Deep anterior lamellar keratoplasty for Maroteaux-Lamy syndrome.

PURPOSE: To present a case of Maroteaux-Lamy syndrome (MLS), which underwent deep anterior lamellar keratoplasty (DALK) for visual rehabilitation. METHODS: A 15-year-old girl with MLS was admitted with severe corneal opacity. We performed DALK on her left eye for visual rehabilitation. Big-bubble technique was used to perform lamellar separation. RESULTS: Corneal graft was clear 24 months after surgery. Best spectacle-corrected visual acuity of left eye was 20/25 with the correction of +0.75/-0.50 diopters × 170. At the last follow-up, in vivo confocal microscopy revealed mild haze in the posterior stroma at the graft interface level. Endothelial cell count was 2473.4 cells per square millimeter using a noncontact specular microscope. CONCLUSIONS: Given systemic problems in patients with MLS and less postoperative complications of DALK in comparison with penetrating keratoplasty, it seems DALK is the better choice for these patients.

Dissection plane in deep anterior lamellar keratoplasty using the big-bubble technique.

PURPOSE: To find the level of dissection in keratoconic corneas undergoing deep anterior lamellar keratoplasty (DALK) using the big-bubble technique. METHODS: In 3 keratoconic eyes that underwent DALK, the operation was converted into penetrating keratoplasty after complete big-bubble formation because of extensive tear in Descemet's membrane (DM) during stromal excision. The corneal stroma and DM taken from these eyes were submitted for light and transmission electron microscopy. RESULTS: Both light and transmission electron microscope revealed a thin layer of corneal stroma adhered to DM in all cases. In 2 eyes, the residual stromal thickness was almost constant (6.4 µm and 12.3 µm), whereas it varied from 9.5 µm to 25.8 µm in the other one. CONCLUSION: Dissection plane in DALK using the big-bubble technique can be within corneal stroma rather than exactly between stroma and DM. Various corneal pathologies as well as different techniques of dissection may have influence on this level.

Effect of hydrodynamic parameters on corneal endothelial cell loss after phacoemulsification.

PURPOSE: To evaluate the effect of power, vacuum, and flow rate on endothelial cell loss after phacoemulsification. SETTING: Labbafinejad Medical Center Medical Center, Tehran, Iran. METHODS: In a prospective randomized clinical trial, phacoemulsification was performed in 2 groups (high vacuum and low vacuum) with 3+ nuclear sclerosis. The stop-and-chop technique was used with the Sovereign machine. Machine parameters during the chop stage were vacuum 400 mm Hg in the high-vacuum group and 200 mm Hg in the low-vacuum group and flow rate, 40 cc/min and 20 cc/min, respectively. Endothelial cell density preoperatively before and 1, 6, and 12 weeks postoperatively were compared. RESULTS: Each group comprised 30 eyes. The mean US power was 9.2% +/- 4.3% (SD) in the low-vacuum group and 13.1% +/- 4.6% in the high-vacuum group (P = .001) and the mean phaco time, 1.28 +/- 1.0 minutes and 0.88 +/- 0.6 minutes, respectively (P = .04). Total US energy and total fluid consumed were similar between groups. After 12 weeks, the mean endothelial cell loss was 9.0% +/- 4.0% in the low-vacuum group and 9.6% +/- 4.6% in the high-vacuum group (P = .6). There was a relationship between total US energy and endothelial loss (P<.001); however, total fluid volume was not a significant predictor (P = .19). CONCLUSIONS: Vacuum level did not have a significant effect on total US energy or total fluid consumed during phacoemulsification. There was a strong relationship between total US energy and endothelial cell loss but not between total infused fluid and endothelial cell loss.

Mutation screening of TGFBI in two Iranian Avellino corneal dystrophy pedigrees.

PURPOSE: Genetic analysis and phenotypic features of Avellino corneal dystrophy patients from Japan and some European countries have been published. We report for the first time the genetic analysis and phenotypic features of two Avellino corneal dystrophy pedigrees from the Middle East. METHODS: Slit-lamp biomicroscope photographs of cornea were obtained, and corneal tissue sections were stained with masson-trichrome and Congo red. DNA was isolated from peripheral blood leucocytes and exons 4 and 12 of TGFBI were screened for mutations by direct sequencing. RESULTS: The probands of the pedigrees had phenotypic features consistent with diagnosis of Avellino corneal dystrophy. They were homozygous for the same R124H mutation in TGFBI as previously reported in Avellino patients from Japan and European countries. Heterozygous carriers of the mutation were identified in the pedigree and shown to have symptoms of disease milder than those of the probands. CONCLUSION: The finding of R124H in the Middle Eastern (Iranian) population supports the proposal that perhaps only substitution of histidine for arginine at position 124 of tumour growth factor beta induced protein results in the Avellino corneal dystrophy phenotype. As both probands were originally diagnosed with granular corneal dystrophy, and as heterozygous carriers of R124H were unaware of their disease status prior to genetic analysis, the importance of genetic analysis is emphasized.

Laser in situ keratomileusis for correction of induced astigmatism from cataract surgery.

PURPOSE: To evaluate the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) to correct residual astigmatism after cataract surgery. METHODS: LASIK was performed on 20 eyes of 20 patients with refractive myopic or mixed astigmatism (3.00 to 6.00 D) at least 1 year after extracapsular cataract extraction with posterior chamber intraocular lens implantation without complication. Each eye received bitoric LASIK with the Nidek EC-5000 excimer laser and the Automated Corneal Shaper microkeratome. RESULTS: At 6 months after LASIK, mean refractive cylinder decreased from 4.64+/-0.63 D to 0.44+/-0.24 D (P<.001). Mean percent reduction of astigmatism was 90.4+/-5.0% (range 80% to 100%). Mean spherical equivalent refraction decreased from -2.19+/-0.88 D (range -1.00 to -3.88 D) to -0.32+/-0.34 D (range -1.25 to +0.38 D) (P<.001). Vector analysis showed that the mean amount of axis deviation was 0.7+/-1.2 degrees (range 0 degrees to 4.3 degrees) and the mean percent correction of preoperative astigmatism was 92.1+/-5.9% (range 85.6% to 108%). Eighty-five percent of all eyes had a mean spherical equivalent refraction and mean cylinder within +/-0.50 D of emmetropia. Change in spherical equivalent refraction and cylinder from 2 weeks to 6 months was < or = 0.50 D in 90% (18 eyes) and 95% (19 eyes), respectively. Spectacle-corrected visual acuity was not reduced in any eye. Diffuse lamellar keratitis occurred in three eyes (15%) after LASIK, and were treated successfully with eyedrops. CONCLUSION: LASIK was an effective, predictable, stable, and safe procedure for correction of residual myopic or mixed astigmatism ranging from 3.00 to 6.00 D with a low spherical component after cataract surgery.