The effect of oral magnesium therapy on visual field and ocular blood flow in normotensive glaucoma.

PURPOSE: To evaluate the effect of oral magnesium therapy on ocular blood flow and visual field perimetry indices in patients with normotensive glaucoma (NTG). METHODS: Fifteen patients with NTG (study group) received 300 mg oral magnesium citrate for 1 month, while 15 patients with NTG (control group) received no treatment. Blood magnesium level measurement, visual field analysis, and color Doppler imaging of the orbital vessels were done before treatment and at 1 month. RESULTS: In the study group, mean deviation improved from -3.7+/-1.9 (mean +/- standard deviation) at baseline to -2.5+/-1.8 at 1 month (p<0.05), and pattern standard deviation improved from 3.6+/-2.3 at baseline to 2.8+/-2.6 at 1 month (p<0.05). Color Doppler imaging indices did not change after magnesium therapy. CONCLUSIONS: Oral magnesium therapy may provide improvement in the visual field, but does not seem to affect ocular blood flow in patients with NTG. Other mechanism than increased ocular blood flow may be responsible for the improvement in the visual field with oral magnesium therapy.

Matrix metalloproteinase-9 expression in retinal ganglion cell layer and effect of topically applied brimonidine tartrate 0.2% therapy on this expression in an endothelin-1-induced optic nerve ischemia model.

The purpose of this research is to investigate the expression of matrix metalloproteinase-9 (MMP-9) in retinal ganglion cells (RGC) and the impact of topically applied brimonidine tartrate 0.2% (BMD) on this expression in an endothelin-1 (ET-1)-induced chronic optic nerve (ON) ischemia model of rabbit. Osmotically driven minipumps were implanted in one eye of 16 New Zealand albino rabbits to deliver ET-1 at the constant rate of 0.5 microl/h for 2 weeks. ET-1 was given with (group 3) and without topical BMD therapy (group 1). Groups 2 and 4 were taken as controls. MMP-9 expression by immunohistochemically and proportion of cells undergoing apoptosis in RGC layer were investigated. The correlation between the MMP-9 immunopositivity and the proportion of cells undergoing apoptosis in the RGC layer was evaluated. MMP-9 immunopositivity was found to be significantly higher in both groups 1 and 3 compared to that of the controls. There was no difference between groups 1 and 3 regarding MMP-9 expression (p = 0.495). A positive correlation was found between the proportion of cells undergoing apoptosis and MMP-9 expressions in the RGC layer in group 1 (p = 0.031, r = 0.754). MMP-9 expression in the RGC layer seems to significantly increase in the ET-1-induced chronic ON ischemia model. Topical BMD therapy does not seem to affect this MMP-9 expression.

Changes in intraocular pressure, and corneal and retinal nerve fiber layer thickness during hemodialysis.

The aim of this study is to evaluate the changes in intraocular pressure (IOP), central corneal thickness (CCT), and retinal nerve fiber layer thickness (RNFLT) in patients with chronic renal failure undergoing hemodialysis (HD). A complete ophthalmological examination together with IOP, CCT, and RNFLT measurements were performed for each patient both before and after HD sessions. RNFLT parameters were detected by scanning laser polarimeter. Total body weight and serum osmolality were also measured. Only the left eyes were recruited for statistical analysis. Thirty-three eyes of 33 patients were enrolled in the study. Mean IOP decreased from 14.7 +/- 3.1 to 13.4 +/- 2.4 mmHg after HD (paired t test, P = 0.005). Mean CCT also decreased significantly after HD, from 556.5 +/- 33.5 to 550.2 +/- 34.6 mum (paired t test, P = 0.002). CCT change in the left eyes was found to be correlated with total body volume loss (Pearson correlation test, R = 0.391 and P = 0.030). Considering RNFLT parameters before and after HD, no significant alterations were detected by scanning laser polarimeter (paired t test, P > 0.05). We conclude that IOP may decrease to some extent after HD. CCT may be affected by fluid loss after HD sessions, with a resultant decrease in corneal thickness. In patients with chronic renal failure undergoing HD, RNFLT parameters can be measured as in healthy individuals. Underestimation of intraocular pressure values after HD sessions should be taken into account, especially in patients with chronic renal failure.

Tick- borne infection revealing human immunodeficiency virus (HIV) positivity in a young adult.

PURPOSE: To describe a patient whose retinal findings suggestive of tick-borne disease but evaluations led to early diagnosis and treatment of human immunodeficiency virus (HIV) infection. OBSERVATION: A young patient presented with bilateral uveitis, branch retinal artery occlusion and retinal findings suggestive of infective/inflammatory etiology. Laboratory evaluations revealed that the patient was positive for co-infection with Rickettsia conorii and Bartonella henselae. On further investigation, the patient tested positive for HIV infection. The patient was treated with doxycycline as well as highly active anti-retroviral therapy (HAART) to control both opportunistic infections as well as HIV infection. CONCLUSION AND IMPORTANCE: Patients with HIV infection are at risk for multiple, simultaneous opportunistic co-infections, including those with tick-borne diseases.

Nonpenetrating glaucoma surgery: meta-analysis of recent results.

PURPOSE: To evaluate the efficacy of nonpenetrating glaucoma surgery for open angle glaucoma with respect to target intraocular pressure (IOP) and severity of glaucoma. MATERIALS AND METHODS: A literature search with the terms "nonpenetrating glaucoma surgery, deep sclerectomy (DS), viscocanalostomy (VC), and open angle glaucoma" was carried out for the reports in the last 5 years. Studies encompassing only combined glaucoma and cataract surgery were excluded. Measurement of effectiveness was determined on the basis of achievement of target IOP. Data related to postoperative goniopuncture and needling with antimetabolite application were noted. RESULTS: The percentage of cases achieving

Enhancement of the success rate in trabeculectomy: large-area mitomycin-C application.

BACKGROUND: To compare the effects of variable mitomycin-C (MMC) applications during trabeculectomy on target intraocular pressure (IOP), number of antiglaucomatous therapy, bleb morphology and surgical complications. METHODS: 66 glaucoma cases who underwent trabeculectomy combined with small-area (Group 1) or large-area (Group 2) MMC application were included. This study is a retrospective case series comparison. In Group 1, MMC had only been applied to the scleral flap area, whereas additional MMC applications were performed on upper temporal and nasal quadrant in Group 2. The cases with diabetes, narrow angle glaucoma, secondary glaucoma, history of previous ocular surgery and follow-up period less than 2 years were exluded from the study. A routine ophthalmological examination was performed in all cases and IOP measurements, morphology and the function of the blebs, necessity for antiglaucomatous medications and complications at first month and second year were evaluated. RESULTS: There were 32 cases (48.5%) in Group 1 and 34 cases (51.5%) in Group 2. The mean IOPs were 12.6 +/- 5.5 and 10.8 +/- 5.3 mmHg at first month (P > 0.05), whereas 14.4 +/- 2.8 and 10.1 +/- 2.6 mmHg at second year, respectively (P < 0.05). The mean number of medications were 3.3 +/- 1.6 and 3.2 +/- 0.2 preoperatively (P > 0.05), whereas 0.8 +/- 1.2 and 0.26 +/- 0.70 at second year (P < 0.05). The number of diffuse blebs was higher in Group 2 whereas the number of cystic blebs was higher in Group 1 (P > 0.05). There was no difference between two groups with regards to the number of eyes with hypotonia (P > 0.05). CONCLUSIONS: Large-area MMC application seems to increase long-term success without increasing the complication rates in trabeculectomy.

Long-term results of pars plana lensectomy with double-capsule-supported intraocular lens implantation in children.

BACKGROUND: To report the long-term results of the pars plana lensectomy with double-capsule-supported intraocular lens implantation technique for the treatment of pediatric cataracts. METHODS: A lensectomy and an anterior vitrectomy were performed through the pars plana approach, followed by implantation of a posterior chamber intraocular lens (IOL) to the sulcus over the capsules. Patients with a minimum follow-up of 5 years were included in the study and patient data were collected retrospectively from the patient reports. RESULTS: Sixteen eyes of 10 patients with a mean age of 4.3 (SD 1.1) years were included in the study. Only one case was traumatic, and the others were congenital cataract cases. A 6.5 mm polymethyl methacrylate posterior chamber IOL was used in all cases. The visual axis was clear in all the cases through the mean follow-up period of 79.2 (SD 14.1) months. IOL decentration was observed in 1 eye at postoperative month 24, and it needed to be repositioned. There was no posterior capsular opacification in any of the cases. Best-corrected visual acuity was 20/40 or better in 81.3% of the eyes. INTERPRETATION: The pars plana lensectomy with double-capsule-supported intraocular lens implantation technique seems to be a safe and easy method in children, limiting postoperative IOL-related complications and posterior capsule opacification in the long term.

Postoperative secondary glaucoma and anterior staphyloma in a patient with homocystinuria.

We describe recurrent bilateral homocystinuria-related lens dislocation into the anterior chamber in a patient who had postoperative anterior staphyloma and secondary intractable aphakic glaucoma in only one eye. We discuss the possible causes of and treatment modalities for this complication.

Trabeculectomy with large area mitomycin-C application as a first-line treatment in advanced glaucoma: retrospective review.

AIM: To evaluate the outcomes of trabeculectomy with large area mitomycin-C (MMC) application as a first line treatment in advanced glaucoma. METHODS: The records of 55 patients with severe visual field defects undergoing trabeculectomy were retrospectively reviewed. The patients were classified as first-line therapy to either early trabeculectomy (initial trabeculectomy-Group 1) or long term medical therapy followed by trabeculectomy (primary trabeculectomy-Group 2). Trabeculectomy was performed with large-area MMC application. Intraocular pressure (IOP) values, visual acuities, mean deviations, morphology and function of the blebs, necessity for anti-glaucomatous medications and surgical complications were reported. RESULTS: There were 20 eyes of 18 patients in Group 1 and 37 eyes of 37 patients in Group 2. The mean preoperative IOPs in Groups 1 and 2 were 40.2±10.0mmHg (27-68mmHg) and 29.0±4.4mmHg (21-41mmHg), respectively (P=0.001). Average preoperative mean deviations (MD) in Groups 1 and 2 were 17.4±2.8dB (13.3-23dB) and 17.9±2.4 dB (13.7-23.2dB), respectively (P=0.441). Postoperative IOPs significantly decreased and were comparable in both Groups. The mean number of medications was significantly higher in Group 2 (P=0.005). No cystic bleb formation was observed in Group 1, whereas 4 patients from Group 2 (10.8 %) developed cystic bleb (P=0.040). No visually devastating complication has occurred in both Groups. CONCLUSION: Initial trabeculectomy with large area MMC application might be applied in patients with advanced glaucoma with low complication rates. Long-term topically applied anti-glaucomatous medications seem to increase the risk of cystic bleb formation.

Apoptosis in the iris and trabecular meshwork of medically treated and untreated primary open angle glaucoma patients.

AIM: To compare the trabecular meshwork (TM) and iris apoptosis of treated and untreated primary open angle glaucoma (POAG) patients. METHODS: Eight treatment-naive, newly diagnosed (group 1) and 11 medicaly treated (group 2) patients with POAG were included in the study. Each patient underwent a limbus-based trabeculectomy. The TM and peripheral iris specimens were dissected out and were snap-frozen in liquid nitrogen and stored at -80°C until they were assayed. Apoptosis in each group was assesed by TUNEL method. RESULTS: The mean patient age was 60.6±5.8 years (53-68 years) vs 58.9±8.9 years (47-70 years) in group 1 and group 2 (P=0.859). The mean treatment time in group 2 was 22.2±7.3 months (12-34 months). Apoptotic indexes in TM and iris were significantly higher in POAG patients using medication (group 2) compared to treatment-naive POAG patients (group 1) (P=0.004, 0.015; respectively). CONCLUSION: Long term administration of topical antiglaucoma medications causes additional toxic effects on TM.

Neuroprotective effect of topically applied brimonidine tartrate 0.2% in endothelin-1-induced optic nerve ischaemia model.

BACKGROUND: To investigate the neuroprotective effects of topically applied brimonidine tartrate 0.2% (BMD), an alpha(2)-receptor agonist, on the retinal ganglion cell (RGC) layer and inner nuclear layer (INL) of rabbit retina in endothelin-1 (ET-1)-induced optic nerve (ON) ischaemia model. METHODS: Osmotic minipumps were surgically implanted into one eye of 16 New Zealand Albino rabbits to deliver ET-1 at the constant rate of 0.5 microL/h for 2 weeks. Eyes were divided into four groups. ET-1 was given with (Group 3) and without topical BMD therapy (Group 1). Groups 2 and 4 were taken as controls. Rabbits were sacrificed at day 14. Morphological alterations, total cell number and proportion of cells undergoing apoptosis in INL and RGC layer were assessed by histopathological analysis to determine the survival of the cells of the INL and RGC layer. RESULTS: Endothelin-1 led to severe reduction of cells in both the RGC layer and INL in Group 1 (P < 0.05). In Group 3, the total cell number and the proportion of cells undergoing apoptosis in the RGC layer were comparable with the control group (Group 4), whereas the former was found to be higher and the latter was found to be lower than those recorded for Group 1. However, the total cell number in the INL was found to be lower in Group 3 compared with that of Group 4, despite topical BMD therapy (P < 0.05). CONCLUSIONS: Topically applied BMD seems to be neuroprotective and antiapoptotic in the ET-1-induced ON ischaemia model, especially for RGCs. BMD might be used as an adjuvant agent for its neuroprotective effects in hypoxic-ischaemic conditions such as diabetic retinopathy, normotensive glaucoma and other retinal vascular occlusive conditions which require further investigations.

Effect of mitomycin C on ciliary body and intraocular pressure with various application depths: an experimental study.

BACKGROUND: To evaluate the effects of mitomycin C (MMC) on intraocular pressure (IOP) and ciliary body via transmission electron microscopy when applied under conjunctiva or different depths of sclera, without performing any filtering surgery. METHODS: Thirty-six eyes of 36 New Zealand albino rabbits were used in this study. MMC was prepared in a concentration of 0.4 mg/mL and 0.05 cc (20 microg) was soaked in preprepared sterile surgical sponges. Six groups each consisting of six eyes were formed and IOP was measured preoperatively. Group 1 was the control group: the superior conjunctiva was opened and only irrigated with balanced salt solution (BSS). In group 2, MMC soaked sponges were applied under the conjunctiva. In groups 3 and 4, a scleral flap of approximately 1/3 scleral thickness was prepared and in groups 5 and 6, and a scleral flap of approximately 2/3 scleral thickness was prepared, all with a standard size of 4 x 4 mm. MMC soaked sponges were applied under these areas for 5 min in eyes in groups 3 and 5 followed by an irrigation of the relevant areas with 10 cc BSS, whereas only irrigation with BSS was done in groups 4 and 6 as control groups. No filtering procedure was performed in any of the eyes. Eyes were enucleated on the 30th day following measurement of IOP and the ciliary body regions were evaluated using transmission electron microscopy. Kruskal-Wallis test was used for the statistical assessment of IOP between groups. RESULTS: The deep scleral flap group (group 5) showed statistically significantly more IOP reduction than both the superficial scleral flap group (group 3; P = 0.004) and the subconjunctival group (group 2; P = 0.002) on postoperative day 30. Electron microscopic evaluation of the surgical groups revealed a wide range of different histopathological effects due to different MMC application methods. The histopathological changes were more evident in the group 5, where MMC was applied under deep scleral flap. CONCLUSIONS: Subscleral application of MMC seems to provide greater IOP decrease than subconjunctival application, possibly caused by a more significant ciliary body toxicity. This may be the beginning of a non-penetrating, easy to perform and safe method to decrease IOP in glaucoma patients, which the authors call 'toxic ciliary ablation surgery'. However, the long-term results and complications must be assessed with further studies.

An unusual ocular manifestation in Fanconi anemia: congenital glaucoma.

Fanconi anemia is an autosomal recessive disorder characterized by growth retardation along with many congenital abnormalities involving the eyes. We report herein two siblings with Fanconi anemia who also have bilateral congenital glaucoma. To the best of our knowledge, this is the first report of congenital glaucoma in patients with Fanconi anemia.

Effects of thick Tenon's capsule on primary trabeculectomy with mitomycin-C.

PURPOSE: To investigate the effects of thick Tenon's capsule on primary trabeculectomy with adjunctive mitomycin-C. METHODS: In this prospective interventional case series of 45 consecutive uncomplicated glaucoma patients, 45 eyes with thick Tenon's capsule underwent primary trabeculectomy with intraoperative mitomycin-C (0.4 mg/ml for 3 min). Success was defined as intraocular pressure (IOP)

Postoperative 5-fluorouracil versus intraoperative mitomycin C in high-risk glaucoma filtering surgery: extended follow up.

PURPOSE: To compare the long-term efficacy and safety of postoperative subconjunctival 5-fluorouracil (5-FU) injections with that of intraoperative mitomycin C (MMC) in eyes at high risk for failure of trabeculectomy. METHODS: In a retrospective, non-randomized comparative trial, 36 eyes of 36 consecutive patients at high risk for failure of trabeculectomy underwent glaucoma filtering surgery with either postoperative subconjunctival 5-FU injections (19 eyes) or intraoperative application of MMC (17 eyes). Intraocular pressure, number of postoperative antiglaucoma medications, postoperative visual acuity, interventions, and complications were evaluated. RESULTS: Overall success (intraocular pressure 0.05) between the groups. CONCLUSIONS: These results suggest that both postoperative 5-FU injections and intraoperative MMC application have long-term success in high-risk patients. However, MMC results in a greater decrease in intraocular pressure than 5-FU.

The effect of blood glucose regulation on retinal nerve fiber layer thickness in diabetic patients.

PURPOSE: To evaluate the effect of blood glucose (BG) regulation on the retinal nerve fiber layer (RNFL) in diabetic patients by using a scanning laser polarimeter (NFA-GDx). METHODS: We prospectively assessed RNFL thickness in diabetic patients and an age-matched control group. Patients without diabetic retinopathy, with BG >250 mg/dl, HbA1c >8%, fructosamine >285 micromol/l and triglyceride >200 mg/dl were included in the study. RNFL assessment was performed before and after metabolic regulation of diabetes. Symmetry, superior maximum, ellipse modulation and the average thickness variables of NFA-GDx were used for the assessment. Mann-Whitney U and Wilcoxon tests were used for the statistical analysis. RESULTS: A total of 40 diabetic patients were included in the study and a repeat RNFL examination could be performed in 22 of them following regulation of BG levels. None of the GDx variables were significantly different between pre- and postregulation measurements (p > 0.05, Wilcoxon test). The mean superior maximum, ellipse modulation and average thickness values of the diabetic group were significantly lower than the control group (p < 0.05, Mann-Whitney U-test). CONCLUSIONS: Poor metabolic control of diabetes mellitus adversely affects the thickness of RNFL and this effect does not seem to be acute since it was not reversed by short-term BG regulation. This issue needs to be kept in mind when assessing glaucomatous progress in diabetic patients.