BINA
Year:2012 | Volume:18 | Issue:1 (70)|Papers Count:22

Purpose: To compare the frequency and severity of anterior segment ischemia (ASI) after disinsertion of 2, 3 and 4 rectus muscles in rabbit eyes, to evaluate the clinical course of the condition without any therapeutic intervention, and to report the histopathological features of affected eyes.Methods: This is a prospective experimental study on rabbit eyes. One eye of all rabbits randomly underwent three muscles surgery including disinsertion and myectomy, and in the fellow eye either 2 or 4 rectus muscles were operated. Each eye was examined daily in order to detect the presence of ASI, severity of inflammation and duration of involvement until complete resolution of inflammatory signs. Finally the involved eye and the non-involved eye of the same rabbit were enucleated and studied by a pathologist. The results in each group and subgroups were compared and statistically analyzed.Results: 84 rabbits were operated and examined, in 42 animals one eye underwent three and the fellow eye underwent two rectus muscle surgery; in the other 42 rabbits, one eye underwent three muscles and in the fellow eye four rectus muscles were operated. The incidence of ASI was 4 eyes (9.5%) in two muscle group, 26 eyes (31%) in the three muscle group and 21 eyes (50%) in the four muscle group (P=0.001). Inflammation improved spontaneously in all cases of ASI within about two weeks and histopathology study was reported within normal limits in most cases.Conclusion: In all eyes with ASI, the inflammation resolved spontaneously without therapeutic intervention in an almost similar period of time; destruction or loss of the eye was not detected in any case. ASI is a selflimiting complication of strabismus surgery and may be less disastrous than what was thought before.

Purpose: To assess the results of combined penetrating keratoplasty and cataract extraction by extracapsular extraction versus phacoemulsification and to compare outcomes and complications.Methods: In this interventional retrospective study, 76 eyes that had undergone triple surgery were included.Cataract surgery was done in two different methods of extracapsular extraction and phacoemulsification. In the extracapsular group, intraocular lens was inserted in the ciliary sulcus however in the phacoemulsification group, the intraocular lens was fixed within the capsular bag. Outcomes were compared with respect to uncorrected visual acuity, best spectacle corrected visual acuity, refractive error, keratometric readings, graft clarity and intra and postoperative complications.Results: Overall, 76 eyes were included in this study. Mean patient age was 61.4±14.2 years and mean follow up period was 61.4±37.2 months. Mean preoperative best spectacle corrected visual acuity was 1.40±0.68 Log MAR which increased to 0.44±0.33 Log MAR (P<0.001). Mean preoperative spherical equivalent refractive error was -2.40±1.5 diopter which had a significant difference with target refractive error (-0.73±0.29 diopter) (P=0.004). The study subgroups (phacoemulsification and extracapsular extraction) were comparable in terms of graft survival and time between penetrating keratoplasty and graft rejection. However the phacoemulsification subgroup had better best spectacle corrected visual acuity, lower refractive error and less complications including high intraocular pressure and posterior capsular opacification.Conclusion: Simultaneous penetrating keratoplasty, cataract extraction, and intraocular lens insertion is a safe and effective method. Phacoemulsification is superior to extracapsular cataract surgery when combined penetrating keratoplasty and cataract surgery is indicated.

Purpose: To assess alterations in parameters measured by the ocular response analyzer (ORA) after photorefractive keratectomy (PRK) with or without 0.02% mitomycin C (MMC) in myopic eyes.Methods: In 33 right eyes of 33 patients, IOP was determined using the Goldmann applanation tonometry (GAT) before and 3 months after PRK. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmanncorrelated IOP (IOPg), and cornea-compensated IOP (IOPcc) were also measured. Pre- and postoperative values were compared and the effect of ablation depth, optical zone, and duration of MMC application on changes in corneal biomechanics was examined.Results: Mean ablation depth was 56.6±20.8 microns. Postoperatively, there was a significant reduction in corneal biomechanical properties and IOP readings by the GAT and ORA. Ablation depth was significantly associated with percentage change in CH (P=0.021), CRF (P=0.001), and IOP GAT (P<0.001). However, the size of optical zone and duration of MMC application was not correlated with these parameters. The percentage of change in IOP GAT and in IOPg but not in IOPcc was significantly associated with percentage of change in CH and in CRF.Conclusion: PRK reduces corneal biomechanical properties which is proportional to the amount of ablation.However, other variables including optical zone and duration of MMC application have no effect. IOPcc appeared to be less dependent on alterations in corneal properties than IOPg and IOP GAT.

Purpose: To evaluate visual outcomes and intraocular pressure (IOP) after Single-site phacotrabeculectomy with mitomycin C in patients with senile cataract and primary open angle glaucoma (POAG), pseudoexfoliative glaucoma (PXG), or chronic angle closure glaucoma (CACG).Methods: In this retrospective study, patients older than 50 years who had significant cataracts (BCVA≤20.60) and uncontrolled POAG, PXG, or PACG (IOP>21 mmHg with at least two anti-glaucoma medications) were enrolled.Exclusion criteria included the presence of corneal pathologies, uveitis, diabetic retinopathy, neovascular or phacomorphic glaucoma, posterior segment pathologies, or a history of ocular trauma or intraocular surgery.Preoperative examination included uncorrected and best-corrected visual acuity (UCVA and BCVA, respectively), slit lamp biomicroscopy, IOP measurements, gonioscopy, and dilated funduscopy. The participants underwent single site phacotrabeculectomy with mitomycin C. Postoperative follow-up examinations were scheduled on days 1, 3, 7, and 14, and months 1, 3 and every 3 months thereafter. In each follow-up examination, the patients were re-evaluated for BCVA, IOP, the number of anti-glaucoma medications if needed, appearance of the bleb, and postoperative complications.Results: Forty (24 right) eyes of 32 (12 female) patients with POAG (15 eyes), PXG (18 eyes), or CACG (7 eyes) were enrolled. Mean patient age was 73±9 (range, 46 to 88) years and the study groups were comparable in this regard (P=0.88). Mean postoperative follow-up period was 13.1±9.5 months, raging from 1 to 40 months. Of the participants, 6 had diabetes mellitus and 6 had systemic hypertension. Mean preoperative BCVA was 0.64±0.32 logMAR (20/80) which improved to 0.38±0.19 logMAR (20/50) postoperatively (P<0.001). Preoperatively, mean IOP was 18.6±6.0 (range, 7 to 33) mmHg which was decreased to 12.3±3.0 (range, 6 to 17) mmHg postoperatively (P< 0.001).The PXG group demonstrated the highest reduction (P=0.001) and the POAG group experienced the lowest reduction (P=0.021) in IOP. At the last follow-up examination, the number of anti-glaucoma medications was reduced to 0.9±1.1, on average (P<0.001). The reduction in the number of medication was highest in the POAG (2.1±1.1, P=0.001) and lowest in the CAGC group (1.3±0.5, P=0.08). At final follow-up IOP was controlled with no medications in 21 eyes (52.5%), with timolol in 8 eyes (20%), and with 2 or more medications in 11 eyes (27.5%). With respect to intra- and postoperative complications and the appearance of the bleb, the study groups were comparable.Conclusion: One-site phacotrabeculectomy with mitomycin C is a safe and effective approach to decrease IOP and improve BCVA in patients with coexisting cataract and glaucoma.

Purpose: To determine the sensitivity and specificity of posterior corneal elevation in discriminating keratoconus and subclinical keratoconus from normal corneas by Galilei and Orbscan II diagnosed on the basis of topography.Methods: Three groups (keratoconus, subclinical keratoconus and normal) were evaluated with Galilei and Orbscan II and results were compared to those obtained by gold standard placido disc-based topography.In one eye of each patient, posterior corneal elevation was measured in the central 3 mm zones using the Galilei rotating double Scheimpflug camera. Posterior corneal elevation in keratoconus and subclinical keratoconus was compared to that in normal corneas. Receiver operating characteristic (ROC) curves were used to determine the test’s overall predictive accuracy (area under the curve) and to identify optimal posterior corneal elevation cut off points to maximize sensitivity and specificity in discriminating keratoconus and subclinical keratoconus from normal corneas. Similar analysis was done using Orbscan II, in the central 5mm zone.Results: In Galilei mean posterior corneal elevation in the 3 mm zone was statistically higher in keratoconus (50.6 ± 34.5 microns), and subclinical keratoconus (12.8 ± 4.3 microns) versus normal corneas (9.9 ± 4.5 microns). ROC curve analyses showed high overall predictive accuracy of posterior elevation for both keratoconus and subclinical keratoconus (area under the curve 98% and 71%, respectively). Optimal cutoff points were 18.5 microns for keratoconus and 11.5 microns for subclinical keratoconus. These values were associated with sensitivity and specificity of 92% and 95% respectively for keratoconus, and 64.3% and 75.7% for subclinical keratoconus. In Orbscan II mean posterior corneal elevation in the 5 mm zone was 106.8 ± 43.7 microns in keratoconus, 36.6 ±22.8 microns in subclinical keratoconus and 25 ± 9.2 microns in normal corneas. Optimal cutoff points were 50 microns for keratoconus and 33.5 microns for subclinical keratoconus.These values were associated with sensitivity and specificity of 89.1% and 98.6% respectively for keratoconus, and 50% and 85% for subclinical keratoconus.Conclusion: Posterior corneal elevation very effectively discriminates keratoconus from normal corneas. Its accuracy is lower in subclinical keratoconus and thus data concerning posterior elevation should not be used alone to stratify patients with this condition.

Purpose: To compare low volume transconjunctival anterior peribulbar anesthesia with transcutaneous posterior peribulbar anesthesia in phacoemulsification.Methods: Patients scheduled for phacoemulsification were randomly divided into two groups: In first group 5ml of 2% lidocaine was injected transcutaneously in the posterior orbital space. In the second group, 2ml of 5% lidocaine was injected transconjunctivaly in the anterior orbital space. Pain during injection, pain during surgery and akinesia at the beginning of surgery were compared in two groups.Results: 383 patients were enrolled in the study, 179 were allocated in the first group and 204 patients were assigned to the second group. Average pain level during injection was 1.42 ±1.1 in the first group and 0.7 ±0.3 in the second group (P=0.0001). Average pain level during surgery was 1.1 ±0.6 in the first group, and 1.5 ±1.3 in the second group (P=0.0001). Average akinesia at the beginning of surgery was 1.3 ±1.1 in the first group and 2.3 ±0.7 in the second group (P=0.00001). Serious complications such as perforation of the globe or orbital hemorrhage were not observed in either study group. Intraoperative posterior capsular rupture happened in 2 cases in the first group versus 3 cases in the second group.Conclusion: Low volume transconjunctival anterior peribulbar anesthesia in comparison with transcutaneous posterior peribulbar anesthesia has less pain during injection but is associated with higher pain during surgery and lower akinesia at the beginning of surgery. This method can be used for patients with high myopia, because of the very low risk of globe perforation.

Purpose: To evaluate the efficacy of riboflavin administration and ultraviolet A (UVA) cross-linking on advanced symptomatic bullous keratopathy (BK).Methods: 10 patients with symptomatic pseudophakic bullous keratopathy (PBK) were included. Slit-lamp examination, visual acuity, foreign body sensation (FBS) and corneal thickness as measured by Pentacam, were performed before corneal cross-linking. After using sodium chloride solution for one week, the central 8 mm zone of the corneal epithelium was removed, and cross-linking, with riboflavin instillation every 3 minutes for 30 minutes, and UVA irradiation for 40 minutes was performed. VA, FBS and corneal thickness were evaluated up to 6 months.Results: Three male and 7 female patients with mean age of 66±13 years were included. Mean follow-up duration was 6.2 months. VA increased in 9 eyes postoperatively, FBS subsided in 70% of patients. Mean corneal thickness was reduced by 74mm 6 months after the procedure (P=0.059).Conclusion: Collagen cross linking for BK improves FBS & VA and decreases corneal thickness; this extends the time interval for corneal transplantation and improves visualization for DSAEK procedures.

Purpose: To determine the general population’s knowledge and awareness about cataract, glaucoma and diabetic retinopathy (DR) in Tehran, the most populated and capital city of Iran, in order to assess the need for health education programs.Methods: This cross-sectional population-based survey was conducted during 2010 and a structured questionnaire was filled by 5 trained interviewers via telephone conversation for non-institutionalized inhabitants aged 45 years. The phone numbers were selected with a systematic random sampling among different regions of the city after providing sampling frame from the telecommunication center. In each house we only enrolled one person according to the scheduled table with defined sex and age groups.Awareness was defined as having heard about each disease and knowledge was acceptable if participants stated at least a short correct related sentence.Results: Of 1, 084 eligible people including 574 women (53%) and 510 men (47%), 957 subjects completed the interview (response rate=88.3%). Among the participants 60.2% believed visual impairment (VI) has high or very high effect on daily performance. On the contrary, 8.4%, 16.2% and 15.1% said that VI has none, little or moderate effect, respectively. The percentage of awareness for glaucoma, cataract and DR were 46.6, 82.9% and 86.2% respectively, and 19.2% and 57.3% had knowledge about glaucoma and cataract. Only 22.6%, 77.2% and 41.6% knew that glaucoma, cataract and DR are treatable.Conclusion: Although the majority of people over 45 years of age in the capital city had heard of cataract and DR, the total knowledge about all assessed diseases and their treatment was insufficient.

Purpose: To compare outcomes of two techniques (Anwar vs. Melles) of deep anterior lamellar keratoplasty (DALK) in patients with keratoconus.Methods: This randomized double-blind clinical trial was performed on 57 eyes of 57 patients with keratoconus. Patients aged 20-35 years with a clinical diagnosis of keratoconus who were contact lens intolerant and had corrected distance visual acuity (CDVA) of less than 20/80 were included. Eligible eyes were randomly allocated into 2 groups: Anwar (23 eyes) versus Melles (25 eyes). The primary outcome measure was CDVA; secondary outcome measures included spherical equivalent (SE), contrast sensitivity, corneal aberrations, corneal biomechanical properties, endothelial cell count, and central corneal thickness.All outcomes were compared 15 months postoperatively.Results: Mean CDVA was 0.17±0.09 vs 0.18±0.11 LogMAR in the Anwar vs Melles groups, respectively (P=0.803) and mean SE was -1.82±2.7 and -2.69±3.94 D (P=0.155). Overall, photopic and mesopic contrast sensitivity function was different between the two groups (P<0.05). There was no significant difference between the two groups in terms of total and higher order aberrations up to fifth order (P>0.05 for all parameters). Corneal hysteresis was not significantly different between the two groups (9.9±0.8 vs 9.9±0.6; P=0.606). Corneal resistance factor was 10.02±0.8 and 10.13±0.76 (P=0.509). There was no significant difference between the two groups regarding percentage of endothelial cell loss (1%±2 vs 1%±3; P=0.869). Central corneal thickness was 525.56±47.87 μm versus 504.64±54.20 µm in the study groups, respectively (P=0.155).Conclusion: Anwar and Melles techniques for DALK have comparable visual and refractive outcomes, aberrometric profile, biomechanical properties, corneal thickness and endothelial cell density. However, patients undergoing Anwar technique show better contrast sensitivity.

Toxic optic neuropathy (TON) is a group of medical disorders which can be defined by visual impairment due to optic nerve damage by a toxin. The exposure to a toxic substance can occur at the workplace, with ingestion of materials/ foods containing a toxin, or the use of systemic medications. TON is a disease entity which is not only under-diagnosed, but also often diagnosed at a stage when recovery of vision is not possible. Both genders and all races are equally affected, and all ages are susceptible. This article gives an overview of common causes, clinical features, and management of TON.

Purpose: To report two cases of corneal keloid and keloid-like lesions and to present an overview of the literature.Case Reports: The first case was a 32-year-old female with past history of trauma to the right eye and subsequent surgery in childhood, who presented with a slowly growing smooth and whitish elevated corneal lesion. Histopathologic and immunohistochemical findings of the excised lesion were consistent with corneal keloid. The second case was a 19-year-old male patient who presented with had nontraumatic, bilateral, mildly elevated, paracentral and annular corneal opacities since childhood, which had aggravated in the past 5 years. Medical and family history was unremarkable. Confocal scan, impression cytology, histopathology and immunohistochemistry revealed evidence in favor of a primary keloid-like lesion.Conclusion: Corneal keloids are well-known lesions with characteristic clinicopathological features. “Keloidlike” is a general and nonspecific term that encompasses a wide range of entities. In primary and bilateral keloid-like lesions, especially in young adults, newly mutated corneal dystrophies that have not been yet defined should be considered.

Purpose: To introduce a patient with Best disease and fluctuation in vision and OCT changes.Case Report: A 26-year-old man presented with decreased VA in his left eye due to CNV secondary to Best disease. VA improved after IVB injection. After 3 years he complained of metamorphopsia in his right eye with a decrease in subretinal deposits which improved spontaneously. The same sequence of events happened in his left eye after a few months.Conclusion: Fluctuation of vision may occur in Best disease with unknown reason.

Purpose: To present a case of spontaneous resolution of essential esotropia Case Report: A 22-month-old girl presented with eye deviation since the age of 4 month. In the first examination, visual acuity of both eyes was C+S+M+. The patient had 35 prism diopters of alternative esotropia in primary position and also bilateral inferior oblique overaction (IOOA). There was no significant refractive error and other ophthalmic and systemic evaluations were normal. In follow up examinations the amount of esodeviation decreased gradually and at the last examination (at the age of 4 years) the patient was orthotropic in primary position in spite of residual bilateral IOOA.Conclusion: The amount of deviaton in patient with essential esotropia usually seems to be stable; however spontaneous resolution of esodeviation is possible, however IOOA, dissociated vertical deviation or latent nystagmus may remain.