BINA
Year:2004 | Volume:9 | Issue:3 (35)|Papers Count:17

Purpose: To report the clinical features of 93 eyes with chronic and delayed onset mustard gas keratitis in 48 patients.Methods: Forty-eight Iranian survivors of lraqi chemical warfare with chronic or delayed onset mustard gas keratitis were enrolled. We reviewed the symptoms, signs, clinical course, and treatment of our patients. In 5 cases, histopathologic features of corneal and conjunctival specimens are presented.Results: Of 48 patients, 31 (64.6%) had chronic symptomatology whereas 17 (35.4%) experienced delayed onset lesions. Visual acuity at referral ranged from hand motions to 20/20. Ocular surface changes included chronic blepharitis and decreased tear meniscus in all, limbal ischemia (81.3%) and conjunctiva vascular abnormalities (50%). Corneal signs in order of frequency were: scar/opacity (87.5%), neovascularization (70.8%), thinning (58.3%), lipoid deposits (52.1%), amyloid deposits (43.8%), and epithelial defects and irregularity (31.3%). Twenty patients received conservative treatment; others underwent allograft stem cell transplantation (20 eyes of 17 patients), penetrating keratoplasty (12 eyes of 12 patients), and lamellar keratoplasty (4 eyes of3 patients).Conjunctival specimens were evaluated by light microscopy. Decreased goblet cell density, attenuated or thickened epithelium, scarring in the substantia propria associated with plasmacytic and lymphocytic infiltration, and dilated lymphatic vessels were noted. Excised corneal buttons disclosed absence of epithelium and Bowman's layer, firbrovascular pannus, stromal scarring, and vascularization.Conclusion: Mustard gas may cause chronic and delayed destructive lesions in the ocular surface and cornea leading to progressive visual deterioration and ocular irritation. The pathophysiology of these changes is not clearly identified. Excised conjunctival and corneal specimens revealed a mixed inflammatory response without any specific features. Based on the clinical appearance of the lesions and histopathologic findings, an immune-mediated component seems possible.

Purpose: To evaluate visual and refractive results, topographic indices, and contrast sensitivity changes after laser in situ keratomilueis (LASIK) for mixed astigmatism using the cross-sylinder ablation method with the technolas 217C excimer laser.Method: in a before-after clinical trial, 15 eyes of 8 potions with mixed astigmatism wer studied. Refraction and topographic indices including asphericity (Q value), predicted corneal acuity (PCA), and corneal uniformity index (CUI) were derived from Holladay diagnostic summary program (EyeSys 2000 Version) before and after surgery. Contrast sensitivities for spatial frequencies of 3, 6, 12, and 18 cyclesper degree were measured using Vector Vision instrument (CSV 1000).Patients were assessed 1 and 3 months after surgery.Results: Before surgery, the range of astigmatism was -1.50 to -6.50 diapers (D) (mean-3.50±1.36 D) and the spherical component was between +0.25 and +3.50D (mean+1.33±1.30 D). Mean cylinder and spherical refraction reduced from -3.50 and +1.33D before surgery to -0.76 and +0.36 D after surgery, respectively. Three months after surgery, 11 eyes out of 15 (72.7%) had less than -1.00D of astigmatism, all eyes had uncorrected visual acuity (UCVA) of 20/30 or better and 53% of the eyes had an UCVA of 20/20. We found a statistically significant reduction in contrast sensitivity at all mentioned spatial frequencies during the first month which recovered to preoperative values by 3 months after surgery. Asphericity decreased by an average of -0.15±0.16 (P=0.01). PCA and CUI were not changed after surgery.Conclusion: The cross-cylinder ablation method found to be effective for correction of mixed astigmatism while the cornea maintains its prolate shape and contrast sensitivity is preserved in all spatial frequencies between 1 and 3 months after surgery.

Purpose: To evaluate the results of trans-scleral diode laser retinopexy for induction of chorioretinal reaction in scleral buckling surgery.Methods: This before-after clinical trial was performed on 69 eyes of 66 patients with rhegmatogenous retinal detachment eligible for scleral buckling.Results: The retina was reattached with scleral buckling in 64 eyes (92.8%). In 4 eyes, the scleral buckling was performed twice (modified). In 5 eyes, significant PVR developed post-operatively (7.2%), two of which had pre-operative PVR grade B. In two eyes, retinal photocoagulation was performed through silicon implants and sclera. Best corrected visual acuity (Log MAR) was 1.22±1.5 preoperatively and 0.74±1.75 postoperatively (P<0.02). In 95% of the eyes with reattached retina (61 eyes), visual acuity improved or remained stable. In 12 eyes, rupture of Bruch's membrane associated with retinal break formation happended which did not affect retinal reattachment. No other complications were seen which could be ascribed to diode retinopexy.Conclusion: Trans-sclera diode laser photocoagulation for induction of chorioretinal reaction in scleral buckling is a safe and effective procedure. The ability to perform retinopexy through episcleral silicon implants is a definite advantage of this method over cryopexy.

Purpose: To evaluate the effect of prism induced heterophoria including esophoria and exophoria on binocular visually evoked potentials (BVEP).Methods: Esophoria and exophoria were induced with base-in and base-out prisms, respectively.Binocular visual evoked potentials for different heterophoia values were recorded using pattern reversal visual stimuli with a 6.5 min arc check size. Amplitude and latency Of P100 component of the potential waves were evaluated.Results: The present study showed that heterophoia significantly causes increase in latency of BVEP, P100 and decrease in amplitude of P100 peak (p<0.001).Conclusion: BVEP maybe a useful technique to evaluate and measure heterophoria values, namely BVEP phorometry.

Purpose: To assess the correlation between refractive error and stereo acuity in school children.Methods: In this correlational study, 202 children with normal visual acuity and 104 children with refractive error and without amblyopia (90 myopic,4 hyperopic,4 astigmatic, and 4 anisome tropes) were included. All children were in 7-12 years age group and sex distribution was equal in two groups. Stereo acuity was measured for each child with the Titmus test at 40 cm distance. In children with refractive error, stereo acuity measurement was repeated after correction of the refractive error with spectacles.Results: Mean stereo acuity in the control group and in children with refractive errors before and after correction with spectacle were 43, 96, and 45 seconds of arc, respectively. Mean stereoacuity in children with refractive error before correction with spectacle was less than the control group (P<0.0001). After correction of the refractive error with spectacle the difference was not statistically significant. Correction of refractive error with spectacle resulted in improved stereo acuity to normal values in all types of refractive errors except anisometropia. There was no significant linear relationship between visual acuity of the worse eye and stereoacuity in children with refractive errors (r=-0.12, P=0.23).Conclusion: Uncorrected refractive errors especially anisometropia can significantly decrease stereoacuity in children. Stereoacuity tests may be used for screening of refractive errors in children.

Purpose: To compare the results of levator aponeurosis resection and Muller's muscle-conjunctival resection in the correction of minimal blepharoptosis.Methods: This randomized controlled study was conducted on 20 patients with minimal ptosis (<2 mm and >1 mm) and good levator function (>10mm) which were assigned to one of two surgical groups: levator aponeurosis resection group or Muller's muscle-conjunctival resection group.Patients were visited on days 1, 3, 7, and 14and at months 1, 2, 3, and 6, postoperatively to evaluate the symmetry, lid contour, lid crease position, lagophthalmos, lid lag, suture keratopathy, and dry eye.Results: Postoperative symmetry was found in 8 cases in both group. Lid crease position symmetry was found in 9 and 5 cases in levator and Muller groups, respectively (P=0.235). Lid lag was found in 7 cases of levator group (mean=1.15mm) and 3 cases of Muller group (mean=0.5mm) (P=0.123). Mean lagophthalmos was 1.75mmand 1.15mm in levator and muller groups, respectively (P=0.749). No patient had abnormal contour, suture keratopathy, or dry eye symptoms or signs. Exposure keratopathy occurred in 2 cases of each group.Conclusion: Muller's muscle-conjunctival resection is at least effective as levator aponeurosis resection in correcting minimal blepharoptosis in patients with good levator function and symmetric lid crease.

Purpose: To evaluate the results of lacrinal probing for the first time in the age above 15 months. Methods: We studied the hospital records of 158 eligible patients with epiphora or mucopurulent discharge who underwent probing for the first time.Results: Mean age was 3±4.2 years; 47% were male and 53% were female. In 78% of the cases unilateral probing and in 22% bilateral probing was required. Overall in 75% of cases, probing was successful. The success rate was 72% in unilateral and 82% in bilateral cases. Success rate was not related to age.Conclusion: Probing of the lacrimal duct can be successful in congenital nasolacrimal duct obstruction even in higher age groups and if a patient with epiphora is referred for the first time at older ages, it is better to do probing as the first line of treatment; silicone intubation or DCR must be preserved only for failed cases.

Purpose: To assess the etiology of oculomotor nerve palsy among 28 patients at Farabi Eye Hospital, Tehran-Iran.Methods: This case series includes 28 patients with third nerve palsy. The diagnosis was divided into six groups based on symptoms and preclinical studies: ischemic, traumatic, aneurysm, neoplasm, miscellaneous, and undetermined.Results: Out of 28 patients, 9 (30%) had diabetes mellitus. The chief complain was mostly ptosis (79%). The pupil was normal in 16 patients (57%) and mydriatic in 12 patients (43%). The etiology was ischemic in 43%, traumatic in 14%, aneurysm in 7%, tumor in 7%, miscellaneous in 11%, and undetermined in 18% of the cases.Conclusion: The most common cause of oculomotor nerve palsy is ischemic lesions and the most common risk factor is diabetes mellitus. Further studies to assess the relationship between third nerve palsy and blood sugar control is suggested.

The success of corticosteroids in the treatment of ocular inflammation catalyzed a search for better synthetic analogues with more potent anti-inflammatory effects, better ocular penetration, and enhanced bioavailability. At present, corticosteroids remain the mainstay of management of ocular inflammatory and immune-mediated diseases. Numerous studies have clearly shown that tissue edema, including retinal edema in uveitis, can be improved by corticosteroids and it also may be possible to modify the course of diabetic macular edema with steroids. Steroid compounds have recently been shown to have antiangiogenic effects in patients with wet type age-related macular degeneration. Topical corticosteroid preparations include dexamethasone, prednisolone, fluorometholone, medrysone, medroxyprogesterone, rimexolone, lodeprednol etabonate.Corticosteroids used for systemic, regional and intravitreal therapy including hydrocortisone, prednisone, prednisolone, methyl prednisolone, triamcinolone, dexamethasone, betamethasone, fluocinolone acetonide, anecortave acetate. Adverse neuropsychiatric and endocrine effects are the most common complications attributed to corticosteroids. Pathologic fractures involving the hip and spine are other complications. The most clinically significant ocular complications of corticosteroid therapy are development of cataract and secondary glaucoma. Other important adverse effects produced by all routes of corticosteroid administration include mydriasis, ptosis, and susceptibility to infection, impaired wound healing and paradoxical anterior uveitis. Corticosteroids are contraindicated in patients with systemic fungal infection or known hypersensitivity to the drug formulation and should be used with great caution in patients with history of excessive alcohol consumption, peptic ulcer, a variety of infectious diseases, diabetes mellitus, severe hypertension or congestive heart failure, psychiatric problems, osteoporosis, in children and during pregnancy and breastfeeding. Steroids are metabolized by hepatic microsomal enzymes. Concurrent use of some drugs may decrease the pharmacologic effects of corticosteroids; these include Phenobarbital, phenytoin, carbamazepine, ephedrine, rifampin, cholestyramine, and high dose antacids. In contrast, some other agents may augment pharmacologic effects of steroids: cyclosporin, indometacin, naproxen, isoniazid, ketoconazole, oral contraceptives, methotrexate, and cyclophosphamide.

Purpose: To report a case of corneal epithelial cyst and its treatment.Patient and findings: A 14-year-old girl with history of strabismus surgery 9 years ago, was referred due to a white lesion in her right cornea. The lesion has been detected first in the nasal limbus 3 years ago and enlarged gradually. Because of progression toward the corneal center and threatening of the visual axis, surgery was done. The lesion was removed and at the same time, ethylic alcohol 96% was injected and applied. No recurrence was seen until 11 months after surgery.Conclusion: Corneal epithelial cysts are benign lesions the removal of which is necessary if center of the cornea is threatened. With timely removal of the lesion, vision will be preserved and with meticulous surgery, no recurrence will occur.

Purpose: To report two cases of peripapillary staphyloma presented to the Rassoul Akram Hospital.Patients and findings: The first case was a 2.5-year-oldboy with a large peripapillary staphyloma. Size of staphyloma was 4 disc diameter with a depth of 8mm. The second case was a 4-year-old girl with a staphyloma measuring 2.5 disc diameter in width and 3mm in depth in her right eye.There were also multiple cilioretinal vessels and a little glial tissue over the disc in the second case. Conclusion: Peripapillary staphyloma is a rare congenital anomaly of the optic disc. Amblyopia therapy and wearing protective glasses are recommended in unilateral cases.

Purpose: To report a case of retained broken probe tip in the lower lid canaliculus as a cause of nasolacrimal duct obstruction.Patients and findings: A 50-year-old female with history of nasolacrimal duct probing 12 years ago was referred to us with epiphora and purulent discharge in her left eye. Radiography revealed the broken tip in the lower lid canaliculus. The broken segment was removed by surgery.Conclusion: Nasolacrimal probing is only of diagnostic value in adults. Integrity of the probe needs to be ascertained before and after the procedure.