Residents Research Forum

Transcription

1 Residents Research Forum Third Annual Symposium 1995 Sponsored by Rhode Island Hospital/Brown Medical School Ophthalmology Department

2 Table of Contents Levocabastine-induced mydriasis. Daniel Petashnick, M.D., Eugene Smith, M.D., King To, M.D. 3 Scleral shell, evisceration, or enucleation: Choice of procedure. Eugene Smith, M.D., Michael Migliori, M.D. 4 Suture lysis using Argon green, Argon blue-green and Krypton red lasers. Ananth Mudgil, M.D., Eugene Smith, M.D., King To, M.D., William Tsiaras, M.D. 5 Hospital consults to the ophthalmology service. Joseph Ducharme, M.D., Francis Figueroa,M.D., King To, M.D., William Tsiaras, M.D. 6 Ocular syphilis: A case report and review. Dilip Thomas, M.D., King To, M.D., William G. Tsiaras, M.D. 7 A new culture method for infectious corneal ulcers. Francis Figueroa, M.D., King To, M.D., Elliot Perlman, M.D., S Josephson, M.D. 8 2

3 LEVOCABASTINE-INDUCED MYDRIASIS Daniel Petashnick, M.D., Eugene Smith, M.D., King To, M.D. Purpose: Levocabastine is a new topical H-1 receptor antagonist used in the treatment of allergic conjunctivitis. While using this medication, we found a number of patients noting photophobia and two patients with widely dilated pupils that could only be explained by the use of Levocabastine. In both the package insert and the literature, no reference was found for a mydriatic side effect to this medication. This study was designed to determine whether Levocabastine induces mydriasis. Methods: Ten subjects without previous ocular surgery or trauma, who were not taking any systemic or topical medications, were recruited. Their pupil size was measured by a single observer, using a pupil gauge, while focusing on a uniform distance object in uniform ambient light. Subjects were then told to place one drop of Levocabastine in one eye every two hours for an eight-hour period, using the other eye as the control. The observer was blinded to the treatment eye. The pupil size was again measured one hour after the final dose with he same conditions noted above. Pupil color was also recorded. Results: The mean pre-treatment pupil size was 3.75 mm (std. dev. = 0.59), and the mean post- treatment pupil size was 4.5 mm (std. dev. = 0/94 mm). A paired T-test of three groups demonstrated a t value of 4.39 and a p value of.002. Additionally, the treatment group was subdivided into light and dark pupil color. An independent sample T-test did not demonstrate any significant difference between these groups (t = -0.65, p = 0/59). There was no change in pupil size in the control eyes. Conclusions: there was a statistically significant increase in pupil size in the treatment group. The mydriasis induced by Levocabastine affected both light and dark pupils equally. 3

4 SCLERAL SHELL, EVISCERATION, OR ENUCLEATION: CHOICE OF PROCEDURE Eugene Smith, M.D., Michael Migliori,.M.D. Treatment of eyes with little or no vision is often necessary for a variety of reasons. Pain relief, cosmesis, severe infections, tumors, burns, chemical injuries or complications or trauma or surgery are common indicators. This presentation will serve as an overview of the indications, contraindications, advantages and disadvantages of the use of nonsurgical and surgical approaches to blind eyes. Emphasis will be placed on the choice of using scleral shells, evisceration or enucleation. Patient and physician concerns, needs and expectations of these procedures will be addressed. Informed consent, preoperative assessment, the need for pathologic specimen, age consideration, sympathetic ophthalmia, phthisical eyes, implant extrusion and other issues will be discussed. The surgeon must be familiar with all options available to the patient in order to appropriately discuss each procedure as it pertains to the particular situation. Since the indications for each procedure are rarely absolute, the final decision is best made in conjunction with the patient with a thorough understanding of his or her options. 4

5 SUTURE LYSIS USING ARGON GREEN, ARGON BLUE-GREEN AND KRYPTON RED LASERS. Ananth Mudgil, M.D., Eugene Smith, M.D., King To, M.D., William Tsiaras, M.D. Purpose: To compare the energy levels needed to cut 10-0 nylon suture using Argon green (514.5 nanometers [nm]), Argon blue-green (488.0, nm) and Krypton red (647.1 nm) lasers. Methods: Black monofiliment 10-0 nylon sutures were cut into 2.5 centimeter (cm) segments and mounted on a uniform white card placed 12.0 cm from the Coherent 920 Argon/Krypton laser. A pilot study determined parameters that allowed suture lysis near the middle of the laser s available power range. These parameters (spot size=200 micron; exposure weight = grams ± 0.001) were held constant throughout time 0.01 seconds; suspended testing. Each laser power was randomly selected and unknown to the experienced laser operator who was blinded to the purpose and methods of this study. Four trials (4 sets of 6 sutures) were completed with each of the three laser wavelengths. The lowest energy level causing lysis of suture following one laser show was used for analysis using the Wilcoxon signed test. Results: Suture lysis occurred at the following mean power settings: Argon green: 396 milliwattts (mw) standard deviation (SD) ±31 mw; Argon blue-green: 380 mw±; Krypton red 368± mw. The difference of the power settings needed to cut the sutures using Argon green and Argon blue-green was not significant (NS). The Krypton red power setting needed for lysis was significantly lower than the Argon blue-green (p=0.04) but not significantly different from the Argon green (p=ns). Conclusions: Lysis of 10.0 black monofilament nylon occurs at similar energy levels using the Argon green and blue-green laser. Krypton red laser suture lysis occurred at a lower energy level compared to Argon blue-green under these conditions. If this observation is also true in vivo, Krypton red laser may prove to be a less traumatic modality for laser suture lysis following trabeculectomy or other eye surgery. 5

6 HOSPITAL CONSULTS TO THE OPHTHALMOLOGY SERVICE Joseph Ducharme, M.D., Francis Figueroa,M.D., King To, M.D., William Tsiaras, M.D. Purpose: This study was designed to examine the ophthalmologist s role in a tertiary-care, teaching hospital. Methods: We reviewed all the consults to the ophthalmology service at Rhode Island Hospital over a one-year period. Consults were grouped based on the referring service, the reason for consult, and our diagnosis. Results: 841 consults, two-thirds inpatients and one-third ER patients, were seen. The hospitalized patients were evenly distributed among the general services of Internal Medicine, Surgery, and Pediatrics. The most common reasons for ophthalmologic consultation were blunt trauma (26.6%), eye pain/red eye (17.9%), and visual loss (11.5%). The most common diagnoses were related to trauma. The remainder of the reasons and diagnoses covered a wide variety of ophthalmic topics. Conclusions: Hospital-based ophthalmology requires knowledge of a diverse spectrum of ophthalmologic topics, as well as an understanding of hospital-based medicine. 6

7 OCULAR SYPHILIS: A CASE REPORT AND REVIEW Dilip Thomas, M.D., King To, M.D., William G. Tsiaras, M.D. For centuries, syphilis, caused by the spirochete Treponema Pallidum, has intrigued physicians by its seemingly limitless manifestations. The so-called general masquerader seemed to have finally been conquered with the advent of penicillin the early part of this century. However, with the emergence of HIV infection, syphilis has reemerged as a clinical quandry. This multisystem disease may present with ocular involvement as its initial manifestation, causing a potentially wide spectrum of disease including interstitial keratitis (IK), iridocyclitis, vasculitis, chorioretinitis, papillitis, or retrobulbar optic neuritis. Pupillary involvement (classically, the Argyll-Robertson pupil, oculomotor nerve palsies and secondary glaucoma and cataracts may also be representations of luetic infection. We describe a case of a 22-year-old, HIV (+) male who presented with a two-week history of decreased vision, pain and photophobia bilaterally and was found to have an acute iridocyclitis and retina-choroiditis, as the clue to the diagnosis of acquired syphilis. We hope to highlight the ocular manifestations of this protean disease, as it pertains to the general practitioner or internist and discuss issues of diagnosis, therapeutics and management consideration. 7

8 A NEW CULTURE METHOD FOR INFECTIOUS CORNEAL ULCERS Francis Figueroa, M.D., King To, M.D., Elliot Perlman, M.D., S Jsoephson, M.D. Purpose: to compare the efficacy of immediate plating of swabs versus transporting swabs in culture or transport medium and then plating at a later date. Methods: We attempted to mimic the clinical setting of corneal ulcers by micropipeting one ul aliquots of 10-5/ml concentrations of Staphylococcus aureus (SA), Staphylococcus epidermidis (SE), and Pseudomonas aeruginosa (PA) suspensions onto collagen corneal shields. Each pseudo-lesion was scraped with a calcium alginate swab and either (1) streaked immediately at time zero on to blood agar, (2) inserted into culturettes containing Amies Transport Medium and streaked onto blood agar after sitting 18 hours at room temperature, or (3) stabbed into semisolid trypticase soy medium and streaked onto blood agar at 18 hours. Results: In each of the three techniques, we were able to retrieve and identify the microorganisms. The mean percentage (%) of recovery of SA, SE, and PA at time zero was 48%, 41% and 27%. With the culturette transport system, the corresponding recovery at 18 hours was 21%, 8% and 100%. Finally, the % recovery with the semisolid medium was 100%, 20%, and 100%. Conclusions: The results indicate that culturettes or semi-solid media can be used to sustain viability of the bacteria on the swab when direct plating is unavailable and transport is required. 8