Rotational stability of toric intraocular lenses by lens model and haptic design: systematic review and single-arm meta-analysis.

Rotational stability is key for optimizing postoperative visual outcomes because even a small degree of rotation of a toric intraocular lens (IOL) from its target axis can result in a significant reduction in astigmatic correction. This systematic review and meta-analysis evaluated the rotational stability of toric IOLs of different lens models and haptic designs. All published studies and clinical trials that investigate postoperative rotation of toric IOLs were searched and evaluated. Quality of studies was assessed using the Methodological Index for Nonrandomized Studies scale. A single-arm meta-analysis was performed in R4.3.1 software with subgroup analysis performed based on lens model and haptic design. 51 published studies of 4863 eyes were included in the meta-analysis. The pooled mean absolute rotation of all toric IOLs was 2.36 degrees (95% CI, 2.08-2.64). Postoperative rotation is dependent on many aspects of lens material and design. Modern commercially available toric IOLs exhibit exceptional rotational stability.

Recurrent Corneal Erosion Syndrome: A Study of 364 Episodes.

The purpose of the study was to investigate the management of recurrent corneal erosion syndrome (RES). A retrospective case series design was employed in which all RES cases presenting to the Duke University Eye Center from 1995 to 2002 were included. In total, 364 episodes of RES occurred in 261 patients during the study period. Of this 61% of patients were female (P < .001), average age was 46.0 years, and etiologies included trauma (51.3%), anterior basement membrane dystrophy (29.1%), other etiologies (10.3%) and unknown (9.2%). Treatments included conservative therapy (83.2%), anterior stromal puncture (ASP)(12.6%) and phototherapeutic keratectomy (PTK)(4.1%). Recurrence by treatment was 31.0% for conservative therapy, 23.9% for ASP and 26.7% for PTK. Subjects treated with ASP and PTK had failed prior treatment efforts. Conclusions include that RES was commonly associated with trauma and the female gender, and that one-third of conservatively treated episodes and one-quarter of surgically treated episodes (ASP or PTK) recurred.

A comparison of three methods for trephining donor corneal buttons: endothelial cell loss and microscopic ultrastructural evaluation.

PURPOSE: To evaluate the ultrastructure of the cut edge and associated endothelial cell loss following donor cornea trephination with a standard punch, vacuum punch, and vacuum trephine and artificial anterior chamber system. MATERIALS AND METHODS: This laboratory investigation compared trephinations (8.0 mm) performed on human corneas using either a standard posterior punch (n = 12), vacuum posterior punch (n = 12), or vacuum trephine and artificial anterior chamber system (n = 12). Specular microscopy was performed before and after trephination to determine central endothelial cell density. Light and scanning electron microscopy were performed to evaluate the structure of the trephined edge. Endothelial cell-free distances from the trephinated edges were measured on light microscopy sections. RESULTS: Central endothelial cell loss (cells/mm(2)) after trephination was -14.0 +/- 49.9 (SD) for the standard posterior punch, -85.6 +/- 87.0 for the vacuum posterior punch, -116.0 +/- 223.1 for the vacuum trephine and artificial anterior chamber system. Endothelial cell-free distances from the trephined margin were 63 +/- 22 microm, 85 +/- 13 microm, and 123 +/- 48 microm for the three respective methods. The edges of grafts cut with anterior trephination were inward sloping from the epithelial to endothelial surfaces, while both posterior punches created outward sloping edges. Increased fibrillar disruption at edges was seen following anterior trephination. CONCLUSION: Different trephination methods produce distinct cut morphologies with the anterior trephination approach, resulting in more irregular margins. The anterior approach was associated with increased variability and greater endothelial cell loss than the studied posterior approaches. The use of corneal scissors may contribute to the morphologic features of the corneal button seen following anterior trephination.

Changes in posterior corneal elevation after laser in situ keratomileusis enhancement.

PURPOSE: To evaluate changes in posterior corneal elevation using the Pentacam topographer (Oculus) in patients having laser in situ keratomileusis (LASIK) enhancement. SETTING: Private practice, Chevy Chase, Maryland, USA. METHODS: The Pentacam device was used to evaluate the changes in posterior corneal elevation above the best-fit sphere before LASIK enhancement and after LASIK enhancement in 24 eyes. The change in posterior corneal elevation in eyes for which pre-primary LASIK data were available was also evaluated. RESULTS: After LASIK enhancement, the mean change in posterior corneal elevation was 5 microm. The mean posterior corneal elevation was 12 +/- 7 microm before LASIK enhancement and 16 +/- 6 microm after enhancement; the difference was statistically significant (P = .004). In eyes for which pre-primary LASIK data were available, the mean change in posterior corneal elevation after primary LASIK was 2 microm. The mean posterior corneal elevation was 11 +/- 5 microm before LASIK enhancement and 11 +/- 7 microm after enhancement. CONCLUSIONS: There was a statistically significant difference in posterior corneal elevation between before LASIK enhancement and after LASIK enhancement. However, the change in posterior corneal elevation was much smaller than previously reported values and below the sensitivity of the Pentacam topographer.

Use of Verisyse iris-supported phakic intraocular lens for myopia in keratoconic patients.

We report 2 patients with stable keratoconus and high myopia who benefited from implantation of an iris-supported phakic intraocular lens (Verisyse, AMO) for correction of their refractive error. Both patients had a postoperative uncorrected visual acuity of 20/40. Endothelial cell density showed at most a 4% decrease, and no evidence of keratoconus progression was witnessed. The use of the Verisyse lens may be beneficial for certain keratoconic patients as an alternative step between rigid gas-permeable lenses and penetrating keratoplasty.

Fourth-generation fluoroquinolone-resistant bacterial keratitis after refractive surgery.

We report the first 2 cases of bacterial keratitis resistant to fourth-generation fluoroquinolones after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). The first patient had Pseudomonas aeruginosa keratitis after PRK despite treatment with moxifloxacin. The second patient was on gatifloxacin post-LASIK when she had methicillin-resistant Staphylococcus aureus (MRSA) keratitis diagnosed. In both cases, culture susceptibilities showed isolates resistant to moxifloxacin and gatifloxacin, and treatment with topical aminoglycosides and surgical intervention was necessary to effect a cure. These cases show the potential limitations in the coverage of these antibiotics.

Implantation of verisyse phakic intraocular lens to correct myopic refractive error after penetrating keratoplasty in pseudophakic eyes.

PURPOSE: We report 2 cases in which a Verisyse phakic intraocular lens (PIOL) was used to successfully treat high myopia after penetrating keratoplasty (PK) in pseudophakic patients. METHODS: Case 1 involved a 69-year-old pseudophakic man with a manifest refraction (MR) of -6.50 + 1.75 x 048 and a best spectacle corrected visual acuity (BSCVA) of 20/40 approximately 16 months after PK in the right eye. Case 2 was a 78-year-old pseudophakic man who had an MR of -9.00 + 5.75 x 132 with a BSCVA of 20/100 approximately 24 months after PK in the left eye. RESULTS: In case 1, 10 months after Verisyse PIOL implantation, the MR was pl +2.00 x 135 with a BSCVA of 20/30. Endothelial cell density (ECD) in this patient decreased from 1926.1 to 815.3 cells/mm over 17 months. In case 2, 24 months after Verisyse PIOL implantation, the MR was -3.25 + 3.50 x 105 with a BSCVA of 20/60. ECD in this patient decreased from 2108.4 to 753.8 cells/mm in 30 months. CONCLUSION: The Verisyse PIOL may provide an alternative method to correct high myopia for anisometropia in pseudophakic patients after PK. In this report, PIOL implantation was associated with a decrease in ECD. Further studies are required to determine the long-term effects and ultimate safety of PIOL placement on the integrity of the cornea endothelium after corneal transplant in pseudophakic patients.

Preparation of donor lamellar tissue for deep lamellar endothelial keratoplasty using a microkeratome and artificial anterior chamber system: endothelial cell loss and predictability of lamellar thickness.

BACKGROUND AND OBJECTIVE: To measure endothelial cell loss and predictability of lamellar thickness after preparing donor tissue for deep keratoplasty with an artificial anterior chamber and microkeratome. MATERIALS AND METHODS: A microkeratome set at a depth of 350 microm and a diameter of 9 mm was used to obtain ten lamellar lenticules from corneoscleral rims mounted in an artificial chamber. A punch trephine then was used to cut the donor tissue 7 mm in diameter. Specular microscopy was performed to evaluate endothelial cell density before the procedure, after cutting with the microkeratome, and after trephination. Pachymetry was performed to determine the predictability of lenticule thickness, before the procedure and after microkeratome incision. RESULTS: Mean post-microkeratome endothelial cell loss was 79 +/- 88 cells/mm2 and post-punch trephination was 85 +/- 94 cells/mm2. This represented a mean percentage loss of 3.2% and 3.5% for the respective steps of this procedure. Nine of the ten lenticules were cut within +/- 75 microm of the intended 350-microm thickness. CONCLUSIONS: Preparing donor lenticules for deep lamellar endothelial keratoplasty with a microkeratome with artificial chamber system caused a relatively small loss of endothelial cells (6.7% of the total) and a reproducible thickness. This may have advantages over manual preparation techniques.

Trends in the indications for penetrating keratoplasty, 1980-2001.

PURPOSE: To study the leading indications and changing trends for penetrating keratoplasty (PK) over the past 3 decades. METHODS: This is a retrospective review of 696 cases of PK. The indications for PKs performed at the Duke University Eye Center during the years 1980-1981, 1990- 1991, and 2000-2001 were tabulated to determine trends over the past 3 decades. The main outcome measures were indications for PK. RESULTS: During this study, 696 PKs were performed. The leading indications for PK and their respective frequencies during 1980-1981, 1990-1991, and 2000-2001 were failed grafts (10.8%, 19.0%, 27.0%, respectively), pseudophakic bullous keratopathy (PBK)/aphakic bullous keratopathy (ABK) (19.4%, 20.6%, 16.7%, respectively), Fuchs dystrophy (15.6%, 13.0%, 23.8%, respectively), keratoconus (13.4%, 8.2%, 11.8%, respectively), and corneal scar (7.0%, 8.9%, 10.7%, respectively). The number of PKs for failed grafts and Fuchs dystrophy increased over time. CONCLUSIONS: In this study, failed graft has gradually become the leading indication for PK, whereas most other studies have reported PBK as the leading indication. Unlike many other studies, Fuchs dystrophy was a common indication for PK.

Novel tissue adhesives to secure laser in situ keratomileusis flaps.

PURPOSE: To evaluate 2 novel biodendrimer tissue adhesives in sealing and securing laser in situ keratomileusis (LASIK) flaps. SETTING: Duke University Eye Center, Durham, North Carolina, USA. METHODS: Laser in situ keratomileusis flaps were created in 10 human eye-bank eyes using the Hansatome microkeratome system (Bausch & Lomb). These eyes were divided into 2 groups. Flaps in the first group (n=4) were secured with a laser-activated biodendrimer adhesive along the flap edge. In the second group (n=6), the flaps were secured with a self-gelling dendritic adhesive. Dry Merocel sponges (Medtronic Solan) were used to test the strength of flap adherence in both groups. Further testing was performed in the second group. The hinges of these flaps were cut with a scalpel blade and fluorescein dye was injected under the flap to observe potential dye leakage along the flap edge. RESULTS: Laser in situ keratomileusis flaps sealed with both adhesives were secure with no flap dislocation. There was no leakage of fluorescein dye observed in the second group. Both adhesives were easy to apply, clear when dry, and had a soft rubbery consistency. CONCLUSIONS: Two novel biodendrimer adhesives successfully sealed and secured LASIK flaps. These adhesives may prove to be an effective alternative for treating LASIK flap complications such as epithelial ingrowth or flap dislocation.

Laser in situ keratomileusis in patients with corneal guttata and family history of Fuchs' endothelial dystrophy.

PURPOSE: To report 1-year results of laser in situ keratomileusis (LASIK) in 7 eyes with corneal endothelial guttata and a family history of Fuchs' endothelial dystrophy. SETTING: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: A retrospective chart review was performed of 4 patients (7 eyes) who had trace to 1+endothelial guttata and a family history of Fuchs dystrophy and then had uneventful LASIK for the correction of myopia and myopic astigmatism. Preoperative and postoperative measurements included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal pachymetry, endothelial cell density (ECD), manifest refraction, and spherical equivalent. The changes in ECD, pachymetry, and spherical equivalent after LASIK were subjected to statistical analysis using a paired Student t test to determine significance. RESULTS: Transient corneal edema was noted in the early postoperative period in 3 eyes of 2 patients. At 1 year, 6 of the 7 (86%) eyes had lost > or =2 lines of BSCVA. A statistically significant decrease in ECD of 12.4% +/- 2.7% was observed at 1 year compared with baseline (P < .001). An increase in corneal thickness (P = .006) and a statistically significant myopic shift in spherical equivalent (P = .017) was also noted at 1 year compared with 3 months. CONCLUSIONS: Patients with mild corneal guttata and a family history of Fuchs' dystrophy are prone to transient corneal edema, loss of BSCVA, endothelial cell loss, and myopic regression after uneventful LASIK for correction of myopia and myopic astigmatism.