مجله چشم پزشکی بینا
سال بیستم شماره 4 (تابستان 1394)

To evaluate the results of one 60-degree block conjunctival limbal autograft (CLAU) surgery in patients with unilateral total limbal stem cell deficiency (LSCD). Five eyes of 5 patients were included. All patients had a history of chronic total unilateral LSCD due to a chemical injury. Two patients underwent one 60-degree block CLAU with amniotic membrane transplantation, two patients had been complicated by inadvertent trephination of one block of a previous successful two-block CLAU at the time of subsequent corneal transplantation, and the last patient had been complicated by one CLAU segment loss due to loose sutures and premature suture removal. The main outcome of the study was corneal epithelial healing. All patients developed persistent epithelial defect unresponsive to the conservative medical management. To restore epithelial integrity in cases with one-block CLAU, classic two-block CLAU was performed later. In two cases with inadvertent one segment trephination, corneal perforation occurred despite both conservative and surgical management. Tectonic keratoplasty was performed in these two eyes. These grafts developed persistent epithelial defect, which was covered with large sectoral vascularized corneal pannus in one eye and with mucous membrane grafting in the other eye. In the last patient with lost lenticule, cultivated limbal epithelial transplantation was performed to treat the epithelial defect. One-block (60-degree segment) limbal transplantation during conjunctival limbal autograft surgery is not sufficient for anatomical and visual rehabilitation of an eye with total unilateral LSCD.

To investigate the effects of surface ablation excimer surgery on higher-order aberrations and to assess the safety and efficacy of wavefront-guided surface ablation excimer surgery in patients with hyperopia and hyperopic astigmatism. In this analytical & descriptive study, wavefront-guided surface ablation excimer surgery was performed in 58 eyes of 31 patients with hyperopia and hyperopic astigmatism. Preoperative mean manifest spherical equivalent refraction was +2.09±1.19 D (range, +0.75 to +5.00 D) and mean refractive astigmatism was 1.00±1.11 D (range, 0.00 to 3.00 D). All patients underwent wavefront-guided surface ablation (Wfg-SA). The outcome measures included preoperative and 6-month postoperative uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), subjective refraction, and higher-order aberrations (coma, trefoil, spherical aberration, secondary astigmatism, quadrafoil, pentafoil, and total). The higher-order aberrations were measured through 6.00 mm pupils by the Zywave II aberrometer. The mean higher-order aberrations were compared pre- and postoperatively to describe the impact of surgery on the optical quality. There was no significant difference between preoperative and postoperative trefoil (P=0.097). However, the difference in pre- and postoperative coma, secondary astigmatism, quadrafoil, and pentafoil was statistically significant (P<0.05). There was a significant increase in spherical aberration after surgery (P=0.005) which demonstrated a shift toward negative values (opposite sign). Wfg-SA for hyperopia increased the coma, secondary astigmatism, spherical aberration, quadrafoil, pentafoil and total higher order aberrations. There was a 1.74-fold increase in total HOA after hyperopic Wfg-SA which was statistically significant.

This study evaluated the effect of donor and eye bank characteristics on graft rating and clinical outcomes after penetrating keratoplasty (PK) in keratoconus-affected patients. A total of 252 consecutive keratoconic eyes that underwent PK were reviewed in this retrospective interventional case series. Donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density and morphology and graft rating. Postoperative outcomes included visual acuity, refractive error, epithelial problems, suture-related complications, graft rejection, and graft transparency. A multivariate regression analysis assessed correlations between donor and eye bank characteristics and graft quality and postoperative outcomes. Mean recipient and donor ages were 29.7±10.0 and 26.2±8.8 years, respectively. Mean follow-up period was 66.7±38.5 months. Death-to-preservation time was significantly associated with the presence of graft epithelial sloughing (P=0.005) and stromal cloudiness (P<0.001). Donor age significantly influenced endothelial cell density (P=0.02), mean cell area (P=0.04), and hexagonality (P=0.01). The presence of epithelial defects on postoperative day 1 correlated significantly with death-to-preservation time (P=0.004). Graft stromal edema on postoperative day 1 was significantly associated with graft epithelial sloughing (P < 0.001). Postoperative visual and refractive outcomes, complications, and graft survival were not correlated with any donor or eye bank factors. Donor and eye bank variables affected the quality of donor corneas and early postoperative course. However, these effects on clinical outcomes, complications, and graft survival were insignificant.

To evaluate the incidence of the oculo-cardiac reflex (OCR) and its associated risk factors during strabismus surgeries performed at a tertiary referral center between 1390 and 1392. Over a 2-year period, all strabismus surgery candidates were enrolled in the study after obtaining consent from the patients or their parents. Vital signs were recorded before the initiation of the surgery. While the depth of general anesthesia was controlled using the BIS instrument, the heart rate was recorded before and after muscle grasping. OCR was defined as a reduction of 15% or more in the heart rate caused by pulling extraocular muscle(s). Vital signs, especially heart and pulse rate, were monitored after recovery from anesthesia. Seventy-six patients (51.3% male subjects) with a mean age of 15±12 years (range: 2 to 55 years) were enrolled. The mean heart rate was 49±25 bpm (range: 44-152 bpm) before muscle grasping and 77±26 bpm (range: 30-152 bpm) at the conclusion of the operation (P<0.001). OCR occurred in 65 out of 76 (85.5%) patients and with 84 out of 173 (48.6%) operated muscles. The incidence of OCR was higher before 20 years of age; however, it showed a decreasing trend afterwards. OCR was more common during operation on cyclovertical muscles than horizontal ones (p=.02). Moreover, in surgeries on horizontal rectus muscles, OCR was more common if heart rate was more than 61 before surgery (p=.008). OCR was not significantly correlated with sex, type of disease, type of surgery, frequency of the surgery, and the order of operated extraocular muscles. The majority of patients undergoing strabismus surgery, especially younger subjects, those undergoing operation on the cyclovertical muscles and ones with a higher baseline heart rate, experience OCR during strabismus surgery. Due to the possibility of catastrophic consequences of OCR such as cardiac arrest, this matter deserves special attention.

To evaluate demographic and ocular features, etiologies and outcomes of surgery in patients with sensory strabismus as well as to detect factors influencing the type of deviation and outcomes. One hundred and seventy-seven patients with strabismus related to low vision included in this interventional case series. Data related to demographic features, visual acuity, refraction, etiologies of low vision, age at the time of visual loss and age of deviation onset, type and amount of deviation, type of surgery and its outcomes after 2 months and at the last follow up visit was collected from the patients’ records. The association between ocular parameters and the direction of deviation and results of surgery was investigated. The mean patient age was 24.4±11.4 years and 110 (62%) patients were male. The mean follow up period was 30 months. One hundred and seventeen (66.1%) patients were exotropic and 60 (33.9%) patients were esotropic (P=0.035). The mean age at the time of visual loss in the esotropic group was lower than that in the exotropic group (5.8±7.2 vs. 11.1±9.7 years, P=0.001). The main causes of visual loss in the esotropic and exotropic patients were congenital and acquired, respectively (P<0.001). The most common congenital etiologies were anisometropia and cataract whereas, the most common acquired cause was trauma. The most common refractive error was hyperopia in the esotropic patients and myopia myopia in the exotropic patients (P=0.01). The mean axial length of the normal fellow eye was significantly shorter in the esotropic patients (22.18±1.24 vs. 23.15±1.77 mm, P=0.001). At the last examination, 69% of patients were orthophoric. Overcorrection and undercorrection more than 20 PD were observed in 4.6% of patients. The success of the surgery correlated significantly with the preoperative amount of deviation (P=0.003) and visual acuity (P=0.026) The most common type of deviation in sensory strabismus is exotropia and its most common cause is ocular trauma. Exotropic patients are predominantly myopic with higher axial lengths in comparison with esotropic patients. Outcomes of surgery in sensory strabismus are acceptable. Preoperative amount of deviation and visual acuity of the deviated eyes were two important factors influencing final outcomes.

To evaluate the nature of obstruction in difficult irrigation after probing for congenital nasolacrimal duct obstruction (CNLDO). In a prospective interventional study, the nature of obstruction in 75 eyes of 68 children aged between 12 and 23 months with CNLDO who had difficult irrigation after probing was evaluated. All patients underwent monocanalicular silicone intubation. The nature of obstructions was classified by the surgeon as simple or complex. Monocanalicular silicone intubation was performed in 75 eyes of 68 patients with CNLDO. The mean age of patients was 15.92±3.7 months (range: 12-23 months). Thirty-eight of 75 eyes (50.7%) had a simple obstruction, whereas, 37 of 75 eyes (49.3%) had a complex obstruction. There was no significant difference in incidence of simple or complex obstructions (P=1). The nature of obstruction was not predictive of difficult irrigation after probing.

To compare peripapillary retinal nerve fiber layer (RNFL) thickness among multiple sclerosis (MS) patients with or without a history of optic neuritis (ON) and a healthy control group. In this retrospective case-control study, 59 MS patients were recruited from a neurology clinic of Imam Hossein hospital. Of which, 36 patients had at least one episode of ON and 23 others had no history of ON. Control group included 30 healthy individuals. Peripapillary RNFL thickness was measured in all cases using Stratus spectral domain optical coherence tomography (OCT). Average RNFL thickness was significantly lower in MS patients with a history of ON compared to MS patients without ON (86.6±11.81 vs. 95.04±11.29 microns, respectively; P<0.001). Both patient groups had lower mean RNFL thickness as compared to the control group (105.83±8.32 microns; P<0.001). The greatest difference was observed in the inferior quadrant followed by the superior quadrant. Patients with unilateral ON demonstrated thinner RNFL (81.52±12.31 microns) in the affected eyes compared to the contralateral unaffected eyes (93.83±10.46 microns, P<0.001). Furthermore, patients with progressive MS had thinner RNFL compared to those with a relapsing remitting course, although the difference was not statistically significant (86.2±13.38 vs. 89.79±12.46 microns, respectively; P>0.05). Patients with the disease lasting between 1 and 5 years had thinner RNFL than those with a duration less than one year (88.87±12.5 vs. 99.07±8.19 microns, respectively; P<0.05). RNFL thickness did not differ in patients with only one ON attack from those with multiple attacks (88.48±12.59 vs. 84.31±10.87 microns, respectively; P>0.05). Measuring RNFL can quantitatively provide an index of axonal damage in MS patients and estimate disease progression and subsequent disabilities.

Optisol-GS is still the most popular cold storage medium used in the United States for short term preservation of donated corneas. CEBI medium is a new cold storage medium made by the Central Eye Bank of Iran for donor cornea storage. This study was conducted to compare the quantitative and qualitative indices of the donated corneas maintained in Optisol-GS versus in the CEBI medium. In this prospective single-blind study, two corneas from each donor with a minimum of ‘‘an apparent fair cornea rating’’ were preserved in corneal maintenance media; randomly one in Optisol-GS and the other in CEBI. After 24 hours, slit-lamp biomicroscopic and specular microscopic examinations were performed and the qualitative and quantitative indices as well as final cornea rating were compared between the two media. Qualitative indices of the corneas in each medium before and after preservation were also compared. Three hundred and ninety-six corneas from 196 donors with a mean age of 35.7±14.3 years were enrolled: 194 corneas in Optisol-GS and the other 202 in the CEBI. There was no significant difference between the two media in terms of endothelial cell density, mean cell area, polymegathism, polymorphism, and vacuolation of endothelial cells. Corneal endothelial rating, Descemet’s folding, and stromal edema observed in donated whole globes improved significantly after preservation of the excised corneas in both Optisol-GS and CEBI media, with no difference between the two media. The results of this study show that the CEBI storage medium is comparable to Optisol-GS in short-term preservation of excised donated corneas. The CEBI medium can be considered as a suitable substitute for Optisol-GS.

Macular edema following diabetic retinopathy is one of the ocular complications associated with diabetes, and it is the leading cause of visual loss in the active young and middle aged population in developed countries. While all patients with diabetes particularly those with diabetic retinopathy are at increased risk of developing eye complications, early detection and timely intervention may prevent or delay loss of visual acuity. Systemic management of diabetes through combined control of blood sugar, hypertension, and hyperlipidemia has remained the most effective method to prevent diabetic retinopathy and its progression. Development of diabetic retinopathy and related complications require, surgical and medical interventions including photocoagulation, vitrectomy, and intravitral drug injection to preserve vision. Considering recently most popular treatment of diabetic macular edema (DME) including intravitreal anti-vascular endothelial growth factor (VEGF) agents, several issues such as ideal regimen, duration of treatment, combination therapy and long -term safety have remained unanswered yet and deserve further investigations. In this review, all the articles that had investigated such treatment modalities for DME as well as pharmacokinetic, efficacy, safety, dose and frequency of intravitreal pharmacologic agents and also the effect of macular ischemia, initial macular thickness and optical coherence tomographic patterns of DME on the final outcomes of treatment with Intravitreal drugs are reviewed. In summary, literature searches reveal that almost all studies that have been published up to now provide some evidence that support the use of intravitreal anti-VEGF agents for treatment of either naïve or persistent DME in short and long term up to two years.

To report the development of cataract after corneal damage by Dungle beetle prongs.Case Report: A 28 year-old man, resident of the village Chah Setareh, Sabzevar, presented complaining of trauma to the right eye with the Dangle beetle while motorcycling. Slit lamp examination revealed six corneal perforations, hyphema (50% of anterior chamber) percent, iris sphincter rupture, and rupture of the anterior lens capsule. Corneal perforations measuring 0.1 mm each were arranged horizontally with a distance of 1 millimeter from each other. Corneal perforations self-sealed after 24 hours. One week later, lens materials were evident in the anterior chamber and intraocular pressure increased to 30 mm Hg. The patient underwent phacoemulsification with foldable posterior chamber intraocular lens implantation. One week after cataract surgery, corrected visual acuity was 0.7. It is prudent to use a helmet while motorcycling to reduce ocular injuries.

To report a rare malignant melanoma with chalazion-like presentation. Case Report: A 36-year old woman with a chalazion-like mass in the left upper lid, having been resected twice, was referred to our center for the management of recurrence. The total resection of the suspicious area was done. Histopathologic examination confirmed the diagnosis of malignant melanoma. The appropriate reconstructive surgery was performed. This case report highlights that the pathologic examination is necessary for any suspicious or recurrent chalazion-like lesions. Malignant melanoma is a rare lesion which may present with various types. This impression should be kept in mind in approach to any suspicious lesion including recurrent chalasia and other pigmented lesions and pathologic evaluation is necessary in such cases