Clinical course and origin of epithelium in cases of epithelial downgrowth after Descemet stripping automated endothelial keratoplasty.

PURPOSE: The aim of this study was to report a case series of epithelial downgrowth associated with Descemet stripping automated endothelial keratoplasty (DSAEK) and to explore the origin of the anterior chamber corneal epithelium. METHODS: This is a case series and literature review. RESULTS: Three histopathologically confirmed cases of epithelial downgrowth after DSAEK were identified. All cases were treated with argon laser ablation, intracameral 5-fluorouracil, and intraocular surgery. Recurrent epithelial downgrowth occurred in 2 of 3 cases. Fluorescent in situ hybridization analysis with fluorescent probes for X and Y chromosomes was used to analyze epithelial downgrowth tissues in all cases. All 3 cases were consistent with donor tissue origin of epithelial downgrowth tissue. However, this could only be confirmed in 1 case. The donor and the recipient were the same sex in 2 cases; thus, no definitive conclusion was possible in these patients. CONCLUSIONS: There have been multiple reports of epithelial downgrowth after DSAEK. We include additional evidence to support the role of donor tissue corneal cells as the source of epithelium in some of these cases. It is surprising that donor tissue would be tolerated immunologically by the patient in these cases. We propose that tolerance for donor epithelium may be mediated through anterior chamber-associated immune deviation.

Carbon dioxide laser-induced combustion of extravasated intraocular silicone oil in the eyelid mimicking xanthelasma.

A 48-year-old woman with a history of retinal detachment repair with vitrectomy, scleral buckling, and silicone oil with subsequent oil removal was referred for unilateral upper eyelid ptosis with edema and overlying skin changes simulating xanthelasma. During surgical excision, a white flare-like plume was noted when the carbon dioxide (CO2) laser was used to make the incisions. The pathology report confirmed silicone oil intrusion in the conjunctiva and upper eyelid. A postoperative in vitro experiment showed that silicone oil was readily ignited by the CO2 laser.

The effect of alpha1-adrenergic receptor antagonist tamsulosin (Flomax) on iris dilator smooth muscle anatomy.

PURPOSE: To characterize and determine the effect of tamsulosin (Flomax) on the human iris dilator muscle anatomy. DESIGN: Retrospective, case-control study. PARTICIPANTS: This study comprised 51 cadaveric eyes from 27 patients (14 with a history of tamsulosin use and 13 control patients) who underwent autopsy at the Duke University Medical Center, Durham, North Carolina. METHODS: Patients' records were reviewed, and age, medical, surgical, and ocular history; gender; medications; and duration and dosage of tamsulosin were recorded. Specimens were sectioned through the pupillary axis in the horizontal meridian and reviewed by light microscopy. A morphometric analysis was performed to measure the maximum and minimum iris dilator muscle thickness and the iris stromal thickness (micrometers) at 6 points in each eye. All microscopic evaluations and measurements were performed by the same masked observer. MAIN OUTCOME MEASURES: To determine whether there is a significant difference in the iris dilator muscle or stromal thickness in those patients receiving tamsulosin treatment compared with age-matched controls. RESULTS: The mean iris dilator muscle thickness in the tamsulosin-treated group (6.53+/-1.99 microm) was significantly thinner compared with that of the control group (8.50+/-1.61 microm) (P=0.006). There was no difference in iris stromal thickness between the 2 groups (P=0.268). There was no direct relationship between duration of tamsulosin use and iris dilator muscle or stromal thickness. Statistical significance was maintained when the iris dilator muscle thickness was compared between the groups using history of diabetes and cataract extraction as separate variables. No difference was noted when comparing the iris stromal thickness using diabetes as a separate variable. However, stromal thickness was significantly different between the groups in pseudophakic eyes (P=0.005). CONCLUSIONS: According to histologic examination of cadaver eyes, patients receiving tamsulosin treatment exhibited decreased iris dilator muscle thickness compared with control patients. There was no difference noted in the iris stromal thickness within the groups. We believe this finding may shed light on the pathophysiology of intraoperative floppy iris syndrome. Further studies need to be performed to assess the significance of this histologic finding.

Higher-order aberrations from the internal optics of the eye.

PURPOSE: To analyze the distribution of human higher-order wavefront aberrations (3rd- to 6th-order) from the internal optics (WA(internal)) and the variations with age and to evaluate the degree of compensation that the internal optics provide for anterior corneal aberrations (WA(cornea)). SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. METHODS: With assumption of a simple model for the eye, the WA(internal) were obtained by direct subtraction of the WA(cornea) from the ocular aberrations (WA(eye)). The WA(eye) were measured using the WaveScan system (Visx, Inc.), and the WA(cornea) were computed from the topographic data (Humphrey Atlas) using the CTView program (Sarver and Associates, Inc.). In 144 eyes of 114 normal patients (age 20 to 69 years), WA(internal) were calculated for a 6.0 mm pupil and a compensation factor (CF) was computed, with positive values representing compensation of WA(cornea) by WA(internal) and negative values indicating that the internal surfaces add aberrations to those of the cornea. RESULTS: There was wide individual variation in WA(internal). The mean coefficient for 4th-order spherical aberration (Z(4)(0)) was -0.145 microm +/-0.094 (SD) (95% confidence interval [CI], -0.160 to -0.130 microm); 95.1% of eyes had negative values. The mean root-mean-square value for HOAs was 0.334 +/- 0.096 microm (95% CI, 0.319 to 0.350 microm). Moderate to high correlations were found between the right and left eyes in HOAs, 4th-order and 6th-order spherical aberration coefficients (Z(4)(0) and Z(6)(0)). With increasing age, the HOAs did not change, whereas the negative coefficients for Z(4)(0) tended to become less negative. Only the term Z(4)(0) had a CF significantly correlated with increasing age (r=-0.338, P<.05 with Bonferroni correction). CONCLUSION: WA(internal) varied widely among patients, and a moderate to high degree of mirror symmetry existed between the right and left eyes. Internal surfaces compensated at least partially for the HOA and Z(4)(0) in most eyes, and this compensation decreased only mildly with increasing age.