The role of intraocular lenses in anterior chamber contamination during cataract surgery

The findings of prenatal ultrasound diagnosis were compared with the autopsy findings in 183 fetuses (between the 14th and 24th week of gestation), aborted for fetal malformations in the period from 1995 to 1997. In these 183 cases, the primary diagnosis showed 50 central nervous system anomalies, 48 cardiovascular system anomalies, 42 genitourinary system anomalies, 18 respiratory system anomalies, 8 skeleton system anomalies, 6 gastrointestinal system anomalies and 11 other abnormalities. Of the total number of cases, 41% had multiple malformations. In 144 cases (78%), the prenatal diagnosis was confirmed by autopsy, in 36 cases (20%) the prenatal diagnosis was confirmed with additional significant pathology, and in only 3 cases (2%) the prenatally detected malformation was not confirmed by pathological examination. Autopsy remains an important component of the evaluation of fetal losses after induced abortion.     

Long-term intraocular pressure control after cataract extraction with trabeculectomy: phacoemulsification versus extracapsular technique

Mutations of the p53 gene are associated with a number of non-lymphoid cancers of the dog. The present study investigates the p53 gene status within canine patients treated for primary and secondary lymphoma. Three out of eight patients exhibited p53 gene mutations. These included one patient with a germ line mutation and two patients with de novo p53 mutations associated with the secondary lymphoma. Allelic loss of the p53 gene was also observed within primary and secondary tumours of the three canine patients. The results indicate that germ line p53 mutations exist in dogs and may be involved in the known predisposition of some breeds to cancer. The presence of therapy-related p53 point mutations was found to be associated with chemoresistant secondary lymphomas. A causative role for DNA-damaging chemotherapy in de novo mutation of the p53 gene is discussed. Characterization of p53 inactivation in canine tumorigenesis may provide a valuable clinical model for assessing the efficacy and optimal therapeutic regimens of anti-cancer agents.     

The frequency of secondary cataract after extracapsular cataract extraction

A complication of extracapsular cataract extraction is posterior capsule opacification (secondary cataract). In this study we found that 26.0% of patients operated for cataract with extracapsular technique were treated for secondary cataract. The average postoperative time to treatment with Nd-YAG-lasercapsulotomy was 15.2 months with a follow-up time of 34 months.     

Conversion from phacoemulsification to extracapsular cataract extraction: incidence, risk factors, and visual outcome

PURPOSE: To evaluate the incidence, risk factors, and visual outcome in cases converted from phacoemulsification to routine extracapsular cataract extraction (ECCE). SETTING: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. METHODS: A retrospective study was performed in 540 eyes that had clear corneal phacoemulsification performed by an experienced phacoemulsification surgeon. The cases in which phacoemulsification was initiated and then converted to ECCE were studied. The main parameters evaluated were the factors responsible for the conversion, corneal endothelial cell loss, and visual outcome. RESULTS: Twenty eyes (3.7%) required conversion to ECCE during phacoemulsification. Pupillary miosis (6 cases), posterior capsule rupture (5 cases), prolonged phaco time (4 cases), posterior extension of the capsulorhexis (2 cases), corneal thermal burn (1 case), subluxation of the lens (1 case), and malfunctioning of the ultrasonic handpiece (1 case) were the reasons for the conversion. The mean percentage of endothelial cell loss was 11.06% +/- 2.3 (SD); 18 cases (90.0%) achieved a visual acuity of 20/40 or better at 6 weeks. CONCLUSIONS: Intraoperative pupillary miosis, posterior capsule rupture, and very hard nuclear cataract causing prolonged phacoemulsification were the major risk factors for conversion to ECCE. Optimal preoperative preparation and prompt recognition of complications during phacoemulsification can lead to timely conversion to ECCE to achieve a good visual outcome.     

Anterior chamber contamination during cataract surgery with intraocular lens implantation

PURPOSE: To measure anterior chamber bacterial and fungal contamination at the beginning and end of cataract surgery with intraocular lens (IOL) implantation in a large series of patients and to determine the influence of preoperative treatment and operative technique on contamination. SETTING: Department of Ophthalmology, County Hospital of Salzburg, Austria. METHODS: This prospective study comprised 700 consecutive patients having planned cataract extraction (511 phacoemulsification, 189 extracapsular cataract extraction [ECCE]). Thirty-four patients required an anterior vitrectomy; 8 myopic patients did not receive an IOL. A preoperative smear and two intraoperative (at the beginning and end of surgery) anterior chamber aspirates were obtained from each patient. Postoperative smears were obtained at discharge. Three preoperative treatments were evaluated: no lacrimal system irrigation, no topical antibiotic (n = 282); lacrimal system irrigation with balanced saline solution, no topical antibiotic (n = 243); lacrimal system irrigation, antibiotic (neomycin) eyedrops (n = 175). All patients received topical indomethacin twice a day preoperatively. RESULTS: Preoperative conjunctival smears showed bacterial growth in 76.6% of eyes, with coagulase-negative staphylococci (75%) the most common bacteria. Anterior chamber aspirates were culture positive in 14.1% at the beginning and in 13.7% at the end of surgery, with coagulase-negative staphylococci and corynebacteria the most common. Contamination rates of conjunctival smears taken at discharge were significantly lower (35%) than those taken preoperatively. There was no statistically significantly higher risk of anterior chamber contamination in eyes having ECCE than in those having phacoemulsification. Preoperative treatment did not statistically significantly influence intraoperative aqueous humor contamination rates. There were no cases of acute postoperative endophthalmitis. CONCLUSION: Bacteria entered the anterior chamber during cataract extraction and remained there at the end of surgery in a significant percentage of patients. Surgical technique, preoperative antibiotics, and preoperative lacrimal system irrigation had no statistically significant effect on contamination.     

Results of trabeculectomy combined with phacoemulsification versus trabeculectomy combined with extracapsular cataract extraction in patients with advanced glaucoma

We compared the results of trabeculectomy combined with phacoemulsification (n = 16) with those of trabeculectomy combined with extracapsular cataract extraction (n = 18). There was no significant difference between the two groups in terms of early or chronic postoperative intraocular pressure (IOP) control or in terms of the number of glaucoma medications prescribed postoperatively. However, by 12 weeks postoperatively, bleb height and extent were significantly greater in the phacoemulsification group. There was no significant difference between the groups in terms of postoperative spheroequivalent, astigmatism, or cylindrical axis. The mean final visual acuity, however, was less in the extracapsular group. We conclude that phacoemulsification combined with trabeculectomy offers a safe and effective technique to control postoperative IOP in patients with glaucoma.     

Corneal endothelium in patients with diabetes after extracapsular cataract extraction with intraocular lens implantation in the posterior chamber

We have examined endothelial cell density before and 3, 6, 12 months after extracapsular cataract extraction with intraocular lens implantation (posterior chamber) in diabetic patients and in non-diabetics. We have not found statistically significant differences between the mean loss of endothelial cells due to surgery in diabetic and non-diabetic patients.     

Intraoperative complications of planned extracapsular cataract extraction versus manual nucleofragmentation

PURPOSE: To compare the intraoperative complications of planned extracapsular cataract extraction (ECCE) with those of manual nucleofragmentation. SETTING: Hospital de la Esperanza, Universitat Autónoma de Barcelona, Spain. METHODS: This retrospective study comprised 567 eyes; 444 had planned ECCE and 123, manual nucleofragmentation through a scleral tunnel incision. RESULTS: No significant differences between techniques were found in terms of intraoperative complications (P < .05). Manual nucleofragmentation did not increase the risk of intraoperative complications (P < .05). CONCLUSIONS: Although phacoemulsification is the procedure of choice in many cases, manual nucleofragmentation is a safe and valid alternative that achieves the goals of small incision cataract surgery.     

Prospective evaluation of external ocular microbial growth and aqueous humor contamination during cataract surgery

Primary cultures of porcine brain capillary endothelial cells grown on collagen coated polycarbonate membranes were used to build up an in vitro-model for the blood-brain barrier. Improved cultivation techniques allowed cell-storage and experiments under serum-free conditions. We employed this model to perform permeability studies in vitro with the radioactively labelled marker substances sucrose, retinoic acid, retinol, haloperidol, caffeine, and mannitol. Permeability values obtained with this blood-brain barrier model (1. 0x10-6 cm/s for sucrose, 6.2x10-6 cm/s for retinoic acid, 4.8x10-6 cm/s for retinol, 49.5x10-6 cm/s for haloperidol, 62.4x10-6 cm/s for caffeine, and 1.8x10-6 cm/s for mannitol) show a good correlation to data which are already known from in vivo-experiments. As judged by the sucrose permeability our blood-brain barrier model is less permeable than numerous other models published so far. Therefore it represents a powerful tool for in vitro-prediction of blood-brain barrier permeability of drugs and offers the possibility to scan a large quantity of drugs for their potential to enter the brain.     

Results and complications after extracapsular cataract extraction in eyes with pseudoexfoliation syndrome

Postoperative results and complications in 136 eyes with pseudoexfoliation syndrome were compared to 744 eyes without pseudoexfoliation syndrome in a consecutive study. The patients were followed for 4 months postoperatively. Excluding cases with glaucoma, 81.4% of the pseudoexfoliation eyes and 83.0% of the eyes without pseudoexfoliation achieved a corrected visual acuity of 5/8.5 or better. IOL malposition was rare in both groups (1.5% in the pseudoexfoliation group and 1.6% in the group without pseudoexfoliation). IOP elevation the first day postoperatively occurred most often in the pseudoexfoliation eyes. In the pseudoexfoliation eyes, postoperative iritis and cellular precipitates were demonstrated in 16.2% and 11.0%, respectively, compared to 3.8% and 3.2% in the eyes without pseudoexfoliation (p < 0.001). The frequency of an inflammatory reaction was highly correlated to small pupil size during operation in both groups.     

Changes in anterior chamber depth and intraocular pressure after phacoemulsification and posterior chamber intraocular lens implantation

BACKGROUND AND OBJECTIVE: To determine anterior chamber depth (ACD) and intraocular pressure (IOP) following uncomplicated cataract extraction with phacoemulsification and posterior chamber intraocular lens (IOL) implantation. PATIENTS AND METHODS: The ACDs and IOPs of 56 patients were prospectively evaluated after phacoemulsification and IOL implantation. Measurements of ACD were performed using ultrasonography and measurements of IOP were performed using a Goldmann applanation tonometer preoperatively and at 1 week and 1, 3, 6, and 9 months postoperatively. RESULTS: The mean IOP had decreased and the mean ACD had increased significantly by 1 month postoperatively (P < .03 and P < .01, respectively). Between 1 and 3 months, a significant increase in ACD (P < .05) and decrease in IOP (P < .01) was also observed. The ACD peaked (3.51 +/- 0.45 mm) and the IOP reached its lowest value (10.05 +/- 2.23 mm Hg) at 3 months postoperatively. The reduction in IOP and increase in ACD remained significant during the follow-up period, compared with the preoperative values. CONCLUSION: These results suggest that increases in ACD and decreases in IOP occur in selected patients after uncomplicated cataract extraction by phacoemulsification with IOL implantation.     

Retinal detachment following intracapsular and extracapsular cataract extraction. A comparative, retrospective follow-up study

In a retrospective study we reviewed the post-operative incidence of retinal detachment in a consecutive series of 762 eyes operated on with intracapsular cataract extraction and a consecutive series of 1351 eyes operated on with extracapsular cataract extraction. Follow-up time was 2 1/2-4 1/2 years in both series. The incidence of retinal detachment was 0.79% after intracapsular cataract extraction and 0.44% after extracapsular cataract extraction. The difference was not statistically significant. Age below 70 years was not statistically significantly correlated to retinal detachment.     

Treatment of anterior chamber fibrin following cataract surgery with tissue plasminogen activator

Three patients who developed anterior chamber fibrinous exudates after cataract surgery were treated with tissue plasminogen activator injected into the anterior chamber. There was prompt dissolution of the fibrinous exudates and no observed complications. When fibrinous exudates occur in high-risk patients after cataract surgery, tissue plasminogen activator provides an excellent means of clearing the fibrin.     

Cell proliferation on the outer anterior capsule surface after extracapsular lens extraction in rabbits

PURPOSE: To use light microscopy to evaluate the presence and distribution of cells that proliferate on the outer surface of the anterior capsule after experimental lens extraction in rabbit eyes. SETTING: Research Laboratory, Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan. METHODS: Extracapsular lens extraction, with or without implantation of a poly(methyl methacrylate) intraocular lens, was performed in 10 adult albino rabbits under general anesthesia. Animals were killed 1 month postoperatively. Each eye was embedded in paraffin and examined by light microscopy. RESULTS: A capsular bag composed of the anterior and posterior capsules was observed. Mononuclear cells, presumed to be lens epithelial cells (LECs), had proliferated in the space between the capsules as well as on the outer surface of the anterior capsules, in association with an accumulation of extracellular matrix. CONCLUSION: After lens extraction, LECs migrated to and proliferated on the anterior surface of the anterior capsule.     

Long-term evaluation of primary anterior chamber intraocular lens implantation in complicated cataract surgery

The long-term visual outcome and complications related to the use of a semiflexible open-loop all-PMMA anterior chamber intraocular lens were evaluated in 40 eyes in which the capsular support was lost. The mean follow up time was 2.3 years (range 6 months to 6.7 years). 55% of the eyes had exfoliation syndrome. 68% (27 of 40 eyes) obtained a visual acuity of 0.5 or better, and only in one of the remaining eyes decreased visual acuity was related to cataract surgery (cystoid macular oedema). No cases of corneal decompensation, uveitis-glaucoma-hyphaema syndrome or retinal detachment have developed, and no IOLs have been explanted. Based on these results, the use of a modern anterior chamber intraocular lens can be suggested at least in old persons, if the capsular support is lost.