first observer was 306.22 ± 51.54 µm (range, 245 to 417 µm) and that measured by the second observer was 303.5 ± 46.98 µm (range, 240 to 390 µm). The same measurements using AS OCT were 300.67 ± 41.56 µm (range, 240 to 385 µm) and 295.72 ± 41.01 µm (range, 228 to 380 µm) for the first and second observer, respectively. Pairwise comparisons did not reveal any statistically significant difference between confocal microscopy and AS OCT measurements for both observers (P = .3219 for the first observer and P = .1731 for the second observer). CONCLUSIONS: Both confocal microscopy and AS OCT have similar results in evaluating the depth of the corneal stromal demarcation line after CXL.

Femtosecond laser-assisted intracorneal biopolymer insertion for the symptomatic treatment of bullous keratopathy.

PURPOSE: To describe a new minimally invasive surgical technique for the symptomatic management of bullous keratopathy in blind eyes. METHODS: Four patients with severe corneal edema due to endothelial decompensation and no visual function in the affected eye presented for the relief of their ocular symptoms (pain and tearing). Femtosecond laser technology was used to create a deep corneal pocket into which silicone oil was inserted. RESULTS: After the procedure, all patients demonstrated immediate relief of their symptoms, along with restoration of a normal corneal surface 7 days after the procedure (no bullae and no epithelial defects). All patients remained free of symptoms during the entire follow-up period (from 24 to 31 months). Anterior to the inserted implant, the corneal lamellae remained compact, transparent, and without bullae; whereas the posterior corneal stroma under the implant was edematous. No intraoperative or postoperative complications were noted. CONCLUSIONS: Intracorneal insertion of silicone oil is a feasible new technique for the symptomatic treatment of bullous keratopathy in blind eyes.

Interface lamellar keratitis induced by a post-Descemet stripping automated endothelial keratoplasty corneal trauma.

A 78-year-old female patient suffering from Fuchs endothelial dystrophy had uneventful Descemet stripping automated endothelial keratoplasty (DSAEK) on the right eye. One and a half months postoperatively, she underwent a corneal foreign body trauma and was referred to our clinic, complaining about vision deterioration. Slit-lamp examination revealed a severe and diffuse interface lamellar keratitis between the DSAEK graft and the recipient's cornea without any signs of graft dysfunction. Intensive treatment with local corticosteroids was applied immediately, resulting in prompt improvement of both visual acuity and clinical condition. A new clinical entity, described as interface lamellar keratitis after corneal trauma in a DSAEK patient, is presented. Early diagnosis and appropriate intensive treatment with local corticosteroids are essential to successfully address this uncommon post-DSAEK complication.

Evaluation of the corneal collagen cross-linking demarcation line profile using anterior segment optical coherence tomography.

PURPOSE: To evaluate the depth of the stromal demarcation line after corneal collagen cross-linking (CXL) using anterior segment optical coherence tomography. METHODS: In this prospective, interventional case series, 23 patients (27 eyes) with progressive keratoconus were enrolled. All patients underwent uneventful CXL treatment. Corneal stromal demarcation line depth was measured centrally, 3 mm temporally, and 3 mm nasally by 2 independent observers using anterior segment optical coherence tomography at 1 month postoperatively in all patients. RESULTS: Mean depth of the corneal stromal demarcation line measured by the first observer was 310.67 ± 31.04 µm (range, 258-364 µm) centrally, 212.07 ± 24.5 µm (range, 178-279 µm) nasally, and 218.04 ± 21.91 µm (range, 191-261 µm) temporally. Mean depth of the corneal stromal demarcation line measured by the second observer was 308.78 ± 29 µm (range, 262-381 µm) centrally, 211.04 ± 23.93 µm (range, 180-277 µm) nasally, and 217.22 ± 25.51 µm (range, 179-271 µm) temporally. There was a statistically significant difference (P < 0.001) between central and both nasal and temporal depths of the corneal stromal demarcation line (paired samples t test) for both observers. There was no statistically significant difference between nasal and temporal corneal stromal demarcation line depths (paired samples t test, P > 0.05) for each observer. CONCLUSIONS: Mean depth of the corneal stromal demarcation line after CXL treatment is greater centrally in comparison with nasal and temporal depths.

Cross-linking as an adjuvant treatment for tectonic corneal lamellar graft preparation.

PURPOSE: To describe a new surgical approach for the tectonic reconstruction of the anterior ocular segment and the management of scleral and conjuctival melting. METHODS: Case series of patients demonstrating anterior segment anomalies, such as scleral and conjunctival melting. The anterior stromal part of a pre-cut corneal graft for Descemet's stripping automated endothelial keratoplasty (DSAEK) was cross-linked with riboflavin and ultraviolet A irradiation and was used to cover scleral (scleral melting in a patient with necrotizing scleritis, one case) and conjuctival (dehiscence of the conjunctiva in patients with anti-glaucomatous valve exposure, two cases) areas. The endothelial part of all corneal grafts was used for DSAEK in patients with need of corneal endothelial transplantation. RESULTS: Repair of scleral and conjuctival melting was successful in all cases. No intra- or post- operative complications occured. Visual acuity of all patients remained stable during the follow up period. One year postoperatively the corneal graft remained in place and no signs of inflammation were evident, while all grafts were epithelialized. CONCLUSIONS: The use of cross-linked corneal graft for the tectonic reconstruction of the anterior ocular segment represents an adequate surgical approach for the management of scleral and conjuctival melting; while, at the same time it offers the advantage of using one corneal graft for two recipients.

Treatment of inferior Descemet membrane detachment secondary to cataract surgery with air injection and supine head position.

PURPOSE: To describe a case of a patient with inferior Descemet membrane detachment that resolved after injection of small air bubble and supine positioning. METHODS: A patient presented two weeks after cataract surgery with inferior persistent corneal edema. A Descemet membrane detachment involving the inferior cornea was revealed. Injection of small air bubble was performed and the patient was advised to stay in a supine position for the next two hours and then as much as reasonably possible to allow the air bubble to press the Descemet to the posterior corneal stroma. RESULTS: Five days after injection, the Descemet membrane was reattached to the corneal stroma and the cornea became clear without any evidence of edema. One month post-air injection the cornea remained clear and the Descement membrane attached. CONCLUSIONS: Air injection with supine position was efficient for the resolution of inferior partial Descemet detachment after cataract surgery. The edema resolved without any further intervention.