Histological changes and wound healing response following noncontact holmium: YAG laser thermal keratoplasty

Histological changes and wound healing response following noncontact holmium: YAG laser thermal keratoplasty

deficiency due to Stevens-Johnson syndrome and patients with preoperative conjunctival keratinization had a significantly worse outcome. The author of...

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deficiency due to Stevens-Johnson syndrome and patients with preoperative conjunctival keratinization had a significantly worse outcome. The author offered his indications for epithelial transplantation as fol­ lows: For patients with unilateral cicatrizing conjunc­ tival disease, the first option recommended was a conjunctival autograft. For patients with unilateral limbal deficiency, conjunctival limbal autograft was the procedure of choice. For patients with bilateral disease, living related conjunctival limbal allograft was recommended first. If this procedure was not available, he suggested consideration of keratolimbal allograft. Keratolimbal allograft was a useful tech­ nique in the management of severe ocular surface disease caused by limbal deficiency.—Thomas J. Liesegang *U Minn Department of Ophthalmology, Box 493, 420 Delaware St SE, Minneapolis, MN 55455-0501.

• Histological changes and wound healing response following noncontact holmium: YAG laser thermal keratoplasty. Koch DD.* Trans Am Ophthamol Soc 1996;94:745-802.

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HE AUTHOR EVALUATED THE ACUTE HISTOPATHO-

logic changes and the induced wound-healing response in rabbit and human corneal tissue follow­ ing noncontact holmium:YAG laser thermal kerato­ plasty (LTK). Laser thermal kerotoplasty was per­ formed on three human corneas 1 day prior to penetrating keratoplasty, using 10 pulses and a range of radiant energies. Rabbit corneas were treated with 10-pulse and 5-pulse LTK and followed for up to 3 months; tissues were studied with light and transmis­ sion electron microscopy and immunohistochemistry. The amount of human acute tissue injury increased with increasing pulses of radiant energy. In human corneas, changes in the irradiated zones included epithelial cell injury and death, loss of fine filamen­ tous structure in the Bowman layer, disruption of stromal lamellae, and keratocyte injury and death. In the rabbit corneas, similar acute changes were noted. Compared to 10-pulse treatments, 5-pulse treatments produced less acute tissue injury and had more rapid restoration of normal stromal architecture. The au­

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thor felt that noncontact LTK produced acute epithe­ lial and stromal tissue changes and in rabbit corneas stimulated a brisk wound-healing response that could contribute to postoperative regression of induced refractive correction.—Thomas J. Liesegang *Cullen Eye Institute, 6501 Fannin NC-200, Houston, TX 77030.

• Visual impairment, visual functioning, and qual­ ity of life assessments in patients with glaucoma. Parrish RK.* Trans Am Ophthamol Soc 1996;94: 919-1028.

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HE AUTHOR STUDIED THE RELATION BETWEEN VISU-

al impairment, visual functioning, and the global quality of life in 147 consecutive patients with glaucoma. Visual impairment was defined by the American Medical Association Guides to the Evalua­ tion of Permanent Impairment; visual functioning was measured with the VF-14 and the Field Test Version of the National Eye Institute-Visual Func­ tioning Questionnaire (NEI-VFQ); the global quality of life was assessed with the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). None of the SF-36 domains demonstrated more than a weak correlation with visual impairment. The VF-14 scores were moderately correlated with visual impairment. Of the 12 NEI-VFQ scales, distance activities and vision-specific dependencies were moderately corre­ lated with visual acuity impairment and with visual field impairment; vision-specific social functioning, near activities, vision-specific role difficulties, general vision, vision-specific mental health, color vision, and driving were modestly correlated; visual pain was weakly correlated, and two other scales were not significantly correlated. The author concluded that the SF-36 was unlikely to be useful in determining visual impairment in patients with glaucoma. Based on the moderate correlation between visual field impairment and the VF-14 score, this questionnaire may be generalizable to patients with glaucoma. Several of the NEI-VFQ scales correlated with visual field impairment scores in patients with a wide range of glaucomatous damage.—Thomas J. Liesegang *Bascom Palmer Eye Institute, P. O. Box 016880, Miami, FL 33101.

AMERICAN JOURNAL OF OPHTHALMOLOGY

APRIL

1997