Malignant nonteratoid medulloepithelioma of the ciliary body in an adult.

BACKGROUND: The authors describe a 62-year-old man with a malignant nonteratoid malignant medulloepithelioma of the ciliary body with extension into the anterior choroid and posterior chamber. He developed gradual loss of vision in his right eye, and a clinical diagnosis of malignant melanoma of the ciliary body and choroid was made. RESULTS: Histopathologic examination of the enucleated eye showed a malignant nonteratoid medulloepithelioma of the ciliary body with extension into the anterior choroid and posterior chamber. CONCLUSION: This report provides clinicopathologic evidence that intraocular medulloepithelioma can occur rarely in an adult. The lesion clinically may mimic a malignant melanoma. The authors also summarize five previously reported cases of this unusual lesion.

Corneal topographic changes after noncontact holmium:YAG laser thermal keratoplasty to correct hyperopia.

PURPOSE: To analyze the changes in corneal curvature induced by laser thermal keratoplasty (LTK) to correct hyperopia. SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas. METHODS: We performed LTK on nine hyperopic eyes using a noncontact holmium: YAG (Ho:YAG) laser. Five eyes received a single ring of eight spots at the 6 mm zone (Group A); four received a second ring of eight at the 7mm zone (Group B). Computerized videokeratography (CVK) was obtained preoperatively and 1, 30, 90, 180, and 360 days postoperatively. We calculated the net dioptric changes in the following CVK values: corneal curvature at the 1, 3, 5, and 7 mm zones; effective corneal refractive power (Eff RP); and spherical equivalent of subjective manifest refraction (SE SMR). We classified difference maps according to the pattern of induced change. RESULTS: At 1 year, steepening at the 1, 3, 5, and 7 mm CVK zones was 0.5 diopter (D), 0.6 D, 0.1 D, and -0.42 D, respectively, in Group A and 1.5 D, 1.5 D, 1.1 D, and 0.54 D, respectively, in Group B. Effective corneal refractive power increased 0.6 D in Group A and 1.5 D in Group B. Mean change in SE SMR was -0.6 D in Group A and -1.4 D in Group B. Most regression occurred during the first 90 days. Difference maps showed five bow-tie, two irregularly irregular, one semicircular, and one homogeneous patterns. CONCLUSIONS: Noncontact Ho:YAG LTK produced peripheral corneal flattening and central corneal steepening. A greater change in curvature was produced using a two-ring treatment.

Computerized videokeratography and keratometry in determining intraocular lens calculations.

PURPOSE: To compare the accuracy of standard keratometry and computerized videokeratography (CVK) in determining intraocular lens (IOL) power calculations. METHODS: Using the EyeSys Corneal Analysis System, we prospectively obtained CVK maps on 75 eyes of 69 patients scheduled to have phacoemulsification with implantation of a posterior chamber intraocular lens. Using manifest refraction obtained at 6 weeks postoperatively, we optimized the calculations for the Hoffer Q, Holladay, and SRK/T formulas for standard keratometric and the following six CVK values: average curvatures at the 1 mm, 2 mm, and 3 mm zones, the keratometric equivalent at the 3 mm zone, and the Stiles-Crawford weighted averages over the 3 mm and 6 mm zones. The accuracy of these parameters was determined by calculating the mean absolute error and percentage of patients with accuracy within < or = 0.5 diopter (D), < or = 1.0 D, and < or = 2.0 D. RESULTS: Keratometrically derived data were slightly more accurate than the CVK-derived values. The average difference in mean absolute error between the keratometric and CVK values was 0.13 D for the Hoffer Q formula, 0.11 D for the Holladay, and 0.08 D for the SRK/T. CONCLUSIONS: In this population of patients, we found the CVK-derived corneal curvature values to be slightly less accurate than standard keratometry in predicting IOL power. However, CVK provides important corneal curvature data for IOL calculations in patients with abnormal or surgically altered corneal surfaces.

Corneal topographic changes and induced astigmatism resulting from superior and temporal scleral pocket incisions.

BACKGROUND AND OBJECTIVE: To determine the corneal topographic changes that are induced by superior and temporal 5-mm scleral pocket incisions. PATIENTS AND METHODS: The authors retrospectively reviewed the records of 43 patients who underwent phacoemulsification with posterior chamber lens implantation through unsutured 5-mm scleral pocket incisions, 24 superiorly and 19 temporally. Corneal curvature was measured using computerized videokeratography, and the induced astigmatism was calculated with the Holladay-Cravy-Koch formula. RESULTS: At 4 to 6 weeks, postoperatively there was mild flattening along with the meridian of the incision in both groups. The change was greater with the superior incisions, but the differences between the groups were not statistically significant. Surgically induced astigmatism was 0.7 D (+/-0.1 D) in the eyes that received superior incisions, and 0.3 D (+/-0.1 D) in the eyes that received temporal incisions; this difference was statistically significant (P < .03). CONCLUSIONS: At 4 to 6 weeks postoperatively, temporal 5.0-mm scleral pocket incisions provide more stable postoperative topography than do superior scleral pocket incisions.

Primary basal cell carcinoma of the limbal conjunctiva.

BACKGROUND: The authors describe a 66-year-old man with primary basal cell carcinoma of the conjunctiva. He presented with a fleshy nodular conjunctival lesion of 4 months' duration, located at the nasal limbus of the left eye. No associated cutaneous lesions were present. RESULTS: The lesion was completely excised, and results of histopathologic examination showed a primary basal cell carcinoma of the conjunctiva. CONCLUSION: This report provides clinicopathologic evidence that primary basal cell carcinoma can rarely occur in the conjunctiva. The authors summarize two well-documented previously reported cases of this unusual lesion.

Thromboxane A2 mediates hemodynamic and respiratory dysfunction in graded bacteremia.

Thromboxane A2 has been implicated as a mediator of cardiorespiratory dysfunction in sepsis. This study evaluated whether or not thromboxane A2 was necessary or sufficient for these adverse effects to occur during bacteremia. Fourteen adult swine under barbiturate anesthesia and breathing room air were monitored with arterial and pulmonary artery catheters. Animals were studied for 4 hours in three groups: group I, graded infusion of 10(9)/ml Aeromonas hydrophila; group II, Aeromonas hydrophila infusion plus SQ 29,548 (thromboxane A2 antagonist); and group III, U46619 (thromboxane A2 agonist) infusion in normal swine to pulmonary artery pressures observed in group I. Hemodynamic parameters, arterial and mixed venous blood gases, and plasma thromboxane B2 and prostaglandin 6-keto-F1 were measured. At sacrifice after 4 hours, wet-to-dry lung weights were calculated. Results indicated that thromboxane A2 was necessary and sufficient for the development of pulmonary hypertension and impaired alveolar-capillary oxygen diffusion in graded bacteremia. It was necessary but not sufficient for increased lung water to occur and sufficient but not necessary for decreased cardiac index and stroke volume index. Thromboxane A2 was neither sufficient nor necessary to the pathophysiology of systemic hypotension during graded bacteremia. Plasma prostaglandin 6-keto-F1 levels were increased in hypotensive animals with sepsis, suggesting its involvement in hypotension during sepsis.