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Biomedical subjects

J I Lim

Publications and source records attributed to J I Lim.

54 records · Page 3Linked to original sources
PubMed1993

A new syndrome of myelinated nerve fibers, vitreoretinopathy, and skeletal malformations.

OBJECTIVE: To report a new vitreoretinopathy with high myopia, myelinated nerve fibers, and skeletal abnormalities. PATIENTS: A mother and daughter with a previously undescribed constellation of severe vitreoretinal degeneration with high myopia and extensive myelination of the retinal nerve fiber layer, and in addition, the daughter has limb reduction deformities. Vision was severely impaired in both patients and results of electroretinography indicated the presence of cone and rod dysfunction. CONCLUSION: This is a previously undescribed autosomal dominant vitreoretinopathy with congenital poor vision, vitreoretinal degeneration, myelinated nerve fibers, and skeletal deformities.

Abnormalities, Multiple↗
PubMed1993

Intraocular tissue plasminogen activator concentrations after subconjunctival delivery.

BACKGROUND: Topical application of recombinant tissue plasminogen activator (tPA) results in detectable intraocular tPA levels. The authors sought to determine whether subconjunctival delivery of recombinant tPA results in enhanced intraocular drug levels. METHODS: One week after first performing a gas vitrectomy in each eye, the authors injected 0.4 ml of a tPA solution (1 or 10 mg/ml) subconjunctivally in one eye of 16 rabbits and 0.4 ml of sterile water in the fellow control eye. Vitreous taps were performed to obtain vitreous samples for measuring tPA concentrations. An anterior chamber paracentesis was then done for each concentration at 15, 30, and 60 minutes. Aqueous and vitreous tPA concentrations were determined using a two-site enzyme-linked immunosorbent assay (ELISA). RESULTS: Vitreous tPA levels were higher than aqueous levels in the treated eyes. Vitreous levels averaged 7 +/- 7 ng/ml for the 1-mg/ml group (n = 7/7) and 202 +/- 230 ng/ml for the 10-mg/ml group (n = 7/8). Aqueous levels were positive in 8 of 16 samples. The authors conclude that subconjunctival delivery of tPA results in both vitreous and aqueous tPA levels.

Animals↗
PubMed1993

Visual abnormalities associated with high-energy microwave exposure.

A 44-year-old man was accidentally exposed to high-energy microwave irradiation. After resolution of facial erythema and iritis, he noted a foreign body sensation and blurring of vision. Ophthalmoscopic examination showed bilateral, small hard drusen. Ancillary tests were consistent with abnormal cone function. Electroretinogram testing revealed a marked decrease in the flicker electroretinogram. Results of D15 and Farnsworth Munsel Hue 100 color tests were abnormal. Two years later, the patient's visual acuity was stable at 20/25 in both eyes; however, results of flicker electroretinogram test remain markedly decreased.

Adult↗
PubMed1992

Atypical parafoveal telangiectasis with subsequent anterior and posterior segment neovascularization.

Bilateral parafoveal telangiectasis typically includes the presence of fluorescein staining of outer retinal capillaries, no macular ischemia, right-angled venules, and migration of pigment along these venules. In the bilateral form, atypical parafoveal telangiectasis with macular ischemia but without right-angled venules or migration of pigment along these venules has been reported in only five patients previously. An atypical case is presented of bilateral parafoveal telangiectasis complicated, not only by areas of macular nonperfusion, but also by peripheral ischemia with subsequent anterior and posterior segment neovascularization in the absence of any systemic abnormalities. As in previously reported cases, this patient had no evidence of right-angled venules or pigment migration. Pan-retinal photocoagulation resolved the rubeosis and caused regression of the retinal neovascularization.

Fluorescein Angiography↗
PubMed1991

Penetrating ocular injury from contaminated eating utensils.

Although the rate of infectious endophthalmitis following penetrating ocular injury is generally less than 10%, certain settings may carry a greater risk of infection. One such setting is penetrating injury resulting from eating utensils contaminated with oral flora. We reviewed six of these injuries. Culture-positive bacterial endophthalmitis developed in four of the six eyes; only one of the eyes retained reading visual acuity (greater than 20/50) and two eyes lost light perception. The potential for infection and limited visual outcome in this series warrants aggressive prophylaxis and treatment. The unexpected isolation of Haemophilus influenzae in two of the four infections suggests that broad-spectrum antibiotic treatment should be considered in all such injuries since less common organisms may be encountered.

Adult↗
PubMed1991

Intraocular penetration of topical tissue plasminogen activator.

Fifty-eight eyes of 31 anesthetized rabbits received one drop of proparacaine hydrochloride, 0.05%, and two drops of tissue plasminogen activator (tPA) separated by 5 minutes. Four eyes of two additional rabbits had epithelial defects created before drug delivery. Tissue plasminogen activator in multiple doses was given to eight eyes of four other rabbits. We used this dosing regimen to investigate the effect of topical tPA on anterior chamber fibrin clots in three rabbits. A two-site enzyme-linked immunosorbent assay test was used to measure tPA levels in the aqueous samples, obtained by paracentesis in each eye. Of 53 eyes treated with the original dosing regimen, 21 (40%) had detectable tPA aqueous levels. Blood and aqueous from eyes of untreated control rabbits, contralateral control eyes of treated rabbits, and eyes with epithelial defects had nondetectable tPA. Multiple tPA drop dosing resulted in 75% of aqueous samples with detectable tPA and a higher average tPA concentration than the original dosing regimen. Eyes treated with tPA showed a significantly faster resolution of anterior chamber fibrin clots than did control eyes.

Administration, Topical↗
PubMed1991

Anterior granulomatous uveitis in patients with multiple sclerosis.

Granulomatous uveitis has infrequently been described as a manifestation of the autoimmune phenomena of multiple sclerosis (MS). The authors describe six cases of anterior granulomatous uveitis in patients with MS. All six patients had features of iridocyclitis and three patients had features of periphlebitis, which were suggestive of granulomatous disease. However, each patient had neurologic symptoms and signs consistent with MS and a negative laboratory workup for sarcoidosis, tuberculosis, and syphilis. Testing for MS in a subgroup of patients with granulomatous uveitis of unknown etiology and neurologic symptoms may result in a diagnosis.

Adolescent↗
PubMed1990

Assessment of intraocular pressure in vitrectomized gas-containing eyes. A clinical and manometric comparison of the Tono-Pen to the pneumotonometer.

Elevation of intraocular pressure (IOP) in gas-containing eyes occurs not infrequently, and applanation tonometry in eyes with epithelial irregularities is not accurate. The pneumotonometer and TonoPen (Oculab, La Jolla, Calif) are alternative tonometers for use in these eyes, yet the accuracy of determining IOP with the Tono-Pen has not been determined manometrically. We performed a clinical and manometric study comparing the Tono-Pen with the pneumotonometer in gasfilled vitrectomized eyes. In our clinical study, we measured IOP in 50 eyes of 50 patients with corneal irregularities following vitrectomy and air/gas-fluid exchange. Tono-Pen measurements were highly correlated with those of the pneumotonometer. However, there was a mean difference of 1.4 mm Hg between Tono-Pen and pneumotonometer IOP readings. A larger percentage of Tono-Pen readings were lower than those of the pneumotonometer as IOP levels increased. To assess the accuracy of these tonometers, we compared manometric readings via an indwelling catheter with Tono-Pen and pneumotonometer IOP readings in 11 eye bank eyes following a lensectomy, vitrectomy, and air-fluid exchange. Overall, Tono-Pen and pneumotonometer readings were highly correlated with those of the manometer. However, both machines showed a significant underestimation of IOP at pressures greater than or equal to 30 mm Hg; pneumotonometer and Tono-Pen readings averaged 10.2 and 12.1 mm Hg lower, respectively, than those of the manometer. We conclude that both the pneumotonometer and the Tono-Pen underestimate IOP at pressures greater than or equal to 30 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1986

Comparison of the Challenger digital applanation tonometer and the Goldmann applanation tonometer.

We compared the Challenger electronic tonometer to the Goldmann applanation tonometer in 70 eyes without corneal abnormalities. There was a good overall correlation between the two machines. Correlations between interobserver readings were excellent, demonstrating that obtaining reproducible measurements is possible with either machine. However, the scattergrams indicated that the Challenger tonometer gave consistently lower readings and showed more variability than the Goldmann tonometer. Additionally, the mean underestimation of intraocular pressure increased as the intraocular pressure increased above 20 mm Hg. Therefore, the Challenger electronic tonometer as presently calibrated is not accurate enough for clinical use in the detection and management of glaucoma.

Adult↗
PubMedDate not supplied

What to tell the patient with optic neuritis about multiple sclerosis.

If the ophthalmologist tells the patient with an initial isolated attack of optic neuritis that multiple sclerosis may develop, will he/she worry the patient needlessly or provide useful information that the patient is rightfully entitled to have? In this set of articles, the philosophies and individual circumstances that should influence the ophthalmologist in deciding what information to supply are discussed.

Delivery of Health Care↗
PubMedDate not supplied

Iatrogenic choroidal neovascularization.

Iatrogenic choroidal neovascularization is an uncommon complication of laser photocoagulation and other ocular surgical procedures. It appears to be the result of a number of conditions, including damaged Bruch's membrane and/or retinal pigment epithelium, whose reparative processes trigger the release of angiogenic factors. Inflammatory cells and choroidal ischemia may also play a role. The prognosis varies depending on the underlying disease and the type of choroidal neovascularization (subretinal, chorioretinal, or choriovitreal). Minimizing the amount of laser energy used during laser procedures, avoiding repeat laser treatment to the same retinal area, and minimizing direct mechanical trauma to the retinal pigment epithelium and choroid decrease the chance of inducing iatrogenic choroidal neovascularization.

Choroid↗