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• An unpreserved artificial tear substitute containing 0.1% sodium hyaluronate was compared with a preparation containing 1.4% polyvinyl alcohol and 0.5% chlorobutanol in a controlled, double-masked, randomized study in patients with moderately severe keratoconjunctivitis sicca. Patients were evaluated initially, at 1, 4, and 8 weeks. The dry-eye status was evaluated by means of tear-film osmolality, tear breakup time, rose bengal staining, Schirmer's test (without anesthesia), and ocular surface-impression cytology. In general, neither preparation was found to be superior to the other. In both study groups, the mean tear-film osmolality and rose bengal staining score improved over the eight-week study, but the degree of squamous metaplasia of the bulbar conjunctival surface, as shown by impression cytology, did not change significantly.

• Determinations of tear film osmolarity were performed to evaluate their usefulness in diagnosing keratoconjunctivitis sicca (KCS) and to evaluate the possible role of elevated tear osmolarity in this disorder's pathogenesis. Tear samples were obtained using a new technique that virtually eliminates the problems of reflex tearing and sample evaporation. The tear osmolarity of 36 samples obtained from 31 normal eyes averaged 302 ± 6.3 (SD) mOsm/liter; 38 samples obtained from 30 KCS eyes averaged 343 ± 32.3 (SD) mOsm/liter. The sensitivity of a single measurement was 94.7% and the specificity was 93.7%. Tear samples taken on separate occasions from one normal subject ranged between 295 and 309 mOsm/liter; those obtained from a KCS patient ranged between 312 and 424 mOsm/liter. Hyperosmolarity of the tear film in KCS may play an important role in inducing the disease seen in the cornea and conjunctiva.

• Tear osmolarity and Rose Bengal staining were studied in a group of patients with keratoconjunctivitis sicca (KCS) before and after treatment with isotonic and one-half isotonic saline to compare treatment with these two solutions and to ascertain whether tear film osmolarity could be correlated with ocular surface disease. When 20 KCS eyes were treated with isotonic saline drops every three hours for one week, the average (±SD) tear osmolarity decreased from 365 ± 77 mOsm/L to 329 ± 47 mOsm/L, and the average (±SD) Rose Bengal staining score decreased from 4.1 ± 3.1 to 3.6 ± 3.3. There was no objective difference between treatment with isotonic and one-half isotonic solutions. In a double-masked comparison, however, four of five patients with diagnostically significant Rose Bengal staining preferred the half isotonic solution. There was a significant positive correlation between tear film osmolarity and Rose Bengal staining.

There is convincing evidence that the cornea obtains a significant portion of its oxygen requirements from the ambient atmosphere.1-5 Smelser has shown in the human by means of goggles filled with nitrogen and tightly fitted contact lenses that interference with the access of the corneal surface to atmospheric oxygen produces impaired transparency (Sattler's veil) as a result of increased corneal hydration presumably due to interference with oxygen dependent metabolic processes. Early morning edema after prolonged lid closure, seen in certain cases of endothelial dystrophy, and some of the problems of contact lens fitting are clinical examples of the importance of direct utilization of oxygen by the living cornea. At present there is still little quantitative information on this subject although recently, with the adaptation of the oxygen electrode to corneal studies by Hill and Fatt, important advances have been made.4The present study was undertaken to measure the

Significant corneal swelling was observed during eight hours of corneal contact lens wear in 12 volunteers successful in wearing the initial lenses prescribed. Following one week of daily wear, average increase in corneal thickness was 0.024 mm. Significant change in average corneal thickness occurred also at two to three weeks, six to eight weeks, and six months. Incidence of significant corneal swelling during eight hours of contact lens wear decreased with increasing periods of daily wear. Epithelial edema accompanied corneal swelling in ten of 20 eyes, decreased more rapidly than corneal swelling, and disappeared before corneal thickness had returned to baseline value. There was frequent association between corneal swelling and decreased oxygen uptake of the cornea following eight hours of wear. No simultaneous change was observed in average tear osmolarity with an increase in average corneal thickness.

The purpose of this latest book on contact lens practice is first, to provide the beginning contact lens practitioner with a detailed step-by-step procedure in the work-up and care of the contact lens patient, and, second, to provide essential information in a concise and readily available manner. The question and answer format and an 18-page index serve this purpose well but not without some degree of incompleteness. There is no bibliography and although the author in the preface names three texts and several other sources, answers are primarily those of the author. This is not to say by any means that the author is alone in his conclusions which were developed as a result of nearly 20 years experience in the contact lens field as both an optometrist and ophthalmologist.As one would expect in a clinical field which to some degree is still in its infancy, there are many

Thanks to the editorship of Drs. Becker and Burde, the current thoughts and practices of the present and former ophthalmology staff of Washington University are compiled again in a concise volume. The subspecialties of cornea, retina, and muscle are well represented with several chapters each, and there are also chapters on ophthalmic pathology, thyroid disease, gonioscopy, plastic surgery, and dyslexia. We are given practical information regarding corneal transplant techniques and the treatment of herpes simplex keratitis. The retina also gets fair treatment with chapters about utilization of contact lenses in biomicroscopy and the use of cryotherapy in retinal surgery. The cryosurgical removal of cataracts is discussed in a 39-page chapter which describes with numerous illustrations most of the cryo instruments now available. The chapter on gonioscopy outlines the reasons for utilizing a set of 13 gonioprisms to compensate for varying corneal curvatures. A review of lens induced inflammation with discussion

The First International Symposium on Contact Lenses was organized for the XXth International Congress of Ophthalmology by the Contact Lens Association of Ophthalmology. In the opening address the organization's president, A. Schlossman, MD, places emphasis on the premise that "As Ophthalmologists it is our duty to enlighten other members of the medical profession and also the general public about the nature of contact lenses, their potential dangers, and how to minimize the latter."Two of the papers in the symposium, among others, that are especially concerned with the physiologic and pathologic effects of contact lenses are Boyd's paper about fenestration of contact lenses for corneal edema and Hartstein's case reports of corneal warping due to contact lenses. Considering the increasing number of aphakics who are wearing contact lenses, two papers by Welsh concerned with the proper manufacture of high plus lenses and a paper by Sampson, Soper, and Girard about

Professor Girard and his associates are to be congratulated on two accounts, first, for organizing a highly enjoyable meeting in Houston, and second, for their persistence in bringing together in this single volume the papers of 54 contributors who are largely from North America but who also, in appreciable number, come from areas as widely separated as Australia and Czechoslovakia.A wide range of topics within the contactlens field is covered in the 51 presentations which, as one would expect from a relatively young field of research, lean heavily on clinical experience and observation. The lively discussions following each session of the congress are included in the proceedings, and there is an introductory discussion which consists of each contributor present stating what he feels to be the most important problems to be solved in contact lenses. There is little doubt that this initial portion of the book has already served