Corneal endothelial changes after divide and conquer versus chip and flip phacoemulsification.

PURPOSE: To evaluate changes in central corneal endothelial cells and corneal thickness after divide and conquer phacoemulsification and chip and flip phacoemulsification. SETTING: Houston Eye Clinic, Houston, Texas, USA. METHODS: Forty-four eyes were randomly assigned to one of two groups to have divide and conquer (D/C Group) or chip and flip (C/F Group) phacoemulsification with implantation of a posterior chamber, foldable, silicone intraocular lens performed by one surgeon. Of these, 41 eyes of 37 patients (22 D/C Group, 19 C/F Group) met the inclusion criteria. All surgeries were uneventful. A complete eye examination including specular microscopy and pachymetry was performed preoperatively and 1 week and 1 and 3 months postoperatively. RESULTS: There were no significant between-group differences in any of the following means: sex; age; time at 70% phaco power; total phacoemulsification time. No correlation was found between ultrasound time and increased corneal thickness except for a significant increase in percentage of hexagonal cells in the C/F Group at 1 month. The only statistically significant between-group differences were greater endothelial cell loss in the C/F Group at 1 month and the percentage change in hexagonal cells at 1 week (1.1% increase, D/C Group; 10.7% decrease, C/F Group). CONCLUSION: The divide and conquer technique led to less endothelial loss and hexagonal cell change than the chip and flip technique, although at 3 months the differences were not significant.

The effect of redeepening incisions on radial keratotomy outcome.

BACKGROUND: Patients scheduled to undergo radial keratotomy in both eyes received redeepening incisions in one eye and single pass incisions in the other. Eye and order of surgery were assigned randomly and surgical parameters were otherwise identical in the two eyes. METHODS: This study was designed to measured the improvements in myopia obtained by radial keratotomy, with and without redeepening incisions. RESULTS: There was a greater decrease in spherical equivalent manifest refraction in the redeepening group than in the control group at 1 week (0.41 D) and 1 month (0.36 D) after surgery, as measured by keratometry. The difference in change between groups was 0.41 D at one week, 0.36 D at 1 month, and 0.26 D at 3 months. Change in spherical equivalent was significantly more in the redeepened group at 3 months after surgery (0.37 D); however, the improvement constituted only 8.8 percent of the decrease in myopia achieved by radial keratotomy without redeepening (3.87 D). CONCLUSIONS: Although redeepening yields an incremental effect in the correction of myopia, the technical difficulties of redeepening and the increased chance of perforation of the cornea with redeepening outweigh the benefits of the procedure.

Effect of incision direction on radial keratotomy outcome.

The goal of maximizing radial keratotomy results by using optical-zone-directed (centrally directed) incisions rather than limbus-directed (peripherally directed) incisions is evaluated in this prospective study. Five patients had bilateral radial keratotomy, with optical-zone-directed incisions in one eye and limbus-directed incisions in the other. The order of surgery and eye was randomly assigned. Patients were evaluated preoperatively, at one week, and at one month. There were no significant differences preoperatively between the two groups of eyes in spherical equivalent or keratometry. At one week postoperatively, however, there were significant group differences in spherical equivalent changes (P less than .010). Eyes with limbus-directed incisions were -2.2 diopters (D) myopic, on average, while eyes with optical-zone-directed incisions were near emmetropic, with a mean spherical equivalent of 0.10 D. Because of these results, we stopped randomizing cases at this point. The difference in surgical effect was still significant at three months (P less than .01); eyes with limbus-directed incisions had an average of 3.5 D less surgical effect than eyes with optical-zone-directed incisions.

Combined therapeutic approach to malignant lacrimal gland tumors.

The medical records of 13 patients with primary malignant lesions of the lacrimal gland revealed adenoid cystic carcinoma as the most common malignant tumor. The histologic cell type, neural invasion, and bony destruction were correlated with localized control and ultimate survival. Surgical removal of the lacrimal gland was adequate treatment for low-grade mucoepidermoid carcinoma confined to the gland itself. Combining a radical surgical removal of the area in planned sequence with high voltage radiation therapy offered the only reasonable hope for localized control in the more aggressive cell types or in tumors with neural invasion or bony involvement. A 40%-localized control and survival rate was achieved in the adenoid cystic carcinoma group of patients. Radiation therapy administered for cancer that obviously recurs after surgical resection was generally unsuccessful.