BINA
Year:2016 | Volume:21 | Issue:3 (84)|Papers Count:13

Purpose: To develop a nanofibrous polycaprolacton (PCL) substrate for limbal stem cell (LSC) expansion that can serve as a potential alternative substrate to replace human amniotic membrane.Methods: The human Limbal stem cells (LSCs) were used to evaluate the biocompatibility of substrates (nanofibrous scaffold, and human amniotic membrane) regarding cellular phenotypic profile, viability, proliferation, and attachment ability.Results: Biocompatibility results indicated that the substrates were highly biocompatible, as LSCs could favorably attach and proliferate on the nanofibrous surface. Microscopic figures showed that the human LSCs were firmly anchored to the substrates and were able to retain a normal corneal stem cell phenotype.Microscopic analyses illustrated that cells infiltrated the nanofibers and successfully formed a threedimensional corneal epithelium, which was viable for two weeks. Immunocytochemistry (ICC) and real time–PCR results revealed no change in the expression profile of LSCs grown on nanofibrous substrate when compared to those grown on human amniotic membrane.Conclusion: Electrospun nanofibrous PCL substrate provides not only a milieu supporting LSCs expansion, but also serves as a useful alternative carrier for ocular surface tissue engineering and could be used as an alternative substrate to human amniotic membrane.

Purpose: To design and manufacture Iodine 125 radioactive plaques which can be used in patients with ocular melanoma, and to evaluate the efficacy of plaques in an animal model.Methods: This prospective basic study was performed in collaboration with Farabi hospital and Tehran atomic energy agency. The Iodide 125 plaques were designed and manufactured based on the Collaborative Ocular Melanoma Study (COMS) designation rules.Results: The plaques were manufactured from gold according to the COMS designation rules. Each plaque contained a layer of Iodine 125 particles with an approximate activity of 5 millicurie for each particle. The radiation dosimetry was performed using radiochromic films (HD-810) and film scanner and Osiris software. The results indicated that the absorbed dose was along the central axis of the both manufactured phantoms. The results of the animal study revealed that the plaques had destructive effects of radiation on the retina, choroid and sclera of five rabbit eyes. The destructions were dose dependent and increased with the escalation of radiation dose.Conclusion: The I125 plaques manufactured in the present study had sufficient and dose dependent destructive effects on the retinal and choroidal structures of rabbit eyes in the implanted areas. These plaques were free from chemical toxicity.

Purpose: To evaluate endothelial cell density (ECD) and morphology of clear corneal grafts after Descemet stripping automated endothelial keratoplasty (DSAEK) and to determine the factors that influence graft ECD postoperatively.Methods: Seventy-seven eyes (38 right eyes) of 64 patients (34 female subjects) who underwent DSAEK for Fuchs’ endothelial dystrophy (n=38) or pseudophakic bullous keratopathy (n=39) were enrolled. Precut donor corneas were punched from the endothelial side using a trephine. The donor lamella was inserted into the anterior chamber using the pull-through technique with a Busin glide and forceps through a 5-mm clear cornea incision. In eyes with significant lens opacity, DSAEK was combined with cataract surgery. Confocal microscopy was performed at the final follow up examination to evaluate endothelial cell count and morphology as well as central graft thickness. Univariate analyses and multiple linear regression analyses were used to investigate recipient-, donor-, surgical-, and postoperative-related variables capable of influencing graft endothelial counts after DSAEK.Results: Mean age at the time of surgery was 62.3±15.6 years, and the patients were followed for 26.2±20.9 months postoperatively. Forty-six eyes (59.7%) underwent stand-alone DSAEK, whereas 31 eyes (40.3%) received DSAEK combined with cataract surgery. Donor trephination size was 8.0±0.21 mm, ranging from 7.50 to 8.25 mm. Mean donor age was 30.4±11.2 years and preoperative endothelial cell density was 3127.4±315.1 cells/mm2 which reduced to 1788.6±716.5 cells/mm2 postoperatively (P<0.001). Mean postoperative central graft thickness was 102.4±31.6μm. In the univariate analysis, postoperative ECD was significantly associated with death-to-preservation time (r=-0.31, P=0.046), central graft thickness (r=0.36, P=0.016), followup period (r=-0.56, P=0.005), and lenticule non-attachment (r=-0.31, P=0.049). Multiple regression analyses identified lenticule thickness (=10.62, P=0.003) and follow-up period (=-22.09, P=0.001) as the statistically significant characteristics influencing postoperative ECD.Conclusion: The main predictors of ECD after DSAEK were central graft thickness and the length of followup.Surgeons’ requests for ultrathin DSAEK donor grafts with the hope of improving visual outcomes may not have the desired outcome with respect to the postoperative ECD.

Purpose: To report the evolving indications for keratoplasty and the shift in the technique of keratoplasty performed in Iran over an 8-year period.Methods: This was a retrospective database review of 47, 129 records of corneal transplant tissues at the Central Eye Bank of Iran, from March 2006 to March 2013. The patient demographics, indications, and techniques of corneal transplantation performed were analyzed.Results: The six leading indications were keratoconus (KCN, n=21, 350 eyes, 45.3%), followed by bullous keratopathy (BK, n=8, 566 eyes, 18.2%), corneal opacity and scar (COS, n=7, 158 eyes, 15.2%), graft failure (n= 3, 252 eyes, 6.9%), corneal dystrophies (n=2, 553 eyes, 5.4%), and infectious keratitis (n=2, 238 eyes, 4.7%).Penetrating keratoplasty (PKP) accounted for 71.0% (n=33, 476) of all keratoplasties performed. Since the introduction of Descemet stripping automated endothelial keratoplasty (DSAEK) in Iran in 2008, there was a significant increase in the number of DSAEK (P<0.001) and a statistical decline in the number of PKP (P< 0.005). No significant change was observed in the number of deep anterior lamellar keratoplasty (DALK), tectonic graft, and keratolimbal allograft (KLAL), during the 8-year period (P=0.354, P=0.999, and P=0.151, respectively). An increasing trend in the frequencies of BK (P=0.001) and graft failure (P=0.025), and a decreasing trend in the frequency of COS (P=0.012) were observed. No significant change of frequencies was noted in the prevalence of KCN (P=0.172), infectious keratitis (P=0.107), and corneal dystrophies (P=0.836).Conclusion: KCN is still the leading indication for keratoplasty in Iran, with no significant change of trend over the 8-year period. There was an increasing trend in the rate of DSAEK while PKP demonstrated a decreasing trend; which indicates a shift from PKP to DSAEK performed for corneal endothelial disorders.

Purpose: To investigate demographic, clinical and histopathologic features of consecutive exotropia.Methods: Patients with consecutive exotropia who underwent surgery in Farabi hospital between September 2014 and April 2015 were enrolled in this study. After complete ophthalmologic examination and far and near deviation measurement, all patients with negative forced duction test underwent 4-mm medial rectus resection and advancement. Intraoperative absence of muscle fiber visualization according to surgeon’s opinion was documented and compared with histopathology results. The histopathologic results were compared between 30 cases of consecutive exotropia and 11 cases who underwent 4-mm resection of the medial rectus muscle with no previous surgery on the medial rectus muscle (controls). A dose-response relationship was calculated for medial rectus resection and advancement in consecutive exotropic patients.Results: Thirty eyes of 30 patients with consecutive exotropia were evaluated. Muscle fibers were not observed intraoperatively in 40% of eyes. No correlation was found between surgical success and the absence of muscle fiber visualization at insertion. Dose-response was approximately 4.4 prism diopter per millimeter of resection and advancement of the medial rectus muscle.Conclusion: Intraoperative absence of muscle fiber visualization was an important cause of consecutive exotropia that could be due to stretched scar and muscle slippage. This could be documented by histopathology using Masson trichrome staining. The dose-response relationship calculated in consecutive exotropic patients in the present study can help us better manage these patients. Medial rectus underaction may be a risk factor for absence of muscle fiber visualization at insertion. The outcome of surgery can be predicted based on the intraoperative visualization of muscle fiber at insertion.

Purpose: To report clinical outcomes of crystalline lens extraction and iris claw Artisan intraocular lens (IOL) implantation in patients with lens subluxation secondary to Marfan syndrome.Methods: This retrospective study enrolled 14 eyes of 12 Marfan patients with lens subluxation who underwent crystalline lens removal and Artisan IOL implantation. Pre- and post-operative data, including patient demographics, pre and post-operative comorbidities and complications were compiled. Measured outcomes were visual acuity and occurrence of complications. Uncorrected visual acuity (UCVA), bestcorrected visual acuity (BCVA) and spherical equivalent (SE) refraction were compared before and after lens extraction and IOL insertion.Results: The mean patient age was 30.03 ± 15.02 years and the mean post-operative follow-up duration was 44.5 ±16.4 months. The mean BCVA showed a significant improvement from 0.5 ± 0.3 at the baseline to 0.2 ±0.2 postoperatively (P=0.006). SE refraction significantly decreased from -11.38 ± 1.99 D preoperatively to -0.45 ±1.65 D postoperatively (P=0.003). The IOL position was desirable in all eyes except one which had IOL dislocation. One eye developed retinal detachment. No other complication such as ocular hypertension, angle abnormalities, clinical cystoids macular edema, or corneal decompensation was observed during the follow-up period.Conclusion: Artisan IOL implantation after lens extraction appeared to be an appropriate alternative for optical correction in cases of Marfan syndrome with ectopia lentis. It resulted in a significant improvement in visual acuity with an acceptable complication profile.

Purpose: To measure macular thickness in normal subjects with respect to age and gender using Cirrus HDOCT in Rasht city.Methods: In this cross-sectional study, 112 normal subjects were randomly selected. Both eyes of each subject were included and all subjects underwent complete eye examinations. Macular thickness map protocol with macular cube 512×128 was selected, and the average thickness of the retina was determined in nine ETDRS regions. To assess the reproducibility and the system’s degree of confidence, the thickness of the retina was measured up to five times in ten healthy subjects, and then the coefficient of variation was measured for each individual. All obtained data were analyzed using SPSS statistical software version 16.Results: The coefficient of variation of macular thickness was 0.15-1.33% in the 1-mm central area. The mean±SD of central subfield thickness (CST), macular thickness (MT), and macular volume (MV) were 245.44±20.39mm, 277.9±11.95 mm and 9.98±0.43 mm3, respectively. The mean CST (p<0.0001), MT (p=0.038), and MV (p=0.030) were significantly greater in men than women. Regardless of age and sex, macular thickness increased from the 1-mm central area to the 3-mm and 6-mm ETDRS regions. Therefore, the upper 3-mm was the thickest and the temporal 6-mm was the thinnest area.Conclusion: The mean macular thickness in healthy subjects was 280.67±12.79mm in men and 276.63±11.61 mm in women with 95% confidence interval. This value was significantly greater in men than women.

Dry eye syndrome is a highly prevalent ocular disorder affecting millions of people worldwide. It is a debilitating condition and can affect the quality of life. Patient-physician contact is of essential importance for the management of dry eye syndrome. Artificial tears of various kinds are important in mild cases. Lid hygiene, a short course of topical steroids and systemic tetracycline are recommended in moderate to severe cases. Punctual occlusion is advisable in special cases. This review article provides updates on the current treatment of dry eye syndrome.

Purpose: To describe three cases of exotropic Mobius syndrome and to report outcomes of the surgical intervention.Case Reports: Three patients including two boys and one girl were referred to our strabismus clinic. All had masked faces and non-progressive congenital bilateral facial palsy and dry eye. Other abnormalities included large angle exotropia and bilateral horizontal gaze palsy. Surgical interventions, which were performed in the first two cases, included bilateral lateral rectus disinsertion followed by bimedial rectus resection in two separate sessions. Occlusion of the puncti and tarsorrhaphy were performed to treat dry eye. Strabismus surgery led to orthotropia with no change in gaze limitations. The third patient declined surgical intervention.Conclusion: The two-step surgical intervention including bilateral lateral rectus disinsertion followed by bimedial rectus resection can effectively treat strabismus in exotropic Mobius syndrome. Dry eye symptoms which are common in this type of Mobius syndrome require special attention.