Macular hole

A macular hole is a full-thickness defect of retinal tissue involving the anatomic fovea, thereby affecting central visual acuity. Macular holes have been associated with myriad ocular conditions and originally were described in the setting of trauma. The pathogenesis of idiopathic, age-related macular holes remains unclear despite a litany of theories. Recently, Gass has described an updated biomicroscopic classification of macular holes and postulated that tangential vitreous traction may play a role. Cellular components surrounding the rim of macular holes may also contribute tangential traction forces and elevate the rim. Pseudomacular holes may be mistaken for macular hole lesions, despite careful clinical examination. Careful biomicroscopic examination with a contact lens and use of the Watzke and laser aiming beam tests help to ensure accurate diagnosis. Newer imaging technology, such as optical coherence tomography, helps distinguish true macular holes from pseudoholes and may provide additional insight into the pathogenesis of this condition. Surgical management with or without pharmacosurgical adjuncts can improve vision in select cases. The most common surgical complication is progressive lens opacification in phakic patients.

Foveolar choroidal blood flow in age-related macular degeneration

PURPOSE

To compare measurements of the foveolar choroidal blood circulation in subjects with nonexudative, age-related macular degeneration (AMD) with those of control subjects.

METHODS

Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChBVel), volume (ChBVol), and flow (ChBFlow) in the center of the fovea. Measurements were obtained in 20 eyes of 20 subjects with 10 or more large drusen, visual acuity of 20/32 or better, and no evidence of choroidal neovascularization. Findings obtained in these subjects were compared with those of 10 eyes of 10 age- and blood pressure-matched control subjects with no large drusen. Foveolar choroidal blood flow measurements were obtained by asking the study participants to fixate on a probing laser beam.

RESULTS

No significant differences in average age, blood pressure, or intraocular pressure were observed between subjects with AMD and control subjects. In subjects with AMD, average ChBVol was 0.24 +/- 0.08 (+/- 1 SD) arbitrary units (AU); this value was 33% lower than that of control subjects (0.36 +/- 0.11 AU; two-tailed, independent Student's t-test, P = 0.005). Average ChBVel, conversely, was not significantly different from normal (0.44 +/- 0.07 AU) in subjects with AMD (0.44 +/- 0.10 AU). Average ChBFlow in subjects with AMD (8.7 +/- 3.1 AU) was 37% lower than that of control subjects (13.7 +/- 3.5 AU) (P = 0.0005). Average blood flow pulsatility was 6% higher in subjects with AMD (0.71 +/- 0.15) than in control subjects (0.66 +/- 0.14), but this difference was not statistically significant (P = 0.42).

CONCLUSIONS

Average ChBFlow in the nonexudative stages of AMD is lower than that of age-matched controls, and the effect is caused mainly by a decrease in ChBVol. Further studies are needed to elucidate whether decreased ChBFlow plays a role in the development of choroidal neovascularization, and whether ChBFlow measurements may help identify subjects with AMD at risk for developing choroidal neovascularization.

Propofol anesthesia in a patient with Isaacs syndrome--report of a case and literature review

Isaacs syndrome is an unusual lower motor neuron disease characterized by myokymia (muscle twitching), muscular stiffness, and decreased tendon reflexes. We reported a patient who was affected with this rare disease, with manifestation of involuntary muscular contractions and required general anesthesia for bilateral tonsillectomies. Understanding the presentation and characterization of this unusual disease may be helpful in making choice of anesthetics or anesthetic techniques. Its possible mechanisms of action and its specific considerations in anesthesia in the literature are reviewed and discussed.

Absorption of irrigating fluid during transcervical resection of endometrium--a report of two cases

It has been recognized for many years that the use of hypotonic solution for the irrigation of the bladder cavity during transurethral resection of the prostate (TURP) may result in hyponatremia and water intoxication due to rapid and excessive absorption of the solution from the exposed prostatic bed, the clinical manifestation of which is termed "TURP syndrome". A similar condition termed "female TURP syndrome" following hysteroscopic transcervical endometrial resection (TCR) has been reported. Since the frequency of TCR continues to increase the increased rate of "TCR syndrome" would come in its wake. Here, we present two cases who developed severe hyperglycemia and hyponatremia while underwent TCR with 10% dextrose in water as the irrigation fluid and the same time emphasize the potential risk of this complication.

Rapidly progressive optic disk neovascularization after diabetic papillopathy

PURPOSE

To determine if diabetic papillopathy may be associated with optic disk neovascularization and visual loss.

METHODS

We examined two young adults with bilateral diabetic papillopathy who had permanent loss of vision associated with rapidly progressive posterior segment neovascularization.

RESULTS

Within three months both patients developed florid optic disk neovascularization. This neovascularization was slow to regress despite full panretinal photocoagulation. One patient developed a macular tractional retinal detachment.

CONCLUSIONS

Diabetic papillopathy may be associated with rapid progression of diabetic retinopathy and, in particular, optic disk neovascularization. Patients should be monitored for this possibility.

Flow cytometric assessment of the cellular pharmacokinetics of fluorescent drugs

Development of multidrug resistance (MDR) in cancer cells decrease net doxorubicin uptake as a result of either increased efflux, or decreased intracellular sequestration, or decreased membrane permeability. Kinetic parameters of drug uptake can distinguish among these forms of altered transport. Cellular uptake of fluorescent drugs was monitored by a flow cytometric assay using a rapid-injection system and analyzed with a three-compartment model in which rapid diffusion from extracellular fluid into the cell was followed by uptake into a nonexchangeable pool. In agreement with our recent studies of 14C-doxorubicin distribution (Dordal et al.: J Pharmacol Exp Ther 271:1286-1290, 1994), sequestration of doxorubicin was decreased 2.7-fold in P-glycoprotein-expressing SU-4R lymphoma cells compared to drug-sensitive SU-4 cells (14.0 +/- 4.8 vs. 5.0 +/- 0.9 nl s-1) without a change in membrane permeability or evidence of active efflux. In contrast, sequestration of the highly fluorescent dye rhodamine 123 was decreased 20-fold (17.1 +/- 8.3 vs. 0.9 +/- 0.8 nl s-1). Resistant cells were significantly less permeable to rhodamine than sensitive cells (3.8 +/- 1.2 vs. 10.2 +/- 2.6 x 10(5) cm2 s-1), and rhodamine efflux was increased by 24%. Thus, SU-4R cells exhibit multiple alterations that cause decreased intracellular drug concentrations, of which decreased sequestration is quantitatively the most significant.

Elevation of maternal alpha-fetoprotein in systemic lupus erythematosus: a controlled study

OBJECTIVE

To determine if maternal alpha fetoprotein (AFP) is elevated in lupus pregnancy and, if so, whether it is associated with treatment or outcome.

METHODS

Maternal serum AFP values were obtained once during Weeks 16.3 to 31.7 in 54 pregnancies followed prospectively. AFP was measured by the Maryland State Health Department, who reported the AFP level and a corrected value, multiple of the median (AFP MOM), adjusted for weight, gestational age, and insulin dependent diabetes. Controls were 1001 consecutive samples measured by the same laboratory.

RESULTS

AFP MOM was higher in lupus pregnancies (1.425 +/- 0.73 vs 1.169 +/- 0.50, p = 0.001), as were the unadjusted AFP levels (lupus 68.26 +/- 42.2, control 52.49 +/- 27.25, p = 0.001). Of lupus pregnancies 7.4 vs 2.6% of control pregnancies had an abnormal AFP MOM (p = 0.06). The 4 patients with abnormal AFP-MOM, using the 2.3 cutoff, were taking more prednisone (27.25 +/- 18.54 mg vs 10.85 +/- 12.29 mg, p = 0.02), were more likely to have delivered preterm (31.50 +/- 36.31 weeks, p = 0.02), and were more likely to have a high anticardiolipin (aCL) antibody during the pregnancy (p = 0.03).

CONCLUSION

AFP is higher in lupus than in control pregnancies, without any increase in neural tube or other birth defects. An abnormal maternal serum AFP level is associated with higher prednisone dose, preterm delivery and aCL. Patients and obstetricians need to be aware that an elevated maternal AFP in lupus pregnancy is not necessarily due to a birth defect, and may be predictive of preterm delivery.

The natural history of idiopathic subfoveal choroidal neovascularization

PURPOSE

To study the long-term natural history of idiopathic subfoveal choroidal neovascularization (CNV) in young patients.

METHODS

A retrospective survey of 19 consecutive patients with idiopathic subfoveal CNV diagnosed in an urban eye hospital and a single practice.

RESULTS

Twenty-three (26%) of 87 consecutive patients with idiopathic CNV demonstrated subfoveal CNV. Nineteen patients with subfoveal involvement were followed for a median of 87 months (range, 5-230 months). On initial examination, the median best-corrected Snellen visual acuity was 20/100 (range, 20/40-counting fingers); at final examination, the median visual acuity was 20/70 (range, 20/20-counting fingers). A total of 95% of patients had stable or significantly improved visual acuity, whereas only 5% had significant visual loss. Size of the CNV was the only variable associated with long-term final visual acuity. Lesions 1 disc area or smaller at the time of initial fluorescein angiography were more likely to be associated with a final visual acuity of 20/60 or better and less likely to be associated with a final visual acuity of 20/200 or worse (P = 0.038) as compared with larger lesions. These results were confirmed with multiple logistic regression analysis (P = 0.027). Fellow eyes remained unaffected during the follow-up period.

CONCLUSIONS

The natural history of idiopathic subfoveal CNV is not necessarily associated with a profound loss of vision. Therapies for this type of subfoveal lesion must take into consideration the possibility of a favorable natural course.

Decreased intracellular compartmentalization of doxorubicin in cell lines expressing P-glycoprotein

After initial rapid [14C]doxorubicin distribution into drug-sensitive HL-60 and SU-4 cells, slow uptake continues for more than 4 hr, accounting for up to 80% of the total intracellular drug. In contrast, in P-glycoprotein-expressing drug-resistant HL-60R and SU-4R cells, doxorubicin distribution rapidly approaches equilibrium. The simplest kinetic model of this behavior consists of rapid diffusion from extracellular fluid into the cell, followed by uptake into a nonexchangeable intracellular pool. At 3.4 microM doxorubicin, transmembrane diffusion clearance was similar for all cell lines (0.78-0.98 microliter sec-1). There was no decrease in the normalized apparent volume of distribution in the P-glycoprotein-expressing cell lines, as would be expected if an active, unidirectional efflux were present. However, in resistant cells, doxorubicin accumulation in the nonexchangeable pool was up to 15-fold slower than in sensitive cells (0.004 vs. 0.050 microliter sec-1 in HL-60R vs. HL-60; 0.004 vs. 0.058 microliter sec-1 in SU-4R vs. SU-4). No pool inflow could be detected in either SU-4 or SU-4R cells exposed to doxorubicin at 0 degrees C, indicating that the nonexchangeable accumulation requires energy. The process preventing accumulation began to saturate in SU-4R cells at 20 microM doxorubicin, whereas no evidence of saturation was seen with HL-60R, which is more highly resistant than SU4R. We propose that alteration in compartmentalization is primarily responsible for the doxorubicin resistance observed in these cell lines.

Color Doppler hemodynamics of giant cell arteritis

OBJECTIVES

To determine quantitative and qualitative hemodynamic alterations within the ophthalmic, central retinal, and short posterior ciliary arteries in patients with giant cell arteritis (GCA) proved by biopsy specimen.

DESIGN, PATIENTS, AND SETTING

A consecutive case series of patients with GCA referred to an urban eye hospital who were evaluated with color Doppler imaging that was used to analyze orbital blood flow velocities and vascular resistance in 22 consecutive patients with GCA compared with age and sex-matched controls.

RESULTS

Patients with GCA all demonstrated significantly reduced central retinal and short posterior ciliary arterial mean flow velocities as well as significantly increased vascular resistance compared with matched controls. Ophthalmic artery mean flow velocity demonstrated marked variation depending on the anatomic location studied. Other color Doppler imaging characteristics of GCA included the following: ophthalmic artery aliasing (high velocity and turbulent flow at presumed focal vasculitic stenoses), reversal of flow within the ophthalmic artery, reduced and truncated time-velocity waveforms of the central retinal and short posterior ciliary arteries, and absolute deficits of flow within the central retinal and short posterior ciliary arteries. Aliasing of flow velocity within the ophthalmic artery (two patients) was associated with clinical progression of GCA.

CONCLUSIONS

These data support the concept that quantitative and qualitative alterations in blood flow or pathophysiologic mechanisms of visual loss in GCA. This technique may be useful in the diagnosis and management of GCA since some of the color Doppler waveforms observed in GCA have not been seen in non-arteritic optic neuropathy. Treatment with corticosteroids often appears to stop the progression of these hemodynamic abnormalities but generally does not improve preexisting vascular abnormalities.

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.

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.

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.

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).

Hemodynamic alterations in the acute retinal necrosis syndrome

BACKGROUND

Clinical and histopathologic observations suggest a role for ischemia in the pathogenesis of the acute retinal necrosis (ARN) syndrome. Disruption of blood flow appears to occur at some level in the retina or choroid and may account for some of the major features of the syndrome.

METHODS

To investigate these potential circulatory changes, color Doppler imaging (CDI) was used to quantitate blood flow velocities and vascular resistance in the central retinal, ophthalmic, and short posterior ciliary arteries in ten consecutive patients with unilateral ARN syndrome. Data were analyzed with a paired Student's t test. The unaffected fellow eyes served as controls.

RESULTS

Blood flow velocities within the central retinal artery were significantly reduced in eyes with ARN syndrome compared with control eyes. In affected eyes, there was a mean reduction of 55%, 60%, and 72% in peak systolic, average, and end-diastolic velocities, respectively (P < 0.01). The calculated vascular resistance of the central retinal artery showed an upward trend, but the data fell short of statistical significance. Blood flow velocities from the ophthalmic and short posterior ciliary arteries were not significantly different compared with controls.

CONCLUSIONS

This study demonstrates marked circulatory changes in the central retinal artery of eyes involved with the ARN syndrome. Although the exact mechanism and clinical significance are yet to be determined, the data support the presence of retinal arterial hemodynamic compromise in this condition.

Pasteurella multocida keratitis and corneal laceration from a cat scratch

A 24-year-old woman was evaluated 12 hours after she sustained a cat scratch to her left eye. Slit-lamp examination revealed a Seidel-positive corneal laceration with a surrounding dense full-thickness corneal ulcer and severe inflammatory reaction. Since the anterior chamber was well formed, it was decided not to repair the laceration on an emergency basis. She was initially treated with intensive topical fortified tobramycin and vancomycin, and intravenous gentamicin and clindamycin. Cultures of the corneal ulcer revealed Pasteurella multocida and the antibiotic regimen was adjusted appropriately. The laceration healed without surgery, and the infection resolved well, with excellent visual acuity.

Color Doppler imaging of the ocular ischemic syndrome

PURPOSE

This study describes hemodynamic characteristics of the ophthalmic, central retinal, and posterior ciliary arteries in 16 eyes of 11 patients with the ocular ischemic syndrome. Understanding the hemodynamic characteristics of the retrobulbar circulation may elucidate the natural history and pathophysiology of the ocular ischemic syndrome and perhaps form the basis for rational treatment of this condition.

METHODS

Color Doppler imaging, a procedure that permits rapid noninvasive imaging of the ophthalmic, central retinal, and posterior ciliary arteries, was used to quantitate peak systolic blood flow velocities and vascular resistance (pulsatility index) within these vessels in study group eyes and in an age-matched control population.

RESULTS

We demonstrated markedly reduced ocular ischemic syndrome central retinal and posterior ciliary artery peak systolic velocities compared with control group eyes. Central retinal and posterior ciliary artery vascular resistance (pulsatility index) was greater in ocular ischemic eyes versus control group eyes. Reversal of ophthalmic artery blood flow was detected in 12 of 16 ocular ischemic syndrome eyes. Study group eyes with poor vision had no detectable posterior ciliary arterial blood flow.

CONCLUSION

Color Doppler imaging quantitates hemodynamic characteristics of the retrobulbar circulation in the ocular ischemic syndrome. There is markedly reduced peak systolic velocity and increased vascular resistance in ocular end arteries such as the central retinal and posterior ciliary arteries. Ophthalmic artery reversal of flow seems to represent collateral blood flow to lower resistance vascular beds. Posterior ciliary artery hypoperfusion may correlate with poor vision in the ocular ischemic syndrome.

Color Doppler imaging identifies four syndromes of the retrobulbar circulation in patients with amaurosis fugax and central retinal artery occlusions

Images

High performance liquid chromatographic determination of phenothiazine residues in sheep tissues

A high performance liquid chromatographic (HPLC) technique is described for the determination of residue levels of the anthelmintic drug phenothiazine in sheep tissues. Phenothiazine was administered to sheep which were slaughtered after withholding periods of 24, 48, and 72 h. Residues of phenothiazine were then extracted from tissue samples by homogenization in methanol. The HPLC analysis of the extracts involved separation on a 10 micrometer silica column using a mobile phase of 0.3% n-propanol in cyclohexane. The lower limit of detection by ultraviolet absorption at 254 nm was 0.05 ppm.

Electron impact studies. CXI. +E Spectra from negative ions. The retro-Diels-Alder process

Abundant peaks produced by retro-Diels-Alder cleavages are observed in the dissociative + E spectrum of a negative ion, whenever such peaks are seen in the corresponding positive-ion spectrum of that compound.