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Biomedical subjects

R J Olson

Publications and source records attributed to R J Olson.

At least 55 records · Page 3Linked to original sources
PubMed1995

Incidence of retinal detachment after cataract surgery and neodymium: YAG laser capsulotomy.

The objective of this retrospective study was to determine the incidence of retinal detachment (RD) in patients following cataract extraction with intraocular lens placement and after neodymium:YAG (Nd:YAG) laser capsulotomy. This study comprised 1092 patients (1168 eyes) who had cataract extraction and related procedures between January 1986 and December 1992 identified from the coding and billing database. Of the 1092 patients, 215 (244 eyes) had had Nd:YAG laser capsulotomy. Their charts were reviewed for incidence of RD, and these data were correlated with age, sex, axial length, surgical complications, and other surgical procedures done at the time of cataract extraction. The incidence of RD following phacoemulsification alone was 0.75% (6/799), with a mean time between cataract extraction and RD of 11.6 months. The cases of RD after extracapsular cataract extraction, combined phacoemulsification and trabeculectomy, combined extracapsular cataract extraction and penetrating keratoplasty, and combined phacoemulsification and anterior vitrectomy were too few to draw any conclusions. The incidence of RD following Nd:YAG laser capsulotomy was 0.82% (2/244), with a mean time of 32 months between cataract surgery and capsulotomy and 13.5 months between capsulotomy and RD. There was a statistically significant higher incidence of RD after posterior capsule rupture and anterior vitrectomy than after uncomplicated phacoemulsification (2/12 versus 6/799). In conclusion, the rate of RD after uncomplicated phacoemulsification was less than or similar to the rate found in other recent studies. It was not statistically different from the rate following phacoemulsification and Nd:YAG laser capsulotomy (0.82%). This study confirms the increased risk of RD following posterior capsule rupture and anterior vitrectomy.

Cataract Extraction↗
PubMed1995

Prospective study of cataract surgery, capsulotomy, and retinal detachment.

We report the incidence of retinal detachment (RD) in 1543 consecutive cases of cataract extraction in a prospective cohort study. Retinal detachment was significantly associated with intracapsular extraction, axial lengths of 24.0 mm or longer and an intact capsule, and capsulotomy in eyes with axial lengths of 24.0 mm or longer. The interval between capsulotomy and RD was significantly shorter in eyes with axial lengths of 24.0 mm or greater. An intraocular lens with stiff, vaulted, poly(methyl methacrylate) optics and a biconvex PMMA optic was associated with significantly less capsule opacification than lenses of other designs.

Cataract Extraction↗
PubMed1995

Astigmatic decay following small incision, self-sealing cataract surgery: one-year follow-up.

Twenty patients who had phacoemulsification using a small, self-sealing incision were evaluated one year after surgery for astigmatic changes. Keratometric analysis was performed using the EyeSys photokeratoscope, and data for the 3 mm corneal zone for each patient were recorded. Results were compared with those reported for the one-week and one-month postoperative periods. From one month to one year, a minimal amount of additional against-the-rule change in cylinder occurred. Because the range of changes was broad, it was difficult to predict the direction of astigmatic change (i.e., against the rule versus with the rule) that would occur over time for a given patient.

Aged↗
PubMed1995

Complications and results of phacoemulsification performed by residents.

The use of phacoemulsification by ophthalmic surgeons has increased markedly over the past five years. Previous studies have reported relatively high rates of vitreous loss by residents learning phacoemulsification. We retrospectively analyzed the complications and results in 300 cases of phacoemulsification with intraocular lens implantation performed by residents. The first 40 cases done by four residents in their second year of training were compared with approximately the last 40 cases done by each resident at the end of the third year. The overall rate of surgical complications was 6.3%, and the total rate of vitreous loss was 3.3%. The rate of surgical complications during the initial surgeries in the second year of residency was 9.3%; it was 3.3% by the end of the third year. The rate of vitreous loss was 5.3% in the second year and 1.3% during the third year. Postoperatively, 90.6% of all eyes had a final best corrected visual acuity of 20/40 or better (95% excluding patients with pre-existing ocular disease). With proper training and supervision, the rate of surgical complications for residents learning phacoemulsification is acceptably low when compared with the rate of extracapsular cataract extraction.

Clinical Competence↗
PubMed1995

Now hear this!

Explore the source record for details and available documents.

Deafness↗
PubMed1994

Crystallization on intraocular lens surfaces associated with the use of Healon GV.

OBJECTIVE: To describe a series of patients who had visually significant crystalline deposits on their intraocular lenses during cataract surgery with the use of Healon GV (a high concentration and high molecular-weight hyaluronate sodium). METHODS: Patients were examined for crystalline deposits on their intraocular lenses. These deposits were compared with intraocular lens type, viscoelastic solutions, any other intraocular substance used, type of surgery, and perioperative medications. RESULTS: In the 11 patients with documented changes (six photographically), the only consistent finding was the use of Healon GV. Furthermore, since we discontinued the use of Healon GV, we have not seen a recurrence of these deposits in more than 500 consecutive patients. The deposits could last a long time (at least 6 months) if sequestered by the posterior capsule, and they are believed to be visually significant at times (Snellen visual acuity of 20/40 or worse). CONCLUSION: Healon GV use is associated with a new clinical finding of crystalline deposits on intraocular lenses. These deposits can be clinically significant.

Aged↗
PubMed1994

Astigmatic decay following small incision, self-sealing cataract surgery.

A series of 22 consecutive patients had phacoemulsification using a small (3.5 to 4.0 mm), self-sealing incision. Preoperative keratometric analysis was performed using the EyeSys photokeratoscope. Results of this analysis were compared with keratometric data obtained at one week and at one month postoperatively. These comparisons were evaluated for surgery-induced cylinder and astigmatic decay at the 3, 5, and 7 mm corneal zones. At one week postoperatively, there was only mild against-the-rule change in cylinder at each corneal zone, and these changes showed minimal decay at the one month follow-up visit.

Aged↗
PubMed1993

Quantitative microdialysis under transient conditions.

A microdialysis method is described which allows for the quantitative determination of extracellular analyte concentration under transient conditions. The method provides the extracellular concentration and the in vivo probe recovery as a function of time. The technique is based on the method for steady-state conditions but differs in the use of a between-group rather than a within-group design. Following cocaine and amphetamine administration, a significantly greater increase in extracellular DA was found than was estimated from the dialysate using conventional microdialysis methods. The discrepancy is due to microdialysis probe recovery decreasing concurrently with the increase observed in extracellular DA following cocaine and amphetamine injections. The method estimates the extracellular concentration independently of any changes in recovery.

Amphetamine↗
PubMed1993

Primary T-cell immunoblastic lymphoma of the orbit in a pediatric patient.

BACKGROUND: The authors report a case of an 8-year-old pediatric patient with a 2-week history of painless periorbital swelling unresponsive to antibiotic treatment. METHODS: Computed tomography (CT) showed a large, lateral, anterior left orbital soft tissue mass with bony erosion into the anterior cranial fossa through the roof of the orbit laterally. Surgical exploration showed a hard white mass that had eroded through the roof of the left orbit and into the anterior cranial fossa, with herniation of the brain and associated dura through the defect. Results of a complete evaluation of the child for systemic lymphoma, including a lumbar puncture, chest x-ray, bone scan, bone marrow aspirate, and chest/abdomen CT, were negative. RESULTS: Results of histopathologic and immuno-histochemical evaluation showed a primary orbital T-cell immunoblastic lymphoma. The patient was treated with intrathecal ara-C (Cytosar-U) and methotrexate, 16.2 Gy of whole brain irradiation, and a chemotherapeutic protocol consisting of cyclophosphamide (Cytoxin), vincristine (Oncovin), methotrexate, daunomycin, and prednisone. The patient remains free of lymphoma 33 months after diagnosis, with 20/20 visual acuity in both eyes. CONCLUSION: The authors believe that this is the youngest documented case of a primary T-cell immunoblastic lymphoma of the orbit.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Spontaneous fistula formation as a complication of relaxing incisions with suture placement for postkeratoplasty high astigmatism.

A 39-year-old man had a corneal relaxing incision with corneal compression suture placement to correct more than 10 diopters of corneal astigmatism. A permanent fistula formed from the compression suture, resulting in a localized corneal pocket of aqueous that broke through the surface. The aqueous drained into the tear film, requiring major surgical repair.

Adult↗
PubMed1993

Progressive constriction of the anterior capsular opening following intact capsulorhexis.

The continuous curvilinear capsulorhexis has rapidly increased in popularity as the procedure of choice when using phacoemulsification for cataract extraction. Only recently, however, have complications of this technique been reported. We review the complications of a continuous curvilinear capsulorhexis and present three cases involving progressive constriction of the postoperative anterior capsular opening. One patient had a history of myotonic muscular dystrophy, another had pars planitis, and the third had high myopia. A review of ocular findings in myotonic dystrophy and pars planitis is also presented, and the possible pathophysiology of this progressive constriction is explored.

Adult↗
PubMed1992

Changing trends in the indications for penetrating keratoplasty.

The indications for penetrating keratoplasty have changed over the past several years. Nine hundred ninety-nine penetrating keratoplasty specimens from 1981 through 1990 were analyzed. Overall, keratoconus was the most common indication for penetrating keratoplasty (24.2%). This was followed by pseudophakic bullous keratopathy (23.0%), regraft (13.1%), scarring (8.2%), and Fuchs' endothelial dystrophy (5.8%). Pseudophakic bullous keratopathy was the most common indication for penetrating keratoplasty in each year from 1984 through 1989 with a peak in 1987 (33%). Since 1987, the number of pseudophakic bullous keratopathy cases has decreased; and in 1990, keratoconus (33.1%) surpassed pseudophakic bullous keratopathy (24.1%) as the most common indication for penetrating keratoplasty. This decreasing incidence of pseudophakic bullous keratopathy may reflect the discontinued use of closed-looped anterior chamber and iris-plane intraocular lenses most commonly associated with this complication.

Cataract Extraction↗
PubMed1992

Quantitative microdialysis of dopamine in the striatum: effect of circadian variation.

Two quantitative microdialysis methods were used to determine the concentration of extracellular dopamine in the anterior striatum of the rat. In the first method, the slow perfusion flow rate method, perfusion was at 57 nl/min and dialysate samples were collected every 90 min for 18 h and assayed for dopamine (DA), DOPAC (3,4-dihydroxy-phenylacetic acid), homovanillic acid (HVA) and 5-hydroxy-indoleacetic acid (5-HIAA). There was a significant increase in the concentration of dopamine during the dark cycle compared with the light cycle (14.7 +/- 1 nM vs. 9.3 +/- 0.7 nM; mean +/- SEM; P less than 0.0001), indicating possible circadian variations in the extracellular concentration of DA. There was a steady decrease in the level of DOPAC and HVA, and no change in the level of 5-HIAA. For the point of no-net-flux method, animals were perfused with 4 concentrations of DA or DOPAC, bracketing the extracellular concentrations. The extracellular concentrations of DA and DOPAC using this method were 10.2 +/- 1.7 nM and 17.4 +/- 2.6 microM, respectively. The in vivo recoveries for DA and DOPAC as derived from the slope of the linear regression curves were 72 +/- 3% and 43 +/- 5%. These values were shown to be significantly different (P less than 0.001). Both methods gave similar results for the level of DA in the striatum.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

Toxic anterior segment inflammation following cataract surgery.

Cataract extraction with posterior chamber intraocular lens implantation is rarely complicated by an acute, sterile, anterior segment inflammation. We report three unrelated cases of acute intraocular inflammation following uncomplicated cataract extraction and posterior chamber intraocular lens placement. A constellation of clinical features were found in these cases. The hallmark of this entity was an acute toxic inflammatory reaction occurring in the anterior segment on the first postoperative day. Typically, widespread corneal edema with diffuse corneal endothelial damage occurred, accompanied by a fixed, dilated pupil with significant iris atrophy and sometimes a severe secondary glaucoma. Since all cultures were negative, the resulting inflammatory processes were not a result of endophthalmitis. We believe that a toxic insult introduced into the anterior chamber at the time of surgery precipitated the acute inflammatory processes seen in these cases.

Aged↗
PubMed1992

Hyperopia, anisometropia, and irregular astigmatism in a patient following revisional radial keratotomy.

We present a patient who underwent bilateral radial keratotomy (RK) followed by a bilateral revisional RK for undercorrection. After the second procedure, the patient had a severely flattened left cornea, with marked hyperopia and irregular astigmatism. The right eye, however, remained myopic, causing extreme anisometropia. We hypothesize that the different results in these two eyes may have been due to a critical number of damaged left corneal stromal fibers. Patients undergoing revisional RK or requiring additional incisions may be at increased risk for such a complication.

Anisometropia↗