Search PubMed⌕ Search

Biomedical subjects

T D Lindquist

Publications and source records attributed to T D Lindquist.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1988

Surgical correction of postoperative astigmatism.

The photokeratoscope has increased the understanding of the aspheric nature of the cornea as well as a better understanding of normal corneal topography. This has significantly affected the development of newer and more predictable models of surgical astigmatic correction. Relaxing incisions effectively flatten the steeper meridian an equivalent amount as they steepen the flatter meridian. The net change in spherical equivalent is therefore negligible. Poor predictability is the major limitation of relaxing incisions. Wedge resection can correct large degrees of postkeratoplasty astigmatism. Resection of 0.10 mm of tissue results in approximately 2 diopters of astigmatic correction. Prolonged postoperative rehabilitation and induced irregular astigmatism are limitations of the procedure. Transverse incisions flatten the steeper meridian an equivalent amount as they steepen the flatter meridian. Semiradial incisions result in two times the amount of flattening in the meridian of the incision compared to the meridian 90 degrees away. Combination of transverse incisions with semiradial incisions describes the trapezoidal astigmatic keratotomy. This procedure may correct from 5.5 to 11.0 diopters depending upon the age of the patient. The use of the surgical keratometer is helpful in assessing a proper endpoint during surgical correction of astigmatism.

Adrenal Cortex Hormones↗
PubMed1988

Implantation of a posterior chamber lens without capsular support during penetrating keratoplasty or as a secondary lens implant.

We have devised a technique to fixate a posterior chamber lens in the ciliary sulcus when no posterior capsular support exists. Our short-term follow-up of 22 eyes with lenses thus fixated has shown these eyes to be quiet and to have good pupillary motility after at least 3 months. We believe this new technique is a significant advancement in corneal and anterior segment surgery.

Corneal Transplantation↗
PubMed1988

Acanthamoeba-contaminated hydrogel contact lenses. Susceptibility to disinfection.

Acanthamoeba keratitis has frequently been associated with contact lens use. In this study, contaminated hydrogel contact lenses of patients were subjected to disinfection by thermal hydrogen peroxide and chemical (quaternary ammonium) systems. New hydrogel contact lenses contaminated by incubation on Acanthamoeba polyphaga plates were similarly subjected to the disinfection systems described above. Thermal disinfection was universally effective in eradicating acanthamoeba, whereas hydrogen peroxide and quaternary ammonium disinfection were ineffective. Scanning electron microscope photomicrographs suggest that acanthamoeba may adhere to surfaces of hydrogel contact lenses. These findings have significant implications for soft contact lens users.

Acanthamoeba↗
PubMed1988

Complications of Nadbath facial nerve block and a review of the literature.

In a retrospective study of complications resulting from the Nadbath facial nerve block, we identified three patients (0.25%) over a 2-year period. Complications included dysphonia, laryngospasm, unilateral vocal cord paralysis, and a sensation of the inability to breathe. As it exits the stylomastoid foramen, the facial nerve lies close to the vagus, glossopharyngeal, and accessory nerves. Particular care must be taken, therefore, when giving Nadbath blocks in very thin individuals. The use of hyaluronidase, which enhances effusion of the anesthetic agent, should probably be withheld.

Adult↗
PubMed1987

Diagnosis of orbital and periorbital tumors. Use of monoclonal antibodies to cytoplasmic antigens (intermediate filaments).

Histopathology provides a definitive diagnosis in the majority of orbital and periorbital tumor biopsies. Occasionally, a tumor cannot be diagnosed by conventional histopathologic means, or the diagnosis is suspect. Special stains have been the primary diagnostic alternative in the past; more recently they have been supplemented with electron microscopy. Immunocytochemistry, classification using monoclonal antibodies to specific cellular antigens, has added a new modality to pathologic diagnosis. Immunocytochemistry can aid in diagnosis in three ways: (a) suggestion of a firm diagnosis, (b) selection from a histopathologic differential, or (c) direction for further evaluation such as special stains or electron microscopy. Immunocytochemistry rarely provides a definitive diagnosis but instead confirms the histopathologic diagnosis. Intermediate filaments are cytoplasmic antigens to which monoclonal antibodies are available. Five antigenically distinct groups of intermediate filaments can help classify tumors derived from mesenchymal, muscle, epithelial, glial, or neural cells. Six cases of orbital or periorbital tumors are presented, which demonstrate the usefulness of intermediate filament immunocytochemistry for classification or confirmation of a histopathologic diagnosis.

Adult↗
PubMed1987

Congenital iris cysts.

Unilateral, spontaneous, non-pigmented iris cysts appeared before the age of 2 years in four patients. Histopathological specimens obtained in three cases showed stratified to cuboidal, non-pigmented, epithelial lined cysts. Goblet cells were recognised in two of the three specimens. The clinical features and histopathological findings indicate that these cysts are derived from surface ectoderm and may be congenital.

Adult↗
PubMed1987

Correction of hyperopia following radial keratotomy: quantification in human cadaver eyes.

Overcorrection is a significant complication following radial keratotomy (RK). This study using human cadaver eyes demonstrates that the use of interrupted sutures placed across radial incisions coincident with a 7-mm optical zone mark can induce a wide range of central corneal steepening and can therefore correct varying amounts of hyperopia following RK. A case presentation confirms the effectiveness of using interrupted sutures to steepen the cornea following RK, but it also shows that significant regression of the effect must be considered at the time of suture placement. Since placement of interrupted corneal sutures is a routine procedure, it is a very convenient technique for treating overcorrection following RK.

Adult↗
PubMed1986

Trapezoidal astigmatic keratotomy. Quantification in human cadaver eyes.

The mechanism by which surgical procedures correct astigmatism are incompletely understood and, therefore, the results are often unpredictable. In this study, a Terry keratometer was used to analyze the effect of each component part of a 3-, 4-, and 5-mm trapezoidal astigmatic keratotomy. Semiradial incisions along the horizontal meridian produced corneal flattening along the horizontal meridian twice that of the vertical meridian, therefore inducing positive cylinder astigmatism at 90 degrees. A single pair of tangential incisions placed 5 mm apart, when added to the semiradial incisions, accounted for 100%, 87%, and 78% of the maximal effect from the 3-, 4-, and 5-mm completed trapezoidal astigmatic keratotomies, respectively. This study suggests that maximal correction of astigmatism may be attained with a single set of tangential incisions placed 5 mm apart between two sets of semiradial incisions.

Astigmatism↗
PubMed1986

Light-induced maculopathy. Potential for recovery.

Operating room microscope-induced maculopathy is described in two patients following cataract surgery without intraocular lens implantation. Sequential fundus photographs of evolving retinal lesions are presented. Serial visual field testing disclosed marked recovery of paramacular scotomas over time. The effect of the pseudophakos in producing photochemical lesions is discussed. Proposed mechanisms for recovery of visual scotomas are reviewed.

Adult↗