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PubMed1994

A comparative study of the elastic properties of continuous tear curvilinear capsulorhexis versus capsulorhexis produced by radiofrequency endodiathermy.

Capsulorhexis using radio-frequency endodiathermy may confer some advantages over continuous tear curvilinear capsulorhexis (CTCC) in certain clinical situations. It is unclear whether a capsulorhexis produced in this fashion has the clinically advantageous elasticity and resistance to tearing that a CTCC has been demonstrated to have. To investigate this, a test of capsular elasticity was carried out on pairs of eyes obtained from an eye bank, 42 eyes of 21 patients in total, using modified digital vernier calipers. One eye of each pair had a CTCC, the other a diathermy capsulorhexis (DC). The elasticity of the capsule in both groups was expressed by comparing the circumference of the capsulotomy at rest with its circumference at rupture. The mean capsular elasticity of the CTCC group was significantly greater than that of the DC group (p << 0.001). The capsular edge in both groups was examined using scanning electron microscopy, and the difference in morphology appears to be the source of the difference in elasticity.

Adolescent↗

PubMed1999

The relationship between capsulorhexis size and anterior chamber depth relation.

BACKGROUND AND OBJECTIVE: To determine whether the diameter of the capsulorhexis has an effect on anterior chamber depth (ACD) following phacoemulsification surgery. PATIENTS AND METHODS: Fifty-one consecutive patients were selected for cataract extraction by phacoemulsification with intraocular lens (IOL) implantation. Twenty-two of 51 patients underwent 4 mm capsulorhexis, while the rest underwent 6 mm. All were implanted with a multi-piece polymethyl methacrylate posterior chamber IOL with 5.0 mm diameter biconvex optic and flexible haptic. They were followed 3 months postoperatively. The width of the capsulorhexis was assured according to the IOL optic implanted intraoperatively, and by the help of slit-lamp measurement after dilatation of the pupil on the first postoperative day. ACD and axial length (AL) of patients was obtained by ultrasonography on both the days before surgery, and the first and seventh postoperative days, and after 30, 60 and 90 days. RESULTS: Early significant increase of ACD and ACD/AL ratios were observed in only the 6 mm capsulorhexis group on the first day postoperatively (P = .012, and P = .018). On the 90th postoperative day, ACD increased significantly both in the 4 mm (P = .002) and the 6 mm capsulorhexis groups (P = .049) when compared to preoperative values. For the same period, meaningful increase in ACD/AL ratio in the eyes with both 4 mm and 6 mm capsulorhexis groups was also noted compared with preoperatively (P = .002 and P = .019). There was a statistical difference between the 90th day ACD values of 4 mm (3.73 +/- 0.32 mm, mean +/- standard deviation) and 6 mm capsulorhexis groups (3.50 +/- 0.33 mm) (P = .028). For the same period, ACD/AL ratio was also significantly different for both groups (0.152 +/- 0.01, and 0.142 +/- 0.01 respectively) (P = .004). The refractive error changes followed the ACD changes and showed meaningful differences between 1st and 90th days postoperative values of each group (P = .029, and P = .014, respectively). CONCLUSION: A 4 mm capsulorhexis results in a longer postoperative ACD than does a 6 mm capsulorhexis for the IOL type used in this study.

Adult↗

PubMedDate not supplied

Capsulorhexis size and posterior capsule opacification.

PURPOSE: Posterior capsule opacification (PCO) after intraocular lens (IOL) implantation has a multifactored pathogenesis. Capsulorhexis and capsular bag implantation of a one-piece, biconvex poly(methyl methacrylate) (PMMA) IOL are likely to reduce the PCO incidence. This study was performed to determine whether an ideal capsulorhexis size able to reduce PCO incidence exists. METHODS: A retrospective study of 107 patients who had extracapsular cataract extraction with capsulorhexis and capsular bag IOL implantation was carried out. The PCO site (central, paracentral, and peripheral) and degree (mild, moderate, and severe) were evaluated in relation to the capsulorhexis edge location relative to the IOL optic. Slitlamp biomicroscopy and photography and examination with a three-mirror Goldmann lens were performed. Patients were divided into three groups. Group 1: capsulorhexis free edge located on the IOL optic for 360 degrees; Group 2: capsulorhexis free edge located asymmetrically on and peripherally to the IOL optic; Group 3: capsulorhexis free edge located peripherally to IOL optic for 360 degrees. Each group was divided into two subgroups; one received polyHema IOLs and the second, PMMA IOLs. RESULTS: In Groups 1 and 2, the capsular transparency was higher than in Group 3 (P < .04). Central opacification percentage was lower in Group 1 than in Groups 2 and 3 (P < .04). No statistically significant differences between the polyHema and the PMMA subgroups were seen. CONCLUSIONS: Capsulorhexis with a slightly smaller diameter than the IOL optic appears to be better than a large-size capsulorhexis in reducing the incidence of PCO.

Aged↗

PubMed1999

Effect of capsulorhexis size on postoperative intraocular pressure.

OBJECTIVE: To determine whether capsulorhexis diameter has an effect on intraocular pressure (IOP) after phacoemulsification. SETTING: SSK Ankara Eye Hospital, Ankara, Turkey. METHODS: This prospective study comprised 58 patients selected for cataract extraction by phacoemulsification using a 5.2 mm temporal, clear corneal incision. Twenty-nine of 58 patients had a 4.0 mm capsulorhexis and the rest, 6.0 mm. All patients received a multipiece poly(methyl methacrylate) posterior chamber intraocular lens with a 5.0 mm diameter bioconvex optic and flexible haptics. Follow-up was 3 months. Postoperative IOP was obtained by Goldmann applanation tonometry 1 and 2 days before surgery and 1 and 7 days and 1, 2, and 3 months postoperatively. RESULTS: A significant decrease in IOP was observed in both the 4.0 and 6.0 mm capsulorhexis groups 1 day postoperatively (P < .0001 and P < .0001, respectively). At 3 months postoperatively, IOP decreased significantly over preoperative values both in the 4.0 mm (P < .0001) and 6.0 mm capsulorhexis (P = .0014) groups. There was a statistical difference between the mean 1 month IOP values in the 4.0 mm (11.34 +/- 2.18 mm Hg [SD]) and 6.0 mm capsulorhexis (13.00 +/- 2.30 mm Hg) groups (P = .0059). A statistical difference between the groups also existed at 3 months postoperatively (P = .0028). CONCLUSION: A 4.0 mm capsulorhexis resulted in lower postoperative IOP than a 6.0 mm capsulorhexis 1 month postoperatively.

Adult↗

PubMed1994

[Original technique of double capsulorhexis].

The current endophako technique with posterior scleral tunnel incision requires perfect continuous curvi-linear capsulorhexis. A rupture in the capsulorhexis ring may produce a posterior capsular tear. An excessively large anterior capsular residue will lead to purse-string fibrosis. The original surgical technique of double circular capsulorhexis resolve these two points. This technique allows a small capsulorhexis (diameter about 4 millimeters), reproductibility in spite of difficult surgical cases (hypertonia, poor visibility); it avoids tearing the anterior capsular edge to the zonula. A second capsulorhexis at the end of the operation, exactly following the optic zone of the intra-ocular implant, helps to guide healing of the anterior capsular edge, reducing fibrosis and avoiding purse-string fibrosis. The double capsulorhexis technique allows a double security: during surgery: it ensures a safe reproducible capsulorhexis; after surgery: the guided ablation of the large anterior capsular residue allows better long-term retinal follow up.

Humans↗

PubMed1999

The effect of capsulorhexis size on posterior capsular opacification: one-year results of a randomized prospective trial.

PURPOSE: Posterior capsular opacification is the most common surgically related cause of reduced vision after cataract surgery. We studied the effect of capsulorhexis size on the pattern and severity of posterior capsular opacification. METHODS: In this prospective study 75 patients underwent standardized phacoemulsification with capsulorhexis and in-the-bag placement of a 5.5-mm polymethylmethacrylate intraocular lens implant. The patients were randomly assigned to receive either a small capsulorhexis of 4.5 to 5 mm to lie completely on the intraocular lens optic or a large capsulorhexis of 6 to 7 mm to lie completely off the lens optic. Patients were examined at days 1, 14, 30, 90, and 180 and at year 1 with logMAR visual acuity assessment, Pelli-Robson contrast sensitivity testing, anterior chamber flare and cell measurement, and high-resolution digital retroillumination imaging of the posterior capsule. The pattern of posterior capsular opacification was determined, and the percentage area of posterior capsular opacification was calculated for each image with dedicated image analysis software. RESULTS: Large capsulorhexes were associated with significantly more wrinkling of the posterior capsule and worse posterior capsular opacification than small capsulorhexes. At 1 year the average percentage area of posterior capsular opacification was 32.7% for small capsulorhexes (95% confidence interval, 19.8 to 45.6) and 66.2% for large capsulorhexes (95% confidence interval, 57.7 to 74.6) (P = .0001). The patients with large capsulorhexes had significantly poorer visual acuities and a trend toward worse contrast sensitivities. CONCLUSION: This study demonstrated significantly greater wrinkling and opacification of the posterior capsule and worse visual acuity with large capsulorhexes than with small capsulorhexes. In cataract surgery with a polymethylmethacrylate intraocular lens, a small capsulorhexis with the edge completely on the surface of the implant is preferable to a large capsulorhexis in reducing posterior capsular opacification.

Aged↗

PubMed1996

Posterior capsulorhexis in adult eyes with intact and clear capsules.

PURPOSE: To evaluate the feasibility and risks of primary posterior capsulorhexis. SETTING: Department of Ophthalmology, University Hospital of Liège, Belgium. METHODS: Retrospective analysis of 319 patients with cataracts who had phacoemulsification or manual extracapsular cataract extraction with a simultaneous circular posterior capsulorhexis between August 1993 and April 1994. The number of intraoperative complications and the number of postoperative complications that could be related to the posterior capsule opening were looked at. Fluorescein angiography was performed in a random sample of patients. RESULTS: Twelve intraoperative complications consisted of 5 irregular tears, 4 vitreous prolapses into the posterior capsulorhexis, and 3 vitreous prolapses into the anterior chamber; 11 occurred in eyes with positive posterior pressure. Postoperative complications consisted of 3 vitreous prolapses into the pupil and 1 retinal detachment. Two of the 3 late vitreous prolapses occurred in eyes in which the posterior capsulorhexis was larger than the intraocular lens (IOL) optic. The retinal detachment occurred in an eye with a 25.79 mm axial length. Fluorescein angiography of 49 cases revealed 3 with cystoid macular edema. CONCLUSIONS: Based on our results, we believe that primary posterior capsulorhexis can be a routine procedure during cataract surgery and IOL implantation in adults, except in cases of positive pressure. The diameter of the posterior capsulorhexis should be smaller than the diameter of the IOL optic.

Adult↗

PubMed1992

[Elasticity of capsulorhexis in the animal model].

A special caliper was designed to determine the stretching capacity of a circular capsulorhexis allowing measurements in 0.02 mm increments. A small capsulorhexis 4.5-6.0 mm in diameter could be stretched 2.7 times; a large capsulorhexis 6.5-8.0 mm in diameter was stretched 2.6 times the original diameter. A smooth circular capsulorhexis is very strong and stabile but also has significant stretching capacity. In a small capsulorhexis, there is the danger that zonular fiber defects or posterior capsular rupture may occur during manual expression, of the nucleus. A large capsulorhexis is more suitable for manual nucleus delivery.

Animals↗

PubMed1996

[Histological observation of anterior capsular edges produced by continuous curvilinear and diathermy capsulorhexis].

Radiofrequency endodiathermy capsulorhexis (DC) is a new method for anterior capsulorhexis in cataract surgery. DC may confer some advantages over continuous curvilinear capsulorhexis(CCC) in certain clinical situations. The elasticity of capsulorhexis produced by DC and the proper diathermy time are still unclear. Histological examination of rabbit lenses, on which a variety of coagulation times (0.5 to 5.0 sec) were tested revealed that 0.5 sec was long enough to coagulate the anterior capsule and that the longer coagulation extend the tissue damage into the deeper cortex. Small capsulorhexis (3.5 mm in diameter) produced experimentally with DC showed less elasticity than that produced with CCC when the edge of the capsulorhexis was pulled. Thus the heat coagulation of the capsular edge produced by DC results in less elasticity than that produced by CCC.

Animals↗

PubMed1992

Posterior continuous curvilinear capsulorhexis. An experimental study with clinical applications.

The posterior continuous curvilinear capsulorhexis technique has been advocated in cases of posterior capsule rupture during extracapsular cataract extraction. The authors compared posterior continuous curvilinear capsulorhexis with posterior capsular sharp-edged tears. Two different types of forces were experimentally created on the posterior capsule of 30 human eyes obtained after death: (1) implantation and dialing of posterior chamber intraocular lenses (PC IOLs) and (2) increased intravitreal pressure by injection of balanced salt solution. All posterior capsular tears extended toward the equator, causing major capsular defects. In contrast, the posterior continuous curvilinear capsulorhexis remained intact in all cases. This experimental study proves that in cases where an inadvertent posterior capsular tear occurs, a posterior continuous curvilinear capsulorhexis is useful in preventing further capsular damage. Also, in cases where a posterior capsulotomy is indicated, a smooth edge created by a posterior continuous curvilinear capsulorhexis may be useful to maintain the integrity of the capsular bag for PC IOL capsular implantation.

Aged↗

PubMed1997

Complicated posterior capsulorhexis: aetiology, management, and outcome.

BACKGROUND: A 1 year retrospective analysis of 650 patients, who underwent a posterior capsulorhexis on their intact capsules, was performed to examine the incidence of complications, their aetiologies, and the outcome. METHODS: Data were analysed on 32 patients with complicated capsulorhexis for type of surgery, preoperative and postoperative factors, and relative risk factors for vitreous issue. RESULTS: There were six patients with vitreous loss. The posterior capsulorhexis was uncontrolled in 14 cases and difficult to perform in 12 cases. Implantation into the capsular bag was possible in all cases. Systemic vascular hazard and old age (over 80 years) were found to be statistically significant risk factors for vitreous loss (p = 0.002 and p = 0.03 respectively). The mean follow up was 13.5 months (range 4-25 months). One patient developed a retinal detachment and two had a transient clinical cystoid macular oedema. Visual acuity of > or = 20/40 was obtained in 93% of the patients. CONCLUSION: Loss of control of the posterior capsulorhexis has a low incidence but can lead to serious problems during surgery. A good knowledge of the technique is necessary to complete the procedure with a posterior capsulorhexis of the optimum size without vitreous loss.

Adult↗

PubMed1994

Nucleus viscoexpression compared with other techniques of nucleus removal in extracapsular cataract extraction with capsulorhexis.

We compared three nucleus delivery procedures used during extracapsular cataract extraction (ECCE) after capsulorhexis in 142 eyes. In 25 eyes, the nucleus was expressed through a capsulorhexis 7 mm or wider. In 40 eyes, the nucleus was broken into two pieces and removed through a capsulorhexis 6 mm or less. In 77 eyes, viscoexpression was used to remove the nucleus from the capsular bag through a capsulorhexis 6 mm or less. Nucleus expression after a wide capsulorhexis was successful in 68% of the eyes in which it was attempted. Nucleus fragmentation was successful in 90%. Postoperative inflammation was high in both of these groups. Nucleus viscoexpression was successful in 93%, with low postoperative inflammation. Although it requires a 7- to 8-millimeter corneoscleral incision, based on our study, viscoexpression would appear to be the best nuclear delivery technique when ECCE, rather than phacoemulsification, is being performed.

Aged↗

PubMed1999

Complete occlusion of the anterior capsular opening after intact capsulorhexis: clinicopathologic correlation.

PURPOSE: To report histopathologic findings of capsule contraction syndrome with complete occlusion of the capsulorhexis opening. METHODS: Case report. In an 81-year-old woman, a complete occlusion of the anterior capsulorhexis opening developed 2 months after phacoemulsification and intraocular lens implantation. We surgically removed the contracted anterior capsule and analyzed the membrane by standard light microscopy and actin immunohistology. RESULTS: Light microscopic analysis of the membrane showed fibrous tissue subcapsularly with metaplastic lens epithelial cells. The contracted capsulorhexis opening was filled completely with proliferated actin-positive lens epithelial cells. CONCLUSIONS: Complete occlusion of the capsulorhexis opening can be attributed to excessive shrinkage of the capsule, probably caused by actin filaments found in the residual lens epithelial cells together with weak zonular support, and to the occlusion of the remaining central defect by massive proliferation of metaplastic lens epithelial cells.

Actins↗

PubMed1997

Capsulorhexis phymosis following uncomplicated phacoemulsification surgery.

PURPOSE: The aim of the study was to assess and compare the degree of capsulorhexis phymosis following uncomplicated phacoemulsification cataract surgery in polymethylmethacrylate (PMMA) and silicone lens implants. METHOD: Sixty-four patients were evaluated 1 day, 6 weeks and 6 months following phacoemulsification cataract extraction. The anterior capsular diameters were measured with the illuminated beam of the slit lamp at 45 degrees and 135 degrees and the surface area of the opening calculated. We have measured and compared the change in the capsulorhexis size for both lens types and assessed its statistical significance with a paired Student's t-test. RESULTS: A statistically significant contraction of the capsulorhexis was noted in all patients within the first 6 weeks (p < 0.001). Capsular contraction continued between 6 weeks and 6 months post-operatively but to a lesser extent (p < 0.05). The difference in the degree of phymosis between the first period (1 day to 6 weeks) and the second (6 weeks to 6 months) was statistically highly significant for all patients (p < 0.001). The capsular areas for the silicone lens implants were significantly smaller than for the PMMA implants at 6 weeks and 6 months. None of our patients had a clinically significant capsular contracture requiring Nd:YAG laser capsulotomy. CONCLUSION: Anterior capsular contraction is commonly observed following capsulorhexis in phacoemulsification surgery. This study demonstrates that the maximum rate of contraction occurs in the first 6 weeks following surgery and is more pronounced with silicone lens implants.

Aged↗

PubMed1997

Double contour of the lens capsule edges after continuous curvilinear capsulorhexis.

BACKGROUND: After curvilinear capsulorhexis in cataract surgery often a double-ring shape of the remaining capsular margins can be observed. In order to better understand this phenomenon we performed a histological study of excised capsules after continuous curvilinear capsulorhexis. METHODS: Ten anterior capsular specimens from cases with double-ring structure of the capsular margins after continuous curvilinear capsulorhexis (D-group) were examined light microscopically and compared with 10 normal cases (N-group) and 10 cases with pseudoexfoliation (P-group). Three cases from each group were also examined electron microscopically. RESULTS: A characteristic step formation in the capsular edges and in addition horizontal capsular splits in the border zone between the zonular lamella of the anterior capsule and the capsule proper could be demonstrated histologically in the D-group. CONCLUSIONS: There seems to be a weak point of the capsular tissue in the border zone between zonular lamella of the lens and the capsule proper. The superficial splits that we found histologically in this region might be a precursor or forme fruste of true exfoliation. The outward-directed traction force exerted by the zonular fibers seems to lead to further disruption in this weakened layer of the lens capsule during capsulorhexis, producing a double-ring contour of the capsular margins.

Aged↗

PubMed1996

Posterior capsulorhexis with optic capture in pediatric cataract and intraocular lens surgery.

BACKGROUND: A major concern in pediatric intraocular lens implantation surgery is the high incidence of posterior capsule opacification. The purpose of this article is to investigate a surgical technique for maintaining a clear visual axis after pediatric cataract and intraocular lens surgery. METHODS: In a prospective evaluation, posterior capsulorhexis with optic capture as a surgical technique for preventing secondary membrane formation after pediatric cataract extraction is investigated. This technique involves capture of an intraocular lens optic through a posterior curvilinear capsulorhexis opening. Perioperative complications and incidence of secondary cataract are presented. Results will be compared to an historic cohort of patients with pediatric cataract-intraocular lens who did not have posterior continuous curvilinear capsulorhexis with optic capture. RESULTS: In 13 consecutive eyes operated on in children aged 2 to 12 years (mean, 5.8 years), there was no opacification of the visual axis at a mean follow-up of 19 months after surgery (range, 8-30 years). CONCLUSION: Posterior capsulorhexis with optic capture holds promise as a technique for preventing secondary membrane formation. This maneuver ensures centration of the posterior chamber intraocular lens while eliminating the need for an anterior vitrectomy. Apposition of the anterior and posterior capsule leaflets anterior to the optic may limit the migration of Elschnig pearls, reducing the incidence of secondary membranes and the need for additional procedures.

Cataract↗

PubMed1997

Radiofrequency diathermy capsulorhexis of the anterior and posterior capsules in pediatric cataract surgery: preliminary results.

PURPOSE: To assess the effectiveness of radiofrequency diathermy capsulorhexis in preventing opacification of the posterior capsule in pediatric cataract extraction. SETTING: The Children's Hospital, Dublin, Ireland. METHODS: Radiofrequency diathermy capsulorhexis to the anterior capsule followed by injection of sodium hyaluronate behind the posterior capsule and primary posterior capsule diathermy capsulorhexis were performed in 14 eyes of 7 children requiring cataract surgery. RESULTS: Six patients had bilateral congenital and 1 patient bilateral developmental cataracts. Ten eyes (5 patients) received heparin-surface-modified intraocular lenses, and 4 eyes (2 patients) were left aphakic. There were no intraoperative complications, and only mild anterior segment inflammation was noted postoperatively. CONCLUSION: With follow-up from 7 to 16 months (mean 12.1 months), our results showed no epithelial regrowth or opacification of the posterior capsule following diathermy capsulorhexis.

Cataract↗

PubMed1993

[Capsulorhexis and manual extracapsular extraction].

Capsulorhexis is the best method of anterior capsulectomy. It is easier to perform a small capsulorhexis, suitable for phacoemulsification than a large capsulorhexis, suitable for a manual extracapsular extraction. We describe manoeuvres enabling the control of tearing the anterior capsule in such a way that the capsulorhexis will be adapted to the passage of the nucleus during the manual extracapsular extraction.

Cataract Extraction↗