David B. Glasser

A Comparison of Corneal Endothelial Changes After Use of Healon or Viscoat During Phacoemulsification

We conducted a prospective, randomized trial comparing the endothelial protective effects of Healon (Kabi Pharmacia Ophthalmics, Inc., Monrovia, California) and Viscoat (Alcon Surgical, Inc., Ft. Worth, Texas) in 59 eyes of 59 patients undergoing iris-plane or posterior-chamber phacoemulsification with posterior-chamber lens implantation. We evaluated postoperative central and superior changes in corneal thickness and corneal endothelial cell density, coefficient of variation in cell size, and percentage of hexagons. In the overall series, at one day postoperatively, corneal thickness increased 17% centrally and superiorly in eyes receiving Healon compared to 12% centrally and 11% superiorly in eyes receiving Viscoat (P < .05). Sixteen weeks postoperatively, superior endothelial cell loss was 11.6% in eyes receiving Healon compared to 2.1% in eyes receiving Viscoat (P < .01). In the iris-plane phacoemulsification group, superior cell loss at week 16 was 13.8% in eyes receiving Healon and 0.5% in eyes receiving Viscoat (P < .04). In the posterior-chamber phacoemulsification group, there were no significant differences between the Healon and Viscoat subgroups. Comparing the surgical techniques, in the Healon group, central cell loss at week 16 was 13.8% in the iris-plane phacoemulsification subgroup and 0.6% in the posterior-chamber phacoemulsification subgroup (P < .03), and coefficient of variation in cell size increased 3.7% in the iris-plane subgroup and decreased 6.8% in the posterior-chamber subgroup (P < .04). In the Viscoat group, there were no significant differences between surgical techniques at week 16. Viscoat provided greater corneal endothelial protection than Healon during iris-plane phacoemulsification. In eyes receiving Healon, posterior-chamber phacoemulsification resulted in less corneal endothelial trauma than the iris-plane technique.

Ocular Jellyfish Stings

BACKGROUND Corneal stings from the sea nettle (Chrysaora quinquecirrha) indigenous to the Chesapeake Bay are usually painful but self-limited injuries, with resolution in 24 to 48 hours. METHODS Five patients who developed unusually severe and prolonged iritis and intraocular pressure elevation after receiving corneal sea nettle stings were followed for 2 to 4 years. RESULTS Decreased visual acuity, iritis, and increased intraocular pressure (32 to 48 mmHg) were noted in all cases. Iritis responded to topical corticosteroids and resolved within 8 weeks. Elevated intraocular pressure responded to topical beta blockers and oral carbonic anhydrase inhibitors. Mydriasis (4 of 5 cases), decreased accommodation (2 of 5 cases), peripheral anterior synechiae (2 of 5 cases), and iris transillumination defects (3 of 5 cases) also were noted. Mydriasis and decreased accommodation persisted for 5 months in 1 case and for more than 2 years in another. One patient has chronic unilateral glaucoma. Visual acuity returned to normal in all cases. CONCLUSIONS The precise relationship between sea nettle venom and the observed clinical responses is not known. Corneal jellyfish stings usually produce a brief and self-limited reaction, but they do have the potential for long-term sequelae.

Necrotizing Scleritis of Scleral Flaps After Transscleral Suture Fixation of an Intraocular Lens

A 56-year-old woman with rheumatoid arthritis underwent intracapsular cataract extraction and sulcus fixation of an intraocular lens using transscleral fixation sutures buried under partial-thickness scleral flaps. Necrotizing scleritis confined to the area of the scleral flaps developed one month postoperatively, resulting in exposure and loosening of one fixation suture and lens implant decentration. The scleritis responded to systemic prednisone and cyclophosphamide treatment, with healing in two weeks. The final visual acuity was 20/30. Surgical trauma may stimulate local intravascular immune complex deposition and initiate the inflammatory process, thereby leading to necrotizing scleritis. This process should be considered when contemplating the use of scleral flaps in patients with collagen vascular disease and systemic vasculitis.

A guinea-pig model of corneal jellyfish envenomations.

Corneal jellyfish stings are painful, self-limited injuries which usually produce conjunctival hyperemia and chemosis, corneal edema, and mild iridocyclitis with resolution in 48 hr. We have developed a guinea-pig model of corneal jellyfish stings in order to study pathogenesis of human injury. Guinea-pig eyes were exposed to sea nettle (Chrysaora quinquecirrha) venom in vivo in the following ways: contact with live tentacles, intracameral injection of crude venom, and intracorneal injection of crude jellyfish venom. Slit lamp examination and histologic sections of the eye performed at intervals up to 8 days after exposure to the venom demonstrated conjunctival hyperemia and chemosis, corneal stromal inflammatory edema, anterior chamber inflammation, and opacities on the anterior capsule of the lens. Nematocysts adherent to the corneal epithelium were noted in eyes exposed to live tentacles.

Changing trends in keratoplasty.

i t P e s t w n H ISTORICALLY, SAFETY AND EFFICACY HAVE BEEN the most important considerations in evaluating new therapies. With rapidly accelerating healthcare expenditures, increasing attention has been paid to the costs of new procedures. Payers consider cost/benefit ratios in addition to safety and efficacy when making coverage and payment decisions. Those decisions exert increasing control over how rapidly and widely new procedures are adopted. The article by van den Biggelaar on cost-effectiveness of deep anterior lamellar keratoplasty (DALK) versus penetrating keratoplasty (PK) in this issue of the Journal addresses this interplay between clinical and economic factors. Zirm performed the first successful penetrating keratoplasty in 1905. PK eventually became the procedure of choice for corneal blindness and has been predominant for the past half-century. Nevertheless, PK has its problems. Suprachoroidal hemorrhage is rare but devastating. Suturerelated problems are common and can lead to graft failure. Visual rehabilitation is delayed by ocular surface problems and variable refractive error. Long-term astigmatism and ametropia leave some patients unable to attain useful visual function without contact lenses or further surgical intervention. Globe rupture after minor trauma is a permanent risk. Graft failure rates of 14% to 36% at 5 to 10 years and regraft failure rates of 50% or greater can be seen, with immunologic rejection in 15% to 20% of cases contributing, along with nonimmunologic endothelial cell loss, to late graft attrition. Over the past decade, lamellar keratoplasty has begun to supplant PK. Endothelial keratoplasty (EK), by eliminating many of the ocular surface and wound integrity problems associated with PK and by offering faster visual rehabilitation, has become the procedure of choice for patients with endothelial disease. Anterior lamellar kertoplasty (ALK) techniques have evolved to the point that hey now challenge the supremacy of PK for patients with tromal disease. Advantages of DALK include retention of recipient endothelium, eliminating endothelial rejection, less steroid exposure and attendant risks of glaucoma and cataract formation, less distortion of angle anatomy and synechia formation, and an expanded donor pool. DALK results in less long-term endothelial cell loss and higher long-