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R J Olk

Publications and source records attributed to R J Olk.

At least 19 recordsLinked to original sources
PubMed1999

Therapeutic benefits of infrared (810-nm) diode laser macular grid photocoagulation in prophylactic treatment of nonexudative age-related macular degeneration: two-year results of a randomized pilot study.

OBJECTIVE: This pilot study collected preliminary information on the effectiveness and safety of infrared (810-nm) diode laser macular grid photocoagulation in patients with nonexudative age-related macular degeneration (AMD). Results from this pilot study were used in designing a larger, multicenter, randomized clinical trial. DESIGN: A multicenter, randomized, controlled, clinical trial. PARTICIPANTS: A total of 229 eyes of 152 patients with AMD were enrolled in the pilot study. Seventy-five patients with 1 eye eligible (75 eyes) were enrolled in the unilateral arm of the study; 77 patients with both eyes eligible (154 eyes) were enrolled in the bilateral arm of the study. In the unilateral study arm, 32 eyes were randomized to the observation group, 27 eyes were treated with visible endpoint burns, and 16 eyes were treated with invisible endpoint (subthreshold) lesions. In the bilateral study arm, 77 eyes were in the observation group, 36 eyes were treated with visible burns, and 41 eyes were treated with subthreshold (invisible) lesions. INTERVENTION: Eyes were treated with infrared (810-nm) diode laser macular grid photocoagulation using either visible burns or subthreshold (invisible) lesions and compared to eyes receiving no treatment. MAIN OUTCOME MEASURES: Reduction of drusen, change in visual acuity, and rate of choroidal neovascularization (CNV) membrane formation. RESULTS: At 12 months after treatment, 62% of eyes treated with visible burns had a clinically significant reduction in drusen, whereas this proportion (65%) was reached in 18 months for eyes treated with subthreshold lesions. At 24 months' follow-up, treated eyes had a significant reduction in drusen compared to observation eyes (P < 0.0001). Visual acuity was significantly improved in treated eyes at 12, 18, and 24 months compared to observation eyes (P < 0.001). Choroidal neovascularization formation was similar in treated and observation eyes through 24 months' follow-up. Complications included CNV associated with six eyes treated with visible burns and a juxtafoveal laser scar in one eye treated with visible burns. CONCLUSIONS: Infrared (810-nm) diode laser macular grid photocoagulation in patients with nonexudative AMD significantly reduces drusen levels (P < 0.0001) and significantly improves visual acuity (P < 0.001) when either visible endpoint burns or subthreshold endpoint lesions are used. Complications were fewer using subthreshold endpoint lesions. A larger, multicenter, prospective clinical trial with longer follow-up is needed to determine the efficacy of treatment in reducing the rate of CNV formation. Data from this clinical pilot study have been used to design the Prophylactic Treatment of AMD Trial (PTAMD), a multicenter, randomized, prospective clinical trial currently in progress comparing subthreshold (invisible) treatment to observation in eyes with nonexudative AMD.

Aged↗
PubMed1999

Macular translocation with retinotomy and retinal rotation for exudative age-related macular degeneration.

PURPOSE: To determine the effectiveness of macular translocation with retinotomy and retinal rotation in exudative age-related macular degeneration. METHODS: After written informed consent was obtained, 20 patients underwent macular translocation. We created a 180-degree retinotomy superior, inferior, and temporal to the macula near the equator. The hinged retinal flap was rotated superiorly or inferiorly to place the center of the fovea over an area of healthy retinal pigment epithelium. The retina was flattened under silicone oil and laser photocoagulation was placed. RESULTS: The fovea was moved 425 to 1,700 microm (965+/-262 microm) superiorly or inferiorly. Follow-up time was 2 to 12 months (median 8 months). Complications included macular pucker (3 eyes), subfoveal hemorrhage (2 eyes), macular hole (1 eye), and progression of cataract in phakic eyes (3 eyes). Thirteen of 20 eyes showed various degrees of proliferative vitreoretinopathy with epiretinal membrane formation over the inferior peripheral retina with the inferior retinal detachment stabilized by the silicone oil. One eye progressed to phthisis bulbi. Initial visual acuity ranged from 20/80 to 20/800 (median 20/150) and final visual acuity ranged from light perception to 20/200 (median 20/1000). CONCLUSION: The fovea can be moved up to 1,700 microm with retinotomy and retinal rotation; however, there is a high rate of complications. Proliferative vitreoretinopathy is the major complication of this technique and is probably related to the extensive retinotomy and subretinal irrigation inherent in the technique. Other techniques such as scleral shortening may have fewer complications.

Aged↗
PubMed1998

Indocyanine green angiography patterns of zones of relative decreased choroidal blood flow in patients with exudative age-related macular degeneration.

BACKGROUND AND OBJECTIVE: To investigate the incidence and patterns of posterior zones of relative decreased choroidal blood flow in patients with exudative age-related macular degeneration. PATIENTS AND METHODS: Digital indocyanine green (ICG) angiograms from 100 patients with exudative age-related macular degeneration were reviewed for the presence of posterior zones of relative decreased choroidal blood flow. The patterns of these zones and their location relative to the choroidal neovascular process were noted. RESULTS: Ninety-five percent of the angiograms displayed the presence of either a complete or an incomplete zone of relative choroidal hypoperfusion. The zone was most apparent in the early frames of the angiogram. Five different patterns of relative decreased choroidal blood flow were identified: horizontal (32%), vertical (14%), bipartite (9%), tripartite (31%), and quadripartite (9%). The choroidal neovascular process was located within or at the edge of the zone of relative choroidal hypoperfusion in all cases. CONCLUSION: Most cases of choroidal neovascularization localize to areas of relative choroidal dye nonfilling on ICG angiography. These patterns of choroidal nonfilling may have implications in the pathogenesis and management of choroidal neovascular membranes in age-related macular degeneration.

Choroid↗
PubMed1997

Macular ischemia as a cause of decreased vision in a patient with acquired immunodeficiency syndrome.

PURPOSE: To report macular ischemia as a cause of decreased vision in a patient with acquired immunodeficiency syndrome (AIDS). METHODS: A 50-year-old man with AIDS who had previously diagnosed human immunodeficiency virus retinopathy and peripheral cytomegalovirus retinitis was initially examined with decreased vision in both eyes. He underwent complete systemic and ocular evaluation, fundus photography, and fluorescein angiography. RESULT: Fluorescein angiography disclosed irregular enlargement of the foveal avascular zone in both eyes. CONCLUSIONS: Macular ischemia may cause decreased vision in patients with AIDS and can be detected by fluorescein angiography.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Perfusion of the subfoveal choriocapillaris affects visual recovery after submacular surgery in presumed ocular histoplasmosis syndrome.

PURPOSE: To determine the relationship between the visual result and perfusion of the subfoveal choriocapillaris after surgical excision of subfoveal neovascularization in presumed ocular histoplasmosis syndrome. METHODS: We reviewed the records of 38 eyes of 37 patients with gradable postoperative fluorescein angiograms and color photographs after surgical excision of a subfoveal neovascular membrane in presumed ocular histoplasmosis syndrome. The postoperative photographs and fluorescein angiograms were graded in a masked fashion for the presence of perfusion of the subfoveal choriocapillaris. We used preoperative and postoperative best-corrected visual acuities to determine the correlation between postoperative perfusion of the subfoveal choriocapillaris and both final visual acuity and visual improvement after surgery. RESULTS: After surgery, the subfoveal choriocapillaris was perfused in 24 of the 38 eyes (63%) and nonperfused in 14 (37%). Best-corrected visual acuity improved by at least 2 Snellen lines in 17 of the 24 perfused eyes (71%) and two of the 14 nonperfused eyes (14%) (P = .0089). Best-corrected visual acuity of 20/100 or better was achieved in 18 of the perfused eyes (75%) and four nonperfused eyes (29%) (P = .0076). CONCLUSION: Both final visual acuity and improvement in visual acuity were correlated with postoperative perfusion of the subfoveal choriocapillaris in patients with presumed occular histoplasmosis syndrome. Development of techniques to maintain or reestablish perfusion of the subfoveal choriocapillaris after surgery may improve visual outcome in these eyes.

Capillaries↗
PubMed1997

Diode laser (810 nm) versus argon green (514 nm) modified grid photocoagulation for diffuse diabetic macular edema.

OBJECTIVE: To compare argon green (514 nm) versus diode laser (810 nm) modified grid laser photocoagulation treatment in diffuse diabetic macular edema (DDME). DESIGN: Randomized, prospective clinical trial. PARTICIPANTS: Patients with DDME and diabetic retinopathy of fewer than two high-risk characteristics in severity, no previous laser photocoagulation for diabetic macular edema, and no other ocular condition that could interfere with assessment of treatment results. INTERVENTION: One hundred seventy-one eyes of 91 patients were randomized to either argon green (514 nm) or diode laser (810 nm) modified grid laser photocoagulation for DDME. Follow-up was conducted for a minimum of 12 months (16.55 +/- 3.52 months). Retreatment was performed for residual edema involving the foveal avascular zone. MAIN OUTCOME RESULTS: Visual improvement, visual loss, reduction-elimination of macular edema, and the number of supplemental treatments. RESULTS: A comparison of visual improvement, visual loss, reduction-elimination of macular edema, and the number of supplemental treatments showed no statistical difference between the groups (P > 0.05 for all groups). Reduction-elimination of DDME was better in the group without cystoid macular edema than the group with cystoid macular edema, but visual outcome appeared to be similar in both groups. History of hypertension or poor initial visual acuity (< or = 20/80) at entry into the study had no significant effect on the outcome. However, the patients without systemic vascular disease have improved more than those with systemic vascular disease regardless of the type of the laser used. CONCLUSIONS: Diode laser (810 nm) modified grid laser photocoagulation for DDME is equivalent to argon green (514 nm) and patients without systemic vascular disease are more likely to improve after laser treatment with either wavelength.

Adult↗
PubMed1996

Diagnostic indocyanine green angiography in preeclampsia.

PURPOSE: To determine the role of the choroidal vasculature in the pathogenesis of exudative retinal detachments in preeclampsia using indocyanine green angiography. METHODS: We reviewed both fluorescein and indocyanine green angiographic findings for four patients with preeclampsia. RESULTS: Indocyanine green angiographic findings in patients with preeclampsia include nonperfusion in the early phases of the angiogram and staining of the choroidal vasculature with subretinal leakage in the late phases of the angiogram and multiple punctate areas of blocked fluorescence. CONCLUSION: Indocyanine green angiography indicates that damage to the choroidal vasculature leads to many of the retinal changes seen in preeclampsia.

Adult↗
PubMed1995

Quantitation of retinal ablation in proliferative diabetic retinopathy.

PURPOSE: We studied 294 eyes of 182 patients, to quantitate the amount of retinal ablation required for regression of proliferative diabetic retinopathy. METHODS: Eyes included in the study had two or more proliferative diabetic retinopathy risk factors, received panretinal photocoagulation, and had a minimum follow-up of one year. Laser photocoagulation or cryotherapy was given to eyes that failed to regress or had progression of retinopathy. Eyes treated by other physicians, treated with xenon arc photocoagulation, or undergoing laser treatment or vitrectomy for other retinal conditions were excluded. The total area of retina ablated was calculated and used as a quantitative measure of treatment. RESULTS: Regression was observed in 275 eyes (93%); 19 eyes (7%) failed to regress and eventually required vitrectomy. Panretinal photocoagulation alone successfully led to regression in 229 eyes (77%), whereas 46 eyes (15.6%) required both photocoagulation and peripheral anterior retinal cryotherapy. An average of 1.7 treatments per eye led to regression. Eyes were bimodally distributed by requirement for treatment, into low and high treatment groups. Low treatment eyes received an average of 510 mm2 of retinal ablation (2,600 500-microns burns), and high treatment eyes, 1,280 mm2 (6,500 500-microns burns). More extensive treatment was required with more retinopathy risk factors (P = .002 for four vs three risk factors and P = .0007 for four vs two risk factors); duration of diabetes mellitus longer than 15 years (P = .004), and onset of diabetes mellitus before 30 years of age (P = .0008). CONCLUSION: Patients with proliferative diabetic retinopathy should be treated aggressively with panretinal photocoagulation, cryotherapy, or both. The amount of initial treatment required for regression may be considerably more than that recommended by the Diabetic Retinopathy Study.

Adolescent↗
PubMed1994

Pars plana vitrectomy for treatment of stage 2 macular holes.

OBJECTIVE: To assess the anatomic outcome and visual acuities at follow-up after pars plana vitrectomy in the management of stage 2 macular holes. DESIGN: Retrospective. SETTING: Retina Consultants, Ltd, St Louis, Mo. PATIENTS: Thirty-three patients, aged 43 to 75 years, with stage 2 macular holes. INTERVENTION: Total pars plana vitrectomy with separation of the posterior hyaloid membrane and injection of intraocular gas followed by postoperative face-down positioning. MAIN OUTCOME MEASURES: Visual acuity and anatomic appearance of the macular hole. RESULTS: Postoperatively, 20 (61%) of 33 eyes attained a visual acuity of 20/50 or greater. Twenty (61%) of 33 eyes showed an improvement in visual acuity, while nine (27%) of 33 were stable. Four (12%) of 33 eyes showed a decline in postoperative visual acuity with progression to a stage 3 macular hole. Twenty-five (76%) of 33 eyes showed stabilization or improvement in the appearance of the macular hole. CONCLUSIONS: Pars plana vitrectomy in conjunction with postoperative intraocular gas tamponade may result in visual and anatomic stabilization or improvement in eyes with stage 2 macular holes. However, because of limited natural history data, it is unknown whether these results are any better than those that might occur without surgery.

Adult↗
PubMed1994

External argon laser choroidotomy versus needle drainage technique in primary scleral buckle procedures. A prospective randomized study.

PURPOSE: To compare the rates of intraoperative and postoperative complications of external argon laser choroidotomy and needle drainage techniques during scleral buckle procedures for primary retinal detachment. METHODS: A group of 175 patients undergoing scleral buckling for primary retinal detachment was randomly assigned to undergo either external argon laser choroidotomy or needle drainage. Complications associated with drainage of subretinal fluid were categorized as retinal break, retinal incarceration, or hemorrhage (dot, < or = 1 disc diameter [DD], or > 1 DD), and recorded during surgery and 24 hours after surgery. RESULTS: In the group that underwent laser choroidotomy, 12 (13%) of 92 patients had complications, including 4 dot hemorrhages, 3 hemorrhages 1 DD or smaller, 3 hemorrhages larger than 1 DD, 1 retinal incarceration, and 1 suprachoroidal hemorrhage. In the group that underwent needle drainage, 13 (16%) of 81 patients had complications, including 3 dot hemorrhages, 4 hemorrhages 1 DD or smaller, 5 hemorrhages larger than 1 DD, and 1 suprachoroidal hemorrhage. No significant difference was noted between the two groups in the incidence of complications (P = 0.657). CONCLUSION: External argon laser choroidotomy and needle choroidotomy are comparable, safe, and effective ways to drain subretinal fluid during scleral buckle surgery.

Body Fluids↗
PubMed1993

Corticosteroid-induced ocular hypertension in the treatment of aphakic or pseudophakic cystoid macular edema.

PURPOSE: To examine the relationship between corticosteroid-induced ocular hypertension and the reduction and/or resolution of chronic aphakic or pseudophakic cystoid macular edema (CME). METHODS: The authors retrospectively reviewed 454 cases coded for CME between 1971 and 1991 and identified 21 patients with aphakic or pseudophakic CME greater than 6 months' duration who experienced a documented rise in intraocular pressure (IOP) on corticosteroid therapy. These patients were compared with similarly treated controls who did not experience a rise in IOP, and visual acuity and the biomicroscopic appearance of CME were examined. RESULTS: Sixteen of 21 patients showed improved visual acuity and reduction and/or resolution of CME. In all five cases of treatment failure, there was evidence of vitreous attachment to anterior segment structures. This is statistically significant compared with controls, in which 4 of 14 patients with normal vitreous anatomy showed similar improvement (P = 0.00003). CONCLUSION: This small retrospective series suggests that in the absence of vitreous traction, corticosteroid-induced ocular hypertension possibly leads to reduction and/or resolution of chronic aphakic or pseudophakic cystoid macular edema.

Adult↗
PubMed1992

Pneumatic retinopexy perfluoroethane (C2F6) in the treatment of rhegmatogenous retinal detachment.

Due to differences in expansile properties and duration, perfluorethane gas may offer advantages over other gases presently used for pneumatic retinopexy. Seventeen eyes with retinal detachments with single retinal breaks or groups of breaks no greater than 1 clock hour in extent were prospectively treated with perfluoroethane gas injection and retinocryopexy and followed up for a minimum of 6 months. Twelve eyes (71%) were attached with one procedure, and five eyes (29%) were attached with two or three procedures. Post-operative proliferative vitreoretinopathy occurred in two eyes (12%), new or missed breaks in three eyes (18%), and premacular fibroplasia in one (6%) eye. No eyes had an apparent progression of cataracts. Seven (88%) of eight eyes with preoperative macular detachments had improved visual acuity after surgery. All nine eyes (100%) with preoperative macular attachment had the same or improved visual acuity after surgery. The efficacy of perfluoroethane appears similar to that of other perfluorocarbon gases.

Fluorocarbons↗