Journal of Current Ophthalmology
Volume:24 Issue: 2, Jun 2012

A review of posterior capsule opacification (PCO) after cataract surgery and some affecting factors A cross-sectional study was designed to study cataract patients who underwent cataract surgery between 2003 and 2006 in Farabi Eye Hospital, Tehran, Iran. Random sampling was done. Those with a history of uveitis, intraocular surgery, and eye trauma were excluded from the study. The patients were then invited for follow-up visits and study of the results. Postsurgical PCO percentage was calculated, and its association with variables like sex, age, history of cataract surgery, type of surgery, and type of lens was studied. The incidence of PCO in patients was 14.2% (11.3 to 17.0 CI=95%) with an incidence of 8.7% and 19.9% in males and females, respectively (P<0.001). PCO was not significantly correlated with age. The incidence of PCO in those who had undergone cataract surgery at least one year ago was 10.9% while it was 22.7% in those who had received surgery at least 4 years ago (P=0.005). PCO incidence in those with and without partial opacity was 31% and 13.2%, respectively (P=0.011). The highest and lowest incidence of PCO belonged to those who were operated on with small incision cataract surgery (SICS) and phacoemulsification techniques, respectively (P=0.009). The incidence of PCO was 24.2% and 12% in cases in whom PMMA and foldable lenses were used, respectively (P=0.002). Of those with PCO after cataract surgery, 31.6% (21.5 to 41.8 CI=95%) needed Nd:YAG laser capsulotomy. In our study, the incidence of PCO after cataract surgery was relatively low with a higher incidence in females. Preoperative corneal opacity, surgical technique and the lens type can be factors affecting the incidence of PCO.

Identifying the predisposing factors of the infectious keratitis results in understanding the underlying mechanisms of its expansion and severity that is essential for initiation of optimal empirical antimicrobial therapy. This study identified main predisposing factors of bacterial keratitis in a sample of Iranian population. Ninety patients with bacterial keratitis were prospectively enrolled. Demographic and clinical features were collected by a face to face interviewing as well as physical examination. Predisposing factors and final outcomes were analyzed. Trauma was the most commonly identified predisposing factor (40.0%), followed by blepharitis and cataract surgery that were observed in 27.8% and 23.3% of patients, respectively. 5.6% of cases were associated with contact lens wear and 4.4% with prior herpetic keratitis. No significant differences were found in overall prevalence of predisposing factors of infectious keratitis between men and women. Fifty-three patients experienced cornea scar and 15.6% of them had corneal neovascularization. Moreover, graft of cornea was programmed in 11.1% of cases and 5.6% of them underwent conjunctive flap. Ocular trauma, followed by surgery and ocular surface diseases are the major predisposing factors for bacterial keratitis. Identification of the appropriate predisposing factors aids in early recognition and treatment of microbial keratitis.

To report a study design for assessing the cataract surgery outcome We conducted the study in an eye hospital in which over 13,300 cataract extractions are performed annually. Sampling framework and recruitment included International Classification of Diseases (ICD)-10-based electronic hospital records of patients who underwent age-related cataract extraction within the preceding 5 years that were sampled randomly for 470 patients. Phone recruitment was made and the surgical records were reviewed. Novel variables were ‘mature cataract rate’, ‘surgeon competence’, ‘surgically challenging eye’, ‘wound enlargement’ and ‘use of an injector to insert an intraocular lens’, ‘posterior capsule status’, ‘postoperative spectacle use’, and ‘unmet need’. Causal diagrams (to facilitate modeling), data mining (clustering and decision matrix), and outlier analysis were used. Subjects were categorized as deceased, unavailable, or successfully contacted with the last subcategorized as participants or non-participants (declined or noncompliant), in a participants’ flow chart. The participation rate was 51%. Participants and non-participants were comparable regarding baseline and surgical characteristics. The causes of visual impairment were reviewed and a standardized diagnostic scheme was developed that included eight anatomic headings and 18 disease-specific subheadings. A reporting scheme was sketched. Despite shortcomings in the quality and availability of the hospital and surgical records and a relatively low participation rate compared to prospective data collection, this retrospective cross-sectional approach was practical for evaluating the quality of cataract surgery in a hospital in a developing country and the protocol is recommended as a guideline to manage such a project.

To determine the maximum non-toxic dose of recombinant human erythropoietin (EPO) in rabbit eyes Eight rabbits (sixteen eyes) were scheduled for evaluating side effects of four intravitreal doses of 1000, 2000, 4000 and 5000 IU of EPO, two rabbits for each dose. For each dose (two rabbits), the drug was injected for the right eyes. Balanced salt solution (BSS) was injected into the left eye of one rabbit (placebo eye) and the other left eye remained uninjected (control eye). All eyes were examined in 1, 2, 3, 7, 14 and 28 days after intravitreal injections. Electroretinogarphy (ERG) was performed before and 14 days after intravitreal injection. After four weeks, animals were euthanized and eyes were enucleated and submitted for Hematoxylin & Eosin (H&E) and immunohistochemistry evaluations. Traumatic cataract developed in one of placebo group eyes. Neither anterior nor posterior segment inflammatory reactions were observed after injections. H&E staining and immunohistochemistry examinations did not revealed any sign of retinal and retinal pigment epithelium toxicity with injected doses. ERG changes were within normal limits in all eyes. Intravitreal injection of recombinant human EPO in rabbit eyes was not associated with adverse toxic effects up to 5000 IU doses.

To determine the prevalence of refractive errors, strabismus and amblyopia in the schoolboys of Varamin city, Iran In a cross-sectional population-based study in 2010, we used random cluster sampling to select the participants from Varamin high school students. Examinations were conducted at the school site under standard conditions. All students had non-cycloplegic refraction, visual acuity (VA) test and cover test. Of the 1,430 selected, 79.2% participated in the study: their mean age was 16.3±1.3 years (range, 14 to 18). The prevalence of myopia [spherical equivalent (SE)≤-0.5 diopter (D)], hyperopia (SE≥+0.5 D) and hyperopia (SE≥+1.0 D) were 33.2% (95% confidence interval (CI): 25.0 to 41.4), 17.5% (95% CI: 8.6 to 26.4) and 6.1% (95% CI: 2.6 to 9.6), respectively. Astigmatism (cyclinder power ≥0.75 D) and anisometropia (difference in SE ≥1.0 D) were detected in 10.5% (95% CI: 8.4 to 12.6) and 3.8% (95% CI: 1.8 to 5.8) of the students. The prevalence of strabismus was 1.5% (95% CI: 0.9 to 2.1) and exotropia was the most prevalent type of strabismus (0.9%). The prevalence of amblyopia was 2.1% and anisometropia was the most common cause (54.2%). There was an unmet need for refractive correction in 15.4% (95% CI: 13.3 to 17.4) of the students. The most common refractive error in the students in this study was myopia, however, the prevalence rate of hyperopia was relatively higher than that in other studies. The unmet need for refractive correction was higher as well. In comparison to other populations, the prevalence of strabismus was low while the prevalence of amblyopia was similar.

To evaluate the retinal nerve fiber layer (RNFL) and central corneal thickness (CCT) in patients with exfoliation syndrome (XFS) In this comparative case series we measures RNFL thickness and CCT 30 patients with XFS and 30 age and sex matched healthy subjects who met the inclusion criteria. Average RNFL in XFS group were significantly thinner than controls (94.36±8.70 µm vs. 100.80±6.68 µm) (P=0.002). In the analysis with regard to quadrants, no statistically significant reduction in RNFL thickness was found between groups. XFS patients and controls did not differ in CCT measurements (522.90±40.71 µm vs. 517.30±30.50 µm) (P=0.549). No significant differences in CCT and RNFL thickness in temporal, nasal, superior and inferior quadrants between XFS and controls were observed. However, average RNFL measurements in eyes with XFS showed lower values.

To compare central corneal thickness (CCT), corneal endothelial cell density, and lens capsule thickness in normotensive patients with and without pseudoexfoliation syndrome (PXS) This was a prospective, comparative, descriptive study. Normotensive candidates for cataract surgery with (study group) and without (control group) PXS were enrolled in the study. CCT and corneal endothelial cell density were measured preoperatively, and central lens capsule thickness was measured postoperatively. Forty-three eyes of 43 patients in the study group and 39 eyes of 39 age-matched patients in the control group were studied. The mean age was 68.6±11.2 years and 69.3±13.1 years in the PXS and control group, respectively (P=0.5). The mean CCT was 511.9±27.9 µm in the PXS group and 531.4±32.7 µm in the control group (P=0.005). The mean central endothelial cell density was 2045±493 cell/mm2 in the PXS group and 2098±431 cell/mm2 in the control group (P=0.57). In the PXS group, the mean lens capsule thickness was 15.85±3.31 µm, and it was 15.27±3.35 µm in the control group (P=0.4). The mean CCT in PXS group was significantly lower than control group. However, there were no significant differences between corneal endothelial density and anterior lens capsule thickness between PXS group and control group.

To compare outcomes of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) in keratoconic eyes in a university teaching hospital setting In this longitudinal cross-sectional study all patients who underwent PK or DALK for keratoconus at 2 years period were included to the study. The patients were recalled and complete eye examination including best spectacle corrected visual acuity (BSCVA), refraction, topography and contrast sensitivity were accomplished and the results were compared in the two groups. A total of 106 patients underwent PK or DALK for keratoconus which were included in our study, of them 57 eyes underwent PK and 49 eyes underwent DALK. Mean follow-up time in PK and DALK groups were 35.0±2.4 and 30.3±2.5 Mo respectively (P=0.17). The mean postoperative BSCVA in DALK group was 0.28±0.04 logMAR and in PK group was 0.28±0.03 logMAR (P=0.99). The postoperative mean SE in PK and DALK groups were -2.74±0.58 diopter (D) and -3.46±0.52 D, respectively (P=0.36). Mean topographic Astigmatism in PK group was 3.81±0.28 and in DALK group was 4.21±0.42 (P=0.42). The contrast sensitivity functions (CSFs) in all special frequencies in DALK group was significantly lower than PK group. One graft in PK group and four grafts in DALK group were failed during follow-up time. Visual and refractive outcomes in PK and DALK for keratoconus are comparable. Whereas CSFs were lower in DALK in comparison to PK and graft failure was higher in DALK.

To report two young patients with unilateral pseudoexfoliation (PEX) syndrome Case reports: Two young patients with PEX syndrome were examined. The first was a 30-year-old woman who had a history of penetrating ocular trauma with iris prolapse in the right eye that subsequently developed PEX material deposition on pupillary border and anterior lens capsule. The second was a 13-year-old girl with history of trabeculectomy in infancy and subsequent needle bleb revision in her right eye with PEX material deposits on anterior lens capsule. In both patients history of iris manipulation in the form of iridectomy was present. The time between ocular trauma or surgery with iris manipulation and detection of PEX syndrome were 16 and 11 years, respectively. According to a few previous reports of occurrence of PEX syndrome in young patients and surgical histories of our patients, there may be a role for ocular and particularly iris trauma in the development of PEX syndrome in younger patients.

Churg-Strauss syndrome (CSS) is a rare form of small vessel necrotizing vasculitis. Retinal artery and vein occlusion are very rare findings in these patients and they are treated by high-dose corticosteroids and cytotoxics. We describe a rare case of CSS under high-dose corticosteroids and cytotoxic treatment, presenting central retinal artery occlusion (CRAO). Case report: A 45-year-old man with a history of CSS, who had been admitted in the rheumatology ward to receive high-dose pulse corticosteroids, was presented with sudden loss of vision in his left eye four days after admission. He was receiving high doses of oral and intravenous prednisolone and a pulse of cyclophosphamide. Visual acuity (VA) was poor light perception and relative afferent papillary defect was present (3-4 +). A CRAO was diagnosed by the funduscopic appearance of retinal whitening, macular thinning, and mild optic disc paleness. In fluorescein angiogram, retinal filling and normal choroidal filling were absent. CSS-associated CRAO should be considered when acute visual loss occurs. Although taking corticosteroids and cytotoxics is the main treatment of patients with CCS, patients may progress to CRAO under this treatment.

To report an idiopathic retinal vasculitis, aneurysm, neuroretinitis (IRVAN) case treated with one session of panretinal photocoagulation (PRP) and intravitreal bevacizumab (Avastin) Case report: A 13-year-old boy was diagnosed as an IRVAN syndrome. Systemic examination, fundus angiography, brain MRI were performed to evaluate the patient. Treatment with one session of PRP, retinopexy and 3 consecutive monthly intravitreal injection of 1.25 mg Bevacizumab was performed. After the second Bevacizumab injection, complete regression of neovascularizations and improvement of visual acuity (VA) to 3/10 for right eye and 6/10 for left eye was noted. By the other 2 additional monthly intravitreal injection of Bevacizumab, VA improved to 6/10 and 8/10 for right and left eye. The Aneurysms became smaller. After 6 months of his treatment, his VA was remained stable. We reported a successful treatment effect of Bevacizumab as an adjunctive therapy in combination with PRP and retinopexy, for stage 3 IRVAN. Bevacizumab seems to have promising effects in the treatment of IRVAN.

To report a patient with Urrets-Zavalia (U-Z) syndrome after penetrating keratoplasty (PKP) in both eyes Case report: A 22-year-old woman with keratoconus associated with a central full thickness scar in both eyes underwent PKP in her right eye that was postoperatively associated with a fixed dilated pupil and severe fibrin reaction, posterior synechiae and mild anterior sub capsular cataract. However he developed fixed dilated pupil leading to posterior synechiae after PKP in the second eye. This case shows an intrinsic susceptibility for U-Z syndrome which alerts surgeons in the case of second eye surgery.

To evaluate the vascular occlusion in Coats’ disease In this non-comparative case series, 13 consecutive patients with Coats’ disease from January 2011 to September 2011 were included. The hypercoagulability states were evaluated in these patients. The mean age of the patients in this series was 15.4 years. All but one patient had high anti-Cytomegalovirus antibody (IgG) level and two third of the patients had higher than normal levels of alpha-2 globulin. It seems that there is a possible relation between history of old Cytomegalovirus old infection and ocular vascular changes in Coats’ disease deserving more evaluations in a larger series.

Human has always been trying to become familiar with different parts of the eye. It seems that in the beginning of his efforts; he has become familiar with the functions of the pupil of the eye, using these data, he was able to make the dark room and use the hole to relieve the refractive errors. It can be said that the human in the pre-history and post-history periods had been able to solve his visual problems by using the existing facilities including pinholes.

Sir, rabies is an important neurological infection. It is deadly and it is not possible to treat it. Despite the attempt for rabies control via animal control and rabies vaccination, there are many reported cases of rabies in each year. Basically, the transmission of rabies is due to animal bite. Recently, the new mode of rabies transmission, human to human, via transplantation is confirmed. The consideration on corneal transplantation should be mentioned.1,2 From simple literature searching, there are at least 8 reports from several countries, both tropical and non-tropical ones, on rabies after corneal transplantation.3-10 Usually, the rabies develops within a few days after transplantation.3-10 All reports had no history of rabies signs and symptoms in infective donor. Of interest, some reports also mentioned for an infective donor that provides infective cornea and other organs causing rabies to many new rabid recipients.3 Although the rabies transmission due to corneal transplant has been continuously reported since 1970’s, the new reports in the past two years can still be seen. Since corneal transplantation is widely practice and the risk of rabies is existed. It is questionable that the donor screening for rabies before transplantation is required or not.

Sir, the recent published case report on corneal bee sting by Sedaghat et al is very interesting.1 Sedaghat et al concluded that “Bee sting can lead to serious visual impairment despite adequate medical and surgical approaches.1” Indeed, the arthropod sting on cornea is usually serious and difficult-to-manage case. Based on the experience on another similar situation, corneal wasp sting, it can be seen that although medical treatment cannot provide 100% success in management but it can provide satisfied outcome in case with early treatment.2 Management of corneal sting should use these concepts: a) early identification of the problem, b) management of inflammation reaction as early as possible, c) following up of the visual property of the patient and d) surgical approach in the worst case.