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Intraocular pressures (IOP) and tonographic outflow facilities were measured following neodymium (Nd): YAG laser posterior capsulotomy in 13 pseudophakic and 8 aphakic eyes. Mean intraocular pressure (IOP) peaked by three hours with a mean increase of 13 mmHg, remained elevated by 5 mmHg at 24 hours but returned to baseline by one week. Fourteen eyes (67%) had greater than or equal to 10 mmHg elevation and eight (38%) had greater than or equal to 40 mmHg maximum IOP. All the patients who eventually demonstrated a greater than or equal to 10 mmHg elevation within six hours of the capsulotomy initially had an IOP elevation greater than or equal to 5 mmHg at one hour. The mean outflow facility was reduced from 0.18 microl/min/mmHg before capsulotomy to 0.08 microl/min/mmHg (55%, P less than 0.0001) at four hours and was still decreased at 0.13 microl/min/mmHg (27%, P less than 0.05) at one week. Seventy-five percent of aphakic and 15% of pseudophakic patients had maximum IOP greater than or equal to 40 mmHg (P less than 0.01). Measurements should be performed one hour postlaser in all patients for IOP and three to four hours in aphakic patients, glaucomatous patients, patients receiving greater than or equal to 200 mjoules total laser energy, and patients with greater than or equal to 5 mmHg elevation at one hour in order to detect and treat significant IOP elevations.

Choroidal neovascular membranes often are poorly defined on fluorescein angiography because of rapid or indistinct fluorescein leakage or because of blockage of hyperfluorescence by overlying hemorrhage, lipid, turbid fluid, or pigment. Indocyanine green (ICG) is a highly protein-bound dye with peak absorption (805 nm) and peak fluorescence (835 nm) in the near infrared portion of the spectrum. At these wavelengths, penetration through overlying pigments is increased. Using an infrared videoangiography system, the authors obtained ICG angiograms of 32 eyes with suspected choroidal neovascularization. Compared with fluorescein angiography, ICG improved visualization of the choroidal circulation and enhanced visualization of some membranes that were poorly defined with fluorescein. In addition, after clearance of the dye from the retinal and choroidal circulations, ICG remained in and around the neovascular tissue. The authors conclude that ICG videoangiography may aid in the evaluation of selected patients with poorly defined membranes on fluorescein angiography.

A ten-week, double-masked, randomized, clinical trial compared timolol ophthalmic solution and pilocarpine in the therapy of open-angle glaucoma. Timolol decreased the intraocular pressure at least as much as pilocarpine and did not induce miosis, accommodative spasm, or other annoying side effects. The pulse was slowed by timolol, but blood pressure was unaffected. Significant decreases in intraocular pressure were still present after ten weeks of maintenance therapy with the same concentration of drug.

A pulsed ultraviolet excimer laser was used to ablate bone in vitro at 193, 248, 308, and 351 nm and in vivo at 193 nm. Ablation was dependent on sufficient fluence (energy delivered per unit area per pulse) for plasma formation at the target site at all wavelengths. Adjacent tissue damage at various fluences for each wavelength was examined using a light microscope. Damage was minimal at 193 nm (1 to 3 microns) and most extensive at 351 nm (60 to 75 microns). This is in sharp contrast to the 1 to 3 mm of adjacent thermal damage produced when carbon dioxide lasers are used to ablate bone. Differences in the degree and type of damage to adjacent tissues among the wavelengths studied indicated that other ablation mechanisms and tissue interactions are involved in addition to simple plasma vaporization of bone. Bleeding during and after ablation demonstrated that the use of this laser does not cause thermal damage, which would cauterize adjacent vessels. Pre- and post-mortem lesions made at identical power and pulse settings were of equal depth, indicating that bleeding does not affect the ablation rate. The excimer laser has potential as a microsurgical instrument for the precise removal of bone with minimal damage to adjacent structures.

Timolol was used by 37 glaucoma patients from 1 to 18 months. Of those 37 patients, 31 used timolol for three months or longer and 7 used timolol for over one year. Timolol produced sustained reductions in intraocular pressure with continuous administration and did not induce miosis, accommodative spasm, or other annoying side effects. Systemic absorption produced a mild slowing of resting pulse rate. In some patients, timolol's ocular hypotensive effects are additive to miotics and carbonic anhydrase inhibitors.

The bone ablation characteristics of five infrared lasers, including three pulsed lasers (Nd:YAG, lambda = 1,064 micron; Hol:YSGG, lambda = 2.10 micron; and Erb:YAG, lambda = 2.94 micron) and two continuous-wave lasers (Nd:YAG, lambda = 1.064 micron; and CO2, lambda = 10.6 micron), were studied. All laser ablations were performed in vitro, using moist, freshly dissected calvarium of guinea pig skulls. Quantitative etch rates of the three pulsed lasers were calculated. Light microscopy of histologic sections of ablated bone revealed a zone of tissue damage of 10 to 15 micron adjacent to the lesion edge in the case of the pulsed Nd:YAG and the Erb:YAG lasers, from 20 to 90 micron zone of tissue damage for bone ablated by the Hol:YSGG laser, and 60 to 135 micron zone of tissue damage in the case of the two continuous-wave lasers. Possible mechanisms of bone ablation and tissue damage are discussed.

• We performed a morphologic investigation of the corneal endothelium following in vivo excimer laser ablation at 193 and 248 nm in rabbit eyes. Control experiments were performed in eyes with incisions of similar depth made with a diamond surgical knife, and normal control eyes were studied in parallel. We found that 193-nm excimer laser incision to 90% of corneal depth produces endothelial alterations similar to those seen underlying diamond knife incisions of similar depth. Scanning electron microscopy revealed an incisional ridge and endothelial cellular edema; endothelial cell loss was not observed. In contrast, 248-nm ablations of similar depth and energy density revealed loss of underlying endothelial cells and a surrounding zone of severe cellular damage.

• We investigated physicochemical changes in the vitreous body after photodisruption with a Q-switched neodymiumYAG laser. In vivo proton nuclear magnetic resonance imaging techniques were employed to assess alterations in the vitreous of irradiated rabbit eyes. Measurements of proton relaxation times (T , and T 2 ), viscosity, and chromatographic spectra were made in vitro on irradiated bovine and rabbit vitreous, and circular dichroism measurements were used to study changes in an irradiated sodium hyaluronate solution. Statistically significant changes in T , were observed immediately after irradiation, but the small magnitude and reversibility of those changes, combined with the fact that the other measurements detected no changes, suggest that neodymium-YAG laser photodisruption does not have a direct deleterious effect on the structural integrity of the normal vitreous body.

To the Editor. —Gaucher disease, an unusual inherited metabolic disorder, is characterized by excess storage of glucocerebrosides. Patients with type I disease are free of neurologic involvement. Fundus abnormalities in Gaucher disease include reported retinal hemorrhages and edema, as well as a solitary posterior pole lesion with a pigmented temporal margin. Macular cherry-red spots have been described, but the validity of these observations has recently been challenged.1Granular opacities in a ring-shaped distribution around the fovea of one patient have also been noted. Scattered whitish spots in superficial retinal layers have been reported, most often in patients with neurologic involvement.1 Patients with factor XI deficiency often show posttraumatic and perioperative bleeding, but spontaneous hemorrhage is not common. We are unaware of any fundus abnormalities reported in association with this inherited coagulation disorder. We report three discrete vascular lesions in the peripheral fundus of a patient with type I

This book is based on a laser symposium held at the Dean McGee Eye Institute, University of Oklahoma, Oklahoma City. It reviews all of the most important clinical applications of lasers in ophthalmology: trabeculoplasty, iridotomy, macular and panretinal photocoagulation, and neodymium-YAG laser photodisruption. The emphasis is on current treatment indications and techniques, and this book would be useful for the clinician who wants to review the current status of laser therapeutics in ophthalmology. Most of the information in the book is current. One useful feature of the book is a brief syllabus at the end, summarizing indications, techniques, and complications for the most frequently employed laser procedures. "This is a timely book, with a distinguished group of contributors." The organization, depth of information, and quality of the chapters is not uniform. A chapter by Thomas Stevens, George Bresnick, Mathew Davis, Suresh Chandra, and Frank Meyers provides an outstanding, comprehensive review

In the preface to this book, the editors state: Surgeons recognize that technical or bioengineering advances have been accompanied by striking progress in the development and application of old and new drugs that can be used to protect ocular tissues from trauma. The contributors to this volume wish to convey and consolidate this new knowledge for the ophthalmic surgeon. New information about the relationship of anesthesia, analgesia, antibiotics, and anti-inflammatory drugs to the eye patient as well as to the operating specifics of irrigating solutions, gases, and other useful drugs have been organized and are presented here in an effort to prevent, ameliorate, and treat damage done to the eye in the course of surgery. There are 37 contributors, most of whom are leaders in their field, with a total of 29 chapters. On the whole, these individuals and their contributions meet the goals set by the editors. The book

This volume is a collection of 35 reports presented at the International Symposium on Laser Photocoagulation of the Macula held in New Orleans, Nov 6 through Nov 8, 1986. Collectively, these reports provide an overview of indications, techniques, and complications of laser therapy for retinal disease. At present, this is the most up-to-date book on retinal photocoagulation. It should be quite valuable, not only to retinal specialists but also to those ophthalmologists who wish to obtain an overview of this field. The reports cover a wide range of topics, including basic concepts and instrumentation, diabetic retinopathy and other retinal vascular diseases, subretinal neovascularization in age-related maculopathy, and photocoagulation of retinal angiomas and intraocular tumors. In general, the reports are well written and concise. This is an enjoyable book to read. Many illustrative cases are shown, demonstrating the specifics of treatment techniques. At the conclusion of many of the chapters, the

• Chloroaluminum sulfonated phthalocyanine (CASPc), a novel photosensitizing dye, was evaluated for treatment of experimental intraocular melanoma in 33 rabbit eyes. An argon ion pumped dye laser, operating at an emission of 675 nm, was used in a nonthermal mode to irradiate iris tumors in rabbits 24 hours after they received an intravenous dye injection (23 eyes). The effects of laser irradiation alone and dye alone were examined in ten control eyes. A threshold tumoricidal dose was established for photodynamic therapy with CASPc and laser irradiation. Vascular occlusion was produced in a well-circumscribed area corresponding to the boundaries of laser irradiation after CASPc injection. Tumors successfully treated with CASPc and laser irradiation were arrested in growth and exhibited no viable tumor cells on histologic examination. Control tumors continued rapid growth, unaffected by dye or laser. Our data indicate that CASPc demonstrates a strong photosensitizing effect on both tumor and normal tissue. These results suggest that CASPc is a potential photosensitizing compound that may be useful in the treatment of choroidal melanoma.

The following is a list of current best-selling ophthalmic books, as identified by a survey of major ophthalmic publishing houses. Clinical Orbital Anatomy by Marcos Doxanas and Richard L. Anderson, 242 pp, 209 illus, Baltimore, Williams & Wilkins Co, 1984, $79.95. Current Concepts in Cataract Surgery edited by Jared M. Emery and Adrienne C. Jacobson, 430 pp, with illus, East Norwalk, Conn, Appleton-Century-Crofts, 1984, $75. 1984 Year Book of Ophthalmology edited by J. Terry Ernest, 324 pp, with illus, Chicago, Year Book Medical Publishers Inc, 1984, $44.95. Clinical Low Vision ed 2, by Eleanor E. Faye, 505 pp, with illus, Boston, Little Brown & Co, 1984, $28.50. External Infections of the Eye ed 3, by Helena Feducowicz and Susan Stenson, 388 pp, with illus, East Norwalk, Conn, Appleton-Century-Crofts, 1984, $58.50. Current Ocular Therapy ed 2, by F. T. Fraunfelder and F. H. Roy, 647 pp, Philadelphia, WB Saunders Co, 1985

This is an unusually well-written and timely volume, full of information and insights not easily obtained elsewhere. As the title indicates, the focus is on ophthalmic lasers and glaucoma therapy. The book consists of 25 chapters on a variety of topics in these two areas written by participants at the 33rd annual symposium of the New "... an unusually well-written and timely volume... on ophthalmic lasers and glaucoma therapy." Orleans Academy of Ophthalmology, March 1 to 5,1984. Unlike many books that are transactions of a meeting, the contributions to this volume are more than simply transcripts of the proceedings. Each is a well-developed, nicely illustrated, and amply referenced paper. The emphasis is on new developments of clinical relevance. The scientific quality of the papers presented is good. For a multiauthored text of this type, the book is exemplary. The chapters on glaucoma review issues of scientific interest and clinical relevance. Harry