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The aim of the present study was to investigate the regenerative ability of the central corneal epithelium in an in vivo situation, as previous studies have been contradictory regarding the proliferative potential of these cells. Paracentral ringshaped defects were made in rat corneal epithelium, using filter paper soaked in n-heptanol. Cell counts, labelling indices and mitotic rates were measured in sections from the corneal and the adjacent conjunctival epithelium 12 and 28 h after the injury. The cell counts indicated that also central corneal epithelial cells migrate in the early phase of wound healing. No proliferative response was seen in the central corneal epithelium after 12 h. At 28 h both the peripheral and central corneal cells showed an enhanced labelling index, while the mitotic rate only was increased in the periphery. Different cell cycle times and different levels of differentiation of the cell population across the cornea may explain the delayed proliferative response in the central cornea.

Central corneal epithelial defects with diameter 3.5 mm were made with n-heptanol in the right eyes of rats. Erosions of the same size were made by mechanical scraping in the left eyes of the same animals. All the erosions were covered by epithelium after one day. After one day the mitotic rate and the labelling index were higher in the n-heptanol treated corneas compared to the mechanically abraded ones. Both methods produced similar mitotic rates and labelling indexes after 3 and 12 days. The results from wound healing studies using n-heptanol or mechanical scraping are therefore not entirely comparable because of the different regenerative responses after one day. However, the n-heptanol method is easier to perform and to standardize, and is therefore preferable.

PURPOSE The present study was to investigate, using cell kinetic methods, whether previous excimer laser treatment affected healing of later corneal epithelial erosions. METHODS The right eyes of rats underwent central excimer corneal stromal-epithelial ablations (ArF 193 nm, 228 pulses, diameter 3,5 mm, 17,3 mJ per pulse, depth about one third of corneal thickness) and were allowed to heal for 15 weeks. Then central circular epithelial abrasions (diameter 3 mm), using N-Heptanol and mechanical debridement, were made on both corneas. The rats were killed 1,2,4 and 6 days after the last treatment. The central stromal thickness, the epithelial cell density, the labelling index (LI) and the mitotic rate (MR) of the peripheral, the midperipheral and the central areas of the corneal epithelium were calculated for each timepoint. RESULTS The central stromal thickness increased equally in the two groups the first day after making the erosion, normalising in both groups during the following days. The corneal epithelium was restored at the same rate in both groups. The cell number per microscopic visual field, the LI and the MR were very similar for the two groups at all timepoints. CONCLUSION Previous excimer laser treatment does not seem to interfere with healing of later epithelial erosions, when studied with cell kinetic methods.

Purpose: To compare contrast sensitivity (CS) after implantation of a diffractive bifocal intraocular lens (IOL) and a monofocal IOL of similar design. Setting: Seven European centers. Methods: In this randomized, prospective study, CS was tested 5 months after cataract and IOL implantation surgery in 115 patients with a diffractive bifocal IOL and 106 patients with a monofocal IOL. It was also tested in a subgroup of 38 patients who had bilateral implantation of a diffractive bifocal IOL. Contrast sensitivity was tested using the Vision Contrast Test System (VCTS). Results: In patients with a best corrected visual acuity (BCVA) of 1.0 or better, the CS at all spatial frequencies (1.5 to 18 cycles/degree), both at distance and near, was slightly lower in the bifocal IOL group than in the monofocal group. Mean values were within the normal range. In patients with a BCVA of less than 1.0, the CS was lower and the difference between the bifocal and monofocal groups was less. In patients with bilateral bifocal IOLs, CS was better when tested bilaterally than when testing the better eye alone. Pupil size affected the results to a small degree. Contrast sensitivity appeared to improve over time after implantation of a diffractive bifocal IOL. Conclusions: In patients with cataract and no other eye pathology, the diffractive bifocal IOL will slightly reduce the CS at all spatial frequencies. In those with reduced visual acuity after cataract surgery, CS will be reduced accordingly. In this situation, the reduction from the diffractive bifocal optic would be minor.

In the present transmission electron microscopic study, regenerating rat corneal epithelium is examined at three different time points after chemical abrasion. Four days after the initial injury classical signs of regeneration are observed. At day 6 regeneration is less pronounced and epithelial differentiation dominates the morphological picture. Many basal cells are swollen and single electron-dense basal cells have a shrunken morphology (dark cells). Intercellular cytoplasmic sacs are common and some appear to be phagocytosed. At day 8 there are no signs of regeneration and neither dark cells nor swollen cytoplasmic sacs are seen. No signs of intraepithelial inflammation are seen at any time. "Odland"-like granules, which possibly play a role in epithelial desquamation, occur suprabasally in large numbers at all time points. We believe the simultaneous presence of dark cells and phagocytosis at day 6, without signs of inflammation, indicates ongoing apoptosis. Intraepithelial cell loss might explain the discrepancy between an increased proliferation rate and the absence of hyperplasia which has been reported at this time point.

The labeling index and the mitotic rate were measured at 4-hour intervals during the first 24 hours after a central abrasion had been made in the corneal epithelium of six groups of four rats each. The proliferative response was noted in the conjunctival, the limbal, and the corneal epithelium. After 24 hours, the density of epithelial cells was equal throughout the corneal epithelium, but there was only half the normal number of cells. Physiological mechanisms seem strongly to regulate the total number of cells per square unit throughout the healing corneal epithelium, but the nature of these mechanisms is unknown.

PURPOSE Study the efficacy and safety of a combined procedure for coexisting cataract and open angle glaucoma. METHODS Forty eyes of 33 patients with cataract and coexisting open angle glaucoma underwent phacoemulsification and trabeculectomy with Crozafon-De Laage punch. Data was recorded from the patients' hospital files and from a questionnaire answered by the patients' regular ophthalmologist. RESULTS After a mean follow-up time of 20.6 months (SD 4.9, range 12-31) the mean reduction in number of anti glaucoma drugs was 1.2 (SD 1.2) from 2.6 (SD 0.71) before operation to 1.4 (SD 1.12) at last visit (p

To determine the incidence, clinical presentation, etiology, and outcomes of postoperative endophthalmitis in Norway and to explore the potential of and establish a platform for improving diagnostics, prophylaxis, and treatment of postoperative endophthalmitis.All ophthalmic surgical units and relevant microbiology laboratories in Norway.A national registry of cases of postoperative endophthalmitis was established in 1996. All ophthalmic surgery units in Norway were asked to return forms including preoperative, perioperative, and postoperative data for each case of endophthalmitis occurring between January 1996 and December 1998 after any intraocular surgery irrespective of the time between the surgery and the onset of endophthalmitis symptoms. All microbiology laboratories in Norway were asked to return questionnaires regarding their routine handling procedures of eye specimens in cases of endophthalmitis.From 1996 to 1998, 111 suspected endophthalmitis cases were reported, all after cataract surgery. Eighty cases were culture positive, 75 with gram-positive bacteria, 4 with gram-negative bacteria, and 1 with Candida albicans. Depending on the definition, the incidence of postoperative endophthalmitis was between 0.11% and 0.16%. Thirteen percent of cases had "delayed" endophthalmitis. Twenty-nine percent of eyes had an outcome of permanent amaurosis or light perception visual acuity; 56% (47/84) retained or improved their categorized visual acuity in the affected eye compared to preoperatively. Positive bacterial growth was associated with a worse visual outcome (P =.008). The degree of inflammation when endophthalmitis was diagnosed and the visual outcomes were worse in cases with growth of streptococci than in cases with growth of staphylococci (P =.009 and P.001, respectively). The questionnaire to the microbiology laboratories revealed a lack of consensus on how to handle the specimens.Postoperative endophthalmitis remains a serious complication of intraocular surgery, although the prognosis depends greatly on the microbe isolated. Common guidelines should be established regarding clinical and microbiological diagnosis and treatment. Further improvement of the registry would make it a suitable platform for evaluating prophylactic treatments.

We present 3 patients diagnosed with myotonic dystrophy who developed recurrences of secondary opacification. One developed a dense posterior vitreous membrane. Patients with myotonic dystrophy may have an increased risk for recurrent secondary opacification and for developing intraocular fibrosis after cataract extraction.

Rats with excimer corneal ablations (ArF 193 nm, 228 pulses, diameter 3,5 mm, 17.3 mJ per pulse, depth about 1/2 of corneal thickness) in one eye were killed 1, 2, 4, 6 and 13 days after treatment. The other eye served as control. The cell number per microscopic vision field, the labelling index (LI) and the mitotic rate (MR) were calculated for the peripheral, midperipheral and central areas of the corneal epithelium. The cell number showed a uniform depression in the remaining corneal epithelium at Day 1, normalizing from the centre to the periphery. The LI was only significantly increased at Day 1, while the MR was statistically significantly increased peripherally at Day 2 and in all areas at Day 6. However, when the corneal epithelium was evaluated as a whole, the MR was significantly increased at days 1, 2 and 6. The proliferative response of the epithelium was very homogenous irregardless of the distance to the original lesion. Both the migratory and the proliferative phases of the healing process seemed to be delayed when compared to the healing of pure epithelial wounds. However, the initiation of an increase in DNA synthesis seems not to be delayed, indicating that it is primarily the G2 phase that has been prolonged with this ablation procedure. The stromal thickness was increased from about one half of the normal values immediately after the treatment to above normal values at Day 4, thereafter decreasing to normal values at Day 13. Thus, the regenerative ability of the stroma is more pronounced in rats than in humans, but also in humans regeneration of the stroma can possibly explain the regression of the myopic shift seen some time after excimer laser treatment.

Purpose: To compare a Pharmacia diffractive bifocal intraocular lens (IOL) with a monofocal lens of the same design without the diffractive grating. Setting:. Multicenter study. Methods: This randomized, prospective study comprised 70 patients with a monofocal IOL and 79 with a diffractive bifocal IOL. Follow-up was 5 to 6 months. Near and distance visual acuities, contrast sensitivity, patient satisfaction, and spectacle use were evaluated. Results: All patients achieved a best corrected visual acuity of 0.5 or better; 80% in the monofocal and 71 % in the bifocal group had a best corrected visual acuity of 1.0 or better. Without correction, 93% of the bifocal and 9% of the monofocal group could read J3 or better. With distance correction, 99% and 4%, respectively, could read J3 or better. Contrast sensitivity was slightly lower in the bifocal group at distance and near for all spatial frequencies. In the bifocal group, 46% never used spectacles for near tasks. Overall satisfaction was rated good by 86% of the monofocal and 85% of the bifocal group. Conclusions: The diffractive bifocal IOL performed well at distance and near. Patients who no longer require spectacles will benefit significantly from a bifocal IOL, but many with a bifocal IOL in one eye will require spectacles for the fellow eye.

In the present study a central corneal epithelial defect (diameter 3.5 mm) was made in both eyes at 12:00 h in one group of rats and at 24:00 h in another group to see if the regenerative proliferation is influenced by circadian rhythms. The labeling index and the mitotic rate were registered at 4-h intervals in the perilimbal conjunctiva, the limbal area, and different parts of the cornea from the following morning until noon the day after that. The most pronounced regenerative proliferation was seen in the midperipheral and peripheral cornea. The regenerative response occurred in both groups 24-28 h after the injury, but was highly influenced by the normal circadian rhythms, especially with regard to the mitotic rate. The results support the theory that even regeneration is influenced by a circadian proliferative factor.

A randomized, prospective, multicenter study evaluated the efficacy and safety of using collagen shields to deliver drugs after cataract surgery. Collagen shields saturated with an antibiotic and a steroid were placed in 90 eyes postoperatively. A control group of 93 eyes received the same drugs through a peribulbar/retrobulbar injection. One day after surgery, the shield group had significantly less corneal edema, conjunctival hemorrhaging, and postoperative pain and fewer corneal opacities. All symptoms except the conjunctival hemorrhaging disappeared by day seven. Our study suggests that using collagen shields for drug delivery after cataract surgery decreases tissue damage and increases patient comfort without adverse side effects.

Purpose: To compare intraoperative and postoperative complications in eyes with and without pseudoexfoliation having cataract surgery by phacoemulsification. Setting: Department of Ophthalmology, National Hospital, Oslo, Norway. Methods: Of 1152 consecutive phacoemulsification procedures, 164 cases with pseudoexfoliation (Group 1) and 916 cases without (Group 2) were followed for 4 months after cataract surgery in a prospective study. Of all cataract operations performed during that time, 96.2% were phacoemulsification procedures: 90.4 and 97.4% in eyes with and without pseudoexfoliation, respectively ( P Results: The frequency of capsular/zonular tear or vitreous loss was 9.6 and 3.7% in Groups 1 and 2, respectively ( P = .0002). A visual acuity of 0.5 or better was achieved in 86.5% of eyes in Group 1 and 92.4% in Group 2 ( P = .02). There were no statistically significant between-group differences in the frequency of a postoperative inflammatory response 1 day (6.7 versus 4.4%), 1 week (2.4 versus 1.6%), or 4 months (1.8 versus 0.9%) postoperatively. Conclusion: Phacoemulsification was safe in most eyes with pseudoexfoliation even though significantly more complications occurred intraoperatively in these eyes. The low frequency of an inflammatory response indicates that the presence of pseudoexfoliation does not significantly increase the risk of inflammation.