Maximize Donor Cornea Use in a Hepatitis B Endemic Area via Serology Matching.

BACKGROUND: This study aims to investigate the rationality of the allocation guidelines in a hepatitis B endemic area that uses corneas from hepatitis B donors. METHODS: Under Taiwan's current guidelines, corneas donated from hepatitis B surface antigen (HBsAg)(+) donors can be allocated to HBsAg(+) or hepatitis B surface antibody recipients. From January 1, 2015, to December 31, 2019, corneas donated to National Taiwan University Hospital were divided into HBsAg(+), HBsAg(-)/hepatitis B core antibody (anti-HBc)(+), and HBsAg(-)/anti-HBc(-) groups. Hepatitis B virus (HBV) DNA extracted from corneoscleral rims was quantified by polymerase chain reaction and correlated with donor serum HBsAg, anti-HBc, and HBV DNA. Recipients of HBV DNA(+) grafts were called back for serology and serum HBV DNA tests. RESULTS: The corneoscleral HBV DNA of 170 corneas (113 donors) was quantified, of which 45 corneas were from 28 HBsAg(+) donors, 87 were from 57 HBsAg(-)/anti-HBc(+) donors, and 38 were from 28 HBsAg(-)/anti-HBc(-) donors, and HBV DNA was detected in 80.0%, 9.2%, and 0% of the corneoscleral rims in each group. Donor anti-HBc(+) provided the highest sensitivity (1.00) and negative predictive value (1.00) for corneoscleral HBV DNA. Twenty-eight of 40 recipients (70%) using HBV DNA(+) grafts were called back, and none developed hepatitis in follow-up periods ranging from 6 to 55.5 mo. CONCLUSIONS: Donor anti-HBc should be tested routinely with HBsAg. Allocating corneas from HBsAg(+) or anti-HBc(+) donors to HBsAg(+) or hepatitis B surface antibody recipients maximizes cornea usage from hepatitis B donors without compromising transplant safety in a hepatitis B endemic setting.

Long-term outcomes of penetrating keratoplasty for corneal complications of herpes zoster ophthalmicus.

BACKGROUND/AIM: To review the long-term outcomes of penetrating keratoplasty (PKP) for corneal complications of herpes zoster ophthalmicus (HZO). METHODS: We reviewed the medical records of 53 eyes of 53 patients who underwent PKP due to corneal complications of HZO at the Kellogg Eye Center. RESULTS: The mean age of patients at the time of PKP was 68.0±16.4 years, with a follow-up of 4.0±3.8 years and quiescent period of 6.5±5.3 years from active HZO to PKP. Preoperatively, 25 (47.2%) eyes were completely anaesthetic, while 16 (30.2%) had deep corneal neovascularisation in four quadrants. Comorbid ocular disease, including cataract, glaucoma and macular disease, was present in 25 (47.2%) eyes. Twenty patients (37.8%) received acyclovir for the entire postoperative period. There were no recurrences of zoster keratitis in any eye. The most common complications were difficulty healing the ocular surface (12/53, 22.6%) and glaucoma (14/53, 26.4%). Thirty per cent of the eyes required one or more additional postoperative procedures, most commonly tarsorrhaphy (10/53, 18.9%) and amniotic membrane graft (6/53, 11.3%). At 1, 2-4 and ≥5 years, 94%, 82% and 70% grafts remained clear, respectively. Visual acuity improved at 1 year postoperatively (p<0.0001), but this improvement was not sustained. There was no significant benefit of long-term acyclovir on visual acuity (p=0.2132) or graft survival (p=0.241). CONCLUSIONS: Even in eyes with significant preoperative risk factors, PKP for the corneal complications of HZO can achieve favourable tectonic and visual results. Although most grafts remained clear, long-term visual potential may be limited by comorbid ocular diseases. Prophylactic postoperative oral acyclovir did not improve outcomes.

Outcomes of cataract surgery in graft-versus-host disease.

PURPOSE: To study the outcomes of cataract surgery in patients with graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: Retrospective review of 72 eyes of 41 patients (age, 17-69 years at the time of surgery) with chronic GVHD after HSCT, who underwent cataract surgery between 2008 and 2012 at the Department of Ophthalmology and Visual Sciences, W. K. Kellogg Eye Center, University of Michigan. Ophthalmic data collected included best-corrected visual acuity (BCVA), responses to Ocular Surface Disease Index (OSDI) questionnaire, dry eye severity, and postoperative complications. RESULTS: BCVA improved from 20/49 to 20/25 (P < 0.0001) after surgery. Eight patients (20%) had pretransplantation total body irradiation and 39 patients (95%) received systemic corticosteroids for the treatment of GVHD. Postoperative complications included cystoid macular edema (4 eyes), corneal ulceration with perforation (2 eyes: 1 infected and 1 sterile), and band keratopathy (1 eye). After surgery, subjective OSDI responses and dry eye disease (DED) did not change significantly from before cataract surgery, although OSDI showed a trend toward worsening. CONCLUSIONS: With careful monitoring and management of DED and concurrent ocular surface disease, cataract surgery generally has good visual outcomes in patients with GVHD. However, aggravation of the preexisting ocular surface disease is frequent, and despite meticulous postoperative maintenance therapy, vision-threatening complications may occur.

Outcomes of cataract surgery in eyes with previous herpes zoster ophthalmicus.

PURPOSE: To report the outcomes of cataract surgery in eyes with previous herpes zoster ophthalmicus (HZO). SETTING: Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA. DESIGN: Retrospective case series. METHODS: Eyes with a history of HZO that had phacoemulsification and intraocular lens implantation were reviewed. The information analyzed included the ophthalmologic history, visual acuity, preoperative and postoperative adjunct treatments, and complications. Analysis of the mean corrected distance visual acuity (CDVA) at 1 month, 1 year, and the last follow-up was performed. RESULTS: Twenty-four eyes were evaluated. The mean CDVA improved from 20/112 (0.75 logMAR ± 0.63 [SD]) preoperatively to 20/53 (0.42 ± 0.56 logMAR) 1 month postoperatively (P = .007) and 20/44 (0.34 ± 0.55 logMAR) at 1 year (P = .052) but decreased to 20/71 (0.55 ± 0.72 logMAR) by last follow-up (P = .605 versus preoperative CDVA). Eleven patients (45.8%) had recurrent keratouveitis after the first episode, 5 before cataract surgery and 6 after cataract surgery. Three had penetrating keratoplasty for worsening corneal opacification. Two patients had tractional retinal detachment from chronic uveitis and required vitrectomy and retinal repair. CONCLUSIONS: Visual recovery after cataract surgery in HZO might be compromised by chronic factors such as ocular surface disease and keratouveitis. Despite long quiescent waiting periods before surgery and aggressive preoperative and postoperative maintenance therapy, visual improvement might be hindered by the inherent pathology associated with HZO. Nevertheless, with careful patient selection, reasonable visual improvement can be achieved. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Acute hydrops with corneal perforation in post-LASIK ectasia.

PURPOSE: To report a case of corneal hydrops with perforation in a patient with ectasia after undergoing laser in situ keratomileusis (LASIK). METHODS: An observational study with clinical, optical coherence tomographic, and histopathologic findings. RESULTS: A 41-year-old woman had an acute onset of blurry vision, pain, photophobia, tearing, and foreign body sensation in the right eye 10 years after undergoing unilateral LASIK in Jordan. According to her, the surgeon elected not to operate on the left eye because of a "corneal abnormality." On slit-lamp examination, a tear in Descemet membrane with a stromal cleft extending to the overlying LASIK flap interface was noted. The flap was partially dehisced by a diffuse channel of aqueous humor draining from the cleft and streaming out the temporal flap edge. When leakage failed to stop after 2 weeks of treatment with a bandage contact lens, the patient underwent penetrating keratoplasty. Histopathological examination of the host button showed a fluid-filled cleft connecting the flap interface. Slit-lamp examination and corneal topography of the contralateral left eye were consistent with keratoconus. CONCLUSIONS: Corneal hydrops with perforation in the setting of post-LASIK ectasia is extremely rare and may be associated with flap dehiscence requiring penetrating keratoplasty.

Long-term use of autologous serum 50% eye drops for the treatment of dry eye disease.

PURPOSE: The aim of this study was to describe the outcomes of 50% autologous serum (AS) eye drops after long-term use in a large cohort of patients with dry eyes. METHODS: A retrospective cohort study was conducted on all patients treated with 50% AS eye drops at our institution between June 2008 and January 2013. Records were reviewed for clinical history, systemic risk factors, dry eye etiology, patients' symptoms, and adverse events. Ocular surface evaluation included Schirmer testing with topical anesthesia, fluorescein staining, and ocular surface disease index. Data were reviewed at initial visit, 1 month, and every 3 to 6 months during treatment with AS. Paired t tests were performed to compare the progression of signs and symptoms of dry eye disease. RESULTS: A total of 123 eyes of 63 patients were evaluated with a mean follow-up of 12 months (range, 3-48 months). Corneal fluorescein staining (mean baseline, 1.77 ± 1.1) improved at the 3- to <6-month, 6- to <12-month, and final follow-up (mean: 1.2 ± 1.0, 1.3 ± 1.0, and 1.1 ± 1.1; P = 0.003, 0.017, and 0.0003, respectively). Schirmer scores (mean baseline, 6.6 ± 6.5 mm) improved at the 12- to 24-month follow-up (mean = 10.7 ± 11.4, P = 0.03), whereas ocular surface disease index scores (mean baseline, 54.1 ± 22.3) improved at the 3- to <6- and 6- to <12-month follow-up (mean: 49.5 ± 8.2 and 39.3 ± 21.4, P = 0.029 and 0.003, respectively). No complications were noted. CONCLUSIONS: Fifty percent AS eye drops seem to be a safe and effective long-term treatment for dry eye disease, especially in patients with severe disease who have exhausted all other conventional forms of treatment.

Prone positioning to facilitate graft adherence in the late postoperative period after descemet stripping automated endothelial keratoplasty.

PURPOSE: The aim of this study was to report the use of prone positioning to facilitate graft adherence in the late postoperative period after Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: A 75-year-old woman with Fuchs dystrophy had repeated endothelial graft detachments after simultaneous DSAEK and phacoemulsification cataract surgery. Multiple attempts in the operating room to reposition the tissue, including placement of air into the anterior chamber, postoperative face-up positioning, and the use of new donor tissue, were unsuccessful. In the late postoperative period, the patient was placed in a prone (face-down) position at home to promote graft adherence. RESULTS: After the maneuver, the endothelial graft was well attached, although it was slightly decentered. The remainder of the patient's postoperative course was routine, and her best-corrected visual acuity is 20/25 with a clear cornea 9 months later. CONCLUSIONS: Prone positioning can be used as a conservative maneuver to promote graft adherence after DSAEK when there is difficulty in achieving attachment postoperatively, especially when a return trip to the operating room may not be practical.

Anterior chamber gas bubbles during femtosecond laser flap creation in LASIK: video evidence of entry via trabecular meshwork.

UNLABELLED: Femtosecond laser photodisruption of corneal stroma during laser in situ keratomileusis flap creation is accompanied by the formation of cavitation gas bubbles consisting of carbon dioxide and water vapor. Entry of these bubbles into the anterior chamber is an infrequent complication. We present video evidence that these bubbles enter via the trabecular meshwork. FINANCIAL DISCLOSURE: Neither author has a financial or proprietary interest in any material or method mentioned.

Management of pain with diclofenac after femtosecond-assisted laser in situ keratomileusis.

PURPOSE: To evaluate the safety and efficacy of topical diclofenac sodium 0.1% after femtosecond laser-assisted laser in situ keratomileusis (LASIK). SETTING: W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA. DESIGN: Clinical trial. METHODS: Pain was assessed in patients treated with topical diclofenac sodium 0.1% or artificial tears immediately after LASIK using a numeric pain scale and a combined picture-numeric pain scale 0, 2, 4, 12, and 24 hours postoperatively. Visual outcomes and complications were noted up to 24 hours. RESULTS: The study enrolled 100 eyes of 50 patients. Patients treated with diclofenac 0.1% reported less pain than the control group on both pain scales 2, 4, 12, and 24 hours after surgery, with the maximum benefit at 4 hours (P=.02). Fewer patients in the diclofenac group (76.0%) than in the control group (91.3%) used oral pain and/or anxiolytic medications during the first 24 hours after surgery (P=.25). Ninety-eight eyes had an uncorrected distance visual acuity of 20/40 or better. Mild peripheral diffuse lamellar keratitis accounted for the majority of perioperative complications (n = 15). CONCLUSION: Pain after femtosecond laser-assisted LASIK was mild and was reduced with a single dose of topical diclofenac sodium 0.1% given immediately after surgery.

Treatment of ocular graft-versus-host disease with topical cyclosporine 0.05%.

PURPOSE: To evaluate the efficacy of topical cyclosporine-A 0.05% (CsA) in the treatment of dry eye syndrome in ocular graft-versus-host disease after bone marrow transplantation (BMT) of hematopoietic stem cells. METHODS: One-hundred five patients were enrolled in a retrospective, comparative, interventional case series. Eighty-one patients received topical CsA starting 1 month before BMT (treatment group), and 24 patients did not receive CsA until at least 6 months after the transplantation (control group). Mean follow-up time was 17.5 ± 11.0 months (range: 6.0-49.0 months). Clinical history, ocular surface disease index questionnaire, slit-lamp examination, lissamine green and fluorescein staining of the ocular surface, tear breakup time, and Schirmer test with topical anesthesia were obtained to create a composite dry eye-grading score. RESULTS: Dry eye symptoms were significantly more severe in the control group at 3 months, 1 year, and 2 years (P < 0.05). There was no correlation with type of stem cell transplant (related vs. unrelated donor), presenting indication for BMT, or concurrent systemic immunosuppressive medications. CONCLUSIONS: Pre-BMT initiation of topical CsA may reduce the inflammatory response in the lacrimal glands that may be responsible for the development of post-BMT keratitis sicca.

Wound integrity of clear corneal incisions closed with fibrin and N-butyl-2-cyanoacrylate adhesives.

PURPOSE: To compare the integrity of clear corneal incisions closed with fibrin (Tisseel) and n-butyl-2-cyanoacrylate (Histoacryl) tissue adhesives to those closed with conventional sutures. METHODS: Four replicate experiments were performed on porcine eyes with each of the following conditions: three limbal clear corneal incision sizes (3.0 mm, 4.5 mm, and 6.0 mm), three incision closure techniques (fibrin adhesive, n-butyl-2-cyanoacrylate adhesive, and 10-0 interrupted nylon sutures)-1, 2, and 3 sutures at the 3.0-mm, 4.5-mm, and 6.0-mm incision sizes, respectively. Wound integrity was then measured by elevating the intraocular pressure of the eye to the point where wound leakage (IOP(L)) occurred. Two-way repeated measures analysis of variance (ANOVA) was used to analyze the IOP(L) data. RESULTS: Incision closure technique and incision size showed significant interaction in the ANOVA model (p = 0.0008). Fibrin adhesive demonstrated higher IOP(L) compared to suture closure at the 3.0-mm incision size (p < 0.0001). There was no significant difference in IOP(L) when comparing wound closure with fibrin adhesive and sutures at the 4.5-mm and 6.0-mm incision sizes (p = 0.52 and p = 0.56, respectively). There was no significant difference between the three closure techniques for the 6.0-mm incisions (p > 0.15). When comparing the wound closure techniques for all incision sizes, the mean IOP(L) significantly increased in the following order: suture(s), fibrin adhesive, n-butyl-2-cyanoacrylate glue. CONCLUSIONS: Fibrin or n-butyl-2-cyanoacrylate tissue adhesive may be used as a more stable alternative to conventional sutures in the closure of clear corneal incisions.

Long-term outcome of combined penetrating keratoplasty with scleral-sutured posterior chamber intraocular lens implantation.

PURPOSE: To evaluate the long-term outcomes of combined penetrating keratoplasty (PKP) with scleral-sutured posterior chamber intraocular lens (PC-IOL) implantation. METHODS: Medical records from patients with aphakic and pseudophakic bullous keratopathy were retrospectively reviewed for preoperative indications and postoperative results of 105 consecutive patients (105 eyes) who underwent combined PKP and scleral-sutured PC-IOL implantation over a 13-year period. Main outcomes measures were graft survival rate, visual acuity, and intraoperative and postoperative complications. RESULTS: The principal indications for PKP were pseudophakic and aphakic corneal edema. Graft survival rates were 97% at 1 year, 91% at 2 years, 75% at 5 years, and 68% at 7 years. Mean postoperative follow-up was 44.8 +/- 37.0 months (range 1-156). The best-corrected visual acuity improved at least 1 line on the Snellen chart in 59.0% of the patients, with 42.9% of the eyes achieving acuities of 20/100 or better. Postoperative complications included new glaucoma in 21.4%, worsening of pre-existing glaucoma in 28.6%, cystoid macular edema in 17%, infectious endophthalmitis in 3.8%, and intraocular lens dislocation in 1.9%. No intraoperative complications were encountered. CONCLUSIONS: PKP combined with scleral-sutured PC-IOL implantation can achieve acceptable outcomes with a low rate of intraocular lens dislocation, but may be associated with significant short and long-term complications.

Rupture of anterior lens capsule from blunt ocular injury.

We report 3 cases of blunt trauma causing rupture of the anterior lens capsule with cataract formation. The injuries were caused by a paintball gun, a ball-bearing air pistol, and an aluminum rivet. In all 3 cases, the anterior capsule tears were central and the posterior capsules and zonules intact; uneventful cataract extraction with implantation of an intraocular lens was performed. The postoperative visual acuities was 20/40 in 1 case and 20/20 in the other 2 cases. We propose that the anterior lens capsule may have been torn by direct contusion from rapid focal indentation of the cornea onto the lens (coup injury) or by a fluid-mechanical, anteriorly directed rebound of the vitreous, bursting open the anterior capsule (contrecoup injury).

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.

Femtosecond lasers in ophthalmology.

PURPOSE: To provide an update and review of femtosecond (FS) lasers in clinical ophthalmology. DESIGN: Perspective, literature review, and commentary. METHODS: Selected articles from the literature and the authors' clinical and laboratory studies. RESULTS: The FS laser employs near-infrared pulses to cut tissue with minimal collateral tissue damage. Although its major use at present is in the cutting of laser in situ keratomileusis flaps, the laser has proven its versatility in laser-assisted anterior and posterior lamellar keratoplasty, cutting of donor buttons in endothelial keratoplasty, customized trephination in penetrating keratoplasty, tunnel creation for intracorneal ring segments, astigmatic keratotomy, and corneal biopsy. Current laboratory studies include all-FS laser refractive keratomileusis sans flap, cutting corneal pockets for insertion of biopolymer keratoprostheses, noninvasive transscleral glaucoma surgery, retinal imaging and photodisruption, presbyopia surgery, and anterior lens capsulorrhexis. CONCLUSIONS: Advances in ultra-fast laser technology continue to improve the surgical safety, efficiency, speed, and versatility of FS lasers in ophthalmology.

Different application volumes of ethyl-cyanoacrylate tissue adhesive can change its antibacterial effects against ocular pathogens in vitro.

PURPOSE: To analyze the antibacterial effects in vitro of ethyl-cyanoacrylate (EC) tissue adhesive in different application volumes. METHODS: Volumes of 4, 6, 8, 10, 12, 14, 25, and 35 mu l of EC were applied onto the surface of monolayer cultures of Staphylococcus aureus (ATCC25924), Streptococcus pneumoniae (ATCC49619), Escherichia coli (ATCC25922), Pseudomonas aeruginosa (ATCC27853), and Klebsiella pneumoniae (ATCC13883). The diameter of each EC drop was measured, and the area of the circle of EC (formed after its application onto the monolayer culture) was calculated. The area of the antibacterial inhibitory halo surrounding the drop of EC on the monolayer culture was calculated. The ratio between the area of the EC and of the corresponding inhibitory halo was obtained for each EC volume and for each of the 5 types of bacteria studied. RESULTS: EC volume-dependent inhibitory halos were seen in Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli, but not in Pseudomonas aeruginosa or Klebsiella pneumoniae. CONCLUSION: The in vitro antibacterial effect of EC against Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli varies in a dose-dependent fashion with its volume. No effect was observed against Pseudomonas aeruginosa and Klebsiella pneumoniae.

Delayed-onset isolated central Descemet membrane blister detachment following phacoemulsification.

We report 2 patients who developed delayed-onset isolated central Descemet membrane (DM) blister-like detachment following phacoemulsification. The detachments were not associated with a DM tear or inadvertent injection of fluid under DM, and no fluid tracks from the periphery were present. When the detachments failed to resolve spontaneously over several months, intracameral air or C(3)F(8) gas was injected. In 1 patient, a therapeutic paracentral puncture in DM was also performed to facilitate escape of the entrapped fluid. Although a small residual detachment (confirmed by optical coherence tomography) remained in both cases, the visual acuity improved to 20/25 in 1 patient and 20/30 in the other. We think these unique focal detachments in DM may be associated with an underlying preexisting weakness in the DM attachment to the stroma.

Postoperative endophthalmitis associated with sutured versus unsutured clear corneal cataract incisions.

AIM: To compare the incidence of postoperative endophthalmitis in clear corneal cataract surgeries performed with and without suture closure, antibiotics and povidone iodine. SETTING: Ambulatory surgery facility. METHODS: In a retrospective, consecutive case-series study, we reviewed the incidence of endophthalmitis in 815 consecutive eyes that underwent cataract surgery by a single surgeon over a 5-year period (379 unsutured and 436 sutured, 294 without and 521 with antibiotic drops in the immediate postoperative period, and 247 without and 568 with povidone iodine before patching). RESULTS: There were five cases of culture-positive postoperative endophthalmitis in the unsutured group and none in the sutured group (p = 0.022). Although patients in these two groups received routine preoperative antibiotic and povidone-iodine drops, those in whom antibiotic eye drops were not initiated until the day after surgery (p = 0.006) and those who did not receive 5% povidone-iodine drops immediately after wound closure (p = 0.031), had a higher incidence of endophthalmitis. CONCLUSION: Results suggest that by suturing the corneal incisions, by initiating antibiotic eye drops within the first 24 h of surgery and by instilling povidone-iodine drops after closure, the incidence of endophthalmitis after cataract surgery could possibly be reduced.

In vivo femtosecond laser-assisted posterior lamellar keratoplasty in rabbits.

PURPOSE: To develop a rabbit model for femtosecond laser-assisted posterior lamellar keratoplasty. METHODS: The femtosecond laser was used to make the posterior corneal lamellar interface and trephine (side) cut in 12 eyes of 11 rabbits. Laser parameters were energy 6.0 to 8.7 (lamellar cut) and 6.0 to 8.8 microJ (trephination cut), spot size 2.4 microm, firing rate 15 kHz, and trephination diameter 6.0 to 7.0 mm. In all eyes, the posterior corneal disc was removed from the eye after laser treatment through a blade incision in the peripheral cornea. The same excised corneal disc was repositioned into the posterior stromal bed to simulate posterior lamellar transplantation. Four eyes of 3 rabbits were enucleated immediately after surgery, and 8 eyes of 8 rabbits were enucleated after a mean follow-up of 17.9 +/- 6.5 weeks. The corneal cut surfaces were examined by light microscopy and scanning electron microscopy. RESULTS: The femtosecond laser was successful in producing posterior lamellar and trephination cuts in rabbit eyes. The thickness of the posterior corneal discs was 204.3 +/- 21 microm (56.9% of central corneal thickness), and postoperative keratometry was 49.1 +/- 5.8 D. Clinical appearance consistent with corneal ectasia was noted in 3 eyes. CONCLUSION: The femtosecond laser can make nonmechanical cuts for posterior lamellar keratoplasty with relative ease and reliability in rabbit eyes. A minimum residual anterior corneal thickness may need to be maintained to prevent ectasia.