Predicting the refractive result after cataract surgery

PURPOSE: To study the accuracy of predicting visual results after cataract surgery using a mathematical model of surgically induced refractive change and a previously published regression formula predicting uncorrected visual acuity as a function of the resulting spherocylinder. SETTING: Outpatient cataract clinic at a university hospital. METHODS: In this prospective study with a 4 month follow-up, 333 patients had phacoemulsification using a 6 or 4 mm scleral tunnel incision. Final refraction and uncorrected visual acuity were predicted based on preoperative and 1 day postoperative measurements, which were compared with the final visual results. RESULTS: A significant correlation was found between the observed and the predicted visual acuity in each eye (P < .01). CONCLUSION: The visual outcome of cataract extraction can be predicted from a theoretical model of the surgically induced refractive change.     

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.     

Phacoemulsification versus extracapsular cataract extraction: a comparative study of cell survival and growth on the human capsular bag in vitro

AIMS/BACKGROUND: Phacoemulsification is rapidly replacing conventional extracapsular cataract extraction (ECCE) as the method of choice for cataract surgery in the Western world. However, posterior capsule opacification (PCO) still remains the major postoperative complication, affecting 20-50% of patients, and results from persistent cell growth of epithelial cells remaining after surgery. This study aimed to compare cell survival and growth on capsular bags following ECCE and phacoemulsification surgery using an established human capsular bag culture system. METHODS: Sham ECCE and phacoemulsification cataract operations were performed on pairs of human donor eyes. Capsular bags were dissected free, pinned flat on a petri dish, and incubated with Eagle's minimum essential medium (EMEM) alone or EMEM supplemented with 10% fetal calf serum (FCS). Ongoing observations were made using phase contrast microscopy. RESULTS: Cell growth was observed across the posterior capsule of all preparations studied. It was found that there was no significant difference in the rate of cell growth on the posterior capsule with the two extraction methods, such that 50% confluency was achieved in 7.0 (SD 1.8) (n = 7) days for ECCE and 7.43 (2.1) (n = 7) days for phacoemulsification surgery. The physical changes to the capsule as a result of cell growth, such as wrinkling and capsular tensioning, were also seen in both groups. CONCLUSIONS: Cell survival and growth is dependent on the donor, rather than the surgical technique performed. There is no significant difference between phacoemulsification and ECCE surgery on the rate and nature of cell growth on the posterior capsule in vitro.     

Peroperative microbial contamination of anterior chamber aspirates during extracapsular cataract extraction and phacoemulsification

BACKGROUND: The normal conjunctival flora is one of the main sources of intraocular contamination during cataract surgery. The theory that the positive anterior chamber (AC) pressure during phacoemulsification (phaco), and the smaller wound utilised, might reduce the rate of contamination was studied. METHODS: The peroperative AC aspirates of 210 consecutive patients undergoing cataract surgery were assessed. In group 1, 100 patients underwent a standard extracapsular cataract extraction (ECCE). In group 2, 110 patients underwent phacoemulsification of the crystal-line lens through a scleral tunnel. AC aspirates from the Simcoe irrigation/aspiration cannula (group 1) and phaco probe (group 2) were collected and microbiological studies performed after direct and enrichment cultures. RESULTS: There were 29 (29%) positives in the ECCE group compared with 22 (20%) positive cultures from AC aspirates in the phaco group. Coagulase negative staphylococcus (CNS) was the commonest contaminant in both groups. CONCLUSION: Although there was a higher rate of AC contamination during ECCE, the difference was not statistically significant (p > 0.10, chi 2 = 2.31).     

Distressed or relieved? Psychological side effects of breast cancer screening in The Netherlands

PURPOSE: To compare three methods of combined cataract extraction and glaucoma surgery. METHODS: Retrospective review of 35 eyes of patients who had extracapsular cataract extraction and trabeculectomy using a corneoscleral incision (SAME), 54 eyes undergoing extracapsular cataract extraction and trabeculectomy using a separated corneal incision for cataract extraction and 43 eyes undergoing phacoemulsification and trabeculectomy. RESULTS: Ninety-one percent of the eyes in the SAME group, 85% of the SEPARATE group and 97% of the phacoemulsification and trabeculectomy group had an IOP < 22 mmHg at 6 months with or without medication (NS). Postoperative visual acuity and astigmatism were not significantly different between the groups. The number of eyes requiring YAG laser capsulotomy was significantly greater in the extracapsular cataract extraction and trabeculectomy (same and separated incision) as compared to the phacoemulsification and trabeculectomy group (P < 0.001). CONCLUSION: Phacoemulsification and trabeculectomy was not significantly more successful than the other methods of combined surgery. Although complication rates were similar, visual rehabilitation was faster and there was a reduced incidence of early posterior capsule opacification.     

Optimizing the review process of food additive and GRAS petitions. Overview of the workshop

PURPOSE: To assess endothelial barrier function, morphological appearance and corneal thickness three months after cataract surgery in order to evaluate intraoperative endothelial damage. METHODS: Endothelial permeability was examined by fluorophotometry, and contact specular microscopy and corneal pachymetry measurements were made in 40 patients (40 eyes) with senile, non-complicated cataracts one month before and three months after cataract surgery. Twenty eyes underwent uneventful phacoemulsification (Group 1) and 20 uneventful extracapsular cataract extraction (ECCE) with continuous curvilinear capsulotomy (Group 2). Results were analyzed using the two-tailed Student's t test, analysis of variance, and multifactorial and regression analysis. RESULTS: There was a significant postoperative increase in endothelial permeability in both groups (p < 0.001), but no real differences between the postoperative values (p = 0.07). Mean cell loss was 15.2% in ECCE and 18.3% in phacoemulsification (p = 0.4). There was a significant linear correlation between ultrasound time, cell loss and functional damage. Postoperative pachymetric measurements were not significant. CONCLUSIONS: Endothelial response showed no differences between the surgical techniques. Endothelial barrier function remained disturbed in spite of the apparent morphological stabilization. Corneal pachymetry is not useful for assessing postoperative endothelial changes.     

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.     

Functional decoupling of left ventricular beta-adrenoceptor in a canine model of obesity-hypertension]

OBJECTIVE: To determine whether selected preoperative medical, social, or behavioral factors predict the occurrence of cataract wound complications. PATIENTS AND METHODS: Patients who underwent cataract surgery at a Veterans Administration hospital were used in a case-control study. Cases were defined by the occurrence of any postoperative cataract wound gape with or without iris prolapse within 12 weeks of surgery and requiring repair in the operating room. Controls were patients who had no postoperative complications. Two controls were selected for each case patient and matched for surgeon. RESULTS: Thirty-one patients with postoperative wound complications occurred after 2041 cataract extractions (1.5%). Occurrence of wound complications was predicted by previous hematologic disorder (odds ratio, 2.9; 95% confidence interval, 1.1-8.1). Phacoemulsification surgery had a protective effect against wound complication (odds ratio, 0.2; 95% confidence interval, 0.09-0.64). There was no difference in final visual acuity and refractive indexes in patients with and without wound complications (P = .6 by Student t test). CONCLUSIONS: Most medical social and behavioral preoperative factors have limited discriminatory power in predicting who will have postoperative cataract wound complications. The association of previous hematologic disorders to predict the occurrence of wound complications varied with the level of alcohol use. Although this study was not primarily designed to assess the role of surgical technique, phacoemulsification cataract extraction had a statistically significant protective effect against wound complications. Visual outcome in patients with postoperative wound complications is generally very good.     

Vitrectomy for retained lens fragments after phacoemulsification

PURPOSE: Posterior lens fragments after phacoemulsification can be a serious complication of cataract surgery. This study is designed to evaluate the clinical features of eyes after pars plana vitrectomy has been performed to remove posteriorly dislocated lens fragments after phacoemulsification. METHODS: The authors performed a retrospective chart review of 126 consecutive eyes of 126 patients with dislocated lens fragments after phacoemulsification, managed with pars plana vitrectomy at Associated Retinal Consultants of Michigan. These eyes were operated on from January 1986 through January 1996. RESULTS: The relation of the intervals between cataract surgery and vitrectomy to various postoperative clinical parameters was studied. Clinical features at presentation included elevated intraocular pressure (IOP over 25 mmHg) in 52.4% of the eyes, uveitis in 69.6%, and corneal edema in 50.8%. Initial visual acuity was 20/400 or worse in 73.8% of the eyes. The mean preoperative visual acuity was 20/278 (median, 20/400), whereas the mean final visual acuity was 20/40 (median, 20/50) after a mean follow-up of 18.9 months. Retinal detachments were found in 20 eyes: 7 before vitrectomy and 13 during or after it. After surgery, 44% of eyes achieved a final visual acuity of 20/40 or better and 90% were 20/400 or better. The distribution of best-corrected final visual acuities among the eyes showed statistically significant differences based on the type of intraocular lens (IOL) used, with posterior chamber IOL greater than anterior chamber IOL, and anterior chamber IOL greater than aphakia. Reasons for a poor visual outcome included persistent corneal edema (four eyes), retinal detachment (two eyes), central retinal vein occlusion (two eyes), age-related macular degeneration (two eyes) glaucoma (one year), and endophthalmitis (one eye). CONCLUSIONS: There were no statistically significant differences between early (< 7 days) and delayed (8 days or more) vitrectomy when increased IOP, corneal edema, choroidal effusions, cystoid macular edema, and visual acuity were analyzed. The use of vitrectomy to remove posteriorly dislocated lens fragments has been shown to be an effective treatment method that significantly reduces the inflammatory response and hastens visual recovery.     

Impact of genetics on disease resistance

PURPOSE: To evaluate the safety and efficacy of phacoemulsification, primary posterior capsulorhexis (PCCC), and primary intraocular lens (IOL) implantation for uveitic cataracts. SETTING: Institutional practice. METHODS: Fifteen consecutive eyes of 13 patients with various causes of uveitis received anterior capsulorhexis, phacoemulsification, PCCC, and in-the-bag implantation of a heparin-surface-modified IOL for visually disabling cataract. The safety and efficacy of the combined operation were studied prospectively. RESULTS: At a mean follow-up of 16.9 months (range 8 to 30 months), all eyes had a clear central visual area. Fourteen of 15 eyes (93.3%) had good visual improvement after surgery. Eight eyes (53%) achieved a best corrected visual acuity (BCVA) of 20/30 or better and 6 (40%), 20/20 or better. Seventy-three percent of eyes attained a BCVA of 20/80 or better. The mean improvement in visual acuity was 5.2 Snellen lines (range 0 to 11 lines). No cases of uveitis flare-up or other major complications related to the cataract surgery occurred. CONCLUSIONS: The study's preliminary results are encouraging and indicate that phacoemulsification, PCCC, and IOL implantation can be considered in patients with visually disabling uveitic cataract.     

Functional impairment associated with psychological distress and medical severity in rural primary care patients

PURPOSE: To evaluate intraoperative endothelial damage after planned extracapsular cataract extraction (ECCE) with difference capsulotomy techniques and phacoemulsification. SETTING: San Carlos University Hospital, Castroviejo Institute, Madrid, Spain. METHODS: In this prospective, randomized study, 60 patients with senile cataract scheduled for cataract surgery were divided into three groups of 20 each: Group 1 had phacoemulsification; Group 2, planned ECCE with continuous curvilinear capsulorhexis; and Group 3, ECCE with letter-box capsulotomy. Preoperatively and 3 months postoperatively, endothelial cell density, percentage of hexagonality, and the cell size variation coefficient were determined by contact specular microscopy; endothelial permeability was examined by anterior segment fluorophotometry and central corneal thickness, by ultrasonic pachymetry. Results were analyzed using the two-tailed Student's t-test and analysis of variance. RESULTS: In all three groups, endothelial permeability and cell loss increased significantly from the preoperative values, but there were not significant differences among the postoperative values. Mean cell loss was 11.8% in Group 1, 12.8% in Group 2, and 10.1% in Group 3. There were no differences between the preoperative and postoperative morphometric indexes. Postoperative pachymetric measurements were not significant. CONCLUSIONS: Endothelial response was not statistically significantly different among the surgical techniques, although endothelial damage was lower in Group 3, which could indicate a protective effect of the anterior capsule during cataract extraction. Endothelial barrier function remained disturbed despite the apparent morphological stabilization.     

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.     

Evaluation of a 3-piece silicone intraocular lens with poly(methyl methacrylate) haptics

PURPOSE: To evaluate the safety and performance of a foldable silicone intraocular lens (IOL) in small incision phacoemulsification surgery. SETTING: Vaasa Central Hospital, Vaasa, Finland. METHODS: Phacoemulsification with primary implantation of a posterior chamber IOL was performed in 50 patients. All eyes were implanted with a CeeOn IOL (model 920, Pharmacia & Upjohn) with a silicone optic and poly(methyl methacrylate) haptics. The ease of folding, implanting, and unfolding the IOL in the bag were recorded. Visual acuity, postoperative complications, optic decentration, and optic tilt were measured at 5 postoperative visits. The IOLs were evaluated for haze and discoloration and the IOL surface, for inflammatory or pigment deposits. Follow-up was 12 months. RESULTS: In 44 of 50 cases, folding the IOL was easy, and in 46 of 50, unfolding the IOL was controlled. The mean follow-up was 11.45 months +/- 0.52 (SD). No postoperative complications occurred, and 96% of patients achieved a best corrected visual acuity (BCVA) of 0.5 or better and 56%, a BCVA of 1.0 or better. The IOL decentration was less than 0.25 mm in 89% of cases, and there was no optic tilt. The neodymium:YAG laser capsulotomy rate was 11%. CONCLUSION: Good visual outcome and excellent centration were achieved with the CeeOn model 920 IOL. It is therefore suitable for small incision cataract surgery. Because of the IOL's smooth, polished surface, the choice of instruments for folding and implantation is important.     

Secondary intraocular lens implantation after cataract surgery in children

PURPOSE: To report results of secondary intraocular lens implantation after cataract surgery in children. METHODS: We reviewed clinical records for a 5-year period of patients who had cataract surgery in childhood and received a secondary intraocular lens implant. We studied indications for secondary intraocular lens placement; surgical procedures for intraocular lens implantation; preoperative and postoperative visual acuity, refractive error, and binocular status; and complications of the procedure. RESULTS: A secondary intraocular lens was placed in 28 eyes of 25 patients who had cataract surgery in childhood. In 20 eyes, the lenses were placed in the ciliary sulcus. The other eight eyes had insufficient capsular support for an intraocular lens; in two, the intraocular lens was placed in the anterior chamber and, in six, in the posterior chamber with suture fixation to the sclera. Twenty of 28 eyes (71%) had measurable improvement in visual acuity; only one eye had a decrease in visual acuity of 2 lines. Fifteen patients (54%) had a final refraction within 1.50 diopters of the fellow eye; 21 (75%) were within 3.00 diopters. During follow-up, two eyes developed glaucoma. One had transient pressure elevation; one required two filtration procedures. Three patients required Nd:YAG capsulotomy. Six patients demonstrated Worth fusion at distance and near; three demonstrated 200 seconds of arc or better stereo visual acuity. CONCLUSION: Secondary placement of an intraocular lens in the posterior chamber appears to be a safe, effective alternative for correction of aphakia in the contact lens- or spectacles-intolerant child or young adult.     

Assessment of waiting time and priority setting by means of a national register

To increase access to care for cataract patients in Sweden, it was decided, starting in 1992, that all cataract patients listed for surgery and with priority should have their cataract extraction performed within three months. To evaluate the effect of this waiting time guarantee, a National Cataract Register (NCR) was initiated in late 1991. In 1992, 81% of all cataract extractions performed in Sweden were reported to the NCR; in 1993 this figure was 92%. Reasons for this high participation ratio are discussed. In 1993, 74.4% (range between different clinics, 40-99%) of the patients with priority had their operation performed within three months. Great variation in visual acuity and age was found in patients with priority among the different surgical units.     

Prothrombin gene G20210-->A transition is a risk factor for cerebral venous thrombosis

OBJECTIVE: The objective of the study was to determine the long-term outcome of patients with uveitis who underwent extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PCIOL) implantation. DESIGN: Retrospective review. PARTICIPANTS: Twenty-eight patients (36 eyes). INTERVENTION: Extracapsular cataract extraction and PCIOL implantation. MAIN OUTCOME MEASURES: Level of best-corrected Snellen visual acuity, change in visual acuity, length of follow-up, long-term findings, and complications. RESULTS: In long-term follow-up (mean, 81.4 months), 94% of eyes had visual acuity improvement compared with preoperative levels. Average change in visual acuity for all eyes was an improvement of 6.4 Snellen lines; 75% of eyes were 20/40 or better. The prevalences of cystoid macular edema (CME), epiretinal membrane (ERM), and posterior capsule opacification (PCO) were 56%, 56%, and 58%, respectively. CONCLUSIONS: Patients with uveitis who are treated with ECCE with PCIOL implantation can have successful visual results in long-term follow-up despite the prevalence of PCO or macular abnormalities such as CME and ERM.     

A prospective evaluation of a diffractive versus a refractive designed multifocal intraocular lens

OBJECTIVE: To evaluate prospectively a diffractive (811E, Pharmacia; power add +4.0 D) versus a refractive (PA154N, Allergan; power add +3.5 D) designed multifocal lens. PARTICIPANTS: Eighty patients planned for cataract surgery without additional ocular pathologies were randomized into the diffractive or refractive group, respectively. INTERVENTION: A standardized no-stitch phacoemulsification with implantation of one of the two multifocal lenses was performed in each patient. MAIN OUTCOME MEASURES: Distance and near-visual acuity, contrast sensitivity, low contrast visual acuity, glare visual acuity, and depth of focus were measured after surgery. RESULTS: All treated patients had best-corrected visual acuities of 20/30 or better. Near-uncorrected vision was significantly better (P < 0.0001) with the diffractive lens (mean, J1) than with the refractive lens (mean, J4). Low contrast visual acuity (61 +/- 12% versus 59 +/- 9%), glare visual acuity (39 +/- 19% versus 38 +/- 14%), and contrast sensitivity (1.48 +/- 0.08 versus 1.50 +/- 0.12) were not significantly different between the groups. CONCLUSIONS: Both lens designs showed satisfactory functional results with advantages for the diffractive lens design.     

Astroglial changes in the cerebral cortex of AIDS brains: a morphometric and immunohistochemical investigation

Sutureless phacoemulsification with implantation of a 7-mm PMMA intraocular lens was performed through a modified scleral tunnel in 100 consecutive patients. This was done to minimize postoperative astigmatism while retaining the advantages of implanting intraocular lenses with large optics. Visual and keratometric results and complications are reported after completion of a follow-up period of 6 months for the first 30 patients. Average uncorrected visual acuity improved from 0.13 preoperatively to 0.30 as early as 1 week postoperatively. Average best-corrected visual acuity improved from 0.23 before surgery to 0.51 as early as 1 week after surgery. No significant changes in visual acuity were recorded thereafter. The absolute value of keratometric astigmatism was not increased significantly at any postoperative examination time. The induced cylinder (Jaffe and Clayman) shifted from -1.27 D x 166 degrees at 1 week to 1.18 D x 91 degrees at 1 month postoperatively without further relevant changes thereafter. Endothelial cell loss did not differ from that reported by other authors after conventional cataract surgery. Corneal thickness was not increased significantly at any postoperative examination time. Implantation of intraocular lenses with large optics through a scleral tunnel allows quick visual rehabilitation as well as early stability of refraction.     

Posterior chamber intraocular lens use in children

PURPOSE: The authors report on the efficacy of intraocular lens implantation during pediatric cataract surgery and the results of a consecutive series of intraocular lens implantation in children. METHODS: Twenty-one children underwent implantation of intraocular lenses in 23 eyes. Twenty-one surgeries were primary implantation immediately following anterior lensectomy. Two surgeries were secondary implantations. Primary posterior capsulectomy was performed in 18 of 21 primary implantations. All but two eyes underwent a primary anterior vitrectomy. Topical prednisolone acetate was administered in all cases. Oral prednisone was administered in 17 of 23 cases. Pre- and postoperative visual acuity, cycloplegic refraction, and postoperative complications related to inflammation such as intraocular lens (IOL) capture, IOL decentration, and posterior capsule opacification were examined. RESULTS: Eighteen of 23 eyes have achieved a visual acuity of 20/40 or better. None of the cases in which oral prednisone was used developed complications related to postoperative inflammation. One of the six cases (17%) in which oral prednisone was not used developed such complications. CONCLUSION: Intracular lens implantation accompanied by primary posterior capsulectomy, anterior vitrectomy, and management of postoperative inflammation appears to provide appropriate and safe optical rehabilitation in children.