[Effect of relaxing incisions for post penetrating keratoplasty astigmatism on graft curvature]

To evaluate changes in graft steepness after graft refractive surgery [GRS] and to discover influential factors and a coefficient to predict the amount of postoperative shift. Keratoconic patients with history of penetrating keratoplasty [PKP] who underwent GRS due to high post-PKP astigmatism were included. Changes in mean keratometry after GRS were evaluated to find possible influential factors such as age, graft anatomical features, number of incisions, use of compression sutures, and total arc length on achieved vector astigmatic correction. There was a significant increase in average keratometry by 0.86 +/- 1.07 D postoperatively [P<0.001]. Mean keratometric coupling ratio [CR] and coupling constant [CC] were 0.62 +/- 1.09 and -0.34 +/- 0.70, respectively. A significant association was found between preoperative spherical equivalent keratometry and keratometric CR, and between achieved correction in vector keratometric astigmatism and keratometric CC. Additionally, age had a significant negative association with keratometric CR and CC. A significant increase in graft steepening occurred after GRS. For every diopter reduction in vector keratometric astigmatism, a mean of 0.34 D increase in graft curvature is expected postoperatively

[Chemical eye burns]

Chemical injuries of the cornea are ophthalmic emergencies. These injuries often result in significant ocular morbidity and generally strike young adults in the prime years of life. Classification schemes enable the ophthalmologist to determine the severity of injury and the prognosis for the injured eye. Immediate management consists of copious irrigation following exposure. Effective management in the intermediate and late phases requires an understanding of the cellular events that occur during each phase. Appropriate medical and surgical care helps ensure the best outcomes for these potentially blinding injuries. With appropriate management, it is possible to restore vision to all but the most severely burned eyes. While our current understanding of these injuries allows us to save many of these eyes, more work is needed to improve the prognosis of grade IV injuries. Ongoing animal and human research is investigating the use of novel topical agents to reduce angiogenesis, inhibit inflammation, promote repair, and reduce the risk of corneal melting. Efforts at preventing ocular chemical burns are equally important and deserve emphasis

National strategies of ophthalmic education in Iran

Academic medicine is in a state of dramatic transformation. For this reason strategic thinking is the most essential part of educational planning. The main purpose of the present study was developing the strategic educational planning of Ophthalmology in Iran from 2007 to 2010. A qualitative investigation using focus group discussion has been implemented successfully tor developing educational planning. Six to twelve representatives of key stakeholders in the ophthalmic education of Iran participated to this study. Strengths, weaknesses, opportunities and threats of ophthalmology education in Iran were analyzed. Strategic goals in education, research, and health service providing domains were being developed. Educational goals were defined as training of human resources in accordance with the community needs at the level of general practitioner, specialist, and fellowships in ophthalmology. Research goals of the program were defined as scientific interdepartmental and international communications, in order to promote the level of education, research, and treatment in the country. Also, in the field of health services according to the community needs, providing services by the means of advanced and cost effective methods were defined as strategic objectives. Based on this strategic plan in the last three years ophthalmic education in Iran shall be many changes in educational, research and health care provision for social accountability

[Prevalence and causes of blindness and visual impairment in varamin district]

To estimate the magnitude and causes of visual impairment [VI] in subjects aged >/= 50 years in Varamin district in 2009 using the proposed method by the World Health Organization [WHO]. This cross sectional population based survey was performed in Varamin targeting people over the age of 50 years using the proportional probabilities to size and cluster compact segment sampling method. Blindness was defind by WHO definition as best corrected visual acuity [VA] in the better eye less than 3/60. Severe visual impairment [SVI] and visual impairment [VI] were defined as 3/60

[Bilateral nocardia keratitis following photorefractive keratectomy]

To report the clinical, confocal scan, and histopathologic features of bilateral Nocardia keratitis following photorefractive keratectomy [PRK]. A 23-year-old girl underwent simultaneous bilateral PRK for myopia. On the third postoperative day, dense central infiltrates mainly involving the anterior stroma were noticed in both eyes. Clinical and confocal scan features were consistent with a diagnosis of Nocardia keratitis and topical amikacin eye drops 2% were started. Empirical antibiotic therapy was converted into specific therapy after confirming the definite diagnosis by clinical features and confocal scan. Due to poor response to medical therapy, lamellar keratectomy was performed in both eyes which shortened the treatment course. Histopathologic examination confirmed the initial diagnosis. Familiarity with the clinical and confocal scan features of Nocardia keratitis facilitates early diagnosis, proper management and hence a rapid clinical response

[Indications for corneal transplantation at labbafinejad medical center]

To investigate indications and methods of surgery in corneal transplantation in Labbafinejad medical center from 2007 to 2009. Records of 1083 patients who had undergone corneal transplantation from 2007 to 2009 were reviewed. Age, sex and indication and type of surgery were evaluated. Patients included 709 [65.5%] male and 374 [34.5%] female subjects with mean age of 43.2 +/- 10.2 year [range, 17 days to 33 years] keratoconus [36.7%] was the most common indication followed by cataract extraction with or without IOL insertion [12.8%]; corneal ulcers due to bacterial, fungal and acanthamoba infections [11.7%]; non herpetic scar and opacities [7.4%]; trachoma keratopathy [5.6%]; corneal dystrophy [4.6%] and mustard gas keratopathy [4%]. The most common type of surgery was penetrating keratoplasty [56.2%] followed by deep anterior lamellar keratoplasty [24.5], tectonic grafts [9.4%], lamellar keratoplasty [3.4%], endothelial graft [3.5%] and keratolimbal allograft without penetrating keratoplasty [3.1%]. During this 3 years period, keratoconus was still the most common indication for corneal transplantation but rate of regraft is increasing in comparison with previous reports. Corneal edema following cataract surgery with or without intraocular lens implantation was the second most common indication. Rate of endothelial grafts and keratolimbal alografts have increased since our previous reports

[Comparison of cornel graft biomechanical properties following penetrating keratoplasty and deep anterior lamellar keratoplasty using the ocular response analyzer]

To compare corneal hysteresis and resistance factor after penetrating keratoplasty [PK] and deep anterior lamellar keratoplasty [DALK] using Anwar's big-bubble technique using the ocular response analyzer. Forty-five PK eyes and 23 DALK eyes with keratoconus were compared in terms of corneal hysteresis [CH], corneal resistance factor [CRF], Goldmann-correlated intraocular pressure [IOPg] and cornea-compensated IOP [IOPcc]. Mean age was 29.8 +/- 6.1 years in the PK group and 27.2 +/- 6.5 years in the DALK group [P=0.11]; patients were followed for 31.4 +/- 19.0 and 29.2 +/- 17.3 months after corneal transplantation, respectively [P=0.27]. There was no significant difference between the study groups in terms of recipient [P=0.21] and donor [P=0.57] trephine size or BSCVA [P=0.77]. Mean CH was 10.09 +/- 2.5 mmHg in the PK group and 9.64 +/- 2.1 mmHg in the DALK group [P=0.36]; mean CRF was 10.13 +/- 2.2 and 9.36 +/- 2.1 mmHg, respectively [P=0.17]. No significant difference was found between the study groups in terms of IOPg [P=0.25] and IOPcc [P=0.80]. PK and DALK techniques provide comparable graft biomechanics in keratoconic eyes

[Corneal endothelial cell parameters after torsional versus conventional ultrasound mode phacoemulsification]

To compare corneal endothelial cell features after cataract surgery performed using fixed torsional or conventional [Pulse] ultrasound mode. In this randomized comparative study, 60 eyes were randomly and equally divided into two groups of torsional or longitudinal mode phacoemulsification. All surgeries were performed by an experienced surgeon, and the outcomes were evaluated by a masked examiner. Preoperatively visual acuity [VA], age and mean nuclear grade [LOCS III] were recorded; besides automated confocal microscopy was used to measure ECD, polymegathism and pleomorphism at the centre of the cornea. All patients underwent clear cornea phacoemulsification in a similar manner. Intraoperative outcome measures were ultrasound time [UST], cumulative dissipated energy [CDE], and total fluid use. Best corrected VA and confocal measurements were repeated after 1 month. Mean preoperative ECD in conventional and torsional phaco mode groups were 2761.61 +/- 403.36 and 2690.36 +/- 490.92 cells/mm2. Postoperative ECD was 2494.30 +/- 358.63 and 2436.56 +/- 468.39 cells/mm2, respectively. The decrease in ECD, and increase in pleomorphism and polymegatism were statistically significant within both study groups [P<.001], but there were no statistically significant differences in preoperative and postoperative measurements between the 2 groups [P>.01]. No relevant clinical differences or operative complications were seen in either group. There were no statistically significant difference between intraoperative measures in both groups [P>.01]. Both phaco methods provide effective lens removal with no significant difference

[Dry eye syndrome]

Dry eye syndrome is a multifactorial disorder of the tear film and ocular surface that results in eye discomfort, visual disturbance, and often ocular surface damage. Studies suggest that the prevalence of clinically diagnosed dry eye syndrome [DES] is 0.4%. to 0.5%, which is highest among women and the elderly. The burden of DES can be substantial, affecting visual function, daily activities, social and physical functioning, work place productivity and quality of life. This article discusses the normal anatomy and physiology of the lacrimal functional unit and tear film; pathophysiology of DES; DES etiology; classifications and risk factors; and DES diagnosis and management

[Intraocular pressure measurements after penetrating keratoplasty using the ocular response analyzer versus goldmann applanation tonometer]

To compare intraocular pressure [IOP] readings measured by the Ocular Response Analyzer [ORA] with those measured by the Goldmann applanation tonometer [GAT] in keratoconic eyes following penetrating keratoplasty [PKP] and to evaluate the influence of anatomical and biomechanical properties of the grafts on IOP measurements. This cross-sectional study was conducted on 45 keratoconic eyes undergoing PKP. IOP was measured using the GAT [IOP GAT]; corneal hysteresis [CH], corneal resistance factor [CRF], Goldmannrelated IOP [IOPg], and cornea-compensated IOP [IOPcc] were obtained using the ORA; central graft thickness [CGT] was measured by ultrasonic pachymetry. Bland-Altman and mountain plots were used to evaluate agreement between the tonometers. The correlation of graft curvature and astigmatism; central graft thickness [CGT]; and corneal biomechanical properties with IOP readings was investigated using multivariate regression analysis. Mean patient age was 29.8 +/- 6.1 years and mean follow up was 91.2 +/- 35.4 months. Mean CH, CRF, and CGT were 10.2 +/- 2.1 mmHg, 10.1 +/- 2.2 mmHg, and 565.4 +/- 37.7 mm, respectively. Mean IOP GAT, IOPg, and IOPcc were 12.2 +/- 2.4, 15.1 +/- 3.5, and 15.8 +/- 3.3 mmHg, respectively [P<0.001]. The 95% limit of agreement between IOP GAT and IOPg ranged from -3.6 to 9.3 mmHg. CH and CRF, but not CGT or keratometric astigmatism were significantly associated with IOP GAT, IOPg, and IOPcc. Graft biomechanics had more influence on IOP values as compared to anatomical features. In comparison to GAT, the ORA seem to overestimate IOP in post-PKP eyes

[Management of complications of mustard gas keratitis with corneal and limbal stem cell transplantation]

To report the clinical findings and compare the outcomes of different surgical techniques evolved over time in a large series of patients with delayed-onset mustard gas keratitis [MGK]. This interventional retrospective case series includes patients with complications of delayed MGK. Medical and surgical interventions to address dry eye, limbal ischemia and limbal stem cell deficiency [LSCD], and corneal complications were reviewed. Outcomes of limbal stem cell transplantation techniques such as living-related conjunctival-limbal allograft [lrCLAL] and keratolimbal allograft [KLAL], as well as corneal transplantation techniques including penetrating keratoplasty [PKP] and lamellar keratoplasty [LKP] were compared. A total of 175 eyes of 90 patients [all male] aged 34 to 68 years were included. Mean follow up was 101 months. The most common ocular complication was chronic blepharitis and dry eye. Conjunctival vascular abnormalities and limbal ischemia were observed in 27.4% and 29.7% of eyes, respectively. LSCD necessitating stem cell transplantation developed in 41.1% of eyes. The most common corneal signs were central and peripheral anterior stromal opacity [58.9%] followed by corneal stromal thinning [36.0%] and neovascularization [27.4%]. lrCLAL was performed in 32 eyes [18.3%] and KLAL in 40 [22.9%]. The rejection-free graft survival rate was 39.1% in the lrCLAL group and 80.7% in the KLAL group at 40 months with mean duration of 24.9 and 68.8 months, respectively [P=0.02]. 30 eyes [17.1%] underwent PKP and 51 [29.1%] received LKP. Corneal graft failure was observed in 9 [30%] PKP and 6 [11.8%] LKP eyes. The rejection-free graft survival rate was 39.0% in the PKP and 90.3% in the LKP group at 28 months with a mean duration of 29.6 and 85.0 months, respectively [P<0.001]. Chemical warfare victims may ultimately develop significant ocular involvements requiring some sorts of surgical intervention. Limbal and corneal abnormalities can best be managed by KLAL and LKP, respectively

[Lamellar keratoplasty for management of mustard gas keratitis]

To report the outcomes of manual lamellar keratoplasty [LKP] in patients with delayed-onset mustard gas keratitis [MGK] and compare visual outcomes between subgroups with simultaneous or sequential KLAL and LKP. In this retrospective, interventional study, 52 eyes of 37 male survivors of chemical warfare with MGK who underwent LKP were included. The results were evaluated with respect to best spectaclecorrected visual acuity [BSCVA], refractive error, keratometric readings and graft clarity. Eyes with sequential versus simultaneous surgery were compared in terms of BSCVA, refraction, corneal graft surface stability, and stem cell and corneal graft survival rates. Mean patient age at the time of surgery was 43.4 +/- 8.2 [36-48] years, and mean follow-up period was 41.4 +/- 19.6 [19-107] months. Mean preoperative BSCVA was 0.51 +/- 0.48 logMAR, which increased to 0.33 +/- 0.18 logMAR [P=0.03]. Mean preoperative spherical equivalent refractive error was -2.40 +/- 1.5 diopters [D], which remained unchanged postoperatively [-1.52 +/- 3.7 D, P=0.77]. No significant difference between sequential and simultaneous surgery subgroups was observed in BSCVA, refraction, keratometry readings, or corneal graft survival [90.3% and 89.9%, respectively; P=0.68]. However, the simultaneous group had statistically better stem cell survival. LKP can effectively improve BSCVA in MGK. The simultaneous approach is superior to sequential surgery when both stem cell and corneal transplantation are indicated

[ EYESI simulator for training ophthalmology residents]

To assess various aspects of integrating a virtual reality [VR] simulator in the training of ophthalmology residents In this qualitative study, some aspects of the VR EYESI simulator as a health technology were assessed. Data was collected using a multiple-choice questionnaire and several deep interviews addressed to users and administrators of simulator training. Face and construct validity were measured as a score out of 100. Scores were given by 19 novice residents and 4 experienced fellowship candidates. Residents gave a score of 85.08 for face validity and a 70.87 for the construct validity of the EYESI simulator. Fellowship candidates scored its face and construct validity at 60 and 80.66, respectively. 63.2% of residents believed that the simulator is a very useful training tool and 75% of fellowships viewed it as useful. Eighty percent of interviewed attending physicians believed that the simulator reduced the time and improved the quality of training. They also stated that residents who were trained with the simulator were adequately prepared for entering the operating room and showed better eye-hand coordination. All the stakeholders strongly believed that simulation is a necessary method of education. The EYESI simulator is an up-to-date virtual reality medium that enjoys good face and content and face validity. It was also shown to be an effective method of training since it decreased the time and improved the quality of training

[Collagen cross-linking]

Patients with keratoconus constitute a large proportion of patients suffering from anterior segment disorders. As of this time, however, its pathogenesis has not yet been elucidated. A reduction in cross-link between collagen molecules has been observed in keratoconic eyes as compared to normal ones. Present approaches only address refractive errors resulting from the abnormal abnormal corneal shape. Recently, collagen cross-linking using riboflavin and ultraviolet has been introduced to slow down the disease progression. The purpose of the present study is to review the efficacy, clinical outcomes, limitations, and complications of collagen cross-linking

[Association between acute corneal hydrops in patients with keratoconus and mitral valve prolapse]

To investigate the association between acute corneal hydrops in patients with keratoconus [KCN] and mitral valve prolapse [MVP]. This case-control study included KCN patients with corneal hydrops who were referred to Labbafinejad Medical Center or a collaborating private clinic from March 2006 to March 2008 as the case group. The control group included age- and sex-matched individuals who were selected from patients without any ophthalmic diseases among clients of the same medical centers. Patients with history of eye trauma, corneal degenerative diseases, rheumatic fever, Marfan syndrome, rheumatoid arthritis, and systemic lupus erythematous were excluded. The size of the control group was four times that of the case group to increase the power of the study. All subjects were referred for cardiac examination and underwent two-dimensional M-mode and color Doppler echocardiography. Proloff's criteria were used for diagnosis of MVP. Fisher exact test and logistic regression were used to compare these two groups. Overall, 160 patients [32 cases and 128 controls] with mean age of 31.0 +/- 13.2 were studied. Prevalence of MVP was 65.6% in the case group and 9% in controls [P<0.001]. Patients with hydrops had an odds ratio of 26.7 for having MVP [95% confidence interval, 9.5-75.2]. Age- and sex-adjusted analysis revealed a higher correlation between the two conditions in the case group. There seems to be a correlation between corneal hydrops secondary to KCN and MVP suggesting the need for cardiovascular evaluation in these patients to assess mitral valve status

[ outbreak of nocardia keratitis following photorefractive keratectomy]

To report 3 cases of nocardia keratitis following photorefractive keratectomy [PRK]. Report of Outbreak: Four eyes of 3 patients [2 female and one male] who had undergone PRK by a single surgeon at a single center developed nocardia keartitis 3 to 6 weeks postoperatively. Mean age was 25 [range 23-28] years and mean onset of corneal manifestations was 29 [range 21-40] days after PRK. Corneal smear and culture and confocal scan were performed in all eyes. Two eyes from the first two patients required lamellar keratectomy to debulk the involved stroma and to obtain specimens for microbiologic and histopathologic evaluation. Light microscopic examination disclosed gram-positive and acid-fast filaments of nocardia which were confirmed by the microbiologic results. Diagnosis of nocardia keratitis in the third case was not as challenging as the first two cases because of a high index of suspicion. Confocal scan in all cases disclosed hyperreflective and slender fibril-like structures in the corneal stroma. All eyes responded favourably to topical amikacin and the infection resolved without recurrence. Nocardia is a rare cause of keratitis following PRK. Clinical suspicion along with microbiologic, histopathologic and confocal scanning help to establish the correct diagnosis. The most probable cause of the outbreak was inadequate attention to sterility during surgery

[Risk factors for posterior capsular tear and vitreous loss during phacoemulsification in a tertiary eye center]

To report the rate of vitreous loss during phacoemulsification and its contributing risk factors in patients operated on at Labbafinejad Medical Center. This prospective comparative descriptive study included patients with cataract undergoing phacoemulsification by ophthalmology residents or cornea fellows from November 2006 to November 2007. All patients underwent a complete ocular examination including visual acuity, slitlamp examination, and dilated funduscopy, preoperatively. Phacoemulsification was performed under local or general anesthesia using Divide and Conquer technique. Main outcome measures included posterior capsular tear and vitreous loss and predisposing factors such as surgeon's experience, ocular and systemic conditions, and type and severity of the cataract. Overall 767 patients including 393 male and 374 female subjects with mean age of 62.7 +/- 12.0 [range 6-96] years were studied. The overall rate of vitreous loss was 7.3% which was 5-fold higher in the hands of residents than fellows. Patients' age and female sex, small capsulorrhexis, small pupil, pseudoexfoliation, and high myopia were other significant risk factors. The highest rate of vitreous loss occurred in patients with dense nuclear cataracts. Since ophthalmology residents had a higher rate of vitreous loss, patients with risk factors such as pseudoexfoliation, high myopia, and dense nuclear cataracts are better operated by more experienced surgeons

[Keratocyte density in normal and keratoconic corneas using confoscan]

To compare keratocyte density between normal and keratoconic corneas in non-contact lens wearers. Confocal scanning was performed on 39 corneas of 26 patients with keratoconus and 28 corneas of 14 normal control subjects. None of the cases were contact lens wearer. All individuals underwent ophthalmic examination and computed topography in addition to confocal microscopy. Main outcome measures were anterior [10%], middle [33-67%] and posterior [10%] stromal keratocyte densities. Mean age of the subjects was 27.7 +/- 6.6 [range 18-45] years. Mean keratocyte density in the control group was 736.7 +/- 65.6 cell/mm2 in the anterior stroma, 623.4 +/- 72.6 cell/mm2 in the middle stroma and 608.6 +/- 45.8 cell/mm2 in the posterior stroma. Corresponding values in the keratoconus group were 787.9 +/- 103.5, 665.2 +/- 58.1 and 604.2 +/- 69.0 respectively. No significant difference was noted between the two groups regarding stromal keratocyte density; however stromal keratocyte density significantly decreased from anterior toward posterior stromal layers within both groups. Keratocyte density showed statistically insignificant decrease with aging. Keratocyte density was significantly higher in female subjects [P= 0.019]. No significant difference was seen between normal and keratoconic corneas in terms of stromal keratocyte density

[Histopathology of recipient corneal buttons after penetrating keratoplasty]

To report the histopathological diagnoses of recipient corneal buttons in patients undergoing penetrating keratoplasty. In this observational case series, all recipient corneal specimens sent to the ophthalmic pathology laboratory of the Eye Bank of Iran between 2004 and 2007 underwent histopathologic examination. Overall, 315 corneal specimens were evaluated. Histopathologic diagnoses included keratoconus [27.0%], corneal dystrophies [23.5%], acquired corneal endothelial decompensation [13.3%], nonspecific corneal scars and degenerations [11.4%], keratitis [10.8%], mustard gas keratopathy [8.0%], combined dystrophy and keratoconus [1.6%], post-keratorefractive keratectasia [1.6%], chemical burn-induced keratopathy [1.3%] and other causes [1.6%]. In keratoconic corneas, breaks in Bowmans' layer were evident in all cases and hydrops was diagnosed in 17.6%. The most common corneal dystrophy was macular corneal dystrophy [35.0%] followed by Fuchs' endothelial dystrophy [26.25%]. In cases with keratitis, causative microorganisms were found in 35.2%. Histopathologic findings in mustard gas keratopathy included loss of keratocytes, thickening of epithelial basement membrane, foci of acute and chronic inflammation and secondary degenerative changes; the former two were the most common features. To our knowledge, this is the first report on histopathologic evaluation of recipient corneas in Iran. Keratoconus, corneal dystrophies, acquired endothelial decompensation, nonspecific corneal scars and degenerations, keratitis and mustard gas keratopathy were predominant histopathologic diagnoses. Loss of keratocytes and thickening of epithelial basement membrane were the most common histopathologic findings in mustard gas keratopathy. Breaks in Bowmans' layer were found in all keratoconic corneal buttons

[Causes of visual impairment among patients referred to rehabilitation clinics of Shahid Beheshti medical university]

To describe causes of low vision and blindness in patients referred for low vision aids to rehabilitation clinics at Shahid Beheshti Medical University during 2005. Visual acuity was classified to five groups based on best-corrected visual acuity [BCVA] in the better eye according to World Health Organization [WHO] criteria and by using standard Snellen chart which included mild, moderate, severe and profound low vision and blindness. The causes of blindness and low vision were determined using the 10[th] version of International Classification of Diseases [ICD-10] based on the main cause in both eyes. The study was performed on 432 patients including 275 [65%] male and 148 [35%] female subjects with mean age of 43.6 +/- 25.5 [range 3-92] years. Mild to moderate and severe low vision and blindness were present in 28.8%, 46.4% and 24.8% of cases, respectively. The main causes of visual impairment were diseases of the retina and choroid [74.5%], optic nerve and optic tract diseases [9.8%], vitreous and globe disorders [3.5%], congenital cataract [3.1%] and glaucoma [2.6%]. The pattern of distribution of the causes was almost similar in all age subgroups. Diseases of the retina and choroid are the main cause of visual impairment among patients referred to eye rehabilitation clinics