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Biomedical subjects

D R Guyer

Publications and source records attributed to D R Guyer.

At least 19 recordsLinked to original sources
PubMed1994

A pilot study of indocyanine green videoangiography-guided laser photocoagulation of occult choroidal neovascularization in age-related macular degeneration.

PURPOSE: To evaluate the use of digital indocyanine green videoangiography in patients with clinical and fluorescein angiographic evidence of "occult" choroidal neovascularization in age-related macular degeneration and to investigate indocyanine green videoangiography-guided laser photocoagulation as a therapeutic approach. METHODS: Three hundred forty-seven consecutive patients with exudative age-related macular degeneration and symptoms and clinical manifestations of occult choroidal neovascularization were studied with indocyanine green videoangiography. Patients were selected for laser treatment, using conventional guidelines, when indocyanine green videoangiography demonstrated a well-delineated area of hyperfluorescence, presumed to be a focal area of choroidal neovascularization. RESULTS: Seventy-nine (23%) of 347 eyes were found to have a localized and definable lesion that was potentially amenable to laser photocoagulation therapy; 44 (56%) of these 79 treated eyes had complete resolution of their exudative manifestations. Visual acuity improvement was noted in 10 (13%) of 79 eyes, and stabilization of vision achieved in 42 eyes (53%). CONCLUSION: Laser photocoagulation treatment guided by indocyanine green videoangiography was shown to produce promising anatomical and visual improvement in a small number of patients with occult choroidal neovascularization secondary to age-related macular degeneration. This pilot study warrants further research to investigate the efficacy and safety of this form of treatment.

Aged↗
PubMed1994

A pilot study of digital indocyanine green videoangiography for recurrent occult choroidal neovascularization in age-related macular degeneration.

PURPOSE: Digital indocyanine green videoangiography (ICG-V) was used to study recurrent choroidal neovascularization (CNV) in patients with the clinical and fluorescein angiographic findings indicative of ill-defined, or recurrent occult, CNV (RO-CNV). The use of ICG-V-guided laser caphotocoagulation as an alternative form of treatment was also investigated when a well-delineated area of CNV was imaged with this technique. METHODS: A consecutive series of 66 patients were studied who presented with exudative age-related macular degeneration and symptoms and clinical manifestations of recurrent CNV in which fluorescein angiography did not reveal classic, or well-defined, neovascularization. Patients were selected for laser treatment based on conventional guidelines if ICG-V imaged a well-delineated area of recurrent CNV. RESULTS: Indocyanine green videoangiography showed late staining that was consistent with recurrent CNV in 64 (97%) of these 66 patients with RO-CNV. Twenty-nine (44%) of the 66 were eligible for laser treatment, and 18 (62%) of these 29 patients experienced successful anatomic and visual results, which were defined as resolution of the exudative manifestations and improvement or stabilization (+/- 1 line on a Snellen chart) of vision. CONCLUSIONS: This pilot study suggests that ICG-V is of value in imaging patients with RO-CNV after laser photocoagulation for CNV secondary to age-related macular degeneration. Laser treatment of RO-CNV with ICG-V guidance may be successful both anatomically and functionally in a promising number of these otherwise untreatable cases. Further studies are necessary to validate these preliminary findings.

Aged↗
PubMed1994

Digital indocyanine-green videoangiography of occult choroidal neovascularization.

BACKGROUND: Occult choroidal neovascularization (CNV) secondary to age-related macular degeneration occurs in the majority of patients with exudative maculopathy. Since occult CNV cannot be imaged clearly by fluorescein angiography, this condition is untreatable. The authors performed digital indocyanine-green videoangiography (ICG-V) on 657 consecutive eyes with occult CNV by fluorescein angiography to determine if this technique could be useful in enhancing the imaging of the neovascularization, and thus increasing treatment eligibility. MATERIALS AND METHODS: Six hundred fifty-seven consecutive eyes with occult CNV were studied. The fluorescein and ICG angiograms were compared, and the percentage of patients potentially eligible for laser therapy based on ICG findings was calculated. RESULTS: Of 413 eyes with occult CNV without pigment epithelial detachments, focal areas of neovascularization were noted in 89 (22%). Overall, 142 (34.3%) eyes had lesions that were potentially treatable by laser photocoagulation based on additional information provided by ICG-V. Of the 235 eyes with occult CNV and vascularized pigment epithelial detachments, 98 (42%) were eligible for laser therapy based on ICG-V findings. The authors calculate that ICG-V enhances the treatment eligibility by approximately one third. CONCLUSIONS: In diagnosing occult CNV, ICG-V is an important adjunctive technique to fluorescein angiography. This technique is especially useful in delineating occult neovascularization, neovascularization with overlying subretinal hemorrhage or serosanguineous fluid, and neovascularization associated with pigment epithelial detachments. The authors currently suggest that ICG-V be performed in eyes in which well-delineated neovascularization cannot be identified by fluorescein angiography. Based on their preliminary study, it can be expected that one in three patients with occult CNV potentially will be eligible for laser photocoagulation based on ICG-V. Further studies are necessary to confirm these findings.

Aged↗
PubMed1994

Intraretinal leakage of indocyanine green dye.

PURPOSE: Indocyanine green (ICG) dye is known to remain selectively in and around choroidal neovascularization (CNV) associated with age-related macular degeneration, and is thought to be cleared from the overlying retinal circulation without leakage. This is the basis of ICG dye-enhanced laser photocoagulation. The authors have observed, however, leakage of ICG dye into cystoid spaces within the retinal and have determined the incidence, clinical features, and angiographic characteristics of this newly described phenomenon. METHODS: The digital ICG videoangiograms of 149 consecutive patients with exudative age-related macular degeneration and occult CNV were reviewed independently to determine the characteristics of intraretinal ICG dye leakage. RESULTS: Of the 149 patients with occult CNV, 16 (11%) demonstrated intraretinal leakage of ICG dye between 14 and 34 minutes (median = 20 minutes). The clinical features most commonly associated with this phenomenon are: subretinal fluid (88%), subretinal hemorrhage (88%), subretinal lipid (63%), and retinal pigment epithelial detachment (56%). CONCLUSIONS: Indocyanine green dye may not be as concentrated in and around CNV as previously reported. The delayed onset of its appearance within intraretinal cystoid spaces may suggest a diffusible choroidal source of leakage. Intraretinal ICG dye may be a relative contraindication for ICG dye-enhanced laser photocoagulation.

Aged↗
PubMed1994

Analysis of vascularized pigment epithelial detachments using indocyanine green videoangiography.

BACKGROUND: Occult choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) is known to occur with and without an associated serous pigment epithelial detachment (PED). Digital indocyanine green (ICG) videoangiography has been reported to provide enhanced definition of occult CNV. METHODS: A total of 244 of 657 (37%) consecutive patients with AMD, with occult CNV and an associated serous PED evident on fluorescein angiographic examination, were further studied with ICG videoangiography. RESULTS: On ICG videoangiographic examination, 9 of the 244 (4%) eyes had no evidence of underlying CNV, or essentially a pure serous PED. Each of the remaining 235 eyes (96%) had evidence of neovascularization and were defined as having a vascularized PED. These eyes were further divided into two groups, depending on the size and delineation of the neovascularization seen. Of the 235 eyes with vascularized PEDs, 89 (38%) had a solitary area of neovascularization that was well delineated, no more than one disc area in size, and defined as focal CNV. The other 146 (62%) eyes had a larger area of neovascularization, with variable delineation, defined as plaque CNV. Based on conventional guidelines, some patients were considered to be potentially eligible for laser photocoagulation treatment. CONCLUSION: The results of this study suggest that ICG videoangiography may be an important adjunct to the diagnosis, classification, and potential treatment of patients with AMD and occult CNV associated with a serous PED (vascularized PED).

Aged↗
PubMed1994

Indocyanine green dye-enhanced diode laser photocoagulation of poorly defined subfoveal choroidal neovascularization.

Indocyanine green (ICG) is a dye with an absorption peak (795 to 810 nm) similar to the emission peak of the diode laser (805 nm). Therefore, ICG dye-enhanced diode laser photocoagulation may permit the selective ablation of ICG-retaining choroidal neovascular membranes (CNVM) with relative sparing of the neighboring neurosensory retina. Ten patients with poorly defined subfoveal CNVM were treated with ICG dye-enhanced diode laser photocoagulation and followed for an average of 15 months. One of the 10 patients experienced an immediate significant drop in visual acuity after photocoagulation. Obliteration of the CNVM at the site of laser photocoagulation was confirmed by fluorescein angiography and ICG angiography. Subfoveal chorioretinal scar formation was noted postoperatively in all 10 patients. At last follow up, 9 of these 10 patients had no more than a two-line increase or decrease in visual acuity. These preliminary results suggest that poorly defined subfoveal CNVM can be successfully treated by ICG dye-enhanced diode laser photocoagulation with minimal adverse affect on visual acuity in most cases.

Aged↗
PubMed1992

Subretinal fibrosis after laser photocoagulation for diabetic macular edema.

Seven eyes had subretinal fibrosis after grid laser photocoagulation for diabetic macular edema. The fibrosis caused persistent loss in visual acuity, and in six of the seven eyes, was not associated with detectable laser-induced Bruch's membrane rupture or subretinal hemorrhage. Choroidal neovascularization was detected in only one patient, who was notably younger (27 years) than the median age of 70 years in this series. The median preoperative visual acuity was 20/80 (range, 20/40 to 20/400); the median postoperative visual acuity was 20/400 (range, 20/80 to counting fingers). The subretinal fibrosis was detected at a median of three months (range, 14 days to 4 1/2 months) after laser therapy. In one of five bilaterally treated patients (20%), subretinal fibrosis developed in both eyes. Subretinal fibrosis may be caused by undetected choroidal neovascularization or by excessive proliferation after stimulation of an aged retinal pigment epithelium. Subretinal fibrosis may be a potential cause of loss in visual acuity after laser treatment for diabetic macular edema.

Adult↗
PubMed1992

Observations on patients with idiopathic macular holes and cysts.

We reexamined 96 patients with macular holes or cysts. The mean follow-up period was 4.7 years. Of 19 eyes with macular cysts, only two (10.5%) showed progression to a macular hole. In 15 (79%) of those 19 eyes, the cyst disappeared. Of 80 patients with a macular hole or cyst in one eye and a normal fellow eye, a hole developed in the fellow eye in only one patient (1.2%) and a cyst developed in the fellow eye in only two patients (2.5%). Of 66 eyes with a stage 3 full-thickness macular hole, three eyes (5%) showed resolution without any sign of a hole. Our results suggest a favorable prognosis for normal fellow eyes of patients with macular holes or cysts and for eyes with cysts. Eyes with full-thickness macular holes have a less favorable prognosis, although their natural history may not be as poor as previously thought.

Adult↗
PubMed1992

Radiation maculopathy after proton beam irradiation for choroidal melanoma.

PURPOSE: Radiation maculopathy is a microangiopathy of the retina, which is often observed after irradiation of the eye. To quantitatively determine the frequency of anatomic and functional features of this condition, the authors reviewed a large series of patients with choroidal melanomas who were treated by proton beam irradiation. METHODS: Color photographs and/or fluorescein angiograms of 218 patients with paramacular choroidal melanomas were graded by two independent masked readers to determine the frequency of the various lesions of radiation maculopathy. RESULTS: Overall, 194 (89%) of the 218 patients in this study developed some degree of radiation maculopathy. The earliest and most common finding was macular edema, which was observed in 87% of patients, overall, by the end of year 3. Microvascular changes (microaneurysms and/or telangiectasia), intraretinal hemorrhages, and capillary nonperfusion were noted in 76%, 70%, and 64% of eyes, respectively, by the end of postirradiation year 3. Visual acuity was retained at 20/200 or better in 90% of eyes 1 year after irradiation and in 67% of eyes 3 years after treatment. CONCLUSION: Radiation maculopathy is common after proton beam irradiation of paramacular choroidal melanomas. However, ambulatory vision is preserved in many eyes.

Adolescent↗
PubMed1992

Penetrating ocular fish-hook injuries. Surgical management and long-term visual outcome.

BACKGROUND: Ocular penetrating fish-hook injuries represent a rare yet potentially devastating ocular trauma. To date, only five cases have been reported in the medical literature. The authors present five new cases with long-term follow-up. METHODS: All individuals who presented to the Wilmer Ophthalmological Institute emergency room with ocular fish-hook injuries between 1974 and 1990 were identified, and ophthalmic follow-up evaluations were performed. RESULTS: Individuals were male, between the ages of 10 and 27, with follow-up evaluation of 2.0 to 15.5 years (mean, 6.7 years). The left eye was involved in 80% and in no instance had a single hook penetrated the lid and globe simultaneously. Initial visual acuity was uniformly poor (20/200 or worse). Using specialized surgical techniques, ultimate visual outcome was excellent in 80% of cases (4 of 5 with visual acuity of 20/30 or better). One eye was enucleated because of panendophthalmitis after delayed wound closure. Similar overall results are achieved when previous reports are included in the analysis (90% with visual acuity of 20/40 or better). CONCLUSIONS: These results suggest that penetrating ocular fish-hook injuries may have an excellent long-term prognosis if prompt, appropriate surgical intervention is accomplished.

Adolescent↗
PubMed1992

Digital indocyanine-green angiography in chorioretinal disorders.

The authors performed digital indocyanine-green angiography in 37 patients with chorioretinal disorders. Eighteen patients had choroidal neovascularization, 7 patients had atrophic age-related maculopathy, and 12 patients had uncommon choroidal and retinal disorders. A Topcon indocyanine-green camera was integrated with a digital (1024-line resolution) angiography system. Compared with conventional video or photographic indocyanine-green angiography, this technique offers enhanced image resolution, the possibility of direct qualitative comparison with fluorescein angiography, image archiving, hard-copy generation, and tracing capabilities to plan laser treatment strategies and monitor the adequacy of laser therapy after surgery.

Choroid Diseases↗
PubMed1992

Digital indocyanine green videoangiography and choroidal neovascularization.

This report describes a new system for digital indocyanine green videoangiography (ICGV) that provides enhanced imaging of the choroidal circulation. This newly assembled system was used to study a consecutive series of 129 patients with exudative age-related macular degeneration (AMD), and ill-defined or occult choroidal neovascularization (CNV). Overall, 39% of the patients in this study with occult CNV could be reclassified as having well-delineated or so-called classic CNV by virtue of the additional findings provided by ICGV. In this series, ICGV was particularly useful in identifying occult CNV in eyes with a large, serous pigment epithelial detachment (PED) and in eyes with recurrent CNV after previous laser photocoagulation treatment. Some of these patients were selected for laser photocoagulation of the abnormal choroidal vessels in order to evaluate the feasibility of this form of treatment on the basis of combined clinical, fluorescein angiographic, and ICGV findings. The results of this study suggest that ICGV is an important adjunct in the evaluation, classification, and laser treatment of patients with occult CNV secondary to AMD.

Aged↗
PubMed1992

Dislocation of the crystalline lens in a patient with Sturge-Weber syndrome.

A moderately retarded institutionalized patient diagnosed with Sturge-Weber syndrome and bilateral retinitis pigmentosa underwent enucleation OD because of intractable pain secondary to glaucoma in 1965. Twenty-three years later, the patient had a dislocated lens OS. Although the lens dislocation might have been caused by trauma, it also might be associated with either Sturge-Weber syndrome or retinitis pigmentosa. The role of protective eye wear in one-eyed institutionalized retarded patients is discussed. To our knowledge, this combination of Sturge-Weber syndrome, bilateral retinitis pigmentosa, and a dislocated lens has not been reported previously.

Cataract↗
PubMed1990

Histopathologic features of idiopathic macular holes and cysts.

The pathogenesis of idiopathic macular holes and cysts is currently debated. The authors studied the histopathologic features of 41 specimens. Of 22 full-thickness holes, 16 (73%) had epiretinal membranes (ERMs), 15 (68%) had cystoid macular edema (CME), and 3 (17%) were sealed by fibroglial and retinal pigment epithelial hyperplasia. Photoreceptors were variably degenerated, for a mean of 480 microns (range, 200-750 microns) from the hole margins. Of 12 lamellar macular holes, 6 (50%) had an ERM exhibiting tangential traction on the internal limiting membrane. Cystoid macular edema was present in five (71%) of seven macular cysts, and an ERM was noted in only one (14%). The authors' results suggest that ERM tangential traction may play a role in the pathogenesis of lamellar macular holes. Macular holes often have associated ERMs and CME, which may be potentially reversible.

Aged↗
PubMed1990

Bilateral ischemic optic neuropathy and retinal vascular occlusions associated with lymphoma and sepsis. Clinicopathologic correlation.

The authors report the clinicopathologic correlation of a patient with non-Hodgkin's mixed-cell lymphoma who had impairment of the circulation of the optic nerve and retina in both eyes. The results of histopathologic examination showed that the pial septa of the optic nerves were infiltrated by lymphoma and that there was extensive infarction of the orbital portions of both optic nerves and occlusion of both central retinal arteries and the right central retinal vein by thrombi with bacteria. The infiltration of the optic nerves seemed to be resistant to therapy.

Bacterial Infections↗
PubMed1989

Ophthalmic manifestations of leukemia.

We prospectively examined the eyes of 120 patients with leukemia. Only 38% of patients had normal results of examination. Leukemic infiltrates were present in 3% of patients, other findings related to leukemia were seen in 39% of patients, and 20% of patients had unrelated abnormalities. Visual loss was seen in at least 5% of the patients in this study.

Adolescent↗