Search PubMed⌕ Search

Biomedical subjects

D R Guyer

Publications and source records attributed to D R Guyer.

At least 37 records · Page 2Linked to original sources
PubMed1996

Indocyanine green-guided laser photocoagulation of focal spots at the edge of plaques of choroidal neovascularization.

OBJECTIVE: To determine whether indocyanine green-guided laser photocoagulation of focal spots at the edge of plaques of neovascularization is beneficial for patients with untreatable occult choroidal neovascularization by fluorescein imaging. PATIENTS: A pilot series of 23 eyes were identified that had untreatable occult choroidal neovascularization secondary to age-related macular degeneration with focal spots at the edge of a plaque of neovascularization on the indocyanine green study. After informed consent was obtained, indocyanine green-guided laser photocoagulation was applied solely to the focal spot at the edge of the plaque. RESULTS: Anatomical success with resolution of the exudative findings was noted in 15 (79%) of 19 eyes at 6 months, 13 (68%) of 19 eyes at 12 months, and six (37.5%) of 16 eyes at 24 months. The median follow-up period was 18 months (range, 3 to 44 months). Visual acuity was stabilized or improved in nine (69%) of 13 successfully treated eyes at 1 year. Of the successfully treated cases at 1 year, nine (69%) of 13 had a final visual acuity of 20/100 or better. CONCLUSIONS: Our preliminary study of indocyanine green-guided laser photocoagulation of focal spots at the edge of plaques of neovascularization suggests that this technique may improve the visual prognosis of these patients with presently untreatable disease. A prospective, randomized, controlled clinical trial is warranted to evaluate this treatment approach.

Aged↗
PubMed1996

Central serous chorioretinopathy in younger and older adults.

PURPOSE: The purpose of the study is to investigate the demographic characteristics and clinical findings of central serous chorioretinopathy (CSC). METHODS: This study examined a consecutive series of 130 patients with CSC seen over an 18-month period. RESULTS: The mean age of the patients when examined was 51 years, and the male-to-female ratio was 2.6:1.0. A total of 62 patients were older than 50 years of age when first examined. Although the patients shared some clinical and angiographic similarities, the older patients had a lower mean visual acuity and were more likely to have diffuse retinal pigment epitheliopathy, bilateral involvement, and secondary choroidal neovascularization than were the younger patients. With ophthalmoscopic and angiographic examination results, it was possible to differentiate CSC in older adults from choroidal neovascularization. CONCLUSION: This study expands the clinical concept of CSC. The male-to-female ratio was much lower, and the range of ages of the patients was much greater than in previous studies. Disease manifestations in older adults differed somewhat from those seen in younger adults. In older patients, CSC can be distinguished from other exudative maculopathies, particularly that of choroidal neovascularization secondary to age-related macular degeneration.

Adult↗
PubMed1996

Classification of choroidal neovascularization by digital indocyanine green videoangiography.

PURPOSE: The majority of patients with exudative maculopathy due to age-related macular degeneration present with poorly defined or occult choroidal neovascularization (CNV) that cannot be imaged adequately by fluorescein angiography. Digital indocyanine green (ICG) videoangiography is a new technique that allows enhanced imaging of these poorly defined or occult vessels. The authors studied 1000 consecutive cases of occult CNV using digital ICG angiography to describe the various types of neovascularization observed by this technique and to determine the frequency and natural history of the various lesions. MATERIALS AND METHODS: Digital ICG videoangiography was performed as described previously on 1000 consecutive eyes with occult CNV by fluorescein angiography. RESULTS: One thousand consecutive eyes with occult CNV by fluorescein angiography were imaged using digital ICG videoangiography. Three morphologic types of CNV were noted by ICG videoangiography, which included focal spots, plaques (well-defined or poorly defined), and combination lesions (in which both focal spots and plaques are noted). Combination lesions can be subdivided into marginal spots (focal spots at the edge of plaques of neovascularization), overlying spots (hot spots overlying plaques of neovascularization), or remote spots (a focal spot remote from a plaque of neovascularization). The relative frequency of these lesions was as follows: there were 283 cases (29%) of focal spots; 597 cases (61%) of plaques, consisting of 265 cases (27%) of well-defined plaques and 332 cases (34%) of poorly defined plaques; and 84 cases (8%) of combination lesions, consisting of 35 cases (3%) of marginal spots, 37 cases (4%) of overlying spots, and 12 cases (1%) of remote spots. In seven additional cases (1%), a mixture of the above lesions was noted. In 13 additional eyes (1%), no lesions were noted on the ICG angiogram. The studies of 16 eyes were unreadable or unobtainable. CONCLUSIONS: There are three types of CNV that can be observed by digital ICG videoangiography. Plaques are the most common type and have a poor natural history. Focal spots or hot spots are the next most frequently seen lesion and can potentially be treated by ICG-guided laser photocoagulation. Combination lesions, in which both focal spots and plaques are present, are rare. This study of 1000 consecutive cases of eyes with occult neovascularization that were imaged with digital ICG videoangiography serves to classify the various types of neovascularization observed by this technique. Digital ICG videoangiography is an important tool in better delineating eyes with occult CNV. Future studies are necessary to validate our findings.

Choroid↗
PubMed1996

Indocyanine green videoangiography of older patients with central serous chorioretinopathy.

PURPOSE: The authors studied the indocyanine green (ICG) videoangiography findings of central serous chorioretinopathy (CSC) in older adults. BACKGROUND: Central serous chorioretinopathy in older adults may be confused with the exudative forms of age-related macular degeneration (AMD) because the two entities may have similar ophthalmoscopic and fluorescein angiographic findings. Because of its enhanced ability to image the choroidal circulation, ICG videoangiography has been used to describe certain choroidal vascular abnormalities in young adults with CSC, as well as older patients with choroidal neovascularization (CNV). The ICG videoangiography findings in CSC in older adults is largely unknown. METHODS: The authors performed ICG videoangiography on 36 patients aged 50 years or older with CSC to characterize their findings. RESULTS: The ICG videoangiography findings of the patients were consistent, revealing choroidal vascular hyperpermeability manifested by areas of hyperfluorescence that were first seen in the midphase of the angiogram. In the later phases of the angiogram, there were dispersion of the hyperfluorescence and a distinctive silhouetting of the larger choroidal vessels. CONCLUSIONS: Older patients with CSC have a unique temporal and topographic pattern of hyperpermeability that can help establish the proper diagnosis.

Aged↗
PubMed1995

Choroidal neovascularization in second eyes of patients with unilateral exudative age-related macular degeneration.

PURPOSE: To evaluate patients with unilateral occult choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) for the nature of the neovascularization which develops in the fellow eyes. METHODS: Patients with newly diagnosed unilateral occult CNV were followed prospectively for the development of CNV in the fellow eye. Patients were classified based on the type of occult CNV in the first eye: (1) those with associated serous pigment epithelial detachment (serous PED) and (2) those without. Demographic and clinical data, including the type of CNV in the second eyes, were compared. RESULTS: Choroidal neovascularization developed in 115 patients in the second eye. Fifty-six patients had occult CNV with a serous PED (also termed vascularized PED) in the first eye, and 59 patients had occult CNV without serous PED. The two groups did not differ significantly in the demographic and the clinical features evaluated. Well-delineated (or classic) CNV developed in the fellow eye of one patient in each group. Of the remaining 55 patients with vascularized PED in the first eye, the same type of occult CNV developed in 48 (87%) patients in the second eye. Of 58 (84%) patients in the second group, the same type of occult CNV developed in the second eye of 49 patients. This symmetric distribution of type of CNV between eyes is highly significant (P < 0.001). CONCLUSIONS: Eyes with occult CNV secondary to AMD can be classified by the presence or absence of an associated serous PED. Patients with unilateral occult CNV have a significant risk of occult CNV developing in the second eye, and the type of occult disease in the first eye is highly predictive of the type of neovascularized disease in the second eye. These findings are important with respect to natural history, and possibly to the treatment response and visual prognosis of patients with neovascularized AMD.

Aged↗
PubMed1995

Indocyanine-green angiography.

Indocyanine-green angiography represents a major advance in imaging of the choroidal circulation. Recent technical innovations have permitted this diagnostic technique to find clinical application in many chorioretinal conditions. The indocyanine-green molecule has proven to be safe for human study. In age-related macular degeneration, indocyanine-green angiography may play an important role in the diagnosis of patients with occult choroidal neovascularization, leading to eventual increased efficacy with laser photocoagulation treatment. Histopathologic confirmation of a lesion noted by ICG angiography has been made. In multiple inflammatory conditions, as well as with central serous chorioretinopathy, distinct ICG patterns have emerged that may facilitate better understanding of the disease processes. With greater experience, ICG angiography may provide improved imaging, a better understanding of the pathogenesis, and new treatment approaches for various chorioretinal conditions.

Chorioretinitis↗
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 central serous chorioretinopathy.

BACKGROUND: The pathogenesis of central serous chorioretinopathy (CSC) is poorly understood. Abnormalities in the choroidal circulation have been hypothesized to be causative factors. Fluorescein angiography has not been particularly useful in identifying specific choroidal defects in CSC, largely because of inherent limitations in imaging with this technique. Recent technologic advances in digital indocyanine green videoangiography allow enhanced imaging of the choroid and other subretinal structures in comparison with fluorescein angiography. METHODS: We performed digital indocyanine green videoangiography in 29 consecutive eyes with CSC and compared our results with clinical and fluorescein angiographic findings. RESULTS: Several newly recognized subretinal abnormalities in CSC were noted with digital indocyanine green videoangiography, including (1) presumed hyperpermeability of the choroidal circulation surrounding active retinal pigment epithelial leaks, (2) additional focal and multifocal areas of presumed choroidal hyperpermeability not associated with abnormalities detectable by fluorescein angiography or clinical examination, and (3) multiple presumed "occult" serous retinal pigment epithelial detachments with a characteristic indocyanine green videoangiographic pattern. CONCLUSION: We suggest that the pathogenesis of CSC may be due to a choroidal vascular hyperpermeability with and without associated active pigment epithelial leaks and multiple presumed "occult" serous retinal pigment epithelial detachments. Based on these findings, a hypothetical model can be constructed related to the pathogenesis of CSC, beginning with choroidal abnormalities that secondarily affect the retinal pigment epithelium and neurosensory retina.

Acute Disease↗
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

Adverse reactions due to indocyanine green.

BACKGROUND: Although adverse reactions to indocyanine green (ICG) are known to occur, the dye has been used for more than 30 years in tests of cardiac and hepatic function, with a high level of safety. Improved digital video technology has renewed interest in the use of intravenous ICG in ophthalmic imaging. This report describes the authors' experience regarding the safety of ICG for digital angiography and their recommendations for its use in the ophthalmic setting. METHODS: Digital ICG videoangiography was performed in 1226 consecutive patients, and 1923 ICG videoangiography tests were performed. A registry of adverse reactions to ICG was established. Criteria were used to define mild, moderate, and severe adverse reactions, and these data were recorded for every ICG study performed. RESULTS: There were three (0.15%) mild adverse reactions, four (0.2%) moderate reactions, and one (0.05%) severe adverse reaction. There were no deaths. CONCLUSIONS: This study documents the safety of intravenous ICG for use in ophthalmic videoangiography.

Adult↗
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

A prospective natural history study and kinetic ultrasound evaluation of idiopathic macular holes.

BACKGROUND: The role of vitreoretinal traction in the macular region as a causative factor for the development of idiopathic macular holes is widely accepted. The purpose of this study is to provide a prospective evaluation of patients with idiopathic macular holes to determine the risk of hole formation in the fellow eye. METHODS: The authors performed a prospective study of 50 patients with unilateral idiopathic macular holes combining complete ocular examination, including slit-lamp biomicroscopy, with kinetic B-scan ultrasound evaluation of the status of the vitreoretinal interface. Natural history data were obtained by follow-up examinations performed at 3-month intervals throughout the course of the study. RESULTS: During a median follow-up of 33 months, a full-thickness macular hole developed in 1 (2%) of 46 normal fellow eyes. Full-thickness holes also developed in three (75%) of the four eyes that had premacular hole changes (stages 1A and 1B) in the fellow eye on initial examination. All macular holes in fellow eyes occurred within 24 months of entry into the study. Kinetic ultrasound evaluation determined that fellow eyes with separation of the posterior hyaloid membrane in the foveal region were protected from future macular hole development. Those patients with attachment of the posterior hyaloid membrane in both eyes were at highest risk of holes forming in the fellow eye. Patients with posterior hyaloid membrane separation in the macular hole eye only, with an attached vitreous in the fellow eye, were at intermediate risk. CONCLUSION: The authors suggest that fellow eyes in patients with unilateral idiopathic macular holes have a relatively favorable natural history and that kinetic ultrasound examination may help determine which of these fellow eyes is at highest risk for full-thickness macular holes developing.

Adult↗
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↗
PubMed1993

Interferon-associated retinopathy.

Interferon alfa is used to treat various systemic disorders and recently has been suggested as a possible treatment for choroidal neovascularization. We report 10 cases of retinal ischemia associated with the use of interferon alfa for various illnesses. The retinal findings include cotton-wool spot formation, capillary nonperfusion, arteriolar occlusion, and hemorrhage. The retinal complications may sometimes be reversible when treatment is stopped. Our findings emphasize the need to have patients who are receiving interferon alfa therapy monitored for these retinal complications, which may rarely be associated with permanent loss of vision secondary to closure of retinal capillaries.

Adult↗
PubMed1993

The status of indocyanine-green videoangiography.

The use of indocyanine-green videoangiography as an adjunctive technique to fluorescein angiography in the diagnosis of choroidal neovascularization has recently gained widespread attention. In January 1993, the first international symposium on indocyanine-green angiography was sponsored by the Manhattan Eye, Ear, and Throat Hospital. Approximately 300 retina specialists from all over the world convened at this meeting. Our current knowledge of indocyanine-green videoangiography is reviewed.

Angiography↗