Síndrome de la transiluminación iridiana aguda bilateral. A propósito de un caso clínico / Bilateral acute iris transillumination syndrome. A case report

OBJETIVO: Presentar el caso clínico de una paciente con el síndrome de la transiluminación iridiana aguda bilateral (BAIT). MÉTODOS: El síndrome de BAIT es una nueva entidad clínica caracterizada por una transiluminación iridiana, dispersión de pigmento en la cámara anterior y una pupila en midriasis media que no responde o es poco sensible a la luz debido a una parálisis del esfínter. Los pacientes con BAIT suelen presentar dolor ocular agudo, fotofobia y ojo rojo. DISCUSIÓN: Presentamos el caso clínico de una mujer de 53 años que, tras ser tratada de una infección del tracto respiratorio superior con moxifloxacino, desarrolló un síndrome de BAIT, diagnosticado en primera instancia de uveítis anterior aguda. CONCLUSIÓN: Este es, hasta donde se conoce, el primer caso reportado en Navarra, aunque es necesaria mayor casuística para establecer patrones claros acerca de esta enfermedad

OBJECTIVE: To present a case report of a patient with a bilateral acute iris transillumination syndrome (BAIT). METHODS: BAIT syndrome is a new clinical condition characterised by severe transillumination of the iris, acute onset of pigment dispersion in the anterior chamber, and a medial mydriatic pupil that is unresponsive or poorly responsive to light, due to a sphincter paralysis. Patients with BAIT generally present with acute ocular pain, photophobia, and red eyes. DISCUSSION: The case is presented of a 53 year-old woman, who, after being treated with moxifloxacin for an upper respiratory tract infection, developed a BAIT syndrome, which was initially diagnosed as acute anterior uveitis. CONCLUSION: As far as is known this is the first case reported in Navarra, but more case reports are needed to establish clear patterns about this condition

Radiation induced violations of blood circulation in the ciliary body and changes of the anterior chamber angle in the pathogenesis of glaucoma in clean up workers of the Chornobyl NPP accident and residents of contaminated areas. / RADITsIY̆NO INDUKOVANI PORUShENNIa KROVOOBIGU V TsILIARNOMU TILI TA ZMINY KUTA PEREDN'OI KAMERY OKA V PATOGENEZI GLAUKOMY V UChASNYKIV AVARIY̆NYKh ROBIT NA ChORNOBYL'S'KIY̆ AES I MEShKANTsIV ZABRUDNENYKh TERYTORIY̆.

OBJECTIVE: Estimate changes blood filling of the ciliary body and changes of the anterior chamber angle; study their influence to glaucoma pathogenesis in irradiated persons. MATERIALS AND METHODS: Used the results of a randomly selected group survey of 41 clean up workers of the Chornobyl NPP accident (clean up workers), and 18 inhabitants of the zone of guaranteed voluntary resettlement; age at the time of the survey was 45-50 years. The control group consisted of 41 persons of the same age had not radiation exposure. State of the anterior chamber angle studied by gonioscopy, which was conducted 35 clean up workers and 35 persons of the control group. Changes of the blood circulation in the ciliary body examine by the ophtalmoreog raphy, what was done on 12 eyes of 6 clean up workers, control was 12 eyes of 6 persons had not radiation exposure. RESULTS: Detection revealed of the blood circulation in the ciliary body in all clean up workers, reography coefficient was probably lower (p < 0.05), than in the control group. The research of the state of the anterior chamber angle revealed a higher relative risk of appearance of involution changes of the anterior chamber angle in clean up work ers of ChNPP accident, in comparison with the control group was 3.5 (1.27; 9.5) χ2 = 7.48, p = 0.031. The same changes are characteristic for inhabitants of radiation polluted territories. CONCLUSIONS: Influence ionizing radiation causes a blood circulation decrease in the ciliary body and development changes of the angle of the anterior chamber. Presence of these changes can explain the features of the pathogene sis of glaucoma in irradiated late manifestation and, at the same time, severe course.

Plaque radiotherapy in the management of scleral-invasive conjunctival squamous cell carcinoma: an analysis of 15 eyes.

IMPORTANCE: Conjunctival squamous cell carcinoma (SCC) is surgically managed with wide surgical excisional biopsy, superficial keratectomy, and cryotherapy. In eyes with residual tumor showing scleral invasion or intraocular involvement, enucleation is advised. OBJECTIVE: To explore the role of plaque radiotherapy for residual invasive conjunctival SCC as an alternative to enucleation. DESIGN, SETTING, AND PARTICIPANTS: Interventional case series involving 15 patients with histopathologically confirmed scleral and/or intraocular invasion of SCC at Wills Eye Hospital. INTERVENTION: Plaque radiotherapy. MAIN OUTCOMES AND MEASURES: Tumor control, treatment complications, and globe salvage. RESULTS: The primary tumor prior to excision displayed a mean basal diameter of 12.1 mm (median, 12 mm; range, 4-25 mm) and mean thickness of 2.6 mm (median, 3 mm; range, 1-5 mm). In all cases, the tumor was managed by primary surgical resection using wide excisional biopsy, limited superficial keratectomy, and cryotherapy to the remaining conjunctival margins. Histopathology confirmed conjunctival SCC in all cases with residual tumor demonstrating scleral invasion (n = 15) and/or anterior chamber invasion (n = 3). The residual tumor measured a mean basal diameter of 10.6 mm (median, 10 mm; range, 2.5-20 mm) and mean thickness of 1.5 mm (median, 1 mm; range, 1-5 mm). Plaque radiotherapy was applied in all cases for a mean apex dose of 56 Gy (median, 50 Gy; range, 50-80 Gy) over a mean of 132 hours (median, 142 hours; range, 93-170 hours). Over a mean follow-up of 41 months (median, 46 months; range, 9-96 months), local tumor control was achieved in all 15 cases (100%). However, 4 cases showed further distant conjunctival tumor recurrence remote from the site of radiotherapy with positive orbital involvement at a mean of 5 months postradiotherapy, necessitating enucleation (n = 2) or orbital exenteration (n = 2). Globe salvage was achieved in 10 cases, as 1 patient required enucleation for chronic ocular irritation. Radiation complications included cataract (n = 13), iris telangiectasia (n = 5), corneal epithelial defect (n = 4), corneal edema (n = 3), and glaucoma (n = 1). There was no evidence of metastasis. CONCLUSIONS AND RELEVANCE: Plaque radiotherapy delivered over a mean of 6 days can be an effective alternative to enucleation for residual scleral-invasive conjunctival SCC following resection. Local tumor control was achieved in all cases.

Metastasis inhibition after proton beam, ß- and γ-irradiation of melanoma growing in the hamster eye.

Standard ocular tumor treatment includes brachytherapy, as well as proton therapy, particularly for large melanoma tumors. However, the effects of different radiation types on the metastatic spread is not clear. We aimed at comparing ruthenium ((106)Ru, emitting ß electrons) and iodine ((125)I, γ-radiation) brachytherapy and proton beam therapy of melanoma implanted into the hamster eye on development of spontaneous lung metastases. Tumors of Bomirski Hamster Melanoma (BHM) implanted into the anterior chamber of the hamster eye grew aggressively and completely filled the anterior chamber within 8-10 days. Metastases, mainly in the lung, were found in 100% of untreated animals 30 days after enucleation. Tumors were irradiated at a dose of 3-10 Gy with a (106)Ru plaque and at a dose of 6-14 Gy using a (125)I plaque. The protons were accelerated using the AIC-144 isochronous cyclotron operating at 60 MeV. BHM tumors located in the anterior chamber of the eye were irradiated with 10 Gy, for the depth of 3.88 mm. All radiation types caused inhibition of tumor growth by about 10 days. An increase in the number of metastases was observed for 3 Gy of ß-irradiation, whereas at 10 Gy an inhibition of metastasis was found. γ-radiation reduced the metastatic mass at all applied doses, and proton beam therapy at 10 Gy also inhibited the metastastic spread. These results are discussed in the context of recent clinical and molecular data on radiation effects on metastasis.

An experimental steroid responsive model of ocular inflammation in rabbits using an SLT frequency doubled Q switched Nd:YAG laser.

PURPOSE: To develop a minimally invasive rabbit model of postoperative anterior chamber (AC) inflammation using a commercially available frequency doubled Nd:YAG laser [intended for selective laser trabeculoplasty (SLT)]. METHODS: Escalating laser energy was applied to the iris of male Dutch-belted rabbits and the subsequent inflammatory response was observed to determine the laser dose required to generate self-limiting inflammation of at least 3 days' duration. In subsequent experiments, 10 eyes of 10 male Dutch-belted rabbits underwent baseline slit lamp examination, intraocular pressure (IOP), and AC flare meter readings. Starting 1 day before laser application, 5 animals received topical 20 µL dexamethasone 1% to 1 eye 4 times daily for 5 days. Five control animals were treated with saline. Masked assessments of flare, cells, and IOP were made daily for 7 days. Histopathologic changes were assessed in enucleated eyes. RESULTS: Compared to controls, dexamethasone-treated rabbits had less postlaser AC flare on postoperative day (POD)2 (19±5 vs. 44±21photons/ms, P=0.03) and POD3 (16±9 vs. 33±11 photons/ms, P=0.03). In dexamethasone-treated rabbits, clinically graded flare (on POD1) and cells (on POD1 and 2) were lower than controls, but did not reach statistical significance. In the control group, IOP was significantly lower than the dexamethasone-treated group on POD2 (14.1±3.4 vs. 19.8±1.1 mmHg, P=0.03) and POD3 (14.2±2.2 vs. 19.0±2.2 mmHg, P=0.01). Histopathology showed pigment clumping and changes limited to anterior layers of the iris. CONCLUSIONS: Commercially available SLT laser can be used to create a minimally invasive, steroid-responsive animal model of anterior uveitis with the potential for use in the evaluation and comparison of drugs intended to treat AC inflammation.

Light intensity modulates corneal power and refraction in the chick eye exposed to continuous light.

Continuous exposure of chicks to light was shown to result in severe hyperopia, accompanied by anterior segment changes, such as severe corneal flattening. Since rearing chicks in complete darkness results only in mild hyperopia and minor changes in corneal curvature, we hypothesized that light intensity may play a role in the development of refractive changes under continuous light illumination. To test this hypothesis, we examined the effects of rearing chicks under various continuous light intensities. More specifically, we investigated the refractive parameters of the chicks' eyes, and avoided light cycling effects on ocular development. To this end, thirty-eight chicks were reared under 24-h incandescent illumination, at three different light intensities: 10,000 lux (n=13), 500 lux (n=12), and 50 lux (n=13). Their eyes underwent repeated retinoscopy, keratometry, and ultrasound biometry, as well as caliper measurements of enucleated eyes. Both refraction and corneal refractive power were found to be correlated with light intensity. On day 90 after hatching, exposure to light intensities of 10,000, 500, and 50 lux resulted in hyperopia of +11.97+/-3.7 (mean+/-SD) +7.9+/-4.08 and +0.63+/-3.61 diopters (D), respectively. Under those intensities, corneal refractive power was 46.10+/-3.62, 49.72+/-4.16, and 56.88+/-4.92D, respectively. Axial length did not differ significantly among the groups. The vitreous chamber was significantly deeper in the high than in the low-intensity groups. Thus, during the early life of chicks exposed to continuous lighting, light intensity affects the vitreous chamber depth as well as the anterior segment parameters, most notably the cornea. The higher the intensity, the more severe was the corneal flattening observed and the hyperopia that developed, whereas continuous illumination at low intensities resulted in emmetropia. Thus, light intensity is an important factor that should be taken into account when studying refractive development.

Corneal endothelial cell damage by free radicals associated with ultrasound oscillation.

OBJECTIVE: To determine whether ultrasound oscillations in the anterior chamber cause corneal endothelial injury by free radicals. METHODS: A phacoemulsification probe was introduced into the anterior chamber of rabbits' eyes through a limbal incision, and ultrasound oscillation was performed without emulsifying the lens. Rabbits were assigned to 4 treatment groups: (1) no treatment (controls); (2) only irrigation with a salt solution; (3) ultrasound only; and (4) ultrasound oscillations with a salt solution of 0.001M ascorbic acid. The corneas were immunohistochemically examined for oxidative stress using 8-hydroxy-2-deoxyguanosine (8-OHdG), apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) staining, and ultrastructural changes by electron microscopy. The lipid peroxide levels in the aqueous humor were also measured. RESULTS: In the ultrasound-only group, 8-OHdG-positive cells and TUNEL-positive cells were detected at 24 hours; necrotic cells were detected at 12 to 24 hours. Also, lipid peroxide levels were significantly increased at later times in the ultrasound group. Such changes were not observed in other groups. CONCLUSION: Free radicals induced by ultrasound oscillation can cause corneal endothelial damages. Clinical Relevance Clinicians should be aware that free radicals associated with ultrasound oscillation can injure the corneal endothelial cells.

Dynamic analysis of dark-light changes of the anterior chamber angle with anterior segment OCT.

PURPOSE: To describe the use of anterior segment optical coherence tomography (OCT) in studying the dynamic dark-light changes of the anterior chamber angle. METHODS: Thirty-seven normal subjects with open angles on dark-room gonioscopy and 18 subjects with narrow angles were analyzed. The dynamic dark-light changes of the anterior-chamber angle were captured with real-time video recording. The angle opening distance (AOD500) and trabecular iris space area (TISA500) of the nasal angle and the pupil diameter in each of the representative serial images were measured. Linear regression analysis was performed to investigate the association between AOD500/TISA500 and pupil diameter. Demographic and biometry measurements associated with the AOD difference (AOD500((light)) - AOD500((dark))) and TISA difference (TISA500((light)) - TISA500((dark))) were analyzed with univariate and multivariate regression models. RESULTS: The AOD500/TISA500 measured in the light in the open-angle and the narrow-angle groups were 694 +/- 330 microm/0.24 +/- 0.10 mm(2) and 265 +/- 78 microm/0.10 +/- 0.03 mm(2), respectively. These values were significantly greater than the AOD500/TISA500 measured in the dark (492 +/- 265 microm/0.16 +/- 0.08 mm(2) and 119 +/- 82 microm/0.05 +/- 0.04 mm(2), respectively, all with P < 0.001). The ranges of the AOD/TISA difference were 13 to 817 microm/0.011 to 0.154 mm(2), with an average of 180 microm/0.073 mm(2). Multivariate regression analysis identified a positive correlation between anterior chamber depth and the AOD/TISA difference. Fifty eyes showed significant correlations between AOD/TISA and pupil diameter, whereas one eye showed no association. Four eyes in the narrow angle group developed appositional angle closure in the dark. CONCLUSIONS: The dynamic dark-light changes of the anterior chamber angle can be imaged and analyzed with anterior segment OCT. Although the angle width generally decreased linearly with increasing pupil diameter, the differences of the angle width measured in the dark and in the light varied substantially among individuals.

[Quant therapy and the composition of the moister of the eye anterior chamber (an experimental study)]. / Vliianie kvantovoi terapii na sostav vlagi perednei kamery glaza (eksperimental'noe issledovanie).

We examined 12 rabbits, 6 of whom (12 eyes) were exposed to magneto-infrared laser radiation (MILR) and another 6 (12 eyes) were controls. The parameters of pulse and continuous infrared LED radiation were as follows: wavelength--860 nm, pulse capacity--2 W, mean radiation capacity--10 mW, magnetic field strength--up to 17 mTl. A study of the moister of the anterior chamber showed a MILR-induced activated metabolism, i.e. a better acid-base balance (ABB), more intense oxygenation in the ocular tissues and decreased acidosis. Higher concentrations of buffer bases (ABEe and SBEc) cause shifts in ABB towards metabolic alkalosis. A lower concentration of glucose denotes intensified processes related with its utilization. A lack of changes in the quantity of salts in the moister of the anterior chamber rules out the possibility of that the content of glucose would go down due to its dissolution with a big volume of newly produced moister. A lack of an increase in the concentration of whole protein, as observed after MILR, can be regarded as indirect evidence to absence of any adverse effect on the vascular wall.

One-year follow-up of selective laser trabeculoplasty in open-angle glaucoma.

BACKGROUND: Selective laser trabeculoplasty (SLT) targets the pigmented trabecular meshwork (TM) cells without damage to the adjacent non-pigmented tissue. A study was conducted to evaluate the efficacy and safety of SLT in the treatment of uncontrolled open-angle glaucoma. METHODS: In a prospective non-randomized study 44 eyes of 31 patients with uncontrolled open-angle glaucoma were treated with a frequency-doubled, Q-switched Nd:YAG laser. A total of approximately 50 spots were placed over 180 degrees of the TM at energy levels ranging from 0.7 to 0.9 mJ. Intraocular pressure (IOP) was measured 1, 2, and 24 h, 1 and 2 weeks and 1, 2, 3, 6, 9, and 12 months after treatment. RESULTS: The average pre-operative IOP was 25.6 (SD 2.6) mm Hg (range 22-34). The mean IOP reduction from baseline at 24 h, 3, 6 and 12 months was 7.1 mm Hg (SD 3.5) or 27.6%; 4.2 mm Hg (SD 3.5) or 16.4%; 4.7 mm Hg (SD 4.2) or 18.6%, and 4.4 mm Hg (SD 3.8) or 17.1%, respectively. The percent of eyes with IOP reduction of 3 mm Hg or more at 3, 6 and 12 months was 66, 78 and 62%. A pressure spike of 8 mm Hg or more was detected in 4 eyes (9.1%). Anterior chamber reaction was seen 1 h after SLT and was mild to moderate in 16 eyes (40.4%) and marked in 3 eyes (6.8%). CONCLUSIONS: SLT has shown reasonable efficacy in lowering IOP over 1-year follow-up, but there was a tendency for IOP to increase with a longer follow-up. Long-term follow-up studies with a large sample size are needed to determine whether the IOP lowering effect is sustained over time, and to assess the efficacy of repeated SLT.

Custom-designed plaque radiotherapy for nonresectable iris melanoma in 38 patients: tumor control and ocular complications.

PURPOSE: To evaluate plaque radiotherapy for iris melanoma. DESIGN: Prospective noncomparative interventional case series. METHODS: For 38 patients, custom-designed plaque radiotherapy using iodine 125 isotope was applied overlying the cornea with a tumor apex dose of 80 Gy. The main outcome measures were tumor control and ocular complications using Kaplan-Meier estimates and Cox proportional hazards regression analysis. RESULTS: In all cases, the melanoma was nonresectable owing to large or discohesive tumor. The tumor configuration was nodular in 24 cases (63%) and flat (diffuse) in 14 (37%). The mean tumor basal diameter was 9 mm (range 4 to 13 mm). Solid tumor extended into the anterior chamber angle in 36 eyes (95%). Tumor seeds were noted on the iris stroma for a mean of 7 clock hours and in the anterior chamber angle for a mean of 4 clock hours. Five-year follow up revealed tumor metastasis in 0% and tumor recurrence in 8% of patients. Visual acuity of 20/200 or worse was found in 16% at 5 years. Radiation-related complications at 5 years included corneal epitheliopathy (9%), cataract (70%), and neovascular glaucoma (8%). No patients developed corneal necrosis, scleral necrosis, retinopathy, or papillopathy. After treatment, the combined incidence of tumor-related and radiation-related elevated intraocular pressure at 5 years was 33%. Enucleation was necessary in 13% at 5 years, for tumor recurrence (n = 3) and patient preference (n = 1). CONCLUSIONS: Plaque radiotherapy is a useful alternative to enucleation for eyes with nonresectable iris melanoma. Tumor control is 92% at 5 years, but related complications, especially cataract and elevated intraocular pressure, should be anticipated.

Increased interleukin-6 in aqueous humor of a patient with lung-metastatic intraocular adenocarcinoma.

PURPOSE: We report increased interleukin (IL)-6 level in aqueous humor of a case of lung adenocarcinoma with metastasis to iris and anterior chamber. DESIGN: Interventional case report. METHODS: In one case and 11 healthy cataract patients as controls, we checked the levels of IL-6, IL-2, and tumor necrosis factor (TNF)-alpha in aqueous humor and serum by enzyme-linked immunosorbent assay. RESULTS: Levels of these three cytokines in serum were almost the same as with the levels in aqueous humor in the control group. The IL-6 concentrations ranged from 12.6 to 27.0 pg/ml (mean, 23.5 pg/ml) in serum and 15.0 to 43.1 pg/ml (mean, 22.4 pg/ml) in aqueous humor. There was no statistically significant difference between them. Compared with the control, the IL-6 concentration in aqueous humor of this patient, 282.0 pg/ml, increased more than 10-fold. CONCLUSION: This is a report describing elevated IL-6 level in the aqueous humor of a patient with intraocular metastasis from lung adenocarcinoma.

Ring melanoma of the anterior chamber angle: a report of fourteen cases.

PURPOSE: Ring melanoma of the anterior chamber angle is a rare variant of uveal melanoma that manifests as circumferential, flat tumor growth predominantly confined to the trabecular meshwork and other anterior chamber angle structures. We report the clinical and histopathological features, management, and prognosis of ring melanoma of anterior chamber angle. METHODS: A retrospective review of clinical features, management, histopathologic features, and prognosis was performed. Of 8800 patients with uveal melanoma examined on the Oncology Service at Wills Eye Hospital over a 25-year period, only 14 patients (0.2%; 14 eyes) were classified clinically as ring melanoma of the anterior chamber angle. In no case was there appreciable involvement of the iris or ciliary body on clinical examination. RESULTS: The patients were followed elsewhere for a mean of 8 months before intraocular malignancy was suspected. Upon referral to the Oncology Service, the intraocular pressure was greater than 22 mm Hg in the affected eye in all patients (mean, 36 mm Hg; median, 35 mm Hg; range, 24 to 48 mm Hg), and all patients were using at least two glaucoma medications. The melanoma infiltrated the anterior chamber angle for a mean of 10 clock hours (range, 8 to 12 clock hours). Tumor management consisted of enucleation in 13 cases and plaque radiotherapy in one case. Histopathologic examination revealed epithelioid cell type melanoma in one case, mixed cell type in nine, and spindle cell type in four. Of the 13 patients who underwent enucleation, tumor cells were found within the Schlemm canal in all cases. Five cases displayed invasion of the intrascleral canals, and three showed episcleral invasion. With the exception of two recent cases, 12 patients were followed for a mean of 64 months (median, 47 months; range, 23 to 225 months). Distant metastasis to the liver was detected in three of 12 patients (25%) after a mean follow-up of 78 months (median, 70; range, 37 to 128 months). CONCLUSIONS: Ring melanoma of the trabecular meshwork and angle structures is a rare variant of diffuse uveal melanoma. It often masquerades as unilateral glaucoma and can be difficult to recognize clinically unless careful comparative gonioscopy is performed. Despite the relatively small tumor volume, life prognosis is guarded with distant metastasis in 25% at mean 6 years follow-up.

Temperature measurements during phacoemulsification and erbium:YAG laser phacoablation in model systems.

PURPOSE: To compare the potential for thermal injury to ocular structure resulting from phacoemulsification ultrasound energy and erbium:YAG (Er:YAG) laser output. SETTING: Morse Laser Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston. METHODS: Ultrasonic phacoemulsification energy and ER:YAG laser output (10 J/cm2, 10 Hz, 0.3 watts) sufficient for lens removal were applied to model systems and human cadaver eyes. Temperatures were measured with ultrafine thermocouples interfaced to a microcomputer data acquisition system. RESULTS: Although greater than 95% of energy from laser output is converted to thermal energy, temperature rise in model systems and cadaver eyes was 10 to 15 times greater after pulsed application of ultrasound energy than after Er:YAG laser application. At 100% power, approximately 4 watts of ultrasound power is converted to heat. Temperature rise following both laser and ultrasound applications decreased with irrigation in cadaver eyes and increasing volume in a model system. With continuous irrigation (20 cc/min), the temperature rise at 2 minutes measured at the corneal endothelial surface, within the corneal stroma, and in the anterior chamber angle of cadaver eyes was approximately 0.5 degrees Celsius (degrees C) after laser application and 7.0 degrees C after ultrasound application. Without irrigation, temperatures rose 2.5 degrees C after laser application and 35.0 degrees C after ultrasound application. CONCLUSION: At operating parameters sufficient for lens removal, the Er:YAG laser imparted less thermal energy to whole eyes and model systems than ultrasonic phacoemulsification.

Boron neutron capture therapy of anterior chamber melanoma with p-boronophenylalanine.

Boron neutron capture therapy (BNCT) is a form of radiation therapy that requires selective uptake of boron by the tumor and irradiation with thermal neutrons. Phenylalanine is an amino acid precursor of melanin and when boronated (p-boronophenylalanine [BPA]) was found to be selectively taken up by Greene melanoma cells in the anterior chamber of rabbits. This tumor model was irradiated 24 hr after oral administration of BPA and was used for biodistribution studies that compared BPA and sodium pentaborate. Three groups were irradiated: group 1 (11 rabbits) received BPA followed by thermal neutron irradiation, group 2 (9 rabbits) received thermal neutron irradiation only, and group 3 (9 rabbits) served as unirradiated, undrugged control animals. Eight of the 11 tumors in group 1 were treated successfully; all tumors in groups 2 and 3 grew. Histopathologic examination did not reveal vascular or retina damage in group 1. These preliminary experiments confirm that newer boronated compounds, such as BPA, used in BNCT and improved neutron beams can provide selective irradiation of ocular melanomas.

A model for testing the mutagenicity of excimer laser radiation in ophthalmology.

Because excimer laser radiation is applied more and more in therapeutic and refractive corneal surgery, the possibility of mutagenic side effects of this treatment should be considered. A mutagenicity model is presented approximating closely the ophthalmological conditions when mutagenic effects are studied: Heparinized human blood is filled into the anterior chamber of an enucleated cow eye. After irradiation of the cornea with the excimer laser, the blood is removed and whole blood cultures are set up. Lymphocytes are stimulated, fixed during metaphase, and scored for chromatid and chromosome aberrations. First results obtained with this model after 248 nm laser irradiation (500 J, 277 mJ/cm2, 10 or 20 Hz) revealed no mutagenic effects. However, when the blood was exposed under the same physical conditions in a quartz chamber (positive control), statistically highly significant increases of the yields of chromatid aberrations were observed.

Bacteriochlorin a, a new photosensitizer in photodynamic therapy. In vivo results.

The photosensitizing properties of bacteriochlorin a (BCA), a nontoxic derivative of bacteriochlorophyll a, were investigated in vivo. BCA has an absorption band at a wavelength at which tissue penetration is optimal (760 nm), and it shows preferential tumor retention in Greene melanoma implanted in the anterior chamber of rabbit eyes. A dose of 20 mg/kg BCA was administered IV at 4-7 mm tumor diameter; 24 hr later the tumor was irradiated with near-infrared light (30 min, 760 nm, 150-280 J/cm2). On the day after the irradiation it appeared that tumor growth had stopped: fluorescein angiography showed nonperfusion of the tumor. Histopathology after enucleation showed subtotal tumor necrosis with occasionally small clusters of viable cells around a blood vessel and at the tumor periphery. Neither BCA nor light alone had any effect on the eye or melanoma.

Stimulation of cell division by argon and Nd:YAG laser trabeculoplasty in cynomolgus monkeys.

Although laser treatment of the trabecular meshwork is the most common form of surgery for glaucoma, the tissue response to this therapy is still incompletely understood. We applied argon or Nd:YAG laser to the trabecular meshwork of six monkeys. Cell division was identified by injecting tritiated thymidine into the anterior chamber 24 hr after laser application. Autoradiography of tissue sections revealed significantly more labelled cells in eyes treated with laser than in the untreated controls. In addition, cells in neighboring tissues such as iris, ciliary body and sclera showed labelling in association with laser application. Furthermore, comparison of argon-induced lesions with those caused by pulsed Nd:YAG suggests that there are quantitative and qualitative differences in the response of trabecular meshwork and surrounding tissues to these two forms of laser energy.