BINA
Year:2007 | Volume:13 | Issue:1 (50)|Papers Count:30

Purpose: To determine the prevalence of refractive errors and rate of need for spectacles in students of region one in Mashhad, 2006.Methods: By randomized cluster sampling, 2510 students were selected and underwent eye examinations including refraction (cycloplegic, manifest), visual acuity, cover test and determination of the spectacle prescription as well as best corrected visual acuity. Estimated need for glasses and spectacle coverage rate (met need/unmet need + met need) were calculated. Results: Overall, 2150 students were examined (85.7% participation rate). Need for spectacles was 4.7% (95% confidence interval [CI], 3.8% to 5.6%) including met need in 2.3% and unmet need in 2.4%. Need for spectacles was 3.7% in male and 5.5% in female subjects (P=0.059). Spectacle coverage rate was 51.4%.Conclusion: The need for glass was 4.7% in school children of region 1 in Mashhad which was unmet in 48.6% of subjects.

Purpose: To determine the effect of horizontal recti surgery on visual acuity and head posture and electronystagmographic indices in patients with congenital nystagmus.Methods: This prospective comparative case series was conducted on 58 patients with congenital nystagmus who were referred to our clinic over three years. Patients were divided into three groups: the first group (29 cases) had head posture less than 20o, binocular visual acuity (BVA) less than 20/30 and tropia less than 30D who underwent large recess of four horizontal rectus muscles; the second group (23 cases) had head posture less than 20o, BVA< 20/30 and tropia more than 30Δ who underwent large recess of two horizontal rectus muscles; and the third group (6 cases) had head posture more than 20° with any BVA or tropia who underwent Kestenbaum-Anderson surgery.Results: Mean age of the patients was 18.7±9.1 years and mean follow-up period was 17.5±7.4 months. Visual acuity improved in all groups which was statistically significant in the 2-rectus group (P=0.0001). The speed and amplitude of nystagmus waves were decreased in all groups which were statistically significant in the 4-rectus group (P=0.02 and 0.04 respectively). A small myopic shift was seen in the 2- rectus and 4-rectus groups and a small hyperopic shift was found in the Kestenbaum-Anderson group. Statistically significant (P<0.001) improvement was achieved in eye deviation in the 2-rectus group and in head posture in the Kestenbaum-Anderson group. Conclusion: Horizontal recti surgery in congenital nystagmus can improve visual acuity, strabismus and abnormal head posture, especially with 2-rectus recession. Nystagmus intensity indices improve especially with 4-rectus recession.

Purpose: To compare Tecnis Z9000 and Akreos AO aspheric intraocular lenses (IOLs) in terms of spherical aberration and contrast sensitivity.Methods: Thirty-four eyes of 34 patients undergoing phacoemulsification cataract surgery were randomly assigned for implantation of Tecnis or Akreos AO IOLs. Three months postoperatively, bestcorrected visual acuity (BCVA), spherical aberration (with 4 and 6 mm pupil diameters) and contrast sensitivity in photopic and mesopic conditions at spatial frequencies of 1, 2, 5, 10 and 20 cycles per degree (cpd) were determined.Results: Mean BCVA was 0.076±0.080 logMAR in the Tecnis group and 0.115±0.090 logMAR in the AO group (P=0.33). Spherical aberration with 4 mm and 6 mm pupil diameters in the Tecnis group was less than the AO group (0.140±0.097mm vs 0.285±0.087mm, P< 0.001 and 0.303±0.183mm vs 0.329±0.083mm, P=0.4, respectively). Contrast sensitivity was significantly higher in the Tecnis group at 1, 2, 5 and 10 cpd under photopic and at 1, 2 and 10 cpd under mesopic conditions.Conclusion: Tecnis Z9000 IOL seems to entail better visual outcomes in terms of spherical aberration and contrast sensitivity compared to Akreos AO IOL.

Purpose: To compare AcrySof IQ and Sensar intraocular lens (IOLs) in terms of spherical aberration and contrast sensitivity.Methods: Thirty-four eyes of 34 patients undergoing phacoemulsification cataract surgery were randomly assigned for implantation of AcrySof IQ or Sensar IOLs. Three months postoperatively, bestcorrected visual acuity (BCVA), spherical aberration (with 4 and 6 mm pupil diameters) and contrast sensitivity under photopic and mesopic conditions at spatial frequencies of 1, 2, 5, 10 and 20 cycles per degree (cpd) were determined.Results: Patients included 21 male (61.8%) and 13 female (38.2%) subjects. Mean BCVA was 0.083±0.071 logMAR in the IQ group and 0.145±0.097 logMAR in the Sensar group (P=0.079). Spherical aberration with both 4 and 6 mm pupil diameters in the IQ group was less than in the Sensar group (0.183±0.107 mm vs 0.354±0.138mm, P<0.001 and 0.26±0.096mm vs 0.435±0.152mm, p=0.002; respectively). Contrast  sensitivity was higher in the IQ group at 1, 2, 5, 10 and 20 cpd under photopic conditions and at 1, 10 and 20 cpd under mesopic conditions (P<0.02).Conclusion: AcrySof IQ aspheric IOL seems to have better visual outcomes regarding spherical aberration and contrast sensitivity as compared to spheric Sensar IOL.

Purpose: To evaluate the effectiveness of limbal relaxing incision (LRI) during phacoemulsification for correcting pre-existing corneal astigmatism.Methods: The study included 21 eyes of 21 patients undergoing phacoemulsification combined with LRI and 36 eyes of 36 patients undergoing phacoemulsification without LRI as controls. LRI was created according to a nomorgram based on preoperative astigmatism as determined by topography. Jaffe vector analysis was used for evaluation of changes in astigmatism.Results: Mean corneal astigmatism was 2.82±1.07 diopter (D) preoperatively which decreased to 1.68±1.03 D 12 weeks postoperatively in the LRI group. Corresponding figures were 0.66±0.27 D and 0.62±0.22 D in controls respectively. Mean arithmetic reduction in keratometric astigmatism was 1.19±1.04 D and mean vector change in cylinder was 2.37±1.36 D in the LRI group. Thirteen cases (61.9%) of under-correction and two cases (9.5%) of over-correction occurred in the LRI group.Conclusion: Limbal relaxing incision is effective in reducing pre-existing corneal astigmatism during cataract surgery; however a modified monogram is needed.

Purpose: To evaluate the outcomes of cataract extraction by phacoemulsification and posterior chamber intraocular lens (PCIOL) implantation in patients with chronic angle closure glaucoma (CACG).Methods: Consecutive CACG patients with co-existing visually significant cataracts were included in this noncomparative interventional case series. After obtaining informed consent, clear cornea phacoemulsification and foldable PCIOL implantation was performed. Patiens were followed for at least six months. Outcome measures included intraocular pressure (IOP), number of glaucoma medications and visual acuity.Results: Twenty-three eyes of 23 patients with CACG including 14 male and 9 female subjects were evaluated. Mean age was 67.9±7.3 (range 55-80) years. Mean number of glaucoma medications was 1.87±0.81 preoperatively and was reduced to 0.87±1.05 postoperatively (P=0.01). All patients used glaucoma medications before surgery, however 11 patients (47.8%) did not need any glaucoma medications at final follow-up. IOP was decreased from a mean preoperative level of 16.78±3.64 mmHg to 14.08±2.29 mmHg at final follow up (P=0.008). Mean preoperative visual acuity was 1.01±0.32 logMAR which improved to 0.37±0.43 logMAR at final follow up (P=0.001).Conclusion: In CACG patients with co-existing cataracts, phacoemulsification and PCIOL implantation can significantly reduce IOP and requirement for glaucoma mediations.

Purpose: To determine anterior chamber depth (AC depth) changes during a 6 month period after phacoemulsification cataract surgery and foldable intraocular lens (IOL) implantation.Methods: In a cross-sectional study, 85 eyes of 85 patients were evaluated for AC depth and capsulorrhexis size one and six months after the procedure.Results: Patients included 44 male and 41 female subjects with mean age of 58.9±13 (range 21-94) years. Mean AC depth was 4.48±0.54 mm and 4.39±0.64 mm one and six months after the operation, respectively (P=0.26). Although larger capsulorrhexis was associated with greater decrease in AC depth at both visits, the differences were not statistically significant.Conclusion: Reduction in AC depth during six months after phacoemulsification and foldable IOL implantation is not statistically significant. There seems to be no significant correlation between capsulorrhexis size and amount of AC depth reduction.

Purpose: To compare the visual outcomes and complications of lensectomy and posterior chamber intraocular lens (PCIOL) implantation with or without posterior capsulotomy and anterior vitrectomy in pediatric cataracts. Methods: Seventeen eyes of 12 children aged 10 to 15 years with congenital or developmental cataract were randomly divided into two groups. Lensectomy and PCIOL implantation was performed with (8 eyes) and without (9 eyes) posterior capsulotomy and anterior vitrectomy. Acrysof MA60 AC was implanted in all cases.Results: Mean age at the time of surgery was 12.3±1.5 (range 10-15) years. Patients were followed for 18.7±11.2 (range 6-36) months. Posterior capsular opacity was seen in three eyes of the non-vitrectomy group; however, regarding mild opacification of the visual axis, capsulotomy was not needed in any case. All cases of the vitrectomy group had clear visual axis at final follow up. No significant difference was seen between the two groups in term of visual acuity (P=0.3).Conclusion: Although posterior capsulotomy and anterior vitrectomy is a safe method in pediatric cataract surgery, it may not be necessary as a routine.

Purpose: To evaluate the role of transvitreal optic neurotomy (TON) in the management of non-arteritic anterior ischemic optic neurotomy (NAION). Methods: Sixteen eyes of 16 patients with recent onset NAION (less than six weeks duration) were included in this single-masked randomized controlled trial. The patients were randomized to TON (8 eyes) versus observation alone (8 eyes). Pre- and postoperative visual acuity and visual field as well as complications of the procedure were evaluated.Results: After six months of follow up, six eyes in the TON group and two eyes in the observation group had improvement in visual acuity (P=0.04). Mean visual improvement was significantly better in the TON versus the observation group three (0.8±0.49 vs 0.24±0.45 logMAR, P=0.03) and six (1.04±0.83 vs 0.24±0.45 logMAR, P=0.03) months postoperatively. Time to achieve best-corrected visual acuity was not significantly different between the groups. Visual field improvement in the TON group was significantly better than the observation group at final follow up.Conclusion: TON is effective in the management of recent onset NAION in terms of visual acuity and visual field improvement. A multicenter randomized clinical trial with larger sample size is needed to confirm these findings.

Purpose: To compare deep vitrectomy and scleral buckling for management of macula-off retinal detachment regarding the time course of foveal reattachment.Methods: This non-randomized clinical trial included 25 patients with spontaneous rhegmatogenous retinal detachments. Patients underwent deep vitrectomy (11 patients) or scleral buckling (14 eyes) based on the accepted indications. Patients underwent a complete ophthalmic examination as well as optical coherence tomography (OCT) pre- and 1, 6 and 12 months postoperatively.Results: OCT revealed that the fovea was completely attached with no subfoveal fluid in all cases of deep vitrectomy 1, 6 and 12 months postoperatively. However in the scleral buckling group there was a small subclinical area of subfoveal fluid on OCT in 8 eyes (57.2%) at one month, in 7 eyes (50%) at 6 months and in 3 eyes (21.4%) at 12 months postoperatively.Conclusion: Deep vitrectomy for macula-off retinal detachment results in complete foveal reattachment without delay according to OCT results and therefore may be superior to scleral buckling.

Purpose: To determine the prevalence of various types of visual field defects in patients with open angle glaucoma at the time of diagnosis.Methods: This cross-sectional study was performed on patients who were referred to our glaucoma clinic. Open angle glaucoma was confirmed by intraocular pressure measurement, perimetry, fundoscopic examination and gonioscopy. The last perimetry of patients who had at least three reliable visual fields was selected for interpretation. Acceptable reliability indices were false negative and false positive error of less than 33% and fixation loss less than 20%. Patients with other ocular abnormalities were excluded. Based on mean deviation (MD), visual field defects were classified as mild (MD up to -6 db), moderate (MD between -6 to -12 db) and advanced (MD beyond -12 db). Results: We evaluated 308 eyes of 189 patients with mean age of 53.2±12.0 (range 13-79) years. The average MD was -12.3±9.0 (range -0.4 to -34.4 decibel). This average value was -10.7±9.2 in women and - 13.2±9.4 in men (P=0.02). Based on MD, 104 eyes (33.8%) had mild, 74 eyes (24.0%) had moderate and 130 eyes (42.2%) had advanced disease. Visual field defects included generalized depression in 23 eyes (7.5%), superior field defects in 102 eyes (33.1%), inferior field defects in 75 eyes (24.3%) and combined defects in 91 eyes (29.5%). There was paracentral scotoma in 7 (2.3%) and central island in 3 (1.0%) eyes however, 7 eyes (2.3%) had no visual field defect. Arcuate scotoma (35.6%) was the most common form of localized visual field defects.Conclusion: Glaucoma was diagnosed in advanced stages of the disease in a large number of patients. This fact notifies the necessity of screening methods.

Purpose: To determine the prevalence of ocular manifestations in Marfan’s syndrome. Methods: This cross-sectional study was performed on 43 patients referred to ophthalmology clinics of Yazd Medical University over 27 months. Common ocular manifestations of Marfan’s syndrome including lens dislocation, corneal disorders, retinal conditions, glaucoma were evaluated. Results: The study included 24 female (55.8%) and 19 male (44.2%) subjects with mean age of 26.23±7.5 (range 6-44) years. Thirty-nine patients had family history of Marfan’s syndrome. The most common ocular signs included lens subluxation (76.7%), high myopia (41.9%), strabismus (27.9%), glaucoma (14.0%), flat cornea (11.6%) and retinal detachment (7%). Overall 14.0% of patients had previous ocular procedures including lensectomy, scleral buckling and squint repairing.Conclusion: The cardinal ocular features of Marfan’s syndrome include lens ectopia, high myopia, squint, glaucoma and retinal detachment.

Purpose: To evaluate histopathological changes induced by 0.02% mitomycin-C (MMC) in rabbits corneas.Methods: This study was performed on 48 corneas of 24 rabbits (Dutch type, Albino). Under general anesthesia, lamellar keratectomy was performed and either MMC 0.02 % (MMC group) or balanced salt solution (control group) was applied to the stromal bed for one minute. Sixty days later, light microscopic examination was performed on corneal buttons after authentication, corneal tissue fixation and staining with Hematoxylin-Eosin, periodic acid Schiff and Congo red as needed. Results: One of the MMC cases showed decreased keratocyte count. Other findings such as interface scaring, keloid formation, stromal interface vascularization, stromal and flap edema, epithelial hyperplasia over the incision and flap occurred with the same frequency in MMC and control groups. Stromal scaring was less in the MMC group (zero vs two). There was faint eosinophilic staining in the interface in two and epithelial thinning over the flap in eyes of the control group. The endothelium was normal in all samples.Conclusions: Application of MMC 0.02% to the stromal interface in rabbit corneas led to decreased stromal keratocyte count and fibrosis but apparently had no adverse effect on interface healing, epithelial cell regeneration and the endothelium.

Purpose: To characterize the histopathologic, electron microscopic and confocal scan features of Ahram mineral water (AMW)-induced keratopathy in cadaver corneas.Methods: Seven cadaver globes were examined, five of which were exposed to AMW from the corneal side for different durations (30 seconds, 3, 15, 30, and 60 minutes) and the other two were considered as controls. After performing confocal scan on each cornea, the corneo-scleral rim was excised and sent for histopathologic evaluation. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) examinations were performed on the cornea exposed to AMW for 60 minutes.Results: Pending the time of exposure, confocal scan features varied from intra-epithelial high contrast deposits to sub-epithelial bulla formation. Histopathologic features ranged from diffuse intracytoplasmic sulfur deposits to sub-epithelial bulla formation. SEM disclosed rather diffuse irregular bright deposits of high sulfur content over the surface epithelium together with focal cellular destruction and micro-hole formation in the case with 60-minute exposure. On TEM, bulky electron lucent deposits were found underneath the basal epithelial cells and between their basement membrane and Bowman’s layer. Confocal scan of the control corneas disclosed non-specific anterior stromal haze and Descemet’s folds with no evidence of intraepithelial deposits. No intra-epithelial deposits were found on the histopathologic examination of the control corneas.Conclusion: Ahram mineral water induces sulfate keratopathy predominantly involving the anterior cornea with various histopathologic, confocal microscopic and electron microscopic features even with short-time exposure.

The number of people with diabetes mellitus is increasing and cataracts are one of the most common causes of visual impairment in these patients. Advances in cataract surgery have generally resulted in favorable surgical outcomes. However, surgery may not be safe and effective in individuals who were previously not candidates for surgery or who had limited visual prognosis. Many questions remain regarding cataracts in diabetic patients. This study will review the relevant articles. Studies were obtained from computerized searches of MEDLINE with keywords of “diabetes”, “cataract”, “diabetic retinopathy”, and “diabetic maculopathy”.

Age-related macular degeneration (AMD) is the leading cause of blindness in old subjects. It is a multifactorial disease with both environmental and genetic factors playing some role in its pathogenesis. Similar to many other genetic diseases, the inheritance pattern of AMD does not fit into simple mendelian rules. These diseases are caused by the presence of multiple genetic factors and are called complex diseases. There has been extensive research on the role of genetic factors in the pathogenesis of this complex disease in the last few years. We review the methods of genetic research and their advantages and disadvantages in complex diseases such as AMD. Following that, candidate genes and their probable role in the pathogenesis of the disease are described. Finally, we discuss two important genes in the pathogenesis of the disease i.e. complement factor H and the gene for locus LOC387715.

Purpose: To report a patient with factitious (self infected) conjunctivitis.Case Report: A 16-year-old girl presented with pain, redness and edema of lids of her left eye. After exclusion of ocular pathologies, self inflicted conjunctivitis was diagnosed based on the underlying psychological and social problems of the patient.Conclusion: After exclusion of ocular pathologies, self inflicted conjunctivitis should be considered in subjects who are psychologically disturbed and have a gain in assuming the sick role.

Purpose: To present a case of autosomal dominant dystrophic epidermolysis bullosa with symblepharon formation due to eye rubbing.Case Report: A 10-year-old girl suffering from blistering and ulcerative lesions of the trunk and palms  and dystrophic nails since childhood was referred to our clinic with a symblepharon connecting the medial portion of the right upper lid to the upper nasal quadrant of the cornea. The central cornea in both eyes exhibited a mild subepithelial opacity. She had history of eye rubbing due to foreign body sensation in the right eye, resulting in red eye and blister-like conjunctival lesions 3 years ago. She had undergone surgical symblepharon removal which resulted in recurrence of the symblepharon of more severity.Conclusion: Dominant dystrophic epidermolysis bullosa may be accompanied by external ocular manifestations. Protection of the eye from minor trauma such as rubbing may be useful in the prevention of ophthalmic complications in this entity.

Purpose: To specify histopathologic features of corneal involvement in a case with xeroderma pigmentosum (XP).Case Report: A 19-year-old man with a clinical diagnosis of XP presented with bilateral corneal leukoma and decreased visual acuity predominatly in his right eye. Penetrating keratoplasty was performed in the right eye due to severe corneal opacity, vascularization and lipid deposition. The corneal button underwent histopathologic evaluation which disclosed a chronic interstitial lipogranulomatous keratitis.Conclusion: To our knowledge, this is the first report of corneal involvement in a case with xeroderma pigmentosum in Iran; describing the histopathologic features of the affected cornea in this rare condition.

Purpose: To report a case of retinocytoma associated with bilateral retinoblastoma. Case Report: A 3-year-old girl presenting with left eye exotropia was referred to our ophthalmic oncology service for a second opinion. Funduscopy under general anesthesia revealed one prominent retinocytoma associated with five discrete retinoblastomas in the left eye and three discrete retinoblastomas in the right eye.Conclusion: Although retinocytoma is often a benign tumor, it may be associated with retinoblastoma. Therefore, periodic examination of the fundus is necessary in these patients.

Purpose: To report tonic pupil in a patient with ocular siderosis.Case Report: A 12-year-old male patient presented with over-sized right pupil from two weeks before. Visual acuity (VA) was 10/10 in both eyes without afferent pupillary defect. Anisocoria was present with the right and left pupils, measuring 5 and 3 mm in diameter, respectively. Anisocoria was greater in bright light and there was a good constriction of right pupil in response to 0.1% pilocarpine. A metallic foreign body was found on funduscopy and orbital X-Ray. The patient was lost to follow up. Two months later he returned with VA of 6/10 in the right eye. Tonic pupil was still present and pigmetary changes were seen on fundus examination. A foreign body measuring 1.5×1.5 mm in size was extracted with deep vitrectomy. Anisocoria and signs of tonic pupil resolved completely six months after surgery but a faint posterior subcapsular cataract was detected. Best-corrected visual acuity was 7/10 at final follow-up.Conclusion: Ocular siderosis can present with a tonic pupil and should be considered in the differential diagnosis of this condition.

Purpose: To present two cases of axial high myopia with esotropia (heavy eye syndrome) and the results of its surgical management.Case Report: Two female subjects (15 and 17 years old) were referred to Poostchi eye clinic, Shiraz, Iran with axial high myopia and esotropia. Eye examination revealed more than 50 prism diopter (PD) esotropia and more than 10 PD hypotropia in primary position as well as limitation of abduction (-3 to - 4) and elevation (-1 to -2) in both eyes. Orbital CT scan disclosed compression of the lateral rectus muscle between an enlarged globe and the orbital wall. Downward displacement of the lateral rectus muscle was seen intraoperatively. The results of surgery were satisfactory and acceptable.Conclusion: In patients with axial high myopia and strabismus, preoperative imaging, especially orbital CT scan or MRI is recommended for detection of displacement or compression of extraocular muscles against the orbital wall and for planning the surgical management based on the underlying pathophysiological process.