Effects of intravitreal bevacizumab in repeated doses: an experimental study.

PURPOSE: To evaluate the effects of repeated 1.25-mg intravitreal bevacizumab injections on cornea and uveoretinal tissues using histologic and biochemical analyses. METHODS: Twenty-four New Zealand albino rabbits were used. Twelve rabbits received an injection of bevacizumab in their right eyes three times with an interval of 25 days (Group 1); their contralateral eyes served as controls (Group 2). Six rabbits had an injection of vehicle in both eyes (Group 3), with the same regimen as bevacizumab, and six rabbits' eyes were used as a sham group (Group 4). Enucleated eyes were used for histologic and biochemical analyses, which included the activities of caspase 3 and 8 enzymes, glutathione content, catalase activity, and malondialdehyde content. RESULTS: No inflammation in aqueous humor and no sign of corneal or uveoretinal toxicity was found in bevacizumab-injected eyes. The difference of activity of corneal caspase 8 enzyme between Groups 1 and 2 and between Groups 1 and 4 was statistically significant (P < 0.05). In the uveoretinal tissue, in Group 1, the activities of caspase 3 and 8 enzymes were the lowest, and uveoretinal malondialdehyde content was also significantly lower than Group 4. CONCLUSION: A repeated dose of intravitreal bevacizumab injection did not cause a toxic effect on cornea and uveoretinal tissue. Biochemically, it also did not cause any apoptosis, oxidative reaction, or lipid peroxidation. Instead, bevacizumab injection caused a considerable decrease in the apoptotic enzyme activities and lipid peroxidation in the uveoretinal tissue. Further studies are needed to be conducted for possible detrimental side effects and apoptotic and oxidative effects of repeated bevacizumab injections on both the injected and the contralateral eyes.

Persistent pupillary membranes in 3 siblings.

We report 3 siblings from a nonconsanguineous white family with bilateral persistent pupillary membranes with dissimilar forms of severity. Two of the patients required no treatment; 1 was treated surgically for occlusion of the pupillary axis and moderate visual acuity decrease. Anterior segment examination was otherwise normal in the siblings. Although persistent pupillary membranes are usually sporadic, cases in which they are associated with other anterior chamber abnormalities might be inherited autosomal dominant. To our knowledge, this is the first report of a familial isolated persistent papillary membrane case with no other anterior chamber abnormality.

Corpus callosum and optic chiasm in early blind adults.

OBJECTIVES: Certain callosal dimensions, callosal areas, and the optic chiasm (OC) thickness were measured in order to detect any morphometric difference that would imply plastic changes in a selected group of adults. METHODS: Seventeen early blinds were selected among a group of blind adults after performing interviews. These selected blind subjects, and 23 adults with normal vision of both genders were examined by MRI. The study was conducted in Mersin, Turkey between the years 2004 and 2006. RESULTS: Only 14 early blind subjects completed the MR imaging procedure. Statistically significant difference between the OC thicknesses of 2 groups was found whereas no statistically significant difference was detected for the callosal dimensions. CONCLUSION: The difference in the OC dimensions of the 2 groups may be explained by the disuse atrophy. It has been known that if a cortical area of any sense is deprived of stimulus within the critical period, then it may take on another cortical activity. The reasons for the unaffected dimensions of the corpus callosum (CC) in this study may be either the relatively small percentage of the fibers related to vision within the total CC, such as auditory function, of the "normally" visual cortex.

Intravitreal triamcinolone acetonide treatment for serpiginous choroiditis.

PURPOSE: To report the efficacy of intravitreal triamcinolone acetonide injection for acute treatment of a patient with serpiginous choroiditis. METHODS: A 50-year-old male patient with serpiginous choroiditis presenting with the complaint of decreased visual acuity in his right eye for the last 10 days. The best corrected visual acuity (BCVA) of the patient was counting finger from 1 meter. Fundus examination and fundus fluorescein angiography of right eye revealed active macular choroiditis in right eye. Intravitreal triamcinolone acetonide (4 mg/0.1 ml) was injected into vitreous, and the patient was followed with visual acuity testing, intraocular pressure measurement, and fundus examination, including fundus fluorescein angiography. RESULTS: Visual acuity of the patient improved to 20/100 after 2 weeks in spite of the triamcinolone crystals, and to 20/50 after 4 weeks with a single dose intravitreal triamcinolone acetonide injection. Complete resolution of the active lesion has been maintained during the 6 months of follow-up. CONCLUSIONS: Single dose intravitreal triamcinolone acetonide injection is sufficient for controlling the active lesions in serpiginous choroiditis. It needs further evaluation as an alternative treatment for achieving rapid and significant visual acuity recovery.

Effects of caffeic acid phenethyl ester on endotoxin-induced uveitis in rats.

PURPOSE: Caffeic acid phenethyl ester (CAPE) has antimicrobial, anti-inflammatory, antioxidant, immunomodulatory, and carcinostatic properties. In this study, the efficacy of CAPE in endotoxin-induced uveitis (EIU) in rats is investigated. METHODS: EIU was induced by a footpad injection of lipopolysaccharide (LPS). In the treatment group, 10 micromol/kg CAPE was injected intraperitoneally immediately after LPS injection. At 24 hr after LPS injection, the number of infiltrating cells, protein concentration, and levels of myeloperoxidase (MPO) in aqueous humor; malondialdehyde (MDA), MPO, and total antioxidant levels in serum were determined. Eyes were enucleated for histopathologic evaluation, and, counting inflammatory cells in iris-ciliary body (ICB), the efficacy of treatment was determined. RESULTS: CAPE significantly suppressed LPS-induced increase in the number of inflammatory cells (p = 0.0001), protein concentration (p = 0.0001), and MPO levels (p = 0.0001) in aqueous humor as well as MDA (p = 0.001) and MPO (p = 0.0001) levels in serum. Histopathologic evaluation of ICB showed significant reduction in the inflammatory cell counts in the treatment group (p = 0.0001). CONCLUSIONS: CAPE was found efficient in suppressing inflammation and ocular tissue damage induced by LPS in rats.

N-acetyltransferase 2 phenotype may be associated with susceptibility to age-related cataract.

Free radicals and oxidative damage play roles in aging and age-related ocular diseases such as cataracts, so defensive mechanisms become important factors for protection. Because N-acetylation is involved in a wide variety of detoxification processes, this study was conducted to examine the relationship between the acetylator phenotypes and genotypes in a group of patients with age-related cataract. Sixty-one cases of age-related cataract and 104 controls were included in this study. Blood was collected in EDTA-containing tubes, and genomic DNA was extracted from the white blood cells by high pure PCR template preparation kit. Genotyping of NAT2 polymorphisms were detected by using a LightCycler-NAT2 mutation detection kit in real-time PCR. There was a significant difference in the distribution of the NAT2*6A acetylator phenotype between cases and the controls. The odds ratio of cataract for the NAT2*6A slow phenotype was 3.8 (95% CI = 1.08 to 13.11, p = 0.032) compared with the fast type. Our results suggest that slow acetylators are at higher risk of developing age-related cataracts than fast acetylators. As NAT2 is an important xenobiotic-metabolizing enzyme and theoretically xenobiotics such as ultraviolet B radiation, smoking, and alcohol use may induce cataract formation, NAT2 gene polymorphisms may be associated with genetic susceptibility of cataract.

Bilateral congenital anophthalmos and agenesis of the optic pathways.

This report presents a rare example of a bilateral congenital anophthalmos and an agenesis of the optic pathways. The MR imaging studies revealed that the eyeballs, optic nerves, optic chiasm, optic tracts and optic radiation were absent. The chromosomal examination was normal. Mild mental retardation was also observed. Apart from the rarity of the anophthalmos and the total absence of the optic pathways, no etiologic reason for this pathology could be detected, which makes this case more significant.

A case of infected scleral buckle with Mycobacterium chelonae associated with chronic intraocular inflammation.

PURPOSE: To describe a unique case of chronic intraocular inflammation secondary to scleral buckle infection with Mycobacterium chelonae that was successfully treated with buckle explantation. METHODS: Case report. RESULTS: A 59-year-old male with a history of retinal detachment repair at the age of 41 presented with chronic, recurrent intraocular inflammation responsive to topical corticosteroids. Conjunctival erosion with exposure of the scleral buckle occurred five months after initial presentation. The scleral buckle was removed and cultured. After three weeks of postoperative topical tobramycin and dexamethasone treatment, the patient has remained symptom-free without medications. The explanted material grew acid-fast bacilli later identified as M. chelonae. CONCLUSIONS: This case describes a new finding of chronic intraocular inflammation associated with a scleral buckle infected with M. chelonae and the successful resolution of extraocular infection and intraocular inflammation after buckle removal.

Predictors of success in macular hole surgery with emphasis on the internal limiting membrane (ILM) and ILM peeling.

BACKGROUND AND OBJECTIVE: To study the predictors of success in macular hole surgery. PATIENTS AND METHODS: Twenty-two eyes of 21 patients underwent macular hole surgery. The hole closure rate and the visual improvement were studied based on the preoperative visual acuity, stage and duration of the macular hole, the type of intravitreal tamponade used, and internal limiting membrane peeling. The internal limiting membrane was peeled only when it was clinically prominent. RESULTS: Macular holes were closed in 19 of the 22 eyes and visual improvement of 2 lines or more was achieved in 17 eyes. Preoperative visual acuity, duration of the macular hole, type of intraocular tamponade used, and internal limiting membrane peeling did not affect the outcome. A final visual acuity of 20/70 or better was more common after surgery for stage 2 holes (P = .019). CONCLUSION: The best predictor of outcome was the stage of the hole, with best results obtained in stage 2 holes.

Tolerated cilium in the anterior chamber.

PURPOSE: To describe a patient with a tolerated cilium in the anterior chamber. METHODS: A 15-year-old girl, referred with a 5-year trauma history, was examined. A cilium was noted in the anterior chamber without any inflammation during routine ophthalmological examination. RESULTS: The cilium was removed surgically and the prognosis was excellent. CONCLUSION: The decision to remove a cilium surgically is controversial and must be based on the individual clinical examination.

Effect of caffeic acid phenethyl ester on treatment of experimentally induced methicillin-resistant Staphylococcus epidermidis endophthalmitis in a rabbit model.

This study investigated the anti-inflammatory effects of caffeic acid phenethyl ester (CAPE), a natural bee-produced compound, and compared it with corticosteroids in the treatment of experimentally induced methicillin-resistant Staphylococcus epidermidis (MRSE) endophthalmitis in addition to intravitreal antibiotics. An experimental endophthalmitis model was produced in 24 New Zealand albino rabbits by unilateral intravitreal injection of 0.1 ml of 4.7 x 10(4) colony-forming units (CFU) methicillin-resistant S. epidermidis. The animals were then divided randomly into three treatment groups and a control group, group 1 (six rabbits), received only intravitreal vancomycin (1.0 mg/0.1 ml); group 2 (six rabbits), received both intravitreal vancomycin (1.0 mg/0.1 ml) and intravitreal dexamethasone (400 microg/0.1 ml) and group 3 (six rabbits), received both intravitreal vancomycin (1.0 mg/0.1 ml) and subtenon CAPE (10 mg/0.3 ml) after 24 h post-infection. No treatment was given to the control group. Treatment efficacy was assessed by clinical examination, vitreous culture and histopathology. There were no statististically significant differences between clinical scores of all groups in examinations at 24 and 48 h post-infection (p = 0.915 and p = 0.067 respectively), but in examinations at 72 h post-infection and after 7 days post-infection, although the clinical scores of treatment groups were not significantly different from each other, they were significantly lower than the control group (p < 0.05). The culture results of all groups were sterile. As a result, CAPE was found to be as effective as dexamethasone in reducing inflammation in the treatment of experimental MRSE endophthalmitis when used with antibiotics. More studies are needed to determine the optimal administration route and effective dosage of this compound.

May glutathione S-transferase M1 positive genotype afford protection against primary open-angle glaucoma?

PURPOSE: To find out whether the polymorphism at GSTM1, GSTT1 and GSTP1 loci is associated with increased susceptibility to glaucoma. METHODS: We genotyped 153 primary open angle patients and 159 healthy controls. Genomic DNA from peripheral blood was examined using polymerase chain reaction and defined for the genetic polymorphisms of glutathione S-transferase. RESULTS: The frequency of the GSTM1 null genotype individuals among the glaucoma patients was significanlty higher than in controls (54.9 vs 40.9%) with odds ratio of 1.64 (95% CI: 1.10-2.59). The frequency of the GSTT1 and GSTP1 in both groups were not statistically different. CONCLUSION: The present study suggests that the GSTM1 null genotype may be a genetic risk factor for development of primary open angle glaucoma. Further associations studies in other polymorphic genes for xenobiotic-metabolizing enzymes are needed to elucidate the environmental-genetic interaction in the underlying cause of primary open angle glaucoma.

Serum oxidant/antioxidant balance in exfoliation syndrome.

BACKGROUND: To evaluate the relationship between the serum oxidant-antioxidant balance and the presence of exfoliation syndrome (XFS) in a prospective study. METHODS: The study group comprised 27 cases of XFS. Serum concentrations of myeloperoxidase, malondialdehyde, vitamins A, C and E, catalase and total antioxidant were measured and compared with an independent group by t-test. RESULTS: Serum myeloperoxidase, vitamins A and E, catalase and total antioxidant parameters were not statistically different among the groups (P >0.05). Serum vitamin C concentrations were significantly lower and malondialdehyde concentrations were significantly higher in cases of XFS when compared with the control group (P=0.008 and P=0.002, respectively). CONCLUSION: An altered oxidant-antioxidant balance may play a role in the pathogenesis of XFS.

The efficacy of intravitreal levofloxacin and intravitreal dexamethasone in experimental Staphylococcus epidermidis endophthalmitis.

This study was designed to investigate the efficacy of intravitreal levofloxacin, and intravitreal levofloxacin and dexamethasone combined in Staphylococcus epidermidis endophthalmitis. Albino rabbits (n = 25), infected with an intravitreal inoculum of S. epidermidis (1.0 x 10(5) colony forming units/0.1 ml), were divided into five groups (n = 5). Groups 1 and 2 received treatment 24 h after the inoculation, and groups 3 and 4 48 h after the inoculation. No treatment was given to the control group. Treatment efficacy was assessed by vitreous culture, clinical examination and histopathology. Five days after treatment, groups 1 and 2 had significantly lower clinical scores than the control group (p = 0.004, p = 0.007). The culture results of the treatment groups were sterile. The histopathological scores of the treatment groups were lower than the control group (p = 0.007). Studies on retinal toxicity and dose-response relation are needed to prove the efficacy of levofloxacin in S. epidermidis endophthalmitis.