Evidence Of Ocular Toxicity Research Articles

Clinical efficacy and safety of Razumab® (CESAR) study: Our experience with the world's first biosimilar Ranibizumab.

Purpose:The aim of this study was to evaluate the efficacy and safety of Razumab (the biosimilar Ranibizumab by Intas Pharmaceuticals Ltd.) for the treatment of chorioretinal vascular diseases such as diabetic macular edema (DME), choroidal neovascular membrane (CNVM), and macular edema secondary to retinal vein occlusion (RVO).Methods:We conducted a single-center, retrospective study, including patients with DME, CNVM, and RVO, who had received treatment with Razumab® between October 2018 and September 2019. Primary outcome measures were the changes in corrected distance visual acuity (CDVA) and central foveal thickness (CFT) from baseline to 1 month and 3 months. Secondary outcome measures included intraocular pressure (IOP) at day 1, any signs of ocular inflammation or systemic adverse events during the follow-up.Results:One hundred and fifty-three eyes of 141 patients were analyzed. The indications included DME in 70 (45.8%) eyes, CNVM in 70 (45.8%) eyes, and RVO in 13 (8.4%) eyes. Mean CDVA improved from baseline (0.62 ± 0.44) to month 1 (0.45 ± 0.42) and maintained till 3 months (0.42 ± 0.44; P < 0.001). Mean CFT showed significant reduction from baseline (405.68 ± 192.422 μm) to month 1 (286.08 ± 118.36 μm) and month 3 (271 ± 104.24 μm; P < 0.001). None of the eyes recorded IOP >20 mmHg on day 1. No evidence of ocular toxicity or systemic adverse event was noted.Conclusion:Razumab® showed a rapid improvement in CDVA and CFT in most of the eyes with efficacy observed as early as 1 month and maintained till 3 months. The biosimilar Ranibizumab can be a safe and effective low-cost drug for treating macular diseases.

Abstract 3897: Stability and safety evaluation of STRO-002, a site-specific anti-folate receptor alpha antibody-drug conjugate for the potential treatment of ovarian and endometrial cancers

Abstract Antibody-drug conjugates (ADCs) constitute an expanding class of therapeutic molecules in preclinical and clinical development for multiple oncology indications. Folate receptor alpha (FolRα) is a glycosylphosphatidylinositol-linked cell-surface glycoprotein that is overexpressed in ovarian, endometrial, lung, and triple negative breast cancers. In contrast, FolRα is minimally expressed on normal tissues, thus, making it an amenable ADC target. STRO-002, a site-specific ADC, is comprised of 3-aminophenyl hemiasterlin cytotoxic drug (SC209) conjugated to an aglycosylated anti-FolRα IgG1 antibody through a protease-cleavable linker at two engineered non-natural amino acids in each heavy chain (DAR ~4). In vitro and in vivo stability studies, showed that STRO-002 is highly stable in circulation, with the warhead SC209 predominantly accumulating in tumor tissue. Toxicology and toxicokinetic studies were conducted to determine the safety profiles for STRO-002 and its metabolite SC209 in cynomolgous monkeys and rats, respectively. In single-dose toxicology studies in rats, SC209 was tolerated up to 0.6 mg/kg with the main toxicity findings predominantly found in hematopoietic/lymphoid tissue, consistent with tubulin targeting chemotherapeutic drugs. In a tissue cross-reactivity study with normal human tissues, STRO-002-specific membranous staining was detected in Fallopian tubes, kidney (tubules), and placenta (trophoblasts). In a definitive safety study in cynomolgus monkeys, pharmacologically relevant model for toxicity testing, STRO-002 was tolerated at up to 9 mg/kg when intravenously administered on days 1 and 22 followed by a 4-week observation period. The most prominent STRO-002-related antigen-independent toxicity finding was dose-related, minimal to marked, and cyclical neutropenia. There were no antigen-dependent toxicity findings and no evidence of ocular toxicity. Toxicokinetic analysis confirmed dose proportional STRO-002 exposures (total antibody, ADC, and SC209 catabolite) at all doses tested. In summary, STRO-002 ADC has a favorable nonclinical safety and pharmacokinetic profiles and a Phase I study of STRO-002 in patients with ovarian and endometrial cancer has been initiated. Citation Format: Willy Solis, Venita De Almeida, Cristina Abrahams, Xiaofan Li, Tyler Heibeck, Maureen Bruhns, Adam Galan, Heidi Hoffman, Robert Kiss, Trevor Hallam, Mark Lupher. Stability and safety evaluation of STRO-002, a site-specific anti-folate receptor alpha antibody-drug conjugate for the potential treatment of ovarian and endometrial cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3897.

Abstract CT160: A Phase I, open-label, safety, pharmacokinetic, and preliminary efficacy study of STRO-002, an anti-folate receptor alpha (FolRα) antibody drug conjugate (ADC), in patients with advanced epithelial ovarian cancer (including fallopian tube or primary peritoneal cancers) and endometrial cancers

Abstract Background: Folate receptor alpha (FolRα) is overexpressed in 80% of epithelial ovarian cancer (EOC) and endometrial adenocarcinoma (EC), with minimal expression on normal tissues and is thus a relevant target for cancer therapy using antibody drug conjugates (ADCs). STRO-002 is a novel, site-specific FolRα-targeting ADC that was generated using Sutro’s XpressCF+™ cell free protein synthesis platform. STRO-002 has highly specific cytotoxic activity on cells expressing FolRα. STRO-002 demonstrated reproducible and significant therapeutic efficacy in multiple preclinical models in vivo. STRO-002 activity was evaluated in EC patient-derived xenograft (PDX) models with a range of FolRα expression. Statistically significant efficacy was observed in 60% of the FolRα-positive PDX models tested, with response appearing to positively correlate with FolRα expression levels. Toxicology studies in cynomolgus monkeys demonstrate dose-dependent and reversible neutropenia when STRO-002 is administered at up to 9 mg/kg, with no evidence of ocular toxicity (Solis et al. AACR 2019). Methods: This study is a first-in-human Phase 1, open-label, multicenter, dose escalation (Part 1) study with dose expansion (Part 2) to identify the maximum tolerated dose (MTD), recommended phase 2 doses (RP2D) and to evaluate the safety, tolerability, and preliminary anti-tumor activity of STRO-002 in adults with ovarian cancer and endometrial cancer who are refractory to, or intolerant of, therapies known to provide clinical benefit. STRO-002 is given to all patients on study via intravenous infusion on Day 1of each 21-day cycle until disease progression. Dose limiting toxicities will be assessed in the first cycle (Days 1-21) of dose escalation. Part 1 will enroll about 30 ovarian cancer patients to determine the MTD and RP2D for expansion while Part 2 will enroll 2 cohorts based on disease subtypes (ovarian or endometrial). Efficacy will be evaluated per RECIST 1.1 criteria. Key inclusion criteria include relapsed and or progressive disease, adequate bone marrow and renal function, and ability to comply with treatment, testing and pharmacokinetic (PK) schedules. Key exclusion criteria include clear cell, mucinous or sarcomatous ovarian carcinoma, prior treatment with a FolRα-targeting ADC, need for ongoing immunotherapy including systemic corticosteroids and a history of CNS involvement. Samples will be collected to assess FolRα expression levels, PK and immunogenicity. No formal statistical hypothesis testing will be conducted in this study. This study is currently open for enrollment in the US with the ClinicalTrials.gov Identifier: NCT03748186.: Citation Format: Robert Wendel Naumann, Denise S. Uyar, Russell J. Schilder, Michael A. Palumbo, Venita DeAlmeida, Shannon L. Matheny, Arturo Molina. A Phase I, open-label, safety, pharmacokinetic, and preliminary efficacy study of STRO-002, an anti-folate receptor alpha (FolRα) antibody drug conjugate (ADC), in patients with advanced epithelial ovarian cancer (including fallopian tube or primary peritoneal cancers) and endometrial cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT160.

Erratum: Ocular toxicities associated with targeted anticancer agents: an analysis of clinical data with management suggestions.

[This corrects the article DOI: 10.18632/oncotarget.17634.].

Ocular toxicities associated with targeted anticancer agents: an analysis of clinical data with management suggestions.

Ocular toxicities are among the most common adverse events resulting from targeted anticancer agents and are becoming increasingly relevant in the management of patients on these agents. The purpose of this study is to provide a framework for management of these challenging toxicities based on objective data from FDA labels and from analysis of the literature. All oncologic drugs approved by the FDA up to March 14, 2015, were screened for inclusion. A total of 16 drugs (12 small-molecule drugs and 4 monoclonal antibodies) were analyzed for ocular toxicity profiles based on evidence of ocular toxicity. Trials cited by FDA labels were retrieved, and a combination search in Medline, Google Scholar, the Cochrane database, and the NIH Clinical Trials Database was conducted. The majority of ocular toxicities reported were low severity, and the most common were conjunctivitis and “visual disturbances.” However, severe events including incidents of blindness, retinal vascular occlusion, and corneal ulceration occurred. The frequency and severity at which ocular toxicities occur merits a more multidisciplinary approach to managing patients with agents that are known to cause ocular issues. We suggest a standardized methodology for referral and surveillance of patients who are potentially at risk of severe ocular toxicity.

Safety of Tranexamic Acid in Women with Heavy Menstrual Bleeding: An Open-Label Extension Study

An open-label, extension clinical study was conducted to assess the safety of a novel, oral formulation of tranexamic acid (TA) in women with cyclic heavy menstrual bleeding. Eligible patients who completed either a three- or six-cycle double-blinded clinical trial of TA were offered enrollment into a study of nine cycles with TA (1.3 g orally three times/day for a maximum of 5 days per cycle). Safety was assessed by the incidence of treatment-emergent adverse events, ophthalmologic examinations and ECGs, among other evaluations. The most commonly reported treatment-emergent adverse events were menstrual discomfort (46.2%), headache (43.9%) and back pain (23.1%). A small proportion of participants (3.8%) reported ocular adverse events, but there was no evidence of ocular toxicity. No prothrombotic effects were observed. During nine menstrual cycles of treatment, this novel formulation of TA was well tolerated and exhibited a favorable safety profile supporting its use as a therapy for cyclic heavy menstrual bleeding.

Ocular toxicity and distribution of subconjunctival and intravitreal rapamycin in horses

In vitro photosensitivity of rapamycin (RAPA) and ocular toxicity and distribution of intravitreal and subconjunctival RAPA was evaluated in normal horses. RAPA (2.5 mg, 5 mg, and 10 mg) was placed in 10 mL of PBS and maintained in a water bath at 37 degrees C, kept in the dark or subjected to room light, and sampled for up to 3 months for RAPA levels. Six normal adult horses received either 5 mg (n = 2) or 10 mg (n = 2) of RAPA intravitreally or 10 mg (n = 2) subconjunctivally. Ophthalmic exams and electroretinography (ERG) were performed prior to injection and on days 1, 7, 14, and 21 post-injection. Eyes were enucleated and samples were collected for RAPA concentrations and histopathology. No difference in light vs. dark RAPA concentrations was observed, suggesting a lack of RAPA phototoxicity. No evidence of ocular toxicity was noted on ophthalmic examination or histopathology. RAPA was not detected intraocularly 7 days post-injection in eyes receiving subconjunctival RAPA, but was detected in the vitreous at 21 days post-injection. Drug could be detected in both the aqueous and vitreous humor after intravitreal injection. Further study is needed to determine the efficacy of intravitreal RAPA.

A REVERSIBLE THERMOSENSITIVE ADHESIVE FOR RETINAL IMPLANTS

To study the in vivo effects of a thermosensitive retinal adhesive, plasma-polymerized N-isopropyl acrylamide (ppNIPAM), in rabbit eyes. Parylene C(poly(monochloro-p-xylylene)) (20 microm) and poly(dimethyl siloxane) (PDMS) (> or =200 microm) coated with ppNIPAM were used as implant materials. Following pars plana vitrectomy (PPV), ppNIPAM coated parylene (n = 3) and PDMS (n = 3) implants were inserted over the retina in six rabbits. Baseline and follow-up imaging (color fundus photographs, fluorescein angiography, and optic coherence tomography [OCT]) and electroretinogram recordings were performed. Histologic evaluation was performed following enucleation at 6 weeks. Intraoperative retinal adhesion occurred in all eyes with ppNIPAM coated parylene and PDMS implants. Two eyes developed retinal tears during the implantation procedure and the ppNIPAM coated implants closed the retinal tears successfully preventing retinal detachment. OCT findings confirmed the retinal adhesion in all eyes. Four weeks after implantation one parylene and one PDMS implant detached partly from the retinal surface. Histology showed mild changes at the outer retinal segments. There was no evidence of ocular toxicity and inflammation. None of the eyes that had an implant covering the retinal tear developed a retinal detachment but had some inflammatory changes around the implants. ppNIPAM coated implants may provide retinal adhesion in vivo without measurable ocular toxicity in the short term. Covering a retinal tear, the ppNIPAM coated implants may prevent retinal detachment.

Final Amended Report on the Safety Assessment of Octyldodecyl Stearoyl Stearate1

Octyldodecyl Stearoyl Stearate is an ester that functions as a skin-conditioning agent and viscosity-increasing agent. It is reported to be used in 105 cosmetic products at concentrations from 2% to 15%. In an isolated human skin permeation and penetration study, 0.005% of the applied dose permeated the skin, around 3% was found in the epidermis, around 1.5% was in tape stripped skin layers, and around 95% stayed in the material applied to the skin. A formulation having 20.6% Octyldodecyl Stearoyl Stearate was classified as minimally to mildly irritating in an in vitro ocular irritation assay. Several tests of products containing from 7.5% to 12.7% Octyldodecyl Stearoyl Stearate using rabbits produced minimal to mild ocular irritation. One test of 100% Octyldodecyl Stearoyl Stearate (a trade compound) and another of 10% Octyldodecyl Stearoyl Stearate in corn oil using rabbits produced no ocular irritation. Tests using rabbits demonstrated that Octyldodecyl Stearoyl Stearate at use concentrations was non- to mildly irritating to skin; only one study reported moderate irritation. Octyldodecyl Stearoyl Stearate was not mutagenic, with or without S-9 activation, in an Ames test and did not produce a significant increase in micronucleated cells in a mouse in vivo study. In clinical single-insult patch tests at use concentrations, Octyldodecyl Stearoyl Stearate was nonirritating to mildly irritating; in a cumulative irritation study, it caused mild irritation. Octyldodecyl Stearoyl Stearate was nonsensitizing in clinical tests. Because few toxicity data were available on Octyldodecyl Stearoyl Stearate, summaries of data from existing safety assessments of related ingredients (Octyl Dodecanol, Stearic Acid, and Octyl Stearate) were included. Undiluted Octyl Dodecanol was nontoxic during acute oral and dermal studies using rats and guinea pigs. Stearic Acid was nontoxic to rats during acute oral studies, but caused toxicity during subchronic studies. Rabbits treated topically with the acid were not affected adversely, and mild erythema and slight induration were observed when Stearic Acid was administered intradermally to guinea pigs and rabbits. Octyl Stearate had very low acute oral toxicity in rats and mice. Octyl Dodecanol produced only transient mild ocular irritation in rabbits when administered at concentrations up to 100%. Octyl Dodecanol (30% and 100%) was nonirritating to skin in one study using rabbits. In another study using multiple species, 100% Octyl Dodecanol (described as technical grade) caused severe skin irritation in rabbits, moderate irritation in guinea pigs and rats, and no irritation in swine. Stearic Acid was non- to moderately irritating in animal studies, and did not cause photosensitization. In studies using rabbits, undiluted Octyl Stearate caused slight, transient ocular irritation, and minimal skin irritation. Stearic Acid did not induce mitotic crossovers and aneuploidy in Saccharomyces cerevisiae, and was nonmutagenic in the Ames test. In a feeding study using mice, Stearic Acid was noncarcinogenic at doses up to 50 g/kg/day. Mice given subcutaneous injections of the acid had low incidences of carcinomas, sarcomas, and lymphomas. In clinical studies, concentrations of up to 100% Octyl Dodecanol were non- to mildly irritating, nonsensitizing, nonphototoxic, and nonphotosensitizing. Stearic Acid was nonirritating at concentrations up to 100%, and at concentrations up to 13% it was nonsensitizing and nonphotosensitizing. Octyl Stearate (7.6%) in formulation was nonirritating, nonsensitizing, and nonphotosensitizing. Based on skin permeation and penetration data, the Panel does not expect any significant amount of Octyldodecyl Stearoyl Stearate to be systemically available. There is no evidence of systemic toxicity associated with any of the related chemicals reviewed in previous safety assessments. None of the available toxicology or clinical data suggest a concern about adverse skin reactions to Octyldodecyl Stearoyl Stearate, or to any of the related chemicals. There is no evidence of ocular toxicity, except for a mild, transient ocular irritation associated with Octyldodecyl Stearoyl Stearate and the related chemicals. Overall, Octyldodecyl Stearoyl Stearate was considered safe as used in cosmetics.

Comprehensive Evaluation of Ocular Toxicity of Topical Levofloxacin in Rabbit and Primate Models

Levofloxacin, the L‐isomer of ofloxacin and a potent quinolone with a broad spectrum of antibacterial activity, was evaluated in a series of toxicology studies including acute and chronic dosing in rabbits and primates with intact and injured eyes. No evidence of ocular toxicity was observed in rabbits with intact eyes that were topically instilled with levofloxacin ophthalmic solutions under various treatment regimens, including multiple dosing (four to six times daily) for up to 26 weeks at levofloxacin concentrations from 0.3% to 3%. When rabbits were repetitively instilled (10 times at 30 minute intervals) with 0.3%, 1%, or 3% levofloxacin ophthalmic solutions over a single day, they exhibited no increase in ocular irritation scores, whereas dosing with 10% and 25% levofloxacin produced dose‐dependent increases in ocular discharge, conjunctival injection and edema, corneal edema/fluorescein staining, iridic congestion, and behavioral abnormalities. Healing of 7.5 mm diameter epithelial wounds in rabbi...

Pharmacokinetics of systemic versus focal Carboplatin chemotherapy in the rabbit eye: possible implication in the treatment of retinoblastoma.

To characterize the pharmacology and toxicity of intravenous versus focal carboplatin delivery in the rabbit eye. Pharmacological distribution of carboplatin was examined in New Zealand White Rabbits after a single intravenous infusion of carboplatin (18.7 mg/kg of body weight), a single subconjunctival carboplatin injection (5.0 mg/400 microL), or a single application of carboplatin delivered by Coulomb-controlled iontophoresis (CCI; 14 mg/mL carboplatin, 5.0 mA/cm(2), 20 minutes). After each treatment, animals were euthanatized, and the eyes analyzed at 1, 2, 6, or 24 hours by atomic absorption spectroscopy to determine carboplatin concentration in ocular structures. Potential toxicity of focally delivered carboplatin was assessed by histology after six cycles of 5.0 mg carboplatin delivered by subconjunctival injection or six transscleral carboplatin CCI applications at 72-hour intervals (14.0 mg/mL, 20 minutes at 2.5 mA). Determination of concentrations through atomic absorption spectroscopy in the retina, choroid, vitreous humor, and optic nerve after subconjunctival injection or iontophoretic carboplatin delivery revealed significantly higher levels than those achieved with intravenous administration. Carboplatin concentrations in the blood plasma were found to be significantly higher after intravenous delivery than after focal delivery by subconjunctival injection or CCI. No evidence of ocular toxicity was detected after focally delivered Carboplatin. Focal administration of carboplatin using subconjunctival or noninvasive CCI safely and effectively transmits this chemotherapeutic drug into the target tissues of the retina, choroid, vitreous, and optic nerve. These results suggest that focal carboplatin delivery may effectively increase intraorbital carboplatin concentrations while decreasing systemic exposure to this cytotoxic drug.

Posterior vitreous detachment induced by intravitreal injection of the combination of chondroitinase ABC and matrix metalloproteinase-3

To investigate the occurrence of enzymatic induction of posterior vitreous detachment (PVD) by the combination of Chondroitinase ABC (CA) and matrix metalloproteinase-3 (MMP-3), so as to seek a noninvasive and effective pharmacologic approach to facilitate and eventually replace the present mechanical vitreous surgery. Twenty-four pigmented rabbits were randomly assigned to two groups of twelve each, the experimental group was treated with CA (0.2 U) and MMP-3 (10 ng) combination, the control group was received equivalent dose of balanced salt solution (BSS). Clinical examinations and electroretinography were performed before and after injection. Over a different period of time, the rabbits were euthanized and killed and their eyes were examined histologically. The foci of partial synchisis and clinically named PVD were recognized for the first time three days after injection. Complete liquefaction was found in every eye of experimental group, and in which, 5/8 eyes developed clinically detected PVD one week after injection Histologic section showed PVD with various extent in 3/7, 7/7, 7/7 eyes of experimental group 30 minutes, 60 minutes and one week after injection respectively, and complete PVD in 0/7, 1/7, 5/7 eyes of experimental group at the same periodic intervals as above. By contrast, no vitreous liquefaction was found and only one eye showed confined partial PVD in the control group. Clinic, electrophysiologic and histologic evaluation in all rabbits revealed no evidence of ocular toxicity. Vitreous 1iquefaction and PVD can be produced shortly after intravitreal injection using a combination of CA and MMP-3, and the two enzymes were cooperative. Synchisis and weakening of vitreoretinal adherence were almost simultaneously. The dose of 0.2 U CA and 10 ng MMP-3 combination proved to be safe and ideal selection to induce PVD.

Ocular toxicity of intravitreal trovafloxacin in the pigmented rabbit

Purpose. Trovafloxacin is an expanded spectrum, newergeneration fluoroquinolone antibiotic with improved Gram-positive and anaerobic activity compared with existing quinolones, while maintaining Gram-negative activity comparable to ciprofloxacin. Given its broad spectrum of activity, trovafloxacin may have potential use for treatment of acute bacterial endophthalmitis. This study examined the toxicity of intravitreally administered trovafloxacin in the pigmented rabbit eye. Methods. Doses of trovafloxacin ranging from 12.5µg to 1000µg were injected into the mid-vitreous of Dutch Belted rabbit eyes. Clinical examination was performed at 1, 3, and 14 days following injection. Animals were sacrificed and eyes were enucleated 14 days following injection. Light microscopy (LM) and transmission electron microscopy (TEM) studies of the optic nerve head, medullary ray, and inferior retina were performed to determine toxicity. Results. At intravitreal doses of 500µg and less, no toxicity was observed at the ophthalmoscopic or light microscopic level. By TEM, a dose-dependent increase in injury to retinal pigment epithelium, photoreceptors, and nerve fibers in the optic nerve head and medullary ray was observed from 50µg to 500µg. No toxicity was noted at doses of 12.5µg and 25µg. At doses of 750µg and above, edema of the medullary ray was noted on ophthalmoscopy. Swelling of the peripapillary medullary ray and necrosis of the inferior retina were evident on LM. Conclusion. Intravitreal trovafloxacin doses of 50µg and higher in the pigmented rabbit eye cause retinal and nerve fiber injury. Intravitreal doses 25µg and lower appear to be safe, with no evidence of ocular toxicity.

Tamoxifen retinopathy: does it really exist?

Tamoxifen retinopathy is known to be an adverse effect of high-dose tamoxifen treatment. Evidence of ocular toxicity at lower doses is less convincing: the aim of this study was to assess the prevalence of the above-mentioned retinopathy in a population treated with low-dose tamoxifen. One hundred and twenty-nine women treated with low-dose tamoxifen (20 mg/day) were examined. Visual acuity measurement, slit-lamp biomicroscopy and fundus examination were performed. Patients were reexamined after 6-12 months. Refractile retinal opacities, similar to those previously described as tamoxifen retinopathy, were observed in four patients (prevalence 3.1%; mean duration of therapy 806 days). None of them revealed corneal opacities, papillary and/or macular edema, or visual impairment. The ophthalmoscopic aspect did not change after a mean follow-up of 215 days, although one of these patients had interrupted tamoxifen intake. Statistical analysis (Student's t-test) did not reveal any difference between patients with and those without refractile retinal opacities as far as age, treatment duration and ERG values were concerned. An early hyperfluorescence, reminescent of cuticular drusen, was demonstrated by fluorescein angiography in all four cases. The present study would seem to confirm that low-dose tamoxifen may induce retinal toxicity in a low proportion of patients, but we cannot be certain that the refractile retinal opacities observed are really caused by tamoxifen, as differentiation from age-related macular degeneration with cuticular drusen appears nearly impossible.

Effect of suleparoide on fibrinolysis in the anterior chamber of rabbits.

Intra-ocular fibrin deposition following ocular surgery is a serious postoperative complication. The current management of severe postoperative fibrin response is usually ineffective. A quantitative model of fibrin deposition in the rabbit anterior chamber was used to assess the efficacy of Suleparoide I.N.N. (HHS-5) in preventing fibrin formation and in promoting the clearance of fibrinous membranes. Citrated human plasma was injected intracamerally after paracentesis to induce the formation of fibrin clots: 10 min or 24 h after plasma injection, solutions of HHS-5 at different concentrations were injected into the anterior chamber of rabbits. Intra-ocular HHS-5 injection 10 min after plasma injection prevented the formation of fibrinous membranes in a dose-dependent fashion in almost all treated animals. When HHS-5 was injected at 24 h after fibrin clot formation, a reduction of clot areas was observed but the membranes did not completely disappear. No evidence of ocular toxicity was detected by slit-lamp biomicroscopy, intra-ocular pressure and corneal thickness measurements. On the basis of the results obtained with the present animal model, HHS-5 appears as an effective and safe agent for the prevention of fibrinous membrane formation. The data suggest a potential use of HHS-5 for the prophylaxis of fibrin formation in human eyes undergoing extensive intraocular surgery, or in diabetic patients where a hypercoagulable state may be present.

The effect of percutaneous dimethyl sulfoxide on cutaneous manifestations of systemic sclerosis.

DMSO exerts a palliative, therapeutic effect on healing of cutaneous ulcers in systemic sclerosis. The therapeutic response was variable and, therefore, the concentration of DMSO, as well as frequency and duration of treatments, should be individualized to obtain maximum healing effect with a minimum of adverse reactions. There was no evidence of ocular toxicity or other serious toxicity manifestations in this group of patients treated with topical DMSO for one year or longer. Delayed improvement was observed in the untreated extremity in the majority of patients studied. In no instance did improvement in the untreated extremities exceed improvement in the treated, bilateral counterpart. It is believed this resulted from a systemic, carry-over effect of DMSO rather than spontaneous improvement in the disease course. DMSO is a worthwhile, supplemental, therapeutic agent providing the limitations of therapy are understood.

Ethambutol and intra-ocular pressure

Two groups of Korean patients with tuberculosis, matched in pairs for age and duration of chemotherapy, have been studied. One group had received ethambutol in a mean dosage of 14.4 mg/kg and the other antituberculosis chemotherapy not including ethambutol for at least 3 months. All patients had routine ophthalmological assessments on admission to the study, including examination of the fundi, visual fields and macular thresholds. Intra-ocular pressures were measured and a water-drinking test was then carried out. All the assessments were made by the same ophthalmologist who was at all times kept unaware of the treatment which each patient was receiving or which patients were paired. There was no evidence of ocular toxicity or that ethambutol in the dosages studied has an effect on intra-ocular pressure.

Ethambutol in the retreatment of chronic pulmonary tuberculosis

Summary Ethambutol in a dosage of 25 mg/kg for two months and in a dosage of 15 mg/kg thereafter was used in the retreatment of 36 patients with chronic sputum positive pulmonary tuberculosis. In 32 of the 36 culture of respiratory secretions became negative after a period ranging from one month to six months. In 4 cases in which the patients left hospital against medical advice the sputum was still positive, but in all instances the organisms were susceptible to ethambutol when treatment was interrupted. There was no evidence of ocular toxicity or other unwanted effect from ethambutol nor was hypersensitivity observed. If further experience shows that ocular toxicity is not a serious hazard, and if no other toxic effects are seen, ethambutol may take its place as a highly suitable companion for isoniazid in initial treatment.