Capsulorhexis in mature cataracts: why not?

Indocyanine green-assisted phacoemulsification in cases of complicated or simple advanced cataracts

BACKGROUND/PURPOSE

During phacoemulsification for advanced cataracts, particularly when complicated by anterior segment abnormalities, capsulorhexis is very difficult and carries a high risk of complications. This study investigated the efficacy and safety of indocyanine green (ICG)-assisted phacoemulsification in complicated or simple advanced cataracts.

METHODS

Thirty-two patients (35 eyes) underwent phacoemulsification for complicated advanced cataracts (group 1) or simple advanced (mature/hypermature) cataracts (group 2). Anterior segment abnormalities (corneal opacity, small pupil, or glaucoma) in group 1 complicated phacoemulsification. In both groups, 0.5% ICG was used for capsulorhexis, and subsequent procedures were performed in the same routine manner.

RESULTS

Group 1 included 15 patients (17 eyes) with a mean age of 60.0 years. Group 2 included 17 patients (18 eyes) with a mean age of 69.4 years (p<0.05). Continuous curvilinear capsulorhexis was completed in all eyes in group 2, but radial tears occurred in four (23.5%) eyes in group 1 (p<0.05). Phacoemulsification was performed uneventfully in all eyes in both groups. Postoperative complications (corneal edema, vitreous prolapse, posterior capsule opacity, elevated intraocular pressure) were seen in five (27.8%) eyes in group 1 and four (23.5%) eyes in group 2 (p>0.05). None of these were attributed to the use of ICG. Visual acuity improved in all eyes in group 2, but in only 11 (64.7%) in group 1 (p<0.01).

CONCLUSION

ICG-assisted phacoemulsification is safe and helpful for complicated or simple advanced cataracts. Differences between the two groups in patient age, intraoperative complications, and visual outcome could be explained by differences in the cause(s) of advanced cataracts.

Phacoemulsification with indocyanine green versus manual expression extracapsular cataract extraction for advanced cataract

PURPOSE

To compare the outcomes of indocyanine green dye (ICG)-assisted phacoemulsification with manual expression extracapsular cataract extraction (ECCE) in eyes with advanced cataract.

SETTING

Parkland Memorial Hospital and Dallas Veterans Affairs Medical Center, Dallas, Texas, USA.

METHODS

In this retrospective study, 72 consecutive cases of advanced or mature cataract extractions performed in a 1-year period were reviewed. Fifty-nine eyes met the inclusion and exclusion criteria; 33 had ICG-assisted phacoemulsification and 26, manual expression ECCE. Preoperative and intraoperative findings and the postoperative outcomes up to 6 months were analyzed.

RESULTS

Intraoperative complications included posterior capsule tear with vitreous prolapse in 2 eyes (6.6%) and conversion to manual expression ECCE in 1 eye (3.3%) in the ICG phacoemulsification group. There was no intraoperative complication in the manual expression ECCE group. There were significantly more patients with a best corrected visual acuity of 20/30 or better in the ICG phacoemulsification group than in the manual expression ECCE group at all postoperative periods. The mean logMAR visual acuities were significantly better in the ICG phacoemulsification group at all postoperative intervals. The ICG phacoemulsification group had significantly less postoperative astigmatism. There was no significant difference between the groups in the early postoperative intraocular pressure.

CONCLUSIONS

Phacoemulsification with ICG led to better postoperative visual acuity and less postoperative astigmatism than manual expression ECCE. Phacoemulsification with ICG was associated with more intraoperative complications than manual expression ECCE; however, the complication rate is comparable to a previously published rate for phacoemulsification performed in a university training program. Phacoemulsification with ICG appears to be a reasonable alternative to manual expression ECCE for advanced cataract.

Dye-enhanced cataract surgery. Part 1: anterior capsule staining for capsulorhexis in advanced/white cataract

PURPOSE

To evaluate anterior capsule staining using 3 dyes to perform continuous curvilinear capsulorhexis (CCC) in postmortem human eyes with advanced/white cataract.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

In experimental closed-system surgery, CCC was performed in 12 postmortem human eyes with cataract after the anterior capsule was stained with 3 capsule dyes (fluorescein sodium 2%, indocyanine green [ICG] 0.5%, and trypan blue 0.1%). Two commonly used techniques for capsule staining were also compared: staining within an air bubble and intracameral subcapsular injection of dye.

RESULTS

In all globes, CCC was uneventful using the 3 dyes and with both techniques. With the intracameral subcapsular injection, the dye remained trapped in the subcapsular space in contact with the posterior surface of the anterior capsule, allowing enough time to perform any maneuver. The staining provided by ICG, at the concentration used, was slightly superior to that of the other dyes. Leakage of fluorescein sodium into the vitreous cavity was seen using the Miyake-Apple posterior video/photographic technique.

CONCLUSION

Intracameral subcapsular injection of ICG allowed the easiest recognition of the capsular flap by staining the posterior surface of the anterior capsule and without leaking into the vitreous cavity.

Ultrasonographic classification and phacoemulsification of white senile cataracts

OBJECTIVE

To classify the white senile cataracts and report the results of phacoemulsification of white cataracts.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

One hundred eyes were included.

INTERVENTION

White cataracts were examined biomicroscopically before surgery, and their acoustic structure was analyzed with standardized A-scan echography. White cataract surgery was performed with phacoemulsification via a superior temporal near-limbus corneal approach using a bimanual divide-and-conquer or stop-and-chop technique. Patients were followed after surgery for a period of 9 months.

MAIN OUTCOMES MEASURES

The A-scan acoustic structure of white cataracts; successful accomplishment of capsulorrhexis; mean phacoemulsification time, power, and energy; intraoperative and postoperative complications of phacoemulsification; and visual acuity at 9 months after surgery.

RESULTS

White senile cataracts were categorized into three different types. Type I included intumescent, white cataracts with cortex liquefaction and high internal acoustic reflections (44 eyes), type II included white cataracts with voluminous nuclei, little amount of whitish solid cortex, and low internal acoustic reflections (49 eyes), and type III included white cataracts with fibrosed anterior capsule and low internal echospikes (7 eyes). Circular capsulorrhexis was completed in 79 eyes and was significantly less successful in eyes with type I intumescent, white cataracts compared with type II white cataracts (P = 0.0034). Mean phacoemulsification time and energy were higher in type II and type III white cataracts. Posterior capsule rupture occurred in ten eyes, and three of these eyes were complicated by vitreous loss. In 95 eyes, the posterior chamber lens was implanted in the capsular bag and in five eyes in the sulcus. After surgery, a transient corneal edema developed in 31 eyes. At the final 6-month examination, the mean postoperative visual acuity was 20/30.

CONCLUSION

Current phacoemulsification techniques can safely manage eyes with senile white cataracts. The increased risk of difficulty with continuous capsulorrhexis in type-I and type-III white cataracts and the substantial nuclear hardness in type-II and mainly type-III white cataracts would suggest that current phacoemulsification techniques might not be as successful in these patients as they are in ordinary earlier cataracts.

Experimental staining of the anterior lens capsule in albino rabbits

PURPOSE

To study the value and safety of staining the anterior lens capsule in albino rabbits.

SETTING

Ophthalmology Department, Cairo University, and Ophthalmic Pathology Department, Research Institute of Ophthalmology, Cairo, Egypt.

METHODS

The experiment was divided into 3 stages. First, the capacity of different concentrations of crystal violet solution to stain the anterior lens capsule of postmortem albino rabbit eyes was tested. The toxicity of different concentrations of the dye (2% to 0.25%) was then tested to determine the highest concentration that was nontoxic to the cornea and trabecular meshwork. The third step was to detect possible toxicity of lower concentrations (0.1% to 0.05%). Different dye concentrations were injected into the anterior chamber of the rabbit eyes. The eyes were examined after 1 and 3 days, 1 week, and 1 month using light microscopy and scanning and transmission electron microscopy.

RESULTS

Different concentrations of crystal violet stained the anterior lens capsule, allowing for easy capsulorhexis. The use of the 2% and 1% concentrations was accompanied with irreversible damage to all corneal layers. The use of the 0.5% concentration caused damage to stromal keratocytes and endothelium. The use of the 0.25% concentration did not damage any corneal layer or the trabecular meshwork. Lower concentrations of 0.1% and 0.05% also stained the capsule, providing good visibility for successful capsulorhexis, and were less toxic to the corneal endothelium.

CONCLUSION

Staining the anterior lens capsule with 0.25% to 0.05% concentrations of crystal violet solution caused no injury to the cornea or trabecular meshwork in albino rabbit eyes.

Surgical techniques for difficult cataracts

This article reviews some of the advances that have taken place in the surgical techniques for difficult cataracts such as rock-hard, white, and posterior polar cataracts. Fashioning a central space, modified chopping maneuvers, and creation of multiple small fragments have enabled the surgeon to consistently achieve a successful outcome. A judicious combination of chop and separation movement in a step-by-step manner reduce the stress of the procedure and make it safer. Raised intracapsular pressure and poor visibility are dealt with through various innovative techniques. Use of high-viscosity sodium hyaluronate and double capsulorhexis allow the surgeon to achieve capsulorhexis with a high success rate. A controlled and gentle approach to phacoemulsification has proven to be the key factor for success in posterior polar cataracts.

Fluorescein blue, light-assisted capsulorhexis for mature or hypermature cataract

This technique is for use in eyes with mature or hypermature cataract resulting in lack of fundus reflex during capsulorhexis. Fluorescein staining is performed before the capsulorhexis is made. A blue filter in the coaxial light accentuates the remaining rim of bright blue fluorescence and aids in exact formation of the anterior opening. Seven eyes with a postoperative visual acuity of light perception had surgery using this technique. Visual acuity ranged from 20/200 to 20/20 up to 3 months postoperatively. No untoward reaction to the fluorescein was observed; however, the long ultrasound exposure for very hard nuclei (up to 4 minutes) caused corneal edema in two eyes. This technique is regularly used in all eyes with insufficient fundus reflex caused by lens opacity or vitreous disease.