Nd:YAG laser useful for lysis of epinuclear fragment in anterior chamber

In two cases, the procedure was performed after cataract surgery as an alternative to irrigation and aspiration.

Thomas John

Nd:YAG laser has been used most commonly for lysis of an after-cataract to clear the visual axis and improve visual acuity, usually in an office setting. This is a quick laser procedure that has an almost immediate effect in improving the eyesight of our patients in cases of secondary cataracts. Nd:YAG laser has been used for other treatments as well, such as cystotomy for the surgical management of iris pigment inclusion cyst, transscleral cyclophotocoagulation for refractory glaucoma, laser synechiolysis, anterior capsular relaxing incisions and pupilloplasty.

When an ophthalmic surgeon sees a cataract fragment in the anterior chamber, he is usually obligated to take the patient to the operating room and surgically remove the fragment to prevent any adverse effects of a free fragment in the anterior chamber such as secondary corneal edema, mechanical rubbing on the iris surface with secondary inflammation, peripheral anterior synechiae or cystoid macular edema.

In this column, Dr. Khaliq describes a new off-label application of the Nd:YAG laser to dissipate anterior chamber epinuclear fragment after phacoemulsification. Such a procedure obviates the need to take the patient back to the operating room to remove a lens fragment after cataract surgery. This new technique needs to be closely monitored with a larger number of cases to evaluate the overall efficacy and safety of the procedure.

Thomas John, MD
OSN Surgical Maneuvers Editor

Abdul Khaliq

Epinuclear fragments can show up in the anterior chamber from 1 day up to 5 years after cataract surgery and can be associated with corneal edema. At present, treatment of this complication is irrigation and aspiration. A new laser technique eliminates the need for irrigation and aspiration.

Case 1

A 75-year-old white woman presented with blurred vision greater in the right eye than in the left eye for both near and distance vision for the last 6 months. Examination revealed corrected vision was 20/200 in the right eye and 20/50 in the left eye. The cornea in the right eye had fine corneal opacities while the left eye was clear of opacities. The anterior chambers were normal, and the pupils were regular. Fundus exam was normal, and IOP was 22 mm Hg in the right eye and 24 mm Hg in the left eye. Phacoemulsification to remove the cataracts was performed without complication. The patient’s visual acuity was 20/40 in the right eye 1 month after cataract extraction surgery. At 3 months postop, she developed an after-cataract, which was treated by YAG capsulotomy. One week after laser treatment, a nuclear fragment measuring 3 mm × 3 mm was noticed in the anterior chamber at the 6 o’clock position and was lysed with YAG laser (Figure 1).

A YAG laser was used with a power of 5.5 millijoules and a pulse of 1. Four shots were applied to the right eye directly to the epinuclear fragment, which was completely dissipated. Corneal edema resolved after 4 days. The patient used prednisolone acetate 1% four times a day for 1 week. Postop visual acuity was 20/25 (Figure 2).

Figure 1. Slit lamp appearance of the anterior chamber in case 1 at 1 week after Nd:YAG laser capsulotomy showing a nuclear fragment inferiorly at the 6 o’clock position.

Figure 2. Biomicroscopic view of the anterior chamber showing complete resolution of the epinuclear fragment. Images: Khaliq A

Case 2

A 77-year-old woman presented with blurred vision and glare at night at her 6-month examination, revealing a clear cornea, normal anterior chamber, round pupils and a dense posterior subcapsular cataract in the left eye. The fundus appeared normal, and IOP was 16 mm Hg in both eyes. She underwent clear cornea phacoemulsification in the left eye with no complications. At her third postop visit at 1 month, her visual acuity was 20/60 without glasses. Slight corneal edema localized to the lower third of the cornea was noted. In the anterior chamber was a 3 mm × 3 mm epinuclear fragment at the 6 o’clock position, which was treated with YAG laser. The patient’s visual acuity at 3 days after the YAG procedure was 20/40; the cornea was clear, the anterior chamber was clear, and the epinuclear fragment was completely resolved. The pupil was normal, and the posterior chamber IOL was in a good position. Three months after cataract surgery, the patient’s corrected visual acuity was 20/20 in the left eye. Both the cornea and the anterior chamber were clear.

A YAG laser was used with a power of 6 millijoules and a pulse of 1. Six shots were applied directly to the epinuclear fragment, which was completely dissipated. Corneal edema was resolved completely. The patient used prednisolone acetate 1% four times a day for 1 week.

Discussion

Case 1 presented with an epinuclear fragment in the anterior chamber with corneal edema. It was possible to focus the laser onto the fragment through the corneal edema, although high power was needed to dissipate the fragment.

Case 2 presented with a clear cornea. Laser scattering caused iris stimulation and patient discomfort. Therefore, the pupil was dilated, 0.5 cc of 2% Xylocaine was injected subconjunctivally, and the fragment was dissipated with lower power, fewer shots and no patient discomfort.

Conclusion

YAG laser with appropriate power can be successfully used for epinuclear fragment lysis up to 2.5 mm to 3 mm without adverse side effects.

References:

• Beiran I, Rootman DS, Trope GE, Buys YM. Long-term results of transscleral Nd:YAG cyclophotocoagulation for refractory glaucoma postpenetrating keratoplasty. J Glaucoma. 2000;9(3):268-272.
• Flynn WJ, Carlson DW. Laser synechialysis to prevent membrane recurrence on silicone intraocular lenses. Am J Ophthalmol. 1996;122(3):426-428.
• Hayashi K, Yoshida M, Hirata A, Hayashi H. Anterior capsule relaxing incisions with neodymium:YAG laser for patients at high-risk for anterior capsule contraction. J Cataract Refract Surg. 2011;37(1):97-103.
• Kathil P, Chin KJ, Ghaznawi N, Finger PT. Transpupillary Nd:YAG laser cystotomy for iris pigment epithelial cysts with secondary progressive angle closure. Ophthalmic Surg Lasers Imaging. 2011;42 Online:e40-e43.
• Summers CG, Holland EJ. Neodymium:YAG pupilloplasty in pediatric aphakia. J Pediatr Ophthalmol Strabismus. 1991;28(3):155-156.

• Thomas John, MD, is a clinical associate professor at Loyola University in Chicago and is in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at 708-429-2223; fax: 708-429-2226; email: tjcornea@gmail.com.
• Abdul Khaliq, MD, FRCS, can be reached at 45 S. Main St., West Hartford, CT 06107; 860-233-7210; fax: 860-233-7724; email: khaliq42@hotmail.com.
• Disclosure: No products or companies are mentioned that would require financial disclosure.