Femtosecond Laser-Assisted Penetrating Keratoplasty for Treating Infective Keratitis.

PURPOSE: To report the results of penetrating keratoplasty (PKP) assisted by femtosecond laser in the treatment of persistent infective keratitis. METHODS: Seven eyes of 7 patients with diagnosed infective keratitis were recruited. They showed no improvement on maximal medical therapy for a week. The causative organisms were Pseudomonas aeruginosa in 3 cases and Fusarium in 4 cases. All cases underwent femtosecond laser-assisted PKP with a mushroom-shaped cut. Postoperative antimicrobial medications were continued for 8-12 weeks. Sutures were removed after 6 months. Therapeutic success was defined as eradication of primary infection. Functional success was considered when visual function improves to 20/200 or better. RESULTS: All 7 eyes underwent femtosecond laser-assisted PKP. There were no intraoperative complications, and all patients had uneventful recipient cornea separation. Anatomic, therapeutic, and functional success was achieved in all patients. During the 6-month follow-up period, no recurrence of infection was reported. The average preoperative corrected distance visual acuity (CDVA) was 2.07 log of the minimal angle of resolution (LogMAR) ± 0.21, whereas at 6 months postoperatively, the average CDVA was 0.17 LogMAR ± 0.13, with a P value of 0.00025. CONCLUSIONS: Femtosecond laser-assisted PKP was found to be an effective method for treating infective keratitis (particularly that caused by Pseudomonas aeruginosa and Fusarium) that did not respond to medical treatment. Early surgical intervention before the disease becomes advanced is recommended.

Management of dislocated nucleus with corneal opacity by combined deep anterior lamellar keratoplasty, pars- plana vitrectomy and phaco-fragmentation.

A 32-year-old man presented with bilateral diminution of vision for 10 years. Visual acuity was light perception in both eyes with inaccurate projection in the oculus dextrus(OD) and accurate projection in the in oculus sinister (OS). Intraocular pressure was 6 and 12 mm Hg in the OD and OS, respectively. Slit-lamp examination revealed the presence of leucomatous corneal opacification with microcornea in oculus uterque (OU). Both eyes had a dislocated nucleus in the vitreous cavity on ultrasound B-scan with advanced cupping in the right eye. Ultrasound biomicroscopy revealed ciliary body atrophy in the OD and preserved ciliary processes (two quadrants) in the OS. In view of a partially preserved ciliary body function and a potential for gaining useful vision, we planned surgical intervention in the left eye. Deep anterior lamellar keratoplasty with pars planavitrectomy (PPV) and phacofragmentation of the nucleus was done. Donor lamellar graft was sutured after completion of PPV and nucleus fragmentation. The patient regained useful ambulatory vision postoperatively with clear corneal graft.

Corneal neovascularization: updates on pathophysiology, investigations & management.

Objective. Corneal neovascularization is a sight-threatening condition affecting more than 1.4 million people per year. Left untreated, it can lead to tissue scarring, oedema, lipid deposition, and persistent inflammation that may significantly affect visual prognosis and quality of life. The aim was to review the recent evidence relating to the pathophysiology, investigations and management of corneal neovascularization. Methods. Literature review of prospective and retrospective studies, clinical trials and animal models relating to the pathophysiology, investigation and management of corneal neovascularization. Results. Corneal neovascularization is characterized by the invasion of new blood vessels into the cornea caused by an imbalance between angiogenic and antiangiogenic factors that preserve corneal transparency as a result of various ocular insults and hypoxic injuries. Risk factors that have been implicated in the pathogenesis of the disease include contact lens wear, ocular surface disease, trauma, previous surgery and herpes. The results highlighted the current and future management modalities of corneal neovascularization, which includes corneal transplantation, laser - phototherapy, injections and topical treatment. Conclusion. The future of corneal neovascularization is promising and this paper discusses the upcoming revolution in local gene therapy. Abbreviations. HSK = herpes stromal keratitis, VEGF = vascular endothelial growth factor, VEGFR-1 = VEGF Receptor-1, FGF = Fibroblast growth factor, PDGF = Platelet-derived growth factor, IL-6 = interleukin-6, IL-7 = interleukin-7, IL-8 = interleukin-8, IRS-1 = insulin receptor substrate-1.

Comparison Between Polymicrobial and Fungal Keratitis: Clinical Features, Risk Factors, and Outcome.

PURPOSE: To compare the clinical features, risk factors, and outcome of polymicrobial keratitis with monomicrobial keratitis due to fungus. DESIGN: Retrospective, comparative interventional case series. METHODS: Consecutive cases of microbial keratitis with significant growth of more than 1 organism in culture and culture-proven fungal keratitis treated with natamycin alone were retrieved from the microbiology department. Complete success was defined as resolution of the infiltrate with scar formation on medical treatment, partial success as resolution following tissue adhesive application, and failure as inadequate response to medical therapy with increasing infiltrate size, corneal melting, and/or perforation necessitating therapeutic penetrating keratoplasty (PKP) or evisceration. RESULTS: There were 34 eyes of 34 patients with polymicrobial keratitis and 60 cases of fungal keratitis. Compared to patients with fungal keratitis, patients with polymicrobial keratitis were significantly older (50.03 ± 9.81 years vs 42.79 ± 12.15 years, P = .0038), with larger infiltrates at presentation (61.8% vs 24.1%, P = .0007), a higher association with endophthalmitis (11.8% vs 0%, P = .03), previous history of corneal graft (20.6% vs 0%, P = .0012), and prior topical corticosteroid use (23.5% vs 5%, P = .019). In the polymicrobial group, a combination of bacteria and fungus was more frequently isolated (23, 67.6%), among which filamentous fungi (25, 39.1%) and coagulase-negative staphylococci (14, 21.9%) comprised a majority. Complete success was significantly lower in the polymicrobial group compared to the fungal keratitis group (39.3% vs 73.7%, P = .0045). In multivariate logistic regression analysis comparing factors affecting the outcome between the 2 groups, older age (P = .027) and ulcers larger than 6 mm (P = .001) at presentation adversely affected outcome. CONCLUSIONS: Polymicrobial keratitis with fungus and bacteria was more common and more challenging to treat, with a poorer outcome than fungal keratitis. Medical treatment may be effective; however, therapeutic PKP provided globe salvage at best. Early PKP may be advocated for larger ulcers at presentation.

Therapeutic sectorial full-thickness sclero-keratoplasty for recurrent fungal keratitis.

OBJECTIVE: To report the management of a severe and recurrent fungal keratitis that required repeated penetrating keratoplasties. Despite multiple topical, intraocular and systemic antifungal treatments, superotemporal hyphal infiltration repeatedly penetrated the corneal transplant causing continuous recurrences. Cultures collected before and during surgery isolated the same organism, Fusarium spp. CONCLUSION: Corneal infection extending to the sclera and internal angle structures is the main cause of recurrence of fungal keratitis after corneal transplantation. Sectorial full-thickness sclero-keratoplasty combined with a central penetrating keratoplasty should be a surgical technique to be considered in cases where these locations are suspected to be the source of recurrence. It enables a definitive elimination of the infection, with excellent final visual acuities. No postoperative complications were reported in this case.

Excimer laser mushroom penetrating keratoplasty: new technique.

PURPOSE: To evaluate retrospectively the outcomes of 15 consecutive mushroom-shaped penetrating keratoplasties performed by using excimer laser for both the recipient bed and the fresh donor corneas. METHODS: Fifteen eyes of 14 patients who underwent excimer laser mushroom-shaped penetrating keratoplasty from October 13, 2010, to October 14, 2011, were included in our retrospective study. Eight were men and 6 were women, with a mean age of 31.45 ± 6.52 (range 27-65) years. Eleven (73.3%) had postinfective central deep corneal scar; 4 (26.7%) had severe keratoconus with Descemet opacity. RESULTS: The mean follow-up was 11.9 ± 2.7 months. The mean preoperative best-corrected visual acuity (BCVA) was 0.15 ± 0.16; the postoperative BCVA was 0.69 ± 0.24 after 12 months with a mean refractive astigmatism of 1.8 ± 1.1 D. The mean preoperative endothelial cell count of the donor corneas was 2297.0 ± 189.7 cells/mm²; after 12 months, it was 1906.5 ± 165.8 with a decrease of 17.0%. No intraoperative complications occurred. CONCLUSIONS: Our results showed that excimer laser mushroom penetrating keratoplasty is safe. Furthermore, it does not appear to influence the visual outcomes of the penetrating keratoplasty surgery. This technique is useful for those who use an excimer laser.

Penetrating keratoplasty for perforated corneal ulcers under topical anesthesia.

PURPOSE: To evaluate the structural and functional outcomes of eyes with perforated corneal ulcers undergoing penetrating keratoplasty (PKP) under topical anesthesia. METHODS: A prospective analysis of 17 consecutive cases that underwent PKP under topical anesthesia, where infiltrative anesthesia was contraindicated or general anesthesia could not be given for medical reasons or was not available for logistical reasons. RESULTS: Seventeen eyes of 15 patients with a mean age of 47.3 ± 16.2 years underwent a PKP for treating perforated corneal ulcers under topical anesthesia. Perforation involved the pupillary zone in 13 (76.5%) cases. Preoperatively, 8 patients (47.1%) were phakic, 8 (47.1%) were pseudophakic, and 1 (5.9%) was aphakic. The PKP was completed successfully in all the eyes. An anterior capsular tear occurred in 3 eyes (17.6%). A posterior chamber intraocular implant was put in 1 eye, and 2 eyes were found to be aphakic. The patients reported mild to moderate discomfort and tolerated the procedure well. At the final follow-up, 10 patients had clear grafts (58.8%), and 7 patients (41.2%) had partially clear grafts. The best-corrected visual acuity was better than 6/18 in 10 eyes and between 6/60 and 6/24 in 7 eyes. CONCLUSIONS: PKP can be performed successfully under topical anesthesia in cooperative patients who have perforated corneal ulcers.

Femtosecond laser (WaveLight FS200) customized keratoplasty for keratoconus: case report.

PURPOSE: To describe a case of a 52-year-old man with severe keratoconus who underwent femtosecond laser-assisted keratoplasty with the WaveLight FS200 femtosecond laser (Alcon Laboratories Inc). METHODS: The donor and recipient corneas were cut in a mushroom-shaped pattern. The laser parameters used on this platform for the donor and recipient corneas are described. RESULTS: Corrected distance visual acuity improved by 3 weeks postoperatively. Mean keratometry decreased from 60.00 to 46.00 diopters. CONCLUSIONS: This patient underwent a mushroom-shaped keratoplasty with the femtosecond laser to maximize preservation of his own endothelium. Increased energy and/or decreased spot line separation may be required depending on the degree of corneal edema or scarring involved.

Femtosecond laser-assisted keratoplasty: laboratory studies in eye bank eyes.

PURPOSE: To optimize the surgical technique for performing femtosecond laser-assisted keratoplasty (FLAK) using the IntraLase FS to cut both recipient and donor cornea buttons in eye bank globes. METHODS: FLAK was performed in six globes and six corneoscleral buttons for each of the following trephination patterns: top hat, mushroom, tongue-groove, and vertical. Manual trephination was performed as control. The wound integrity was tested in incisions closed with 8 sutures, 8 sutures with fibrin adhesive, and 16 sutures by measuring the intraocular pressure required to produce graft-host wound leakage (IOP(L)). Light microscopy (LM) and scanning electron microscopy (SEM) were performed to assess cut surface quality and graft-host interface regularity. RESULTS: Mushroom and top hat FLAK had significantly higher IOP(L) than vertical or manual trephination (p < 0.0001) for wounds closed with 16 sutures. There was no difference in IOP(L) between top hat, mushroom, and tongue-groove FLAK in wounds closed with 8 sutures with fibrin adhesive (p > 0.75). LM and SEM demonstrated cut surfaces with good quality and smooth edges. CONCLUSIONS: These preliminary studies show that FLAK produces precise trephination cuts of superior wound strength and stability to that of manual trephination. Adjuvant fibrin glue may further improve wound integrity.

Safety of incomplete incision patterns in femtosecond laser-assisted penetrating keratoplasty.

PURPOSE: To evaluate the wound integrity of incomplete contoured corneal incisions created with a femtosecond laser at a refractive surgery center followed by subsequent patient transfer to a separate surgical facility for penetrating keratoplasty (PKP). SETTING: Private tertiary referral center, Indianapolis, Indiana, USA. METHODS: This retrospective consecutive interventional case series comprised 46 eyes that had femtosecond laser PKP. Incomplete contoured incisions were created in the recipient cornea at a refractive surgery center. Patients were then transferred to an ambulatory surgical center for PKP. RESULTS: The indications for PKP included keratoconus, corneal scarring, bullous keratopathy, corneal dystrophy, and failed graft. Three incision contours were used: top hat (n=26), mushroom (n=13), and zigzag (n=7). The incomplete portion of the incision was 70.0 to 300.0 microm in length. Leaving 150.0 to 300.0 microm of the lamellar ring cut incomplete did not ensure wound stability, whereas leaving 70.0 to 75.0 microm of the anterior side cut or posterior side cut incomplete provided excellent wound stability. In all eyes, the partial-thickness incisions enabled safe transport of the patient to the operating room without wound rupture, even with subsequent placement of a retrobulbar injection and a Honan balloon. CONCLUSION: Incomplete femtosecond laser incision patterns that left some collagen lamellae intact maintained sufficient corneal strength to allow safe movement of the patient to a surgical facility for PKP.

Peribulbar anaesthesia for penetrating keratoplasty. A case series.

PURPOSE: To prospectively analyse the efficacy and safety of peribulbar anaesthesia for penetrating keratoplasty through a noncomparative, consecutive series. METHODS: One hundred twenty-four (91.1%) of 136 patients undergoing penetrating keratoplasty (PK) from January 1997 to December 2001, were administered peribulbar anaesthesia. The anaesthetic mixture consisted 5 ml of lignocaine, bupivacaine, and hyaluronidase (to avoid evaluation bias) in the peribulbar space. A repeat injection of 3 ml was used if the primary injection was inadequate. Digital ocular compression was done for 10-15 minutes after the first injection. Each patient was analysed for degree of akinesia, subjective patient comfort, analgesia, subjective surgeon comfort, and types of surgical conditions. RESULTS: The age ranged from 19 to 86 years. Forty-nine of 124 patients (39.5%) received PK only and remaining 75 patients (60.5%) received additional procedures. A single injection was sufficient to achieve adequate akinesia (grade II and III) in 114 (92%) patients and 120 (97%) of patients were satisfied (graded pain as < or = grade II). During surgery, 6 (5%) phakic eyes developed episodes of positive intraocular pressure and 5 eyes (4%) developed chemosis. There were no other local or systemic adverse events. The surgeon level comfort was (grade II or more) 98% (122 of 124). CONCLUSION: One-point, low volume, peribulbar anaesthesia for penetrating keratoplasty is safe and efficacions.

Thermal effects in excimer laser trephination of the cornea.

BACKGROUND: Excimer laser trephination, as an alternative to mechanical trephination of the cornea in penetrating keratoplasty, is expected to reduce long-term postkeratoplasty astigmatism. Trephination with high energy densities may induce thermal epithelial alterations when metal aperture masks are used. METHODS: Ninety porcine eyes fixed in an artificial anterior chamber (20 mmHg) were trephined with a 193-nm excimer laser in order to study the effect of the temperature on the cornea and the aperture mask during and after termination of the laser exposure. Energy levels tested were in the range used in patients. A pyroelectric infrared sensor connected to a PC via an analog-digital converter was used. With a high-speed sampling routine written in C+2 it was possible to monitor on line the temperature in a focus 0.8 mm in diameter. RESULTS: In donor trephination the maximum temperature increase of the metal mask was 11 K (donor tissue 6.1 K, repetition rate 30/s). During recipient trephination the maximum temperature increase of the mask was 9.4 K (7.5 K on the cornea). An increase in the repetition rate and a decrease in the rotation speed resulted in greater temperature increase of the exposed cornea or metal mask. CONCLUSIONS: Online monitoring of cornea and mask surface temperatures during excimer laser trephination is possible using high-speed sampling equipment. Appropriate adjustment of repetition rate and rotation speed may reduce thermal effects, especially in donor trephination.