Stem cell therapy in stargardt disease: a systematic review

This article aimed to review current literature on the safety and efficacy of stem cell therapy in Stargardt disease. A comprehensive literature search was performed, and two animal and eleven human clinical trials were retrieved. These studies utilized different kinds of stem cells, including human or mouse embryonic stem cells, mesenchymal stem cells, bone marrow mononuclear fraction, and autologous bone marrow-derived stem cells. In addition, different injection techniques including subretinal, intravitreal, and suprachoroidal space injections have been evaluated. Although stem cell therapy holds promise in improving visual function in patients with Stargardt disease, further investigation is needed to determine the long-term benefits, safety, and efficacy in determining the best delivery method and selecting the most appropriate stem cell type.

Posterior sub-tenon's bevacizumab injection in diabetic macular edema; a pilot study

Purpose: To evaluate the short-term results of sub-tenon's injection of bevacizumab in patients with clinically significant macular edema [CSME]

Methods: In this prospective non comparative interventional case series, sub-tenon's injection of 2.5 mg/0.1 ml bevacizumab was performed for eyes with CSME. Macular thickness and best corrected visual acuity measurements were performed before and one month after injections

Results: Nineteen eyes of twelve patients with a mean age of 59.8 +/- 5.7 years were evaluated. Thirteen eyes [68.4%] had center-involving macular edema. No significant difference was observed between pre- and post-injection central subfield retinal thickness measurements [P = 0.3]. Central subfield thickness measurements improved or remained unchanged in 13 eyes [68.4%]. Baseline BCVA of 0.48 +/- 0.35 LogMAR improved to 0.36 +/- 0.26 LogMAR after injection [P = 0.01]. Improvement of >2 lines in BCVA was found in 5 eyes [26.3%], and no eye lost >2 lines of BCVA. No complication associated with sub-tenon's injection was observed

Conclusion: Sub-tenon's injection of bevacizumab resulted in significant short-term visual improvement in eyes with CSME. Retinal thickness changes were not significant

Peripapillary nerve fiber layer thickness changes after macular photocoagulation for clinically significant diabetic macular edema

To evaluate the effect of macular photocoagulation [MPC] on peripapillary nerve fiber layer [PNFL] thickness measurement in patients with clinically significant diabetic macular edema [CSME]. This study was a prospective interventional case series. Patients with CSME underwent MPC. Optical coherence tomography [OCT] was used to measure the PNFL and central macular thicknesses before and 3 months after MPC. Thirty-three eyes of 25 patients with a mean age of 59.4 +/- 7.2 years were included. There was no statistically significant difference between pre- and post-MPC mean best corrected visual acuity [0.35 +/- 0.29 and 0.40 +/- 0.23 LogMAR, respectively, P = 0.2]. Mean baseline and 3 months central macular subfield thickness was 305.9 +/- 90.7 and 317.5 +/- 112.4 microns, respectively [P = 0.1]. Peripapillary nerve fiber layer thickness was 105.7 +/- 10.0 before and 106.1 +/- 9.9 three months after MPC [P = 0.7]. No significant differences were found between pre and post MPC measurements in temporal, nasal, inferior and superior nerve fiber layer thickness in each quadrant around optic nerve head [P > 0.05]. Macular photocoagulation has no statistically significant effect on PNFL thickness measurements in patients with CSME

Effect of homatropine eye drops on pain after photorefractive keratectomy: a pilot study

To assess the effect of homatropine eye drops on pain after photorefractive keratectomy [PRK]. This randomized, double masked, interventional study included 15 patients [30 eyes] who underwent bilateral PRK. After operation, patients received homatropine eye drops, 4 times daily in only one eye [homatropine eye]. The level of pain was evaluated using visual analogue scale [VAS], verbal rating scale [VRS] and pain rating index [PRI] at 0.5, 24 and 48 h after operation. The level of pain was statistically similar between the two eyes half an hour after operation, however, homatropine eyes had significantly less pain 24 h after operation compared to fellow eyes [2.5 +/- 1.9 vs 5.3 +/- 2.5, P = 0.004 for VAS, 2.0 +/- 1.2 vs 3.2 +/- 0.9, P = 0.023 for VRS, and 9.4 +/- 5.7 vs 16.0 +/- 9.0, P = 0.031 for PRI]. Also, 48 h after surgery, the pain scales were less in the homatropine eyes [2.3 +/- 1.7 vs 4.0 +/- 2.1, P = 0.014 for VAS, 1.6 +/- 1.0 vs 2.5 +/- 1.0, P = 0.038 for VRS, and 6.8 +/- 5.7 vs 12.0 +/- 8.9, P = 0.005 for PRI]. No delayed epithelial healing was observed. Homatropine eye drops may be useful for reducing pain after Photorefractive keratectomy

Anterior segment study with the Pentacam Scheimpflug camera in refractive surgery candidates

The purpose of this study was to evaluate the anterior segment measurements according to refractive status in a sample of the Iranian population. Rassoul Akram Hospital, Tehran University of Medical Sciences. In this study, refractive surgery candidates were assigned according to the refractive error to one of three groups: emmetropia, myopia, and hyperopia. Myopic eyes were further divided to four Subgroups: simple myopic group, simple myopic astigmatism group, high myopic group, and high myopia with astigmatism group. Anterior segment measurements with the Pentacam Scheimpflug system were performed in the right eye of all subjects. The study sample was comprised of 283 subjects with a mean age of 29.1 +/- 7.5 [standard deviation] years. Mean keratometry reading, Anterior chamber depth [ACD] and volume measurements were significantly higher in the myopic group and mean keratometry reading and anterior chamber angle measurements were significantly lower in the hyperopic group [P < 0.05, all comparisons]. Maximum anterior elevation [AE[max]] and maximum posterior elevation [PE[max]], Q value, progression index, minimum corneal thickness, and corneal volume measurements were similar for all groups [P > 0.05, all comparisons]. In the myopic subgroups, AE[max] and PE[max] and maximum keratometry [K[max]] were significantly higher, and ACD was lower in the astigmatic groups [P < 0.05, all comparisons]. The Q value was less negative in low myopia [P < 0.05]. Myopic eyes had steeper corneas than hyperopic eyes and anterior chamber measurements were significantly higher in the myopic eyes. In myopic eyes, AE[max] and PE[max] and K[max] measurements were higher, and ACD measurements were lower in the astigmatic groups

Vitrectomy for posterior segment intraocular foreign bodies, visual and anatomical outcomes

To evaluate the visual and anatomic results and determine the prognostic factors after pars plana vitrectomy and posterior segment intraocular foreign body [IOFB] removal. This retrospective study reviews the patients' charts of 48 consecutive patients with posterior segment IOFB who underwent pars plana vitrectomy and IOFB removal over a 4-year period, recently. Association between visual outcome and various preoperative, operative, and postoperative variables was statistically analyzed. Data were analyzed with the paired t-test and the chi square test. Statistical significance was indicated by P < 0.05. The mean interval between the time of injury and IOFB removal was 24 +/- 43.1 days and 27 [53%] eyes underwent IOFB removal within 7 days of the injury. Nine [19.1%] patients achieved a visual acuity of 20/40 or better. An improvement of visual acuity of at least three lines occurred in 21 [44.6%] eyes and the vision remained unchanged in 15 [31.9%] eyes. Postoperative retinal detachment occurred in five [10.6%] eyes. Visual improvement was more likely to occur in eyes with lower levels of presenting visual acuity [P = 0.2]. Visual improvement was not associated with an entry site and IOFB location, lens injury, time to surgery, and pre- and post-operative retinal detachment. At the end of follow up, anatomical success was achieved in 97.9% of eyes. High anatomical success could be achieved after the removal of posterior segment IOFBs by vitrectomy, despite a delay in surgery. Poor visual outcome may be mainly due to the initial ocular injury

Intravitreal bevacizumab for pseudophakic cystoid macular edema; a systematic review

Cystoid macular edema [CME] is a major cause of decreased vision after complicated or uncomplicated cataract surgery. This paper reviews the use of intravitreal bevacizumab [IVB] injection for treatment of pseudophakic CME. In a literature search of all articles available on Medline and Scopus databases, 11 studies including one prospective and 4 retrospective studies, 4 case reports, one letter to editor and one review article were identified. All articles except one, reported the use of IVB for chronic CME unresponsive to at least one conventional treatment modality. The level of evidence for all studies was categorized as low or very low. Although intravitreal bevacizumab might be effective for many cases of pseudophakic CME, its use should be reserved for eyes unresponsive to conventional treatment modalities.

Isolates and antibiotic resistance of culture-proven endophthalmitis cases presented to a referral center in Tehran

To evaluate the spectrum of organisms causing endophthalmitis and their resistance pattern to standard antimicrobial agents. Medical records of culture positive eyes treated at Rassoul Akram Hospital for endophthalmitis during the past 5 years were reviewed. Specimens were obtained during pars plana vitrectomy or vitreous tap. Sixty-five isolates including 36 [55.4%] gram-positive organisms, 28 gram-negative organisms [43.1%], and 1 [1.5%] fungus were studied. The most common organism identified was Coagulase-negative staphylococcus in 16 eyes [24.6%]. Among the antibiotics available for intravitreal injection, the least antibiotic resistance was for vancomycin in gram-positive organisms and amikacin and ceftazidime in gram-negative isolates. Gram-positive isolates were the most prevalent organisms; however, a high isolation rate for gram-negative organisms was obtained. Considering that no single antibiotic provides coverage for all of the organisms, a combination therapy using vancomycin/amikacin or vancomycin/ceftazidime seems to be useful as the initial empiric treatment of suspected bacterial endophthalmitis

Scleral fixation of dislocated intraocular lenses by haptic externalization through a clear corneal incision

Several techniques have been employed for repositioning dislocated intraocular lenses [lOLs]. Herein, we describe a simplified and modified technique in which scleral fixation is performed together with temporary externalization of IOL haptics through a small, superior clear corneal incision. The sutures are tied to the externalized haptics; the haptics are then repositioned into the anterior chamber followed by IOL reim-plantation into the ciliary sulcus. Using this technique, the dislocated IOL is repositioned under direct visualization without need for IOL extraction or extensive intraocular manipulations

Normal values of standard full field electroretinography in an Iranian population

To determine normal values of standard full-field electroretinography [ERG] and to evaluate their variations with age in an Iranian population. Through convenient sampling, 170 normal subjects 1-80 years of age were selected from residents of Tehran. ERG amplitudes and implicit time values were measured according to recommendations by the International Society for Clinical Electrophysiology of Vision. Evaluations consisted of light-adapted ERG including single-white flash and 30-Hz flicker response; and dark-adapted ERG including rod, maximal dark-adapted and cone responses. No significant difference in ERG values was observed between men and women, or between right and left eyes. ERG amplitudes were lower [P=0.04] and implicit time values were greater [P=0.03] in subjects 70-80 years of age as compared to younger individuals. ERG parameters are significantly diminished with age. Our results may serve as a reference against which standard ERG responses can be compared

Correlation between retinal nerve fiber layer thickness by optical coherence tomography and perimetric parameters in optic atrophy

To investigate the correlation between retinal nerve fiber layer [RNFL] thickness determined by optical coherence tomography [OCT] and visual field [VF] parameters in patients with optic atrophy. This study was performed on 35 eyes of 28 patients with optic atrophy. RNFL thickness was measured by OCT [Carl Zeiss, Jena, Germany] and automated perimetry was performed using the Humphrey Field Analyzer [Carl Zeiss, Jena, Germany]. The correlation between RNFL thickness and VF parameters was evaluated. Mean global RNFL thickness was 44.9 +/- 27.5] which was significantly correlated with mean deviation score on automated perimetry [r=0.493, P=0.003]; however, no significant correlation was observed between visual field pattern standard deviation and the corresponding quadrantic RNFL thickness. In a similar manner, no significant association was found between visual acuity and RNLF thickness. Mean global RNFL thickness as determined by OCT seems to be correlated with VF defect depth as represented by the mean deviation score on Humphrey VF testing. OCT may be used as an objective diagnostic tool in the evaluation of patients with optic atrophy

Two different doses of intravitreal bevacizumab for treatment of choroidal neovascularization associated with age-related macular degeneration

To compare the efficacy and safety of 1.25 mg versus 2.5 mg intravitreal bevacizumab [IVB] for treatment of choroidal neovascularization [CNV] associated with age-related macular degeneration [AMD]. In this randomized clinical trial, consecutive patients with active CNV associated with AMD received 1.25 mg or 2.5 mg IVB. Best corrected visual acuity [BCVA], foveal thickness and side effects of therapy were evaluated one and three months after intervention. Overall 86 subjects were enrolled and completed the scheduled follow-up. Forty seven and 39 patients received 1.25 and 2.5 mg IVB respectively. The study groups were balanced in terms of baseline characteristics such as age, BCVA and foveal thickness. Mean improvement in BCVA was 0.06 +/- 0.3 logMAR in the 1.25 mg group and 0.07 +/- 0.34 logMAR in the 2.5 mg group [P=0.9]. Mean decrease in foveal thickness was 49 +/- 36 micro m in the 1.25 mg group and 65 +/- 31micro m in the 2.5 mg group [P=0.6]. Three cases of vitreous reaction and one case of massive subretinal hemorrhage were observed in the 2.5 mg group. Double dose [2.5 mg] IVB does not seem to be more effective than regular dose [1.25 mg] injections for treatment of CNV due to AMD and may lead to more complications

Results of amblyopia therapy in unilateral organic ocular abnormalities

To evaluate the visual results of amblyopic therapy in pediatric patients with monocular abnormalities. The hospital records of visually immature patients with unilateral organic ocular abnormalities and decreased visual acuity, who presented to the pediatric ophthalmology clinic over a one year period, were reviewed. Those who had 8 years old of age or less and underwent amblyopic treatment included in the study. Amblyopia was defined as visual acuity difference of more than 2 lines between the two eyes, absence of central fixation or fixation with inability to maintenance. Amblyopic treatment had been performed using full time occlusion method for one month and then reevaluation of the patient. Twenty patients [8 males and 12 females] with the mean age of 4 +/- 3.12 years [range: 1 to 8 years] were included in the study and were followed for a mean of 6 years [range: 2 to 8 years]. No patient was excluded from the study due to loss of follow-up. Among those who were able to read the chart [16 patients], the visual acuity increased from 3 meters counting fingers [range: 1 to 5 meters counting fingers] before treatment to 4/10 [range: 2/10 to 6/10] in last visit [P<0.01]. In 4 remaining eyes visual acuity increased from central to steady or steady and maintenance. A trial of full-time occlusion for visually immature patients with decreased visual acuity associated with unilateral organic ocular abnormalities specially traumatic or surgical injuries is recommended

Vitreopapillary traction in nonarteritic anterior ischemic optic neuropathy

To describe the association between vitreous traction on the optic disc and nonarteritic anterior ischemic optic neuropathy [NAION]. Eighty three eyes of 83 patients with NAION were evaluated by optical coherence tomography [OCT] for detecting vitreous adhesion to the optic nerve head with separation from the adjacent retina [partial posterior vitreous detachment]. Eyes which were negative for such adhesion underwent ultrasonography to detect complete posterior vitreous detachment [PVD]. Fifty male and 33 female subjects with mean age of 51.9 +/- 10 years were studied. Partial PVD with optic nerve head adhesion was found in 54 patients [65.1%] using OCT. Ultrasonography detected complete PVD in all other eyes with optically empty spaces on OCT. Vitreous traction on the optic nerve head from partial PVD may play a causative role in some cases of NAION. This traction may impair vascular supply and/or axoplasmic flow leading to signs and symptoms of NAION