Role of the bandage soft contact lens in the postoperative laser in situ keratomileusis patient.

PURPOSE: To determine whether a bandage soft contact lens (BSCL) is routinely needed in the postoperative laser in situ keratomileusis (LASIK) patient and whether topical tetracaine 0.5% or diclofenac sodium 0.1% (Voltaren) is more effective in relieving patient discomfort than a BSCL. SETTING: LCA-Vision Center, Toronto, Ontario, Canada. METHODS: In this prospective randomized comparative study, all patients had bilateral simultaneous LASIK procedures. Post-LASIK patient comfort was evaluated through 3 arms of the study: BSCL versus no BSCL, 40 consecutive patients with 1 eye randomized to receive a BSCL and no BSCL in the fellow eye; BSCL versus tetracaine 0.5%, 26 consecutive patients with 1 eye randomized to receive a BSCL and tetracaine 0.5% in the fellow eye; tetracaine 0.5% versus Voltaren, 54 consecutive patients with 1 eye randomized to receive tetracaine 0.5% and Voltaren in the fellow eye. RESULTS: The patient preferences after LASIK were as follows: BSCL versus no BSCL-12 (30%) versus 23 (58%) (P =.062); BSCL versus tetracaine 0.5%-4 (15%) versus 22 (85%) (P <.001). On average, the eyes with no BSCL had a 2-line improvement in uncorrected visual acuity over the BSCL eyes. Tetracaine 0.5% versus Voltaren-13 (24%) versus 21 (39%) (P =.170). CONCLUSIONS: The routine use of a BSCL in the postoperative LASIK patient is not necessary. Voltaren and tetracaine 0.5% were safe and more effective in relieving postoperative patient discomfort and resulted in improved visual acuity immediately postoperatively.

Retrobulbar anesthesia for cataract surgery: comparison of bupivacaine and bupivacaine/lidocaine combinations.

Three groups of 15 patients each were randomly assigned to receive a retrobulbar anesthetic block with 0.5% bupivacaine, 0.5% bupivacaine/2% lidocaine or 0.5% bupivacaine/2% lidocaine/1:100 000 epinephrine for unilateral cataract surgery. Hyaluronidase was added to each of the preparations, which were used in double-blind fashion. Lid and globe akinesia and corneal anesthesia were graded after 4 minutes of ocular massage and 36 minutes later (at the end of the procedure) to assess the rapidity of onset and the duration of action of the anesthetics. Overall, bupivacaine/lidocaine/epinephrine was the most effective in producing akinesia of the lids and globe. Bupivacaine alone was more effective than bupivacaine/lidocaine without epinephrine in producing akinesia, although it was slower in producing anesthesia. There was no difference between the groups in the frequency of pain or of the need for analgesia 6 hours postoperatively.

Treatment of herpes simplex keratitis: comparison of acyclovir and vidarabine.

At three university centres 66 patients presenting with herpetic dendritic or geographic ulcers participated in a double-blind comparative study of 3% acyclovir and 3% vidarabine ointment. There was healing in 31 (97%) of the 32 patients treated with acyclovir, in a mean time of 6.3 days, and in 30 (88%) of the 34 treated with vidarabine, in a mean time of 7.1 days. The two medications were statistically equally effective, no difference being demonstrated in the healing rate, in the frequency of punctate epithelial keratitis or stromal keratitis, or in the final visual acuity.

Effect of retrobulbar anesthesia on ocular tension.

To determine the effect of retrobulbar lidocaine, with or without epinephrine, on intraocular pressure, 50 patients admitted to hospital for cataract surgery were selected at random. By applanation tonometry the tension of each eye was measured when the patient was placed on the operating table and 4 minutes after the retrobulbar injection. The decrease in intraocular pressure 4 minutes after the injection was not significant, clinically or statistically, and probably resulted from relaxation of the extraocular muscles.

The effect of pH and osmolarity on the ability of tolerate artificial tears.

Many patients with keratitis sicca complain that the commercially available artificial tears burn when they are instilled and fail to relieve their distressing symptoms. We examined the effects of altering both the pH and osmolarity of hydroxypropyl methylcellulose tear substitute on the tolerance of 15 patients with varying degrees of keratitis sicca. Approximately equal numbers of patients selected the neutral hypotonic tear preparations and the isotonic or near-isotonic alkaline tear substitutes. The isotonic alkaline tear preparation was preferred by the majority of our patients with moderate or severe dry eyes. A commercially available alkaline tear substitute is needed.

Herpes simplex keratitis in renal transplant recipients.

Herpes simplex epithelial keratitis developed in four renal transplant recipients while they were receiving high-dose systemic corticosteroid and immunosuppressive therapy. In all cases the presentation was atypical, and in two cases the course was protracted, leading to some visual loss from corneal scarring and opacification. With the immunocompromised patient it is important to seek early ophthalmologic consultation when even minor ocular symptoms develop.

Toleration of artificial tears - the effect of pH.

We studied the effect of altering the pH of an artificial tear preparation on the tolerance of 20 patients with keratoconjunctivitis sicca. Of those who expressed a preference, 11/17 preferred a tear substitute more alkaline than any preparation now available in North America. We recommend an alkaline tear substitute as a valuable alternative in patients with keratoconjunctivitis sicca.

Surgical management of necrotizing scleritis.

We successfully used autogenous periosteum to reinforce the weakened sclera of two patients with necrotizing scleritis. One of these patients previously had an onlay scleral graft made from homologous banked sclera, which had subsequently melted. Autogenous periosteum is suggested as an alternative to banked sclera for scleral reinforcement.

Dextran flux in M-K medium-stored human corneas.

Dextran, with a minimal molecular weight of 40,000, can pass in and out of the corneal endothelium during storage in M-K medium. Results suggest that the degree of penetration of dextran depends on the length of storage and the condition of the endothelium.

McCarey-Kaufman technique of corneal storage before penetrating keratoplasties in rabbits. An evaluation.

The endothelial function of rabbit corneas stored in modified tissue culture medium (McCarey-Kaufman medium) for periods of 4, 8, or 12 days was studied after penetrating keratoplasty using the specular microscope and the response to temperature reversal. Our results indicate that rabbit donor corneas stored in McCarey-Kaufman (M-K) medium are suitable for penetrating keratoplasty after storage periods as long as 12 days. The limitations of using graft clarity or the morphologic appearance of the endothelium as an index of the success of a penetrating keratoplasty in the rabbit are discussed.

The endothelial function of donor corneas: effects of delayed enucleation and refrigeration.

The endothelial viability of rabbit corneas subjected to various forms of cadaveric and moist chamber storage was evaluated by means of the specular microscope and the rate of stromal deturgescence during a temperature reversal response. Delays in the postmortem enucleation and refrigeration of potential donor corneas was shown to be detrimental to the functioning of the endothelium. To best preserve the endothelial function of donor corneas, the eyes should be removed as soon after death as possible and refrigerated at 4 degrees C. Refrigerated cadaveric storage was found not to be a substitute for early enucleation and refrigeration of the corneas. The limitations in the use of the rate of stromal deturgescence during a temperature reversal response as a quantitative indicator of endothelial function are discussed.

Evaluation of the McCarey-Kaufman technique of corneal storage.

We present our evaluation of the McCarey-Kaufman (M-K) method of corneal storage. Sixty-six rabbit corneas were stored in the M-K medium at 4 C for periods of four, eight, and 12 days. Endothelial viability was assessed, using the specular microscope, the phenomenon of temperature reversal, and known inhibitors of endothelial cell function. Our results support those of McCarey and Kaufman, who showed that rabbit corneas will remain viable when stored by this technique. We were unable to support the contention that M-K medium-stored corneas are functionally superior to those corneas stored in moist chambers in the conventional manner. An unsuccessful attempt was made to correlate the function of the endothelium with either its morphological appearance as seen through the specular microscope or changes in ultrastructure as shown by transmission electron microscopy.