Posterior capsular-zonular disruption in planned extracapsular surgery

Risk Factors for Intraoperative and Early Postoperative Complications in Extracapsular Cataract Surgery

The risk factors for intraoperative and early postoperative complications were evaluated in 351 consecutive cataract operations at the Oulu University Hospital in 1990. Bleeding into the anterior chamber during the operation was recorded in 8.6%, zonular rupture in 6.6%, posterior capsular rupture in 5.4% and vitreous loss in 3.2%, On account of the loss of capsular support an anterior chamber intraocular lens was implanted in 3.1%. Of the early postoperative complications, signs of fibrinous reaction were observed in 24.5%, corneal edema in 53.6% and rise of intraocular pressure to 30 mmHg or more in 27.6%. There was no difference in the complication rate between men and women or in relation to age. The use of anticoagulant (although discontinued before surgery) or antiplatelet medication increased the risk of intraoperative bleeding but no sight-threatening bleeding occurred. The use of acetylsalicylic acid was also associated with an increased risk of postoperative fibrinous reaction. Other systemic diseases like systemic hypertension, diabetes, asthma, or cardiac or mental disorders, or medications, did not increase the complication rate. Of the various ocular parameters, small pupil and exfoliation syndrome were the most important risk factors for both intra- and early postoperative complications, and the presence of glaucoma increased the risk of vitreous loss, postoperative pressure rise and corneal edema. General anesthesia did not seem to reduce the complications rate.

Proposed classification of lens capsule defects

BACKGROUND

Capsule defects are common during or after intraocular surgery of various kinds. The purpose of this work is to establish a classification system of lens capsule defects to provide uniform description of these defects for ophthalmic research and IOL implantation.

METHODS

A retrospective study of 128 patients (156 eyes) with lens capsule injury after ocular trauma and intraocular surgery was performed. The patients were divided into two groups. Capsule defects were defined and classified according to the location, size, shape and tension of the capsule and its effect on posterior chamber IOL implantation.

RESULTS

Lens capsule defects were classified into four types: Type I - complete capsule; Type II - incomplete capsule, but has enough area and tension to support two IOL haptics; Type III - incomplete capsule, is able to support only one IOL haptic and the other haptic needs a suture; Type IV - no capsule, both IOL haptics need suture fixation. Type I and Type II were each divided into three subtypes. Type III was divided into two subtypes. The shape of the capsule defects included fissure-like, triangle, round, irregular and fan-like. All eyes with capsule defects can be sorted into one of these types, and it is easy to guide IOL implantation according to the classification. Type II was the most common among the two groups in this study.

CONCLUSION

The classification of lens capsule defects is feasible and favorable for uniform clinical description, clinical research and IOL implantation.

The incidence of posterior capsule disruption during phacoemulsification and associated postoperative complication rates in dogs: 244 eyes (1995-2002)

OBJECTIVE

The objective of this retrospective study was to report the incidence of posterior capsule disruption during routine phacoemulsification and to document the postoperative outcomes and complications in eyes with posterior capsule disruption compared with eyes with intact posterior capsules.

PROCEDURES

Records of 143 dogs (244 eyes) were reviewed. Data collected included whether the posterior capsule was disrupted, whether the disruption was planned or accidental, whether an intraocular lens was implanted, and visual outcome. Records were reviewed for postoperative complications. Intraocular lens implantation rates, complication rates, and visual outcomes were compared between intact and disrupted posterior capsule groups using Chi-square analyses.

RESULTS

The posterior capsule was disrupted in 33/244 eyes (14%). Planned capsulotomies accounted for 36% of the disruptions. Intraocular lenses were implanted in 76% of eyes without a disruption of the posterior capsule and in 31% of eyes with a posterior capsule disruption. Intraocular lenses were more likely to be implanted in eyes with a planned disruption of the posterior capsule (7/12; 58%) than in eyes with an accidental disruption (3/20; 15%). There were no significant differences in postoperative complications or visual outcome between eyes with posterior capsule disruption and those without.

CONCLUSIONS

The most significant complication of posterior capsule disruption during phacoemulsification is the inability to implant an intraocular lens. Intraocular lenses are more likely to be placed in eyes with intentional disruptions of the posterior capsule than those with accidental ruptures.

Management of posterior capsule tears

Any breach in the continuity of the posterior capsule is defined as a posterior capsule tear. Posterior capsule tears can be preexisting (congenital or traumatic), spontaneous, or intrasurgical. Preexisting/congenital posterior capsule tears have been related to an intrauterine insult. Posterior capsule tears due to trauma may occur as a consequence of direct mechanical impact due to perforation or blunt injury. Depending on the duration of time between the posterior capsular trauma and the cataract surgery, these posterior capsule tears can have different features. Intrasurgical posterior capsule tears are the most common and can occur during any stage of cataract surgery. Also, they may be planned in the form of primary posterior capsulorhexis. The conventional management consists of prevention of mixture of cortical matter with vitreous, dry aspiration, and anterior vitrectomy, if required. In addition, during phacoemulsification low flow rate, high vacuum, and low ultrasound are advocated if a posterior capsule tear occurs. Dislocated nucleus or nuclear fragments require vitrectomy and the use of perfluorocarbon liquids. In the presence of a posterior capsule tear, the IOL can be placed in the sulcus, if the capsular rim is available, or in the bag, if the tear is small. Scleral fixated posterior chamber lenses and anterior chamber IOLs can be implanted when the posterior capsule tear is large.

Effect of surgical technique on in vitro posterior capsule opacification

PURPOSE

To compare the effect of different cataract extraction surgical techniques on residual lens epithelial cell (LEC) density and cell regrowth rates using an in vitro model of posterior capsule opacification (PCO).

SETTING

Comparative Ophthalmology Research Laboratories, North Carolina State University, Raleigh, North Carolina, USA.

METHODS

Lens capsule explants were prepared from freshly enucleated canine globes after extracapsular cataract extraction (ECCE), phacoemulsification, or phacoemulsification followed by capsule vacuuming. Initial cell density on the capsule and cell proliferation were determined by phase contrast microscopy. The effects of the surgical technique on time to confluent growth of the cells across the posterior lens capsule were determined.

RESULTS

Residual cell density on the remaining anterior capsule immediately after lens removal was 31.6% +/- 19.3%, 16.1% +/- 8.9%, and 7.7% +/- 5.7% in the ECCE, phacoemulsification, and phacoemulsification/capsule-vacuuming groups, respectively. Time to confluence (range 5.0 to 6.3 days) was not significantly different among the 3 groups when the lens capsules were cultured in serum-supplemented media. The confluence rate was significantly longer (by approximately 5 to 7 days) in the phacoemulsification/capsule-vacuuming group than in the other 2 groups when the capsules were cultured in serum-free media.

CONCLUSIONS

Phacoemulsification with and without anterior and equatorial capsular vacuuming led to less initial LEC density in the capsular bag than ECCE. However, because cell proliferation rates among the 3 groups were only marginally affected, near 100% removal of LEC at the time of cataract extraction may be necessary to prevent PCO.

Risk factors, complications, and results in extracapsular cataract extraction

PURPOSE

To examine a large series of extracapsular cataract extractions (ECCEs) to determine the risk factors for posterior capsule rupture with vitreous loss (PCR + VL) and the complications and results of this cataract surgery technique.

SETTING

North Riding infirmary, Middlesbrough, United Kingdom.

METHODS

In this retrospective study, the records of 1552 patients who had ECCE performed by two surgeons were examined. Follow-up was 4 months to 4 years. The main outcome measures were the incidence of risk factors, PCR + VL, major and minor postoperative complications, and the visual outcome.

RESULTS

Three hundred twenty-two cases were considered high risk for PCR + VL. In this group, the PCR + VL rate was 5.3%; it was 3.7% in the low-risk group and 4.0% overall. Visual acuity of 6/9 or better was achieved by 76% of all eyes. Postoperative complications were 3 cases of endophthalmitis, 4 of retinal detachment, and 1 of pseudophakic bullous keratopathy. In 323 eyes, loose or broken sutures were removed and in 175, a neodymium: YAG capsulotomy was performed because of posterior capsule opacification.

CONCLUSIONS

The incidence of perioperative and postoperative complications was comparable with those reported in other series. Factors that increased the risk of PCR + VL included pseudoexfoliation, diabetes mellitus, and a traumatic etiology. Previous glaucoma surgery and axial myopia of greater than 26.0 mm did not increase the PCR + VL risk. Loose or broken corneal sutures was a common finding that could be reduced substantially by planned suture removal.

Combined pars plana vitrectomy-lensectomy and open-loop anterior chamber lens implantation

PURPOSE

To investigate the effectiveness of open-loop, one-piece, flexible, Kelman-style, all-polymethylmethacrylate (PMMA) anterior chamber intraocular lenses (AC IOLs) in patients undergoing pars plana vitrectomy surgery for a variety of vitreoretinal disorders.

METHODS

Fifteen patients (6 women and 9 men) underwent combined pars plana vitrectomy with insertion of an open-loop AC IOL. Postoperative results were evaluated.

RESULTS

The average preoperative visual acuity of 20/360 (logMAR scale, 1.25 +/- 0.80) improved to 20/52 (logMAR scale, 0.42 +/- 0.35) after an average follow-up of 10.2 months (range, 1-41 months). Of 15 eyes, 7 (47%) achieved a visual acuity of better than 20/40. There was no evidence of glaucoma exacerbation or corneal decompensation. Visual acuity was limited primarily by chronic cystoid macular edema in 4 (27%) of 15 eyes.

CONCLUSION

In this preliminary series of patients, open-loop, flexible, all-PMMA, Kelman-style AC IOLs appear to be well tolerated and represent a viable, simple alternative to transscleral fixation of a posterior chamber IOL or surgical aphakia in patients undergoing vitrectomy surgery.

Visual prognosis following accidental vitreous loss during cataract surgery

Over the past 7 years there has been a change in the management of accidental vitreous loss during cataract surgery. There has been a reduction in immediate postoperative complications such as hyphaema. No immediate post-operative complications were observed during the last 18 months of the study. Whereas previously many of these patients remained aphakic, there was a change initially to anterior chamber intraocular lenses (IOLs) and now the vast majority receive capsule-supported sulcus-fixated posterior chamber IOLs. All patients had improved vision post-operatively by a mean of 4 Snellen lines, although they did not achieve the acuities of age- and sex-matched controls (p = 0.015).

Continuous curvilinear (circular) capsulorhexis and planned extracapsular cataract extraction--are they compatible?

The successful use of continuous curvilinear (circular) capsulorhexis (CCC) in planned extracapsular cataract extraction (ECCE) is dependent on the feasibility of safe nuclear delivery through the smaller anterior capsular opening. Experimental evidence supports the proposition that the anterior capsular rim can stretch without tearing to dimensions which allow for safe nucleus delivery. Clinical reports of accidental intracapsular expression during nucleus delivery in CCC seemingly contradict the experimental evidence. This paper examines this apparent contradiction and presents clinical evidence in the form of a series of 210 cases of planned ECCE with CCC. The technique used and a detailed analysis of the operative complications are presented. The results indicate that using a modified technique for nucleus delivery, CCC and planned ECCE are fully compatible techniques.

Visual outcome following complicated extracapsular cataract extraction

In a prospective study of 1,597 consecutive extracapsular cataract extractions (ECCE), we review 49 cases complicated by capsular or zonular rupture with or without vitreous loss. The ECCEs were divided into two groups depending on the type of intraocular lens (IOL) implanted. In Group A, whose patients received an anterior chamber lens, we found a significantly (P < .05, t-test) worse postoperative visual acuity than in Group B whose patients received a posterior chamber lens. We therefore suggest that in the presence of a capsular tear and vitreous loss, one should try to implant a posterior chamber lens rather than an anterior chamber lens to obtain as good a visual acuity as possible.

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.

Extracapsular cataract extraction with posterior chamber lens implantation in Fuch's heterochromic cyclitis

Twenty-two patients with Fuch's heterochromic cyclitis had a posterior chamber intraocular lens implanted after extracapsular cataract extraction. After a mean follow-up period of 2.5 years (range, 6 to 70 months) half the patients had a visual acuity of 1.0 or more. The results compare favourably with those in the general population.

Prospective study of posterior capsule-zonular disruption during extracapsular cataract extraction: eliminating iatrogenic disruption

We modified our surgical techniques after analyzing the mechanisms responsible for posterior capsule-zonular disruption with or without vitreous loss in 250 consecutive extracapsular cataract extraction cases. We applied the derived principles and prospectively studied the subsequent 1,500 cases. Modifications in our surgical protocol included the use of a Honan balloon for a longer interval (at least 60 minutes preoperatively) and more aggressive surgical expansion of poorly dilating pupils. Furthermore, complete YAG anterior capsulotomy performed after the retrobulbar block appeared to minimize zonular stress associated with mechanical anterior capsulotomy. We reduced the risk of posterior capsule-zonular disruption from 4.8% (2.4% vitreous loss) to zero, eliminating this complication completely in our last 1,000 cases.

Phacoemulsification and intraocular lens implantation in patients with cataract. Experiences of a beginning 'phacoemulsification surgeon'

Phacoemulsification was performed in 125 eyes (123 patients) selected from 145 eyes (143 patients) referred for planned extracapsular cataract extractions and intended posterior chamber intraocular lens implantations. These procedures were the first clinical phacoemulsification operations performed by the author. In the total material, lesion of the posterior capsule or zonules occurred in 7 eyes (4.9%). Vitreous loss occurred in 3 of these eyes (2.1%). In cases with vitreous loss the operative strategy was changed to implantations of anterior chamber lenses. Five of the 7 eyes that experienced intraoperative complications, had preoperative complicating conditions other than cataract. Visual acuity 6 to 12 weeks postoperatively was 6/12 or better in 87% (126/145) of the eyes. Excluding preoperative posterior segment pathology, 98.4% (126/128) achieved this visual acuity. This study demonstrates that it is possible to include phacoemulsification as the main treatment modality in planned ECCE operations without significant increase in complication rates even for a 'beginning phacoemulsification surgeon'.

Scleral fixation of a subluxated posterior chamber intraocular lens

A surgical technique for the treatment of a subluxated intraocular lens is described. It consists of a scleral incision 2 mm from the limbus, hooking the loop haptic of the implant into the scleral wound, and imbricating the loop into the sclera for permanent fixation. Four eyes in which this technique was applied successfully are reported.

Vitreous loss in posterior chamber lens implantation

Management of posterior capsule rupture and vitreous loss associated with intraocular lens implantation is described and the results of the procedure statistically analyzed. Vitreous loss occurred in 18 (4.3%) of the 416 eyes treated during a one-year period. Of these 18 eyes, 11 received posterior chamber lenses and seven received anterior chamber lenses; all lenses remained adequately fixated. The visual acuity, incidence of postoperative complications, and endothelial cell loss were not significantly different in the eyes that had posterior capsule rupture and vitreous loss and in the control eyes. Although posterior chamber lens implantation is not necessarily contraindicated in eyes with vitreous loss, instances of high endothelial cell loss suggest the need for greater attention to the endothelial cells during vitrectomy.

Risk factors for intraoperative complications in 1000 extracapsular cataract cases

A prospective study of the risk factors in extracapsular surgery was carried out between October 1984 and April 1986. One thousand extracapsular cataract extractions were performed by seven physicians. Decreasing pupil size was the only statistically significant risk factor for vitreous loss (P = 0.0002). Zonular breaks occurred more commonly with pseudoexfoliation syndrome (PX) (P less than 0.0001), with decreasing pupil size (P less than 0.0001), and with one surgeon who used the Simcoe aspirating needle (Storz) exclusively (P = 0.0001). It is acknowledged that it is very difficult to standardize what constitutes a small zonular break; hence, the increase in zonular breaks recorded by this surgeon may have been due only to his using less stringent criteria than the others. Capsule breaks had no significant risk factors at the 0.01 level. High myopia, advanced cataract, glaucoma, advanced age, and diabetes mellitus were not found to be risk factors for vitreous loss, zonular breaks, or capsular breaks.