Journal of Current Ophthalmology
Volume:25 Issue: 2, Jun 2013

In this issue of IRJO Panahi and Naderi and coworkers have presented an extensive and interesting review on ocular manifestations of mustard gas (MG) which includes the clinical, immunochemical, pathology, etc. of MG. MG which has been used as an aggressive, vesicant, and destructive warfare agents in the last century and still being used in our time. Therefore, it is mandatory for all of us to be aware of its manifestations and complications and to be acquainted with its pathology and treatments. MG is a lipophilic, highly reactive alkalizing and cytotoxic agent which has been used during the Iraqi-Iranian war (1980-1988), and it has been well studied by several medical and scientific teams in this country. It has an acute, a chronic and a late-onset presentation. The acute lesions appear within 24 hours and the symptoms include irritation of the eye, corneal erosion, subconjunctival hemorrhage etc. They are observed in more than 90% of the exposed individuals but in most cases they regress and disappear in few weeks.1 The severe forms include the chronic cases where the initial lesions have not disappeared but exacerbated or the late-onset cases which can appear years after exposure.2 These severe forms consist of less than 1% of exposed patients but they are very aggressive and sight-threatening and need special attention, follow-up and care.3 These severe cases which are also called mustard gas keratopathy (MGK) are presented by the following symptoms: chronic, keratitis, limbal and conjunctival pathologic changes. Javadi and coworkers in their presentation of 48 MG patients with chronic and delayed-onset stated that “ocular surface changes included chronic blepharitis and decreased tear meniscus in all patients, limbal ischemia (81.3%), conjunctival vascular abnormalities (50%). Corneal signs in order of frequency were: scar or opacity (87.5%), neovascularization (70.8%), thinning (58.3%), lipid deposits (52.1%), amyloid deposits (43.8%), epithelial defects and irregularity (31.3%)”. They also stated that 31 (64.6%) presented chronic symptoms whereas 17 (35.4%) had delayed-onset manifestations.2 Khateri and coworkers reported the statue of 34000 injured veterans of Iraqi-Iranian war who were exposed to MG after more than a decade of exposure.3 42.5% of their patients had ocular problems but less than 1% had severe ocular manifestations. The management of these severe cases has been indicated by Razavi and his coworkers4 with the emphasis on the importance of a very meticulous and constant follow-up of these patients. In their report and follow-up of 36 to 198 months of their cases 79.4% out of 175 eyes needed an or several interventions during the follow-up. Their treatment included punctual plaque or occlusion, tarsorrhaphy, manual lamellar or perforating keratoplasty, stem cell transplantation or combination of techniques. They particularly insist on lamellar keratoplasty since the deep cornea remains untouched in most areas.

To review current knowledge about ocular effects of sulfur mustard and the associated histopathologic findings and clinical manifestations Literature review of medical articles (human and animal studies) was accomplished using PubMed, Scopus and ISI databases. A total of 274 relevant articles in English were retrieved and reviewed thoroughly. Eyes are the most sensitive organs to local toxic effects of mustard gas. Ocular injuries are mediated through different toxic mechanisms including: biochemical damages, biomolecular and gene expression modification, induction of immunologic and inflammatory reactions, disturbing ultrastructural architecture of the cornea, and long-lasting corneal denervation. The resulting ocular injuries can roughly be categorized into acute or chronic complications. Most of the patients recover from acute injuries, but a minority of victims will suffer from chronic ocular complications. Mustard gas keratopathy is a devastating late complication of sulfur mustard intoxication that proceeds from limbal stem cell deficiency. Sulfur mustard induces several different damaging changes in case of ocular exposure; hence leading to a broad spectrum of ocular manifestations in terms of severity, timing and form. Unfortunately, no effective strategy has been introduced yet to inhibit or restore these damaging changes.

To describe the macular thickness map of adult Iranians with normal retinal status as measured by Cirrus’ optical coherence tomography (OCT) instrument In this cross-sectional study, one eye of subjects with normal ocular examination and retinal status of at least one eye were recruited. The 512×128-scan pattern and scan area of 6×6 mm2 with software 4 protocol in Cirrus OCT apparatus were used for data acquisition and analysis. A total of 98 individuals participated in this study. 45.9% (i.e., 45 patients) of the participants were male. The mean age of the subjects was 49.55±16.31 years; ranging from 23 to 80 years. The mean central subfield thickness (CST) was 251.39±20.57 µm which is the thinnest part. The mean CST in men and women were 259.33±21.26 µm and 244.64±17.48 µm, respectively (p<0.001). The thickest part of macula was located in the foveonasal area with a measurement of 320.2±14.54 µm. There was not any significant correlation among age (p=0.207), gender (p=0.290), and the CST. The nasal, superior, inferior, and temporal parts of macula, consecutively, exhibited a decrease in macular thickness. The mean macular volume was 9.95±0.49 mm3 (i.e., 10.05±0.54 mm3 in men and 9.86±0.41 mm3 in women, respectively). There is, however, a statistically-significant correlation between age and the macular volume (p<0.001). With every one year increase in age, there was a 0.012 mm3 decrease in macular volume. The average retinal thickness was 277.58±11.55 µm. Additionally, there is a significant correlation between age and average thickness (p<0.001) from statistical point of view. With every one year increase in the age, there was a 0.266 µm decrease in the average thickness. The thickest part of the macula was located in the foveonasal area with a measurement of 320 µm while the thinnest part was in the central subfield area with a measurement of 251 µm. The nasal, superior, inferior, and temporal parts of macula, consecutively, exhibited a decrease in macular thickness. In younger adults and among males, the mean thickness was greater.

To compare retinal nerve fiber layer (RNFL) profile in subjects with myopia and emmetropia using GDx variable corneal compensator (VCC) Besides ophthalmologic standard examination (refraction, visual acuity and slit-lamp examination, applanation tonometry, and funduscopy), perimetry and scanning laser polarimetry (SLP) were performed. 171 healthy age-matched subjects with low to high myopia (90 subjects) and emmetropia (81 subjects) underwent RNFL analysis by means of GDx VCC. The mean value of each parameter was compared in myopic and emmetropic eyes. Mean myopia was 3.43±1.19 diopter (D) (range, -0.50 to -6.50). Except for ratio parameters, RNFL parameters were significantly lower in myopic patients. TNSIT standard deviation (p=0.026), nerve fiber indicator (NFI) (p=0.027), superior/nasal (p<0.0001), max modulation (p=0.003), ellipse modulation (p=0.0244) and Symmetry (p=0.028) were higher in myopic group. In both groups, all of RNFL measurements were within the normal range. There was a gradual decrease in RNFL thickness associated with aging in myopic patients (simple regression analysis, p<0.05). There was also a gradual decrease in temporal-superior-nasal-inferior thickness (TSNIT) average and superior maximum with increasing degree of myopia (simple regression analysis, p<0.05). RNFL thicknesses gradually decreased with increasing age in myopic patients. Patients with myopia had significantly lower RNFL thickness than normal subjects and, although weakened by wide age range of myopic group, there was a linear negative correlation between severity of myopia and RNFL thickness in myopic patients.

To determine the prevalence of the refractive errors in the elderly population of Sari, Iran In this study, after selecting the participants through random cluster sampling, they all received ocular examinations including visual acuity (VA) measurement, refraction, fundoscopy and tonometry. After measuring uncorrected visual acuity (UCVA), non-cycloplegic refraction was performed for all participants with an autorefractometer and the results were checked with manual retinoscopy. The prevalence of myopia, hyperopia, astigmatism and anisometropia were 19.7% [95% confidence interval (CI) 17.0-22.4], 39.5% (95% CI 36.1-42.9), 23.6% (95% CI 20.7-26.4), and 7.8% (95% CI 6.0-9.6), respectively. Male gender and cataract were also significantly correlated with myopia. Female gender and age were correlated with hyperopia. Astigmatism was significantly correlated with cataract and a decrease in age. With-the-rule (WTR), against-the-rule (ATR) and oblique astigmatisms were detected in 7.5%, 13.1% and 3.5% of the participants, respectively. Overall, the prevalence of at least one type of refractive error was 64.0% (95%CI 60.7-67.3) among the participants. The results of this study indicated that hyperopia was the major anomaly in our population. Since the combination of presbyopia and hyperopia results in an undesirable visual condition in the elderly, it is important to pay proper attention to visual problems in this age group.

To investigate the efficacy of Intacs implantation in post-LASIK corneal ectasia (PLE) In this retrospective study, 17 eyes of 12 patients with PLE, that had been implanted Intacs, were evaluated. These parameters were assessed: uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), manifest refractive spherical equivalent (MRSE), refractive cylinder (RC), mean Keratometry (Km), and topographic cylinder (TC). Also preoperatively, thinnest point thickness (TPT) was measured with rotating Scheimpflug camera. The results of single and double-segment Intacs implantation were also reported. Mean UCVA logMAR value improved from 0.93±0.41 to 0.57±0.34 (p=0.007), and BSCVA logMAR from 0.36±0.34 to 0.18±0.18 (p=0.007). MRSE reduced from 4.15±2.71 to 2.48±1.57 diopter (D) (p=0.003), and Km from 44.57±3.93 to 43.00±3.96 D (p=0.003). RC changed from 2.65±1.91 to 2.59±1.12 D (p=0.776), and TC from 2.81±1.71 to 2.44±1.41 D (p=0.365), neither change was statistically significant. BSCVA and UCVA improved in both single and double-segment groups. Intacs implantation can improve UCVA and BSCVA in cases of PLE, except when TPT is less than 350 microns. Both MRSE and Km reduced after surgery but astigmatism did not change.

The objective of this study was to evaluate the outcome of Acrysof Toric intraocular lenses (IOLs) implantation in cataract surgery for the correction of regular corneal astigmatism. Twenty eyes of 16 patients with cataract and regular corneal astigmatism of 1.00-4.00 diopter (D) underwent surgery. Depending on the amount of corneal astigmatism, an Acrysof Toric IOL of type SN60T3, SN60T4, SN60T5, SN60T6, SN60T7, SN60T8 or SN60T9 was implanted. Studied parameters before and after surgery included uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), residual refractive astigmatism, change in corneal astigmatism, IOL rotation, and spectacle independence for distance vision. At six months after surgery, all eyes (100%) had a UCVA of 20/32 or better and 80% had a UCVA of 20/25 or better. Spectacle independence for distance vision was 85% in the studied eyes. The change in corneal astigmatism ranged between 0.25 and 0.5 D in all eyes. The residual astigmatism was 0.75 D or less in 100% of the cases and 0.0 to 0.5 D in 90% of the eyes. IOL rotation was zero degrees in 65% of the eyes, 4° or less in 90% of the eyes, and 5° or more in 10% of the eyes by six months after surgery. Using Acrysof Toric IOLs (SN60T3 to SN60T9) during cataract surgery for patients who have regular corneal astigmatism of 1.0 to 4.0 D is an effective, predictable, and rather stable option for correcting astigmatism.

To determine cyclotorsional eye movement between the upright position and the supine position, in Iranian patients with high preoperative astigmatism This prospective cross sectional study contains 102 eyes of 59 patients who were candidates for refractive surgery with Technolas 217z100 excimer laser system for correction of high astigmatism. Wavefront measurements using Zywave II, Hartmann Shack aberrometer were performed in seated position. For all patients the amount of cyclotorsion before surgical procedure in supine position was measured by iris registration and the comparison between preoperative examinations in seated position with the supine position resulting in the amount of cyclotorsion was conducted by iris registration. The mean cyclotorsion was found 3.18±2.37 (SD) degrees significantly greater than zero degrees 3.28±2.28 (SD) degrees in excyclotorsion and 3.01±2.54 (SD) degrees in incyclotorsion. Excyclotorsion was predominant trend of rotation in comparison with incyclotorsion in both right and left eyes. The amount of rotation greater than 2, 5 and 7 degrees occurred in 59.8%, 21.6% and 5.9% of the eyes, respectively. This study confirms significant rotational movement between the upright position and the supine position. Proper registration for appropriate correction of astigmatism and higher order aberrations (HAOs) for achieving optimal visual outcomes is recommended.

To evaluate corneal visco-elasticity and intraocular pressure (IOP) changes measured by an Ocular Response Analyzer (ORA) after scleral buckling Fifty-six eyes with history of scleral buckling surgery three months ago were included in the study. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc) and Goldmann-correlated IOP (IOPg) were measured by ORA 3 month postoperatively. In each group, unoperated (normal) eye was the control eye and operated eye was the case eye. Twenty-seven eyes underwent buckling with encircling elements (group 1) and 29 eyes with segmental sponge (group 2). The mean (±SD) CRF in group 1 was 8.74±2.05 in operated eyes and 9.19±1.96 in control contralateral eyes, with no significant difference between them (p=0.412). In group 2 the mean (±SD) CRF was 8.14±1.95 in contralateral eyes and 9.38±2.1 in control eyes and the difference was statistically significant (p=0.024). In group 1 there was no significant difference between mean CH of cases and controls (p=0.286), but statistically significant difference between mean CH of cases and controls in group 2 (p=0.044). There were no significant differences between IOPg and IOPcc of cases and controls in two groups. Mean CRF and CH measurements were significantly lower after scleral buckling with segmental sponge, but no significant change in encircling procedure was observed. Also no significant change in IOPg and IOPcc in any kind of scleral buckling technique occurred postoperatively. It seems that hysteresis and CRF may measure different biomechanical aspects of ocular rigidity and are likely to be useful additional measurements in the assessment of ocular rigidity when measuring IOP.

The purpose of the present study was to determine the alterations in serum tumor necrosis factor alpha (TNF-α), zinc and copper in the patients with pseudoexfoliation syndrome (PEX). TNF-α, copper and zinc levels were determined in 30 patients with PEX and 30 control patients of the same age and sex, by enzyme-linked immunosorbent assay (ELISA) and atomic absorption method respectively. The serum levels of TNF-α in PEX patients (3.32±0.99 pg/ml) were significantly higher than control group (0.43±0.15 pg/ml, p=0.002). The copper level in serum of PEX patients was significantly higher than control group (0.003±0.001 μg/l vs. 0.002±0.001µg/l, p=0.007). The zinc level in serum of PEX patients was significantly lower (0.05±0.028 μg/l vs. 0.08±0.023 μg/l (than controls (p=0.001). There was no correlation between TNF-α, copper and zinc levels in both study groups. This study showed that serum levels of TNF-α and copper in PEX patients increased but the serum level of zinc decreased in these patients.