Laser photocoagulation for corneal stromal vascularization.
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Adult↗
Biomedical subjects
V S Nirankari
Publications and source records attributed to V S Nirankari.
A new biaspheric contact lens for severe astigmatism following penetrating keratoplasty.
We conducted a study of 26 consecutive post penetrating keratoplasty patients (32 eyes) fit with a Boston Envision biaspheric rigid gas permeable contact lens with limited parameters. The lens was successfully worn by 81% of those fit. Eighty-nine percent of patients' eyes had visual acuity equal to or better than their best possible spectacle acuity, and lens related complications were minimal.
Adolescent↗
Streptococcus sanguis survival in K-Sol. Comparison of gentamicin and the fluoroquinolone antibiotics.
Viridans streptococci are poorly covered by gentamicin sulfate in corneal storage medium. To evaluate possible antibiotic alternatives among the newer broad-spectrum fluoroquinolone antibiotics, we compared the survival of the viridans representative Streptococcus sanguis in K-Sol with gentamicin sulfate (100 mg/L), norfloxacin (250 mg/L), ciprofloxacin lactate (250 mg/L), ofloxacin (250 mg/L), or no antibiotic. At 23 degrees C, K-Sol with gentamicin produced a 2-log kill by 80 minutes. By comparison, only one of the others (norfloxacin) had achieved a 2-log kill by 4 hours. At 4 degrees C, all antibiotics differed little from the control, and none was superior to gentamicin.
Anti-Infective Agents↗
Effects of epikeratoplasty on the host cornea. An experimental study.
The effects of epikeratoplasty on the host cornea was studied using albino rabbits. Eyes underwent midperipheral partial trephination alone (group I), midperipheral partial trephination and peripheral undermining (group II), midperipheral partial trephination and circular keratectomy (group III), and trephination, peripheral undermining, and circular keratectomy (group IV). Corneal topography was assessed weekly using keratometry and photokeratoscopy. All eyes showed central corneal steepening with enhancing effects of increased surgical manipulation. Results were stable by 4 weeks in all eyes. Histopathologic evaluation revealed a constant wound depth of approximately 0.1 mm, with an increased accumulation of glycosaminoglycan material at the base of the wound. This was stained with PAS and alcian blue. Steepening of the host cornea may be another reason for lack of predictability and refractive regression following epikeratoplasty.
Animals↗
An unusual case of epithelial basement membrane dystrophy.
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Aged↗
Polymorphic amyloid degeneration.
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Aged↗
A new modified vitreoretinal surgical approach in the management of massive suprachoroidal hemorrhage.
The authors describe a new surgical approach used in six consecutive patients referred to us between August 1986 and August 1988 with massive suprachoroidal hemorrhage (MSCH) during or after cataract extraction (4 patients), glaucoma filtering surgery (1 patient), or scleral buckling (1 patient). All patients had large hemorrhagic choroidal detachments with five eyes showing "kissing" detachments. Secondary surgery was delayed 7 to 25 days (mean, 14 days) to allow liquefaction of the blood clot and reduce intraocular inflammation. All eyes underwent posterior drainage sclerotomies under constantly maintained limbal fluid infusion line pressure, followed by pars plana anterior and posterior vitrectomy in five of six eyes. Additionally, two eyes underwent secondary lens implantation during surgery and 6 months later, respectively. Mean follow-up was 10 months. Visual acuity improved in all eyes from a preoperative range of light perception-hand motions to hand motions-20/40. Advantages and disadvantages of this aggressive surgical approach in the management of MSCH are discussed.
Aged↗
Survival of Streptococcus viridans in gentamicin-supplemented McCarey-Kaufman medium.
Our experience with three cases of Streptococcus viridans endophthalmitis, following penetrating keratoplasty, prompted us to investigate the ability of gentamicin-supplemented McCarey-Kaufman (M-K) medium to kill S. viridans contaminants. After inoculation of 20 cc of gentamicin-supplemented M-K with S. viridans, the M-K was exposed to temperature conditions similar to those that would be encountered by a donor cornea during storage (4 degrees C) and preoperative warming prior to keratoplasty (23 degrees C). Colony counts were performed at regular intervals. After 1 h of warming, no reduction in the initial inoculum had occurred. This is in contrast to results from similar experiments with Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa in which more than 1 log unit of killing occurred after 1 h. While previously reported clinical experience has demonstrated an overall low incidence of postkeratoplasty endophthalmitis using gentamicin-supplemented M-K, our own recent clinical and laboratory data suggest that additional or alternate antibiotic coverage for S. viridans may be prudent.
Cell Survival↗
Corneal steepening after epikeratoplasty.
Four patients had removal of their epikeratoplasty lenticules for unsatisfactory visual results. This was out of a consecutive series of 36 eyes. Three eyes were myopic and one was aphakic. In all four eyes, there was significant corneal steepening with an average increase in myopia of 2.4 diopters and an average increase in keratometry reading of 4.8 diopters. Corneoscopy was done in three cases and showed central corneal steepening. In addition, one patient (Case 1) had significant scarring of the recipient cornea and a decrease in visual acuity to 20/100. The reasons for corneal steepening may be related to midperipheral partial trephination, annular keratectomy, and spreading of the peripheral cornea.
Adult↗
Streptococcal endophthalmitis from contaminated donor corneas after keratoplasty. Clinical and laboratory investigations.
We report three cases of Streptococcus viridans endophthalmitis following penetrating keratoplasty in which S viridans was cultured from the recipient eye, McCarey-Kaufman (M-K) media, and corneoscleral rims. As a laboratory correlation, we investigated the ability of S viridans to survive in M-K medium supplemented with gentamicin. After M-K medium was inoculated with S viridans, it was stored overnight at 4 degrees C, after which the temperature was raised to 23 degrees C. Periodic colony counts were performed for up to 24 hours after warming. No killing occurred in the cold. Ten hours passed before there was one log reduction in the bacterial colony count. Organisms could still be cultured at 24 hours. We conclude that gentamicin alone may be inadequate prophlyaxis against S viridans contamination of donor corneas.
Cornea↗
Is the corneal posterior cell layer truly endothelial?
The posterior cell layer of the normal human cornea or "endothelium" was investigated by electron microscopy and immunocytochemistry. Ultrastructurally, the cells lacked the characteristic marker for endothelial cells (Weibel-Palade body). Immunoperoxidase studies demonstrated these cells to be negative for factor VIII antigen, but strongly positive for keratine, vimentin, S-100 protein, and neuron-specific enolase. The anterior epithelial cell layer showed identical immunoreactivity. These studies strongly suggest that the posterior cell layer of the cornea lacks ultrastructural and immunocytochemical markers of endothelial cells and both the anterior and posterior cell layers share similar cell markers. The authors propose that the posterior cell layer of the cornea should, therefore, not be misnamed as "endothelium."
Cells↗
Corneal argon laser photocoagulation for neovascularization in penetrating keratoplasty.
Corneal argon laser photocoagulation (CALP) was used in 13 patients to treat deep stromal vascular ingrowth. Eight patients had undergone successful penetrating keratoplasty but had developed deep stromal vessels into the graft associated with signs of graft rejection, which did not improve with steroid treatment alone (group 1). After CALP, there was marked regression of the neovascularization with reversal of graft rejection in all eyes. Three additional patients with vascularized corneas, referred for penetrating keratoplasty, underwent CALP preoperatively with obliteration of the vessels (group 2). Two of these patients have since undergone keratoplasty and, in both, the grafts have remained avascular and clear over a 21-month follow-up. Two other patients with corneal injury and progressive corneal opacification and vascularization have also been treated with CALP (group 3). CALP may be a useful adjunct in the treatment of corneal neovascularization. Further clinical studies are needed to define its exact role.
Argon↗
Bilateral sympathetic dysfunction in post-traumatic headaches.
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Adult↗
Cystoid macular edema following penetrating keratoplasty: incidence and prognosis.
The incidence of clinically significant and angiographically documented cystoid macular edema (CME) following penetrating keratoplasty was studied in a consecutive series of 102 eyes over an average follow-up of 30 months. CME was seen only in the aphakic eyes. Twenty out of 68 eyes in this group developed CME. There was a statistically significant higher incidence of CME in eyes undergoing vitrectomy than in eyes not undergoing vitrectomy (p less than .01). Also, there was a higher incidence of CME in eyes with aphakic bullous keratopathy (p less than .01) and pseudophakic bullous keratopathy (p less than .05), when compared to eyes undergoing combined cataract extraction and corneal transplantation. All eyes with CME were empirically treated with oral prednisone (two eyes) or oral ibuprofen (18 eyes). Over an average follow-up of nine months, 13 of these eyes showed complete resolution of their CME with improvement in visual acuity to 20/60 or better in 12 eyes.
Adrenal Cortex Hormones↗
An improved method for the delivery of artificial tears using an infusion pump.
Patients with markedly decreased or absent tear duct production require the frequent instillation of artificial tear preparations. Through animal experiments, a new method has been developed for the continuous infusion of these solutions. In this procedure, the canalicular system is intubated with fenestrated silastic tubing, which is subcutaneously tunnelled and then attached to a miniaturized and computerized pumping device. This makes it possible for a predetermined volume of solution to be automatically and continuously delivered. Using this technique, artificial tear solution was instilled at a rate of 1.75 microliter/min, a rate approximately the normal basic tear secretion rate (0.5-2.2 microliters/min). This resulted in a 14% increase in tear flow from preoperative values. This represents a 74% increase in tear secretion rates for patients with keratoconjunctivitis sicca. None of the experimental animals developed subcutaneous infections, dacryocystitis, or corneal ulcers. By utilizing the normal anatomy of the lacrimal drainage system, this new technique: does not compromise the conjunctival cul-de-sac or the salivary system, avoids the inconvenience of previous external devices, and allows for the automatic instillation of predetermined volumes of artificial tear solutions.
Animals↗
Complications associated with the use of the neodymium:YAG laser.
The neodymium:YAG laser was used in a consecutive series of 93 eyes. Diagnosis was opacified posterior capsule in 81 eyes of which 52 were pseudophakic, with cystoid macular edema and vitreous strands in eight eyes, pigmented anterior hyaloid in two eyes, opacified anterior capsular flap in one eye and vitreous strand blocking an anterior chamber tube shunt to an encircling band tube in one eye. Despite significant visual improvement and reduction of cystoid macular edema, a variety of complications were seen. These included pitting of the implant in 26 eyes and cracks in four, two of which developed a vitreitis. These occurred more frequently in our earlier cases. Also seen was elevated IOP in six eyes, pupillary block in two, vitreous face rupture in five, cystoid macular edema in four, hyphemas in four, corneal injury in two and acute peripheral retinal hemorrhage in one eye.
Cataract Extraction↗
Anterior chamber tube shunt to an encircling band in the treatment of neovascular glaucoma and other refractory glaucomas. A long-term study.
Long-term follow-up results of the anterior chamber tube shunt to an encircling band (ACTSEB) procedure are reported. Thirty eyes of 28 patients with neovascular glaucoma (Group I) and five eyes with non-neovascular refractory glaucoma (Group II) underwent this procedure. In Group I, the average preoperative intraocular pressure (IOP) was 57.1 mmHg. After surgery and average followup of 25 months 96% of eyes had a successful outcome with an average IOP of 15.8 mmHg (P less than 0.001). In Group II, despite multiple glaucoma surgical procedures, the average preoperative IOP was 54 mmHg. After surgery and average followup of 20 months 80% of eyes had a successful outcome with an average IOP of 19.8 mmHg (P less than 0.01). Revisions in our surgical technique utilizing a small entry with a 25-gauge needle into the anterior chamber and use of Healon resulted in a fully formed anterior chamber by two days. Clinical and experimental evidence is presented which suggest that aqueous filters through the tube to a reservoir around the encircling band.
Adult↗
Temporomandibular joint pain as a manifestation of temporal arteritis.
We have described a patient whose temporal arteritis had several unusual manifestations. Except for a number of systemic complaints of longer duration, her predominant symptom was that of temporomandibular joint pain. Subsequent to the development of acute visual loss, her fundi remained normal, suggesting a posterior neuropathy. A high index of suspicion and meticulous history and physical examination should lead to early identification of temporal arteritis so that treatment can be instituted before permanent visual loss occurs.
Aged↗