Secondary intraocular lens implantation

Mere aphakia is not an indication for secondary intraocular lens implantation. However, many patients with positive indications may be benefited most strikingly by this procedure. These indications are illustrated and results of the author's first 65 secondary implantations are analyzed.     

Endothelial damage from intraocular lens insertion

Previous studies have shown that approximately 40 per cent of the corneal endothelial cells can be lost at the time of intraocular lens insertion. Momentary contact between the methacrylate surface and the endothelial cells causes an adhesion between these surfaces and results in extensive cell damage upon separation of the surfaces. This type of damage appears to be due to a biophysical interaction between these surfaces and may be avoidable by altering the surface of the lens.     

Secondary intraocular lens implantation in children

OBJECTIVE: The study was designed to determine the visual outcome and indication of secondary posterior chamber intraocular lens (IOL) implantation. METHODS: The operation was performed on 34 eyes with aphakia in children after separation of posterior iris synechia from posterior capsule and formation of a posterior chamber space large enough to insert an intraocular lens. Based on whether the integrity of the posterior capsule was complete or not, various techniques of secondary IOL implantation were adopted. RESULTS: The follow-up periods ranged from 6 to 24 months. The results showed that 29 of the eyes (85.29%) achieved a post-operative corrected visual acuity equal to or better than that of the best corrected visual acuity before the surgery; the postoperative uncorrected visual acuities in 16 eyes (47.06%) and corrected visual acuities in 28 eyes (82.35%) reached 0.5 or better. CONCLUSION: Secondary posterior chamber IOL implantation is a safe and effective method in children who have a complete or partial posterior capsule.     

Reduced intraocular pressure after phacoemulsification and posterior chamber intraocular lens implantation

PURPOSE: To ascertain whether phacoemulsification with posterior chamber intraocular lens (IOL) implantation causes long-term reduction in intraocular pressure (IOP). SETTING: Private practice, Kempten, Germany. METHODS: Intraocular pressure was measured in both eyes of 120 consecutive patients who were unilaterally phakic after phacoemulsification a mean of 17 months +/- 17 (SD) previously. Mean age of the 36 men and 84 women was 76 +/- 10 years. Data were analyzed using binomial distribution and the Wilcoxon signed-rank test. RESULTS: The median ratio of IOP in the pseudophakic eye to IOP in the phakic eye was 0.83. The IOP was lower in the pseudophakic eye in 96 patients (80%). The median IOP was 12 mm Hg in the pseudophakic eyes and 14 mm Hg in the phakic eyes (P < .001). As measured by the interquartile range, IOP distribution was more centered in the pseudophakic than in the phakic eyes (3 versus 4). The IOP in the pseudophakic eyes remained lower to the last measurement, 5 years postoperatively, and appeared to be independent of patient age. Lower IOP in the pseudophakic eye was consistently present in patients with higher IOP in the phakic eye (16 to 22 mm Hg). CONCLUSION: Phacoemulsification with posterior chamber IOL implantation reduced IOP in most but not all patients with a preoperative IOP of 22 mm Hg or less. This reduction was maintained over several years, with the cause yet to be established. Lower IOP may decrease the risk of subsequent glaucomatous nerve damage in these patients.     

Refractive changes after pediatric intraocular lens implantation

PURPOSE: To report refractive changes after cataract surgery and intraocular lens implantation in infants and children. METHODS: In an ongoing prospective study, the refractive errors of all patients younger than 18 years undergoing intraocular lens implantation were determined at 6 weeks, 3 months, 6 months, and 1 year, and at least yearly thereafter. All patients with greater than 6 months of follow-up were included in the study. RESULTS: Eighty-three eyes of 81 patients were identified. Cataracts were traumatic in 32 eyes (38%) and developmental in 42 eyes (50%). At implantation, the mean (+/-SD) age was 6.3 +/- 4.6 years (range, 9 months to 17 years). The mean follow-up was 26.6 months (range, 6 months to 6.6 years). Patients 0 to 2 years old at the time of implantation demonstrated a mean myopic shift of -3.00 diopters during a mean follow-up period of 2.5 years. Patients 2 to 6 years old at the time of implantation demonstrated a mean myopic shift of -1.50 diopters in a similar follow-up period. Children aged 6 to 8 years experienced a mean myopic shift of -1.80 diopters during a mean follow-up period of 3.0 years, while children older than 8 years at the time of intraocular lens implantation experienced a mean myopic shift of -0.38 diopters during a mean follow-up period of 1.8 years. On average, the operated-on eye showed a greater mean myopic shift than the fellow eye. No statistically significant differences in refractive change were found in comparing amblyopic to nonamblyopic eyes, traumatic to nontraumatic cataracts, or primary to secondary intraocular lenses. CONCLUSIONS: Our data demonstrate a trend toward increasing postoperative myopia in pediatric patients undergoing intraocular lens implantation. This myopic shift is greatest in the younger age groups and persists until at least 8 years of age. There is much variability in the postoperative refractive changes, and predicting exactly when and where the refraction will stabilize for an individual patient is difficult.     

Phacoemulsification and posterior chamber intraocular lens implantation in uveitis

The effect of a pure alpha-adrenergic agent, methoxamine on ventricular fibrillation (VF) amplitude and the relation between hemodynamic parameters and survival in a rodent cardiopulmonary resuscitation (CPR) model were studied. Our results suggested that: 1) VF amplitude decreased during untreated VF, but it increased during pericardial chest compression: 2) methoxamine significantly increased the mean aortic pressure (MAP) and coronary perfusion pressure (CPP) but not VF amplitude, and the survival also increased due to elevation of CPP; and 3) all surviving animals with successful defibrillation had a higher VF amplitude.     

Myopic shift after intraocular lens implantation during childhood

PURPOSE: The purpose of the study is to evaluate the myopic shift that occurs in children 3 to 9 years of age who undergo cataract extraction with primary intraocular lens (IOL) implantation. METHODS: A review of 18 children (mean, 6.3 +/- 0.5 year; range, 3-9 years) who had undergone primary IOL implantation was undertaken. Patients were observed for an average of 3.2 years. The initial and last postoperative refractive errors were compared. RESULTS: The mean myopic shift was -0.99 +/- 0.22 diopter (D) (median, 1.0 D) with a range of -3.25 to +0.38 D. The difference in the myopic shift of the children 3 to 5 years of age (-0.94 +/- 0.30 D) was not significantly different from the myopic shift occurring in the children 6 to 9 years of age (-1.07 +/- 0.35 D). The myopic shift was less than 1.5 D in 70% of the eyes and only 3 eyes had a myopic shift greater than 2 D. Ninety percent of the children achieved a visual acuity of 20/40 or better in their pseudophakic eye or eyes. CONCLUSIONS: Although each patient should be evaluated on an individual basis, the authors recommend undercorrecting most children 3 to 9 years of age by 1 D from the IOL power predicted to achieve emmetropia.     

Degenerated lens epithelial cells in rabbit and human eyes after intraocular lens implantation

PURPOSE: To evaluate the role of lens epithelial cells (LECs) in posterior capsule opacification. SETTING: Departments of Ophthalmology and Pathology, Wakayama Medical College, Department of Anatomy, Kansai Shinkyu College, and Department of Ophthalmology, Kobe Kaisei Hospital, Japan. METHODS: We examined the presence of degenerated LECs on the capsules of the eyes of rabbits and a patient after intraocular lens (IOL) implantation. Phacoextraction of a crystalline lens and IOL implantation were done in 5 albino rabbits under general anesthesia. The animals were killed after 2 months. Lens capsules were removed and fixed. During vitreous surgery, a lens capsule with an IOL was removed from a patient. Ultrathin sections of specimens were studied by transmission electron microscopy. RESULTS: Presumed LECs proliferated between the posterior capsule and the IOL in association with collagenous matrix. Debris from the degenerated cells and destroyed intracellular organelles was also seen. CONCLUSION: Lens epithelial cells proliferating on the posterior capsule cannot survive indefinitely.     

Determination of visual function after implantation of intraocular lens

OBJECTIVE: To understand whether the binocular visual function could be restored after posterior chamber intraocular lens (IOL) implantation. METHODS: The visual function including corrected vision, simultaneous perception, fusion, stereoacuity, aniseikonia and retinal correspondence point were determined for 50 cases (64 eyes) after the surgery. RESULTS: The corrected visual acuities were 0.6 or better. Visual acuities of 1.0 or better were achieved in 65% and 0.6-0.9 in 35% of the eyes. All patients obtained simultaneous perception and fusion function. The near stereoacuity of 50 cases showed foveal stereoacuity < or = 60 seconds in 23 cases (46%), macular stereoacuity 80-200 seconds 10 cases (20%) and peripheral stereoacuity 400 seconds 17 cases (34%). The far stereoacuity of 50 cases comprised 34 cases of foveal stereoacuity (68%), 9 cases of macular stereoacuity (18%) and 7 cases of peripheral stereoacuity (14%). The postoperative retinal correspondence points were normal. There was no aniseikonia in 35 cases, except 15 cases of aniseikonia which was within normal tolerable limits. CONCLUSION: When binocular corrected vision is > or = 0.4 with ocular alignment, the binocular visual function could be restored for varying degrees.     

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.     

Cataract formation after posterior chamber phakic intraocular lens implantation

Posterior chamber phakic intraocular lens (PCP IOL) implantation is an emerging refractive procedure. We report a case of cataract formation 6 months after uneventful implantation of a Staar PCP IOL to correct high myopia. Visual recovery was achieved after explantation of the phakic IOL and phacoemulsification with implantation of a foldable IOL through the same unenlarged self-sealing corneal incision.     

Neonatal lensectomy and intraocular lens implantation: effects in rhesus monkeys

PURPOSE: To compare the effects of a lensectomy with and without intraocular lens (IOL) implantation on a neonatal rhesus monkey eye. METHODS: A lensectomy and anterior vitrectomy was performed on 75 monkeys during the first 16 days of life; 21 of these monkeys also had an IOL implanted into the posterior chamber. The eyes were examined at regular intervals using biomicroscopy, applanation tonometry, and ophthalmoscopy. RESULTS: The pseudophakic monkeys were studied until they were 92.5 +/- 5.8 weeks of age and the aphakic monkeys until they were 80.4 +/- 5.7 weeks of age. Pupillary membranes (100% versus 55.5%; P < 0.01) and lens regeneration into the pupillary aperture (28.6% versus 5.6%; P = 0.02) occurred more often in the pseudophakic than the aphakic eyes. As a result, the pseudophakic eyes required more reoperations than the aphakic eyes to keep the visual axis clear (P < 0.01). There was not a significant difference in the incidence of ocular hypertension between the pseudophakic and aphakic eyes (9.5% versus 12.7%; P = 0.34). Pupillary capture of the IOL optic occurred in 52% and haptic breakage in 33% of the pseudophakic eyes. All of the eyes with broken haptics had a prominent Soemmerring's ring varying in maximum thickness from 0.6 to 2 mm. Nine of the haptics from the seven eyes with broken IOLs had eroded into the iris, two into the ciliary body, and one into the anterior chamber. CONCLUSIONS: Implanting an IOL into a neonatal monkey eye after a lensectomy and anterior vitrectomy increases the likelihood of a reoperation being necessary. Haptics frequently erode into the iris and ciliary body and may break because of stress placed on the optic-haptic junction by forward movement of the IOL.     

Outcome of combined trabeculectomy with cataract operation and intraocular lens implantation

BACKGROUND: When trabeculectomy and cataract extraction with intraocular lens insertion are combined, do the success and complication rates add. MATERIAL AND METHODS: Follow-up of 47 eyes of 34 patients with combined trabeculectomy and cataract extraction with intraocular lens implantation after 12 to 42 months. RESULTS: With a low perioperative complication rate the intraocular pressure after one year was below 22 mm Hg in 90% without any medication and in 98% additional glaucoma therapy. After 2 and 3 years the intraocular pressure was normal without any additional therapy in 83% of the eyes. The visual acuity was better or equal to the preoperative value in 89% of the cases. CONCLUSIONS: The combination of trabeculectomy and of cataract extraction with intraocular lens implantation has a low complication rate and gives good results regarding intraocular pressure and visual rehabilitation. When a trabeculectomy is indicated, the indication for a simultaneous cataract extraction with intraocular lens implantation should not be to restricted.     

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.     

Visual results of progressive multifocal posterior chamber intraocular lens implantation

PURPOSE: To evaluate corrected and uncorrected near, intermediate, and distance visual acuities in eyes with a progressive multifocal intraocular lens (IOL) and to determine the effect of the lens on contrast sensitivity. SETTING: Multicenter study. METHODS: This prospective study comprised 59 eyes that had uneventful cataract surgery and implantation of a progressive multifocal IOL at three study centers. Uncorrected and corrected near, intermediate, and distance visual acuities were measured, as was contrast sensitivity at different frequencies. One year results are reported. Patient satisfaction was assessed using a subjective questionnaire. RESULTS: Distance visual acuity improved from 0.13 Snellen lines uncorrected and 0.23 with best correction preoperatively to 0.77 and 0.96 lines, respectively, postoperatively. Uncorrected preoperative near acuity was 13.28 Jaeger lines and best corrected acuity, 8.93 lines. These improved to 4.75 and 2.69 lines, respectively. The differences between visual acuity at intermediate distances and best distance and near acuities were not significant. Patient satisfaction was highest with vision under good light conditions and when viewing larger objects. CONCLUSION: Visual performance with the multifocal progressive IOL was adequate at various distances without additional correction. It was less satisfactory under poor light conditions.