Anterior Capsule Tear Research Articles

Indocyanine green staining in traumatic cataract

We report the first case of indocyanine green (ICG) being used in an eye with an anterior capsule that was not completely intact. We found that ICG seems to have a selective affinity for the anterior capsule over cortical lens material. The patient had a corneal perforation with a wire and developed endophthalmitis requiring pars plana vitrectomy with intravitreal antibiotics. He subsequently developed a white traumatic cataract with an anterior capsule tear. Five months after the injury, he had cataract extraction. Indocyanine green was used to better visualize the anterior capsule before capsulotomy. The anterior capsule stained green, but the cortical material exposed to ICG did not stain.

Phaco-chop versus stop-and-chop nucleotomy for phacoemulsification

Purpose To perform a comparative evaluation of phaco-chop versus stop-and-chop nucleotomy techniques of phacoemulsification. Setting Dr. Rajendra Prasad Center for Ophthalmic Sciences, New Delhi, India. Methods Forty eyes of 40 patients with immature senile cataract were included in the study. Twenty eyes each were randomly assigned to have phaco-chop (Group 1) or stop-and-chop (Group 2) nucleotomy during phacoemulsification. The main parameters were corneal endothelial count, effective phaco time, volume of infusion fluid used, central corneal pachymetry, best corrected visual acuity (BCVA), and intraoperative complications during nucleotomy. Follow-up visits were scheduled at 1, 4, and 12 weeks. Results The mean effective phaco time was 27 seconds ± 18 (SD) in Group 1 and 28 ± 16 seconds in Group 2. The mean corneal endothelial cell loss was 6.89% and 7.17%, respectively, at the end of 12 weeks. The difference between groups was not significant. An anterior capsule tear occurred in 3 eyes in Group 1 and 1 eye in Group 2. All eyes achieved a BCVA of 20/20 at the end of 4 weeks. There were no significant between-group differences in any intraoperative or postoperative parameter. Conclusion The phaco-chop and the stop-and-chop nucleotomy techniques were equally efficacious for nuclear management during phacoemulsification.

Factors leading to lens implant decentration and exchange.

To examine the intra- and post-operative factors leading to posterior chamber intraocular lens (IOL) decentration in patients requiring IOL exchange, and to identify avoidable causes of IOL decentration. Case records of 17 patients who had undergone posterior chamber IOL exchange were examined for: (i) any complication or alteration to the original intended surgical procedure, (ii) IOL type and position at the completion of initial surgery, (iii) IOL position at the time of re-operation. The decentred lens implants were injected silicone plate-haptic IOLs in 10 patients, small (5.5 mm) optic diameter PMMA IOLs in 4 patients and large (7 mm) optic diameter PMMA IOLs in 3 patients. In all cases, decentration was due to IOL subluxation. Early decentration of the injected lenses was due to IOL implantation in eyes without a continuous capsulorrhexis. In contrast late decentration was due to subluxation associated with capsule fibrosis. Decentration of small optic PMMA IOLs was found to be associated with an anterior capsule tear and haptic malposition in the ciliary sulcus. Decentration of large optic PMMA IOLs was associated with posterior displacement of one haptic through a posterior capsule defect, zonule dehiscence or fixation of one haptic in the sulcus and one in the capsule bag. Clinically significant post-operative subluxation of injected silicone IOLs may be minimised by implanting only into a lens capsule bag with an intact capsulorrhexis. The risk of decentration of small optic PMMA IOLs may be minimised by positioning the haptics at 90 degrees to any capsulorrhexis tear. After cataract surgery complicated by posterior capsule rupture or zonule dehiscence, it is important to assess the remaining capsule support and, where sufficient, implant a large optic diameter posterior chamber IOL in the ciliary sulcus.

Performance comparison of the Alcon Legacy 20000 1.1 mm TurboSonics and 0.9 mm Aspiration Bypass System tips

Purpose To compare the efficiencies of the operative procedures and the reductions in postoperative corneal endothelial cell density (ECD) after cataract surgery using 2 different phacoemulsification tips and their associated cassettes and tubing. Setting Wolfe Clinic, Marshalltown, Iowa, USA. Methods A randomized prospective study of 100 consecutive cases was conducted. All patients were adults having phacoemulsification using a hybrid in situ fracture technique. All cases were performed by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine. One of 2 45 degree phacoemulsification tips and associated cassettes and tubing were used: the 1.1 mm TurboSonics with normal tubing ( n = 47) or the 0.9 mm Aspiration Bypass System (ABS) tip with high-vacuum cassettes and tubing ( n = 53). Measurements at the time of surgery included metered phacoemulsification time, percentage power used, total time spent in the phacoemulsification process, and milliliters of balanced salt solution (BSS®) used. Corneal ECD was determined preoperatively and 10 weeks postoperatively. An independent statistician performed 2-sample t tests or Wilcoxon rank sum tests on the data. Results There were no cases of anterior radial capsule tear, posterior capsule tear, vitreous loss, iris aspiration, incision leak, or suture closure. There was no correlation between amount of corneal ECD loss and any operative variable measured. Similar measurements for the 1.1 mm TurboSonics and the 0.9 mm ABS included, respectively, ECD loss 7.34% and 8.22%; metered phacoemulsification time 1.29 and 1.22 minutes; total time of the phacoemulsification process 113 and 105 seconds. There were statistically significant differences between the 1.1 mm TurboSonics tip and 0.9 mm ABS tip performance in mean power percentage overall (52% versus 48%) and overall BSS volume used (85 versus 76 mL). Conclusions The 0.9 mm ABS phacoemulsification tip used with the high-vacuum cassette and tubing provided the physical advantages of tip-size reduction while requiring similar ultrasonic power and BSS volumes as the 1.1 mm TurboSonics tip with standard cassette and tubing. Together, they provide a wider available dynamic range in which to integrate ultrasonic power, higher vacuum, and higher aspiration flow rates to improve the efficiency and ease of use than the standard 1.1 mm TurboSonics cataract operation.

Performance comparison of the Alcon Legacy 20000 1.1 mm TurboSonics and 0.9 mm MicroTip

Purpose To compare the efficiencies of the operative procedures, the changes in postoperative corneal endothelial cell density (ECD), and incision performance after cataract surgery using 2 different phacoemulsification tips. Setting Wolfe Clinic, Marshalltown, Iowa, USA. Methods A randomized prospective study of 119 consecutive cases was conducted. All patients were adults having phacoemulsification using a modified in situ fracture technique. All cases were done by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine with normal vacuum cassettes and tubing. One of 2 45 degree phacoemulsification tips was used: the 1.1 mm TurboSonics (n = 65) or the 0.9 mm MicroTip (n = 54). Measurements at the time of surgery included metered phacoemulsification time and mean phacoemulsification power. Corneal keratometry and ECD by contact specular microscopy were determined preoperatively and 10 weeks postoperatively. Results The mean metered phacoemulsification time was statistically significantly different between the 2 groups: 1.1 mm TurboSonics = 1.25 minutes; 0.9 mm MicroTip = 1.66 minutes. The mean ultrasound power was also significantly different: 1.1 mm TurboSonics = 52.98%; 0.9 MicroTip = 49.07%. Loss of corneal ECD was not significantly different: 1.1 mm TurboSonic = 3.68%; 0.9 mm MicroTip = 5.79%. Mean diopters of induced incisional keratometric flattening was similar: 1.1 mm TurboSonics, 0.32 diopters (D) ±0.61 (SD); 0.9 mm MicroTip, 0.25 ± 0.49 D. There were no cases of anterior radial capsule tear, posterior capsule tear, vitreous loss, iris aspiration, suture closure, or incision leak. Conclusions Although a longer mean metered phacoemulsification time was required with the 0.9 mm MicroTip, corneal endothelial cell loss and incisional keratometric performance were not different from those of cases in which the larger 1.1 mm TurboSonics tip was used. Both tips can be used effectively and safely for phacoemulsification of the human cataract.

Elastic properties and scanning electron microscopic appearance of manual continuous curvilinear capsulorhexis and vitrectorhexis in an animal model of pediatric cataract

Purpose: To compare the tear resistance of anterior capsulotomies using manual continuous curvilinear capsulorhexis (CCC) and vitrector-cut capsulotomy (vitrectorhexis) techniques in an animal model of the pediatric eye and in 2 pairs of human infant eyes. Setting: Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: Continuous curvilinear capsulorhexis and automated vitrectorhexis capsulotomy techniques were performed in 20 pig eyes, 10 with each technique. The capsules were then stretched until they ruptured. The forces required for rupture after each technique were compared. The forces required for rupture of the pig eye lens capsule were also compared with those required for the human infant eye lens capsule. Scanning electron microscopy was performed in each group following intraocular lens (IOL) insertion. Results: All capsules stretched adequately for IOL insertion. The percentage ofstretch prior to rupture was higher in the capsulorhexis group (mean 157%, range 147% to 169%) than in the vitrectorhexis group (mean 135%, range 124% to 147%) ( P < .001). The percentage of stretch in the human infant eyes was not statistically different from that in the porcine eyes ( P > .05). Conclusions: The manual CCC offered greater resistance to capsule tearing than the vitrectorhexis and also revealed a more smooth, regular edge. It therefore remains the gold standard. However, the vitrectorhexis displayed more than adequate resistance to unwanted anterior capsule tears when used for IOL insertion through capsulotomy sizes currently used in clinical practice.

Effect of expandable full-size intraocular lenses on lens centration and capsule opacification in rabbits

Purpose: To study the effects of expandable, hydrogel, full-size lenses (FSLs) on lens centration and posterior capsule opacification (PCO) in the rabbit model. Setting: Center for Intraocular Lens Research, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: Small FSLs designed for human eyes were implanted unilaterally in 20 rabbit eyes. Lens centration and PCO in these eyes were compared with those in eyes with conventional poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) or aphakia in the fellow eyes. In a second experiment, medium-size or large FSLs designed for rabbit eyes were implanted in 20 rabbit eyes and the results compared with those in eyes with conventional PMMA IOLs. Slitlamp examination of all eyes was performed regularly; after enucleation, gross inspection and microscopic studies were performed. Results: Decentration of FSLs occurred in the presence of an anterior capsule tear orvery large capsulorhexis. Posterior capsule opacification developed only at sites where the implanted lens was not in contact with the capsule. Aphakic eyes and looped IOLs developed Soemmering's rings peripherally. In eyes with small FSLs, PCO developed between the lens and the center of the posterior capsule, whereas in eyes with large FSLs, only small amounts of central PCO developed. Retained high-viscosity viscoelastic material had no effect on PCO development. Conclusions: Complete refilling of the capsular bag by a full-size IOL was associatedwith excellent centration and only a small degree of PCO. Elastic lenses may thus serve as a starting point for the development of an artificial lens with accommodative function.

Viscoelastic-injecting cystotome

This continuous curvilinear capsulorhexis (CCC) technique is for use in complicated surgical cases such as when the anterior chamber is shallow, the red reflex is not good, or eye movements are present. This technique is easier and safer in such cases because it uses a cystotome connected to a viscoelastic syringe. First, the anterior chamber is filled with viscoelastic material using a conventional cannula. The cannula is replaced with a bent needle (or cystotome), and the CCC is performed in the usual way. This instrument allows the surgeon to inject small amounts of viscoelastic material exactly where and when it is needed. The anterior chamber remains deep while the CCC is performed, and the anterior capsule tear is done in a more controlled fashion.

Intraoperative complications of 1000 phacoemulsification procedures: A prospective study

Purpose: To determine the frequency and nature of intraoperatlve complications of endocapsular phacoemulsification cataract surgery.Setting: Dalcross Private Hospital and the Departments of Ophthalmology, Concord Hospital and Prince of Wales Hospital, Sydney, Australia.Methods: This prospective study included the first 1000 cases of planned endocapsular phacoemulsification cataract surgery performed by an experienced surgeon. A standardized proforma was completed at the time of surgery. Data recorded included pre-existing ocular abnormalities, duration of surgery, nuclear sclerosis grade, and intraoperative complications.Results: Major complications comprised posterior capsule tears with vitreous loss (1.4%), isolated posterior capsule tears (0.7%), and zonulysis (0.1%). Minor complications included anterior capsule tears (3.8%), iris prolapse (0.6%), and ciliary body incision (0.2%). There was a significant trend toward complications as the nuclear sclerosis grade increased. The incidence of major complications was 9.3% in the first 150 cases and 0.9% in the last 850. This represents a relative risk of 9.9 (95% confidence interval 4.2 to 23.0) of a major complication occurring in the first 150 compared with the later 850 cases.Conclusion: The frequency of major and minor complications fell sharply after the first 150 operations and was maintained. This study may provide a guide for beginning phacoemulsification surgeons and a basis for experienced surgeons to compare their performance outcomes.

Change in postoperative refractive error when vitrectomy is added to intraocular lens implantation

Purpose: To compare the actual and expected refractive errors after intraocular lens (IOL) implantation alone with those after IOL implantation with simultaneous vitrectomy.Setting: Shinjo Eye Clinic, Miyazaki, Japan.Method: One hundred thirty-six eyes had cataract extraction and implantation of a single-piece IOL using a frown incision, continuous annular anterior capsule tear, phacoemulsification, and intracapsular lens fixation. Thirty-six eyes also had vitrectomy.Results: Mean postoperative refractive error was 0.55 diopter (D) ± 1.34 (SD) in eyes having no vitrectomy and 0.04 ± 1.24 D in those having vitrectomy. The difference between groups was statistically significant (P = .047; t-test).Conclusion: The refraction after simultaneous IOL implantation and vitrectomy shifted toward myopia by a mean of 0.50 D compared with that after IOL implantation alone.

What to do with limited view: The intumescent cataract

In 1991, 2,967 consecutive cataract cases were analyzed in a prospective, observational study for the incidence of intumescent cataract. Thirty four (1.15%) of the cases were mature intumescent lenses. A deliberately small continuous curvilinear capsulorhexis (CCC) enlarged secondarily by the two-stage continuous curvilinear capsulorhexis (2-CCC) technique was the anterior capsulotomy approach of choice. Depending on the liquidity of the lens material, liquid cortex was aspirated using a 26- or 30-gauge needle before capsulorhexis or through a small CCC. Because of loss of CCC control, a can-opener capsulotomy was used in three of the 34 cases before being converted by the 2-CCC technique. The rigid nucleus was usually extracted using the down-slope nucleofractis phacoemulsification technique. Four (11.7%) of the 34 intumescent cases had anterior capsule tears during capsulotomy. Successful in-the-bag lens implantation was achieved in all cases. We describe a technique of CCC, 2-000, and down-slope sculpting nucleofractis phacoemulsification to manage intumescent cataracts.