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Biomedical subjects

T D Lindquist

Publications and source records attributed to T D Lindquist.

At least 19 recordsLinked to original sources
PubMed1995

Ocular surface flora in drowning victims.

Contaminated allograft donor tissue represents a potential source of infection unique to keratoplasty. We prospectively studied perilimbal cultures of drowning victims over 30 months to determine if the ocular surface flora of drowning victims was unique. Twenty-eight donor eyes were cultured from 14 drowning victims. Ninety-three percent of limbal cultures were positive for one or more organisms, compared to results of a previous study of surface contamination of donor globes in which 65% were found to be culture positive. Fifty-seven percent (16 of 28) of donor eyes grew at least one streptococcal species, while 46% (13 of 28) grew two or more streptococcal species. A previous study identified streptococcal species in 7.9% of perilimbal cultures from nondrowning donor eyes, which demonstrates the unique effect of drowning on the ocular flora. The incidence of gram-negative isolates was also markedly higher in drowning victims, compared to previous studies of donor globes. This prospective study has shown that the ocular surface flora of drowning victims harbors markedly increased numbers of streptococcal species as well as gram-negative organisms. These findings demand careful globe decontamination, and emphasize the need for appropriate antibiotic coverage in corneal storage media.

Adolescent↗
PubMed1992

Effects of povidone-iodine chemical preparation and saline irrigation on the perilimbal flora.

PURPOSE: To analyze the effects of 5% povidone-iodine preparation and saline irrigation on the species composition of perilimbal flora. METHODS: Cultures were taken from the perilimbal conjunctiva in 100 eyes before preparation for ophthalmic surgery, after instillation of povidone-iodine solution, and after saline irrigation. RESULTS: Bacteria were isolated in 75% of eyes before preparation, in 28% after povidone-iodine instillation, and in 24% after saline irrigation. Fifty-one culture-positive eyes became negative with povidone-iodine, while only four culture-negative eyes became culture-positive (P < 0.001). The number of eyes yielding coagulase-negative staphylococci, Staphylococcus aureus, and Propionibacterium were significantly decreased after povidone-iodine instillation. Twenty-three culture-positive eyes became negative after saline irrigation, while 19 culture-negative eyes became culture-positive (P > 0.25). CONCLUSION: Povidone-iodine solution is effective in reducing bacterial recovery from the perilimbal conjunctiva, where most incisions for intraocular surgery occur. Saline irrigation after povidone-iodine preparation has no significant effect.

Bacteria↗
PubMed1992

Capsulorhexis, phacoemulsification, and posterior chamber lens placement following iridocyclectomy.

Two patients developed cataract following iridocyclectomy for iris melanoma invading the angle. Although several clock hours of zonular fibers had been surgically resected, the use of a continuous, circular capsulorhexis followed by phacoemulsification maintained the integrity of the anterior capsular margin and allowed for stable "in-the-bag" placement of a posterior chamber intraocular lens (PC-IOL). Continuous, circular capsulorhexis is the optimal anterior capsulectomy procedure, minimizing the incidence of radial tears and the risk of subsequent PC-IOL decentration.

Aged↗
PubMed1991

An evaluation of saline irrigation and comparison of povidone-iodine and antibiotic in the surface decontamination of donor eyes.

We evaluated the effect of saline irrigation on 38 pairs of donor eyes and determined the relative efficacy of antibiotic rinse/storage (neomycin-polymyxin B-gramicidin) and povidone-iodine immersion. Microbial growth was found in 49 (64.5%) of 76 eyes from which cultures were taken before irrigation, and only four (8.2%) became culture negative after irrigation. Of 27 eyes culture negative before irrigation, 15 (55.6%) became positive after irrigation. One eye of each pair was then assigned randomly to antibiotic rinse/storage and the other eye to 3-minute immersion in 1% povidone-iodine. Both antimicrobial treatments decreased the numbers of positive cultures, with povidone-iodine showing an advantage that did not reach significance. These results demonstrate that saline irrigation of donor eyes in situ does not reduce surface contamination and that povidone-iodine immersion should be considered as an alternative for donor eye decontamination.

Anti-Bacterial Agents↗
PubMed1991

Indications for penetrating keratoplasty: 1980-1988.

A retrospective analysis was undertaken of the clinical diagnoses of 1594 eyes that underwent penetrating keratoplasty performed in a private-referral corneal practice over a 9-year period, 1980-1988. The seven most common indications for surgery were keratoconus (24.0%), pseudophakic or aphakic bullous keratopathy (21.2%), corneal scarring (13.9%), Fuchs' endothelial dystrophy (12.5%), regraft (8.1%), and herpetic keratitis (5.3%). Keratoconus was the leading indication from 1980 to 1985. From 1985 to 1988, pseudophakic bullous keratopathy became the leading indication and correlates well with known complications associated with closed-loop anterior chamber lenses, which were widely used during the early 1980s. Less frequent indications for penetrating keratoplasty included the following: infectious (nonviral) keratitis (3.5%); acute or chronic ulcerative keratitis (2.7%); interstitial keratitis (1.8%); mechanical trauma (1.5%); other (non-Fuchs') corneal dystrophies (1.4%); congenital opacities (0.8%); and chemical burns (0.5%).

Aphakia↗
PubMed1991

Pharmacokinetic study of recombinant human epidermal growth factor in the anterior eye.

This study investigated the pharmacokinetics of recombinant human epidermal growth factor (EGF) in the eyes of live rabbits and enucleated human eyes. After intracameral injection of 1.2 muCi (1.1 micrograms) of 125I-EGF into rabbit eyes, tissues in the anterior segment were analyzed for uptake of 125I-EGF after 1, 2, 4, and 24 hr. The half-life of EGF during the initial 4 hr was 1.3 +/- 0.6 hr (+/- the confidence limit at P = 0.05) in the cornea, 0.7 +/- 0.4 hr in the iris, 1.9 +/- 0.9 hr in the lens, and 0.6 +/- 0.5 hr in the aqueous humor (n = 18 for each tissue). Between 4-24 hr, the percent retention of EGF in the tissues (relative to the initial amount in respective tissue) is in the order of lens greater than cornea greater than iris greater than aqueous humor. The kinetics of EGF uptake by excised human corneas was determined by incubating the endothelial surface with 1.2 muCi/ml (100 ng/ml) of 125I-EGF for 4 hr at 37 degrees C or 4 degrees C. After 4 hr, the total amount of EGF accumulated in the corneas was 2.3 +/- 0.2 ng (+/- standard deviation; n = 6) at 37 degrees C, and 1.4 +/- 0.1 ng at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1991

Surgical treatment of overcorrection following radial keratotomy: evaluation of clinical effectiveness.

Secondary hyperopia following radial keratotomy (RK) may result from an initial overcorrection or from a continued effect of the procedure with time. We retrospectively evaluated the effect of surgical intervention for the management of overcorrection following RK in six patients who had undergone reopening of all RK incisions, followed by irrigation and closure of the incisions with 10-0 mersilene sutures. Three patients with prior 4-incision RK, with follow-up of 4 to 26 months, were steepened a mean of 1.63 diopters keratometrically; three patients with prior 8-incision RK, with follow-up of 3 to 12 months, were steepened a mean of 1.46 D keratometrically. Comparison of intraoperative with postoperative keratometry demonstrated a substantial loss of effect with time, which stabilized by 2 months in 4-incision RK patients and by 3 months in 8-incision RK patients. Nevertheless, placement of interrupted sutures across reopened radial incisions consistently induced central corneal steepening in these six patients.

Adult↗
PubMed1990

Scleral ectasia secondary to Acanthamoeba keratitis.

An unrecognized case of Acanthamoeba keratitis became quiescent after prolonged scleritis, resulting in a central corneal scar with extensive scleral ectasia. Twenty-one months after the onset of the sclerokeratitis, a penetrating keratoplasty was performed. Acanthamoeba cysts were found in the host corneal button. The corneal transplant has remained thin and clear for 2 1/2 years following surgery. Acanthamoeba keratitis extending to the limbus may become self-limited due to immunologic mechanisms available at the limbus, which do not appear to be active within the cornea itself. However, the prolonged inflammatory reaction manifesting as scleritis may result in extensive scleral ectasia.

Acanthamoeba↗
PubMed1989

Visual results following vitreous loss and primary lens implantation.

Implantation of an intraocular lens following vitreous loss at cataract surgery is a controversial decision. To address this issue, we retrospectively identified all cases performed at the University of Minnesota in the last three years that had either a posterior or an anterior chamber lens placed following anterior vitrectomy. Twenty patients had a posterior chamber lens implant; 14 had follow-up longer than six months. All these patients achieved 20/40 or better visual acuity, although one patient had a retinal detachment. Of the six patients with an anterior chamber lens implant, four achieved 20/40 or better acuity and two achieved 20/50 acuity with follow-up of six months; one patient had a retinal detachment. This review demonstrates that with a meticulous anterior vitrectomy, good visual results can be achieved, although the risk of retinal detachment is higher than in uncomplicated cases.

Cataract Extraction↗
PubMed1989

Transscleral fixation of posterior chamber intraocular lenses in the absence of capsular support.

We present results obtained by transscleral ciliary sulcus fixation of posterior chamber intraocular lenses in secondary implantation, lens exchange, and in primary implantation of transsclerally fixated lenses during complicated cataract extraction. Follow-up data on 38 patients, 17 of whom have been followed for more than 12 months, are included. We conclude that the procedure is safe, effective, and predictable.

Ciliary Body↗
PubMed1989

Experimentally induced ocular chlamydial infection in infant pig-tailed macaques.

Four Macaca nemestrina monkeys were inoculated in the conjunctiva with Chlamydia trachomatis (strain E) at 6 weeks of age. A fifth monkey was inoculated with HeLa cell materials only. Ten weeks later, all monkeys were reinoculated with either strain E or strain C. All inoculated monkeys were susceptible to infection with C. trachomatis as documented by fluorescent antibody staining of smears and reisolation of the organism from conjunctival and nasopharyngeal swab specimens. Rectal and vaginal swab specimens remained negative throughout the study. Three of four inoculated animals responded with IgM titers reaching a peak of 1:16 (M#3) and 1:32 (M#1, M#4) 2 weeks after the primary inoculation. IgG appeared in all inoculated animals and titers rose to peak levels of 1:64 (M#2), 1:128 (M#1, M#3), and 1:256 (M#4). Histopathology documented a dramatic difference in immunological response following secondary inoculation. Primary inoculation elicited a typical inflammatory response characterized by moderate stromal infiltration of polymorphonuclear and mononuclear leukocytes. Plasma cells appeared by week 3 postinoculation (pi). Following a secondary inoculation, classic follicle formation was evident by 1 week pi. Mononuclear markers identified a germinal center composed of B cells and a T cell cap. Epithelial thinning near the cap of the follicle was accompanied by a complete loss of goblet cells. This model may be useful for studying the immunopathology of infant chlamydial infections.

Animals↗
PubMed1988

Clinical signs and medical therapy of early Acanthamoeba keratitis.

Several diagnostic signs of Acanthamoeba keratitis have been reported recently. We treated three patients who developed a dendritiform epithelial pattern seen early in the course of Acanthamoeba keratitis that likely represents epithelial infection by Acanthamoeba before any stromal involvement. In these three cases, the early diagnosis of Acanthamoeba keratitis coupled with wide epithelial debridement and medical therapy proved effective in eradicating the protozoan. In two additional cases, Acanthamoeba keratitis was not diagnosed until significant stromal involvement was present. Medical therapy was effective in eradicating the organism in one case, although penetrating keratoplasty was necessary for visual rehabilitation. In the other case, medical therapy was ineffective, as corneal perforation resulted and Acanthamoeba cysts were demonstrated by fluorescent staining in the host corneal button.

Acanthamoeba↗
PubMed1988

Treatment of phacolytic glaucoma with extracapsular cataract extraction.

The treatment of choice for phacolytic glaucoma has been intracapsular cataract extraction (ICCE). The current study was undertaken to determine the efficacy of extracapsular cataract extraction (ECCE) as a definitive treatment for phacolytic glaucoma. Five cases of phacolytic glaucoma that occurred between 1984 and 1986 were studied after a retrospective chart review; ECCE (with placement of a posterior chamber intraocular lens [PC IOL]) was performed without complication and was curative in all five eyes. All patients (100%) maintained intraocular pressures (IOPs) of less than 20 mmHg, without medical therapy. The best-corrected visual acuity for all cases was 20/50 or better (80%, greater than or equal to 20/40) with 5 months to 3 years follow-up. These results suggest that ECCE is an effective alternative for the treatment of phacolytic glaucoma and allows surgeons the freedom to choose the procedure with which they are most comfortable. Additionally, implantation of a PC IOL is a safe and efficacious procedure in restoring visual function in these patients.

Aged↗