Alireza Ghaffariyeh

Brain-derived neurotrophic factor in patients with normal-tension glaucoma

PURPOSEnThe aim of this study was to detect and measure brain-derived neurotrophic factor (BDNF) in the tears of normal subjects and patients with normal-tension glaucoma (NTG).nnnMATERIALS AND METHODSnTwenty patients with NTG as the case group and 20 normal subjects with the same age range as the control group were tested. The control group consisted of 16 men and 4 women, ranging in age from 40 to 75, without any apparent ocular or systemic disease. The case group consisted of 15 men and 5 women, ranging in age from 45 to 74. BDNF levels in tears were determined by enzyme-linked immunosorbent assay using monoclonal antibodies specific for BDNF (R&D Systems, Minneapolis, Minnesota).nnnRESULTSnThe mean level of BDNF detected in the tears of the normal subjects was 77.09 +/- 4.84 ng/mL and the BDNF levels in the tears of case group were 24.33 +/- 1.48 ng/mL (P < 0.001).nnnCONCLUSIONnWe suggest that BDNF in the tears might be a useful biochemical marker for early detection of normal-tension glaucoma (NTG).

Fyodorov–Zuev keratoprosthesis implantation: long-term results in patients with multiple failed corneal grafts

BackgroundThe long term results of the Fyodorov–Zuev keratoprosthesis are presented for ten patients with repeated graft failures.MethodsThe study took place at Dr Khodadoust Eye Hospital. The Fyodorov–Zuev keratoprosthesis was implanted in ten patients with repeated graft failures, including seven patients with old trachoma, two patients with chemical injury, and a patient with thermal injury. The outcome measures were visual acuity, retention, and complications of the keratoprosthesis.ResultsPreoperative best-uncorrected visual acuity (BUVA) ranged from counting fingers to light perception (median: light perception). The keratoprosthesis dramatically improved vision in most patients. Patients retained BUVA of 20/200–20/50 in 50%, 20/60–20/100 in 30%, 20/200 in 10% and 20/400 in 10%. Overall, 90% had 1xa0year postoperative vision of 20/200 or better. 70% of cases had BUVA of 20/200 or better at the last follow-up (average 52xa0months). Of ten keratoprosthesis implanted, three have been removed, and as a result, retention rate was 70% during average follow-up of 52xa0months .The most common postoperative complications were retroprosthetic membrane formation (40%), uveitis (20%), glaucoma (20%), tissue overgrowth (20%), early leakage (20%), late leakage (20%), aseptic necrosis (20%), retinal detachment (10%), endophthalmitis (10%), and granulation tissue growth (10%).ConclusionsFyodorov–Zuev keratoprosthesis is an effective means of managing repeated corneal graft failure.

Novel materials to enhance corneal epithelial cell migration on keratoprosthesis

Purpose To introduce a new modification for silicone optical core Keratoprosthesis. Methods Using mixtures of 2-hydroxyethyl methacrylate and acrylic acid polydimethylsiloxane (PDMS) films were modified with two-step oxygen plasma treatment, and then type I collagen was immobilised onto this modified surfaces. Both the biocompatibility of the modified films and cell behaviour on the surface of these films were investigated by in vitro tests, and formation of epithelial cell layer was evaluated by implantation of the modified films in the corneas of 10 rabbits. Results In vitro studies indicated that the number of attached and proliferated cells onto modified PDMS in comparison with the unmodified PDMS significantly increased. Histological studies showed that corneal epithelial cells migrated on the anterior surface of the modified films after 1u2005week. The corneal epithelial cell formed an incomplete monolayer cellular sheet after 10u2005days. A complete epithelialisation on the modified surface was formed after 21u2005days. The epithelial layer persisted on the anterior surface of implant after 1-month and 3-month follow-up. Conclusion This method may have potential use in silicone optical core Keratoprosthesis.

Amantadine-associated corneal edema ☆

Amantadine HCl is an antiviral agent used to treat and prevent influenza A. It is also indicated for the treatment of Parkinsonism and drug-induced extra pyramidal symptoms. Reported ocular side effects include visual loss, hallucination, oculogyric crises, mydriasis, diffuse white punctate subepithelial, opacities, superficial punctate keratitis, epithelial and stromal edema [1,2]. We report a Parkinson patient with reversible corneal edema associated with amantadine use.

Evaluation of transcutaneous electrical simulation to improve recovery from corneal hypoesthesia after LASIK

PurposeTo evaluate the efficacy, and safety of transcutaneous electrical stimulation (TES) to accelerate corneal nerve regeneration and improved recovery from corneal hypesthasia after laser-assisted in situ keratomileusis (LASIK).SettingKhodadoust Eye Hospital, Shiraz, Fars, IranMethodsThis prospective, randomized, clinical study comprised 40 eyes of 20 patients scheduled to undergo bilateral LASIK. In each patient, one eye was randomly assigned to receive transcutaneous electrical stimulation (20xa0HZ) for 60 minutes, and the other eye allocated as control. Corneal sensitivity was measured using the Cochet-Bonnet esthesiometer in four areas outside and five areas inside the LASIK flap preoperatively, and at 1xa0day, 1xa0week, 1xa0month, and 3xa0months postoperatively. Best-corrected visual acuity and the incidence of adverse events were noted at each visit.ResultsFor all four points outside the LASIK flap, normal corneal sensitivity was maintained throughout the study; no significant difference was found between the study eyes and the control eyes at these points (Pu2009>u20090.05). All points within the LASIK flap except the point closest to the hinge demonstrated profound corneal hypoesthesia at 1xa0day, 1xa0week, and 1xa0month postoperatively, with no differences noted between the control and study eyes (Pu2009>u20090.05). After 3xa0months, points within the flap had statistically significantly better corneal sensitivity in the study group than in the control group (Pu2009<u20090.05).ConclusionsTranscutaneous electrical stimulation significantly improves corneal sensitivity at 3xa0months after LASIK. This may be due to accelerated corneal nerve regeneration by electrical stimulation.

High vitreous urea rebound in a glaucoma patient with increased intraocular pressure during hemodialysis

Intradialytic elevation of intraocular pressure (IOP) has been reported in patients without glaucoma and also in patients suffering from glaucoma. The most common mechanism underlying the rise in IOP may be a rapid fall in plasma osmolarity with a consequent increase in aqueous formation. Some have suggested that decreased aqueous outflow might be the mechanism of an intradialytic IOP increase, since most of the patients who showed an IOP elevation during hemodialysis also had a shallow anterior chamber angle. Low pCO 2 has also been reported as a cause. Tovbin et al. theorized that high postdialysis urea rebound can predict intradialytic increase in IOP in dialysis patients with lowered intradialytic hemoconcentration. The purpose of this case study is to evaluate the relation between changes in IOP with vitreous and plasma urea concentration before and after hemodialysis. A 55-year-old man presented with ocular pain and elevated IOP (38 mm Hg measured with Goldmann applanation tonometer) in the eye with neovascular glaucoma (NVG) during hemodialysis. The patient’s NVG had been recently diagnosed due to central retinal vein occlusion in his left eye, and IOP was controlled with full medication before hemodialysis. The corrected visual acuity levels were 9/10 OD and 4/10 OS. He had renal failure and was undergoing hemodialysis. The administration of a hyperosmotic agent (300 mL of 25% mannitol) controlled the elevated IOP. We measured the concentration of urea nitrogen in the vitreous humour during intravitreal bevacizumab injection 2 hours after hemodialysis, as well as the concentration of urea in blood taken 1 hour before and 2 hours after hemodialysis during bevacizumab injection. We found a high concentration of urea nitrogen (12.13 mmol/L) in the vitreous humour. The concentration of urea nitrogen in blood 1 hour before hemodialysis was 20.70 mmol/L and 2 hours after dialysis was 4.28 mmol/L. It has been reported that a rapid decrease in plasma osmolarity markedly increased the IOP during hemodialysis. The proposed mechanism was the movement of water from the plasma into the aqueous humour due to an osmotic disequilibrium between the 2 compartments. Our data indicate that the relative increase in osmotic pressure in the vitreous humour caused by the rapid removal of urea from blood by hemodialysis generates an osmotic disequilibrium between the plasma and the vitreous, causing water to shift into the vitreous cavity and IOP to become elevated. In the compromised angle, vitreous swelling can also cause further angle narrowing with forward pushing of the lens–iris diaphragm. For glaucoma patients undergoing regular hemodialysis, further evaluation, including information on osmolarity, blood urea nitrogen, vitreous urea concentration, plasma colloid pressure, and gonioscopic findings, might be meaningful in future studies.

Magnet-Assisted Capsular Bag Fixation to Manage Limited Zonular Weakness During Phacoemulsification

A new technique to manage limited zonular weakness during phacoemulsification is presented in this report. The technique, called magnet-assisted capsular bag fixation, uses the magnetic implant to stretch and fixate the capsular bag over the zonular dehiscence area for patients with limited zonular disruption, which stabilizes the capsular bag and facilitates cataract extraction.

Anterior ciliary artery ligation with simultaneous intravitreal bevacizumab: an adjuvant treatment for end-stage neovascular glaucoma.

Editor, W e read with great interest the article entitled ‘Bevacizumab as adjuvant for neovascular glaucoma’ by Beutel et al., which appeared in the September 2008 issue of Acta Ophthalmologica. In this study patients received an average of 2.75 injections. Additional treatments were laser photocoagulation in 13 (65%) eyes, cyclodestructive procedure in 14 (70%), cryopexy in six (30%), drainage procedures in two (10%), and vitrectomy in five (25%) eyes (Beutel et al. 2008). We would like to share our experience of an interventional case series including six eyes in six patients with central retinal vein occlusion, complicated with angle-closure neovascular glaucoma (NVG). In our case series, mean intraocular pressure (IOP) was 45 ± 6 mmHg before treatment, with maximal antiglaucoma medication and panretinal photocoagulation. Visual acuity ranged from no light perception to poor light perception. All patients gave informed consent and the study was performed in adherence to the tenets of the Declaration of Helsinki and in full compliance with the regulations of our institutional review board. All patients were treated with intravitreal bevacizumab (IVB) (1 mg). In all patients, four rectus muscles were tightly ligated at the insertion to the sclera with proline under local anaesthesia and left under the conjunctiva. All cases experienced a regression of the iris neovascularization (INV) in a mean of 6 days (range 2–12 days, median 6 days). In three eyes (50%) IOP decreased, but in three eyes (50%) antiglaucoma surgery (tubeshunt operations) was performed within 3 weeks of the initial surgery in order to control IOP. At the end of the 6-month followup period, all patients were pain-free and IOP was 18 ± 4 mmHg (range 14–22 mmHg). Iris neovascularization recurred in five eyes and stabilized after repeated IVB. No adverse systemic or ocular complications were observed in any of the patients throughout the follow-up period. Anterior ciliary artery ligation can decrease blood flow to the ciliary body and can reduce aqueous production, which lowers IOP (Kornbleuth et al. 1956). However, it must be reserved for use only in patients with end-stage angle-closure NVG because it carries an increased risk for complications such as visual loss and phthisis (Girard & Beltranena 1960). Intravitreal bevacizumab effectively stabilizes INV activity and controls IOP in patients with INV alone and in early-stage NVG without angle closure. In advanced NVG, IVB cannot control IOP. In one study, 11 eyes (73%) required early surgical intervention within 1 week of the initial IVB injection and a total of 14 eyes (93%) underwent surgery to stabilize markedly elevated IOP, indicating that IVB may be used adjunctively to improve subsequent surgical results (Wakabayashi et al. 2008). Intravitreal bevacizumab treatment of INV in proliferative diabetic retinopathy has shown promising shortterm results, but further studies are needed to evaluate longterm outcomes (Jiang et al. 2008). To conclude, anterior ciliary artery ligation with simultaneous IVB was effective in causing regression of INV and in decreasing IOP and ocular pain in end-stage NVG.