dr. mohammad nasser hashemian

To evaluate the safety and efficacy of femtosecond laser-assisted MyoRing implantation with concurrent corneal collagen crosslinking (CXL) compared to MyoRing alone for the treatment of progressive keratoconus.

A total of 60 patients were enrolled in this randomized controlled trial. The patients were randomly allocated into two groups. In the first group, MyoRing was implanted, while in the second, it was inserted in the corneal stroma using the same technique, along with simultaneous CXL. Visual, refractive, topographic, and abberometric outcomes were measured preoperatively and at every postoperative visit.

Data of 47 patients were available at the end of the study; 28 in the MyoRing group and 19 in the MyoRing + CXL group. The mean uncorrected distance visual acuity (UDVA) improved from 0.79 ± 0.39 logMAR to 0.52 ± 0.31 logMAR (P < 0.05) in the MyoRing + CXL group and from 0.65 ± 0.38 logMAR to 0.62 ± 0.23 logMAR (P = 0.70) in the MyoRing group. CDVA changed from 0.33 ± 0.19 logMAR to 0.25 ± 0.16 logMAR (P = 0.10) in the MyoRing + CXL group and 0.32 ± 0.22 logMAR to 0.33 ± 0.17 logMAR (P > 0.50) in the MyoRing group. The mean keratometry (Km) decreased from 47.5 ± 2.7 D to 43.8 ± 3.2 D (P < 0.001) in the MyoRing group and 49.3 ± 3.4 D to 45.1 ± 3.0 D (P < 0.001) in the MyoRing + CXL group. Besides, horizontal coma was significantly lower in the MyoRing + CXL group (P = 0.022).

MyoRing insertion combined with CXL is a safe and effective method for the treatment of keratoconus. The visual and topographic outcomes were comparable to that for MyoRing insertion after 10 months; however, horizontal coma was significantly lower in the MyoRing + CXL group.

To compare the efficacy of subconjunctival administration of bevacizumab and different doses of sunitinib malate in reducing corneal neovascularization (CNV).
In this experimental study, central corneal cauterization was created in the right eye of fifty male Sprague–Dawley rats. On day 1 (1 week after cauterization), rats were randomly assigned into five treatment groups. Group control (n = 10) received subconjunctival injection of 0.02 ml of base saline solution. Group 1 (n = 10) received 0.02 ml of bevacizumab (25 mg/ml). Group 2, 3, and 4 (n = 10 for each group) were treated with 0.02 ml of sunitinib malate (10, 20, and 50 ?g/ml, respectively). On days 1, 7, and 14, digital photographs of the cornea were taken, and the area of CNV was measured.
During the 2?week follow?up, CNV area in treatment groups was less than in control group (P Subconjunctival sunitinib malate is more effective than bevacizumab in regressing CNV. This effect is more prominent on day 14.

To compare the visual, refractive, and keratometric outcomes of single‑segment conventional and severe keratoconus (SK) types of Intacs for correction of inferior keratoconus (KCN). A total number of 41 consecutive eyes of 23 patients with a diagnosis of inferior KCN underwent Intacs implantation. Eight eyes were excluded due to postoperative complications (4 eyes) and loss to follow‑up (4 eyes) and finally 33 eyes underwent statistical analysis. Two groups were created according to Intacs type insertion; conventional group (17 eyes) and SK groups (16 eyes). Intracorneal ring segments (ICRS) implantation was indicated in keratoconic patients with contact‑lens intolerance or reduced best spectacle‑corrected visual acuity (BSCVA). In the conventional group, mean uncorrected distance visual acuity (UCDVA) improved from 0.45 ± 0.41 preoperatively to 0.69 ± 0.39 six months after surgery representing a gain of 2 Snellen lines, and in the SK group mean UCDVA changed from 0.40 ± 0.35 preoperatively to 0.58 ± 0.48 equivalent to two Snellen lines improvement 6 months after operation (P = 0.48). Mean preoperative BSCVA in the conventional group improved from 0.72 ± 0.41 to 0.86 ± 0.39 (2 lines improvement) postoperatively and in the SK group improved from 0.71 ± 0.69 to 0.75 ± 0.45 (0.50 line improvement) (P = 0.29). Mean preoperative spherical equivalent (SE) decreased from −4.86 ± 2.26 D to −3.57 ± 2.21 D (conventional group) and from −4.20 ± 1.82 D to −3.60 ± 1.89 D (P = 0.34), mean astigmatism (AST) decreased from −5.20 ± 2.07 D and −4.50 ± 2.26 D to −4.02 ± 2.57 D and − 3.18 ± 2.14 D in the conventional and SK groups, respectively (P = 0.68). Finally, mean K min decreased from 47.11 ± 2.51 D to 45.40 ± 3.30 D in the conventional group and from 45.05 ± 2.59 D to 44 ± 3.88 D in the SK group (P = 0.63) and mean K max was decreased from 52.82 ± 3.23 D to 50.52 ± 3.57 D and from 49.72 ± 3.17 D to 48.55 ± 4.50 D, respectively (P = 0.48). Single‑segment implantation of conventional and SK Intacs improved UCDVA and BSCVA, decreased corneal AST and keratometry in both groups with comparable outcomes.

To assess the efficacy of polyhexamethylene biguanide (PHMB) in treating Acanthamoeba keratitis (AK) and also to identify related factors affecting final visual outcome in AK patients treated with PHMB In these interventional case series study, 27 eyes of 25 patients with AK received PHMB 0.02% and divided into two groups according to the final visual acuity (VA); VA equal to or greater than 20/25 and VA less than 20/25. Two groups were evaluated for the effectiveness of PHMB in treatment of AK. Before treatment, more than 85% of eyes had VA of less than 20/25 whilst after treatment final VA was 20/25 or better in 66.7% of eyes. VA regressed in 14.8% of eyes during follow-up and improved or remained the same in more than 85% of eyes. Patients with deep stromal keratitis or a ring infiltrate had more than a 28-fold increase in the odds of a visual outcome worse than 20/25 (OR, 28.0; 95% CI, 3.3-240.8, p=0.001). Patients with Initial VA<20/40 had a 9-fold increase in the odds of a visual outcome worse than 20/25 (OR, 8.6; 95% CI, 1.2-59.8, p=0.003). Longer duration of symptoms (≥ 3 weeks) or the medication used prior the first visit were not associated with poorer final VA (p>0.05). Five eyes (18.5%) finally required keratoplasty. Initial stage of corneal involvement at presentation was the most predictive factors for final visual outcome in AK. Although PHMB, even as monotherapy, is effective in treatment of AK, a remarkable proportion of patients still suffer a final grim visual outcome which require aggressive treatments.

Acanthamoeba keratitis (AK) is a sight-threatening corneal infection with a rapidly increased incidence since 1990s along with the growing popularity of contact lenses. In this study we aimed to study patients with AK and its associated risk factors in Farabi Eye Hospital of Tehran, focusing on those with more severe corneal involvement. Patients with clinical or laboratory diagnosis of AK at the cornea clinic of Farabi Eye Hospital during April 2009 to March 2010 were studied regarding their demographics, and clinical characteristics, corneal infection risk factors, and suboptimal hygiene practices. Linear regression analysis was applied to determine factors affecting the stage of corneal involvement at presentation. Twenty five patients (4 males and 21 females) with 27 involved eyes were identified during the one year study. Cosmetic contact lenses accounted for the most common potential risk factor of AK (85.2%). Most of the patients (92.6%) reported a history of antibacterial treatment before the presentation. Only four patients (16%) did not report any suboptimal hygiene practice. In the linear regression model only the first visual acuity (VA) at presentation, and the duration of symptoms were independently associated with the stage of disease. The high number of patients presented with AK in our study suggests a possible outbreak of the disease in Tehran, which is highly associated with cosmetic contact lenses.

To report an unusual presentation of chandler syndrome Case report: A 22-year-old female came to our clinic with complaint of progressive visual loss in her left eye since three days ago. She had a history of trauma with finger-nail to her left eye eight days ago and had been managed with topical antibiotic. In her examination, the left eye had visual acuity (VA) of counting finger at three meters, with intraocular pressure (IOP) of 14 mmHg, and there was a 3+ corneal stromal edema without epithelial defect. After medical management when edema decreased, specular biomicroscopy revealed decreased endothelial cell count and increased average cell size, pleomorphism and polymegathism, and epithelial transformation in the left eye and normal indices in the right eye. After one month, edema was completely resolved and VA improved to 20/25 but specular biomicroscopy remained abnormal. Chandler variant of iridocorneal endothelial syndrome (ICE) was diagnosed. Although corneal edema after blunt trauma is a usual manifestation, in long lasting edema after trauma, we should consider other possible endothelial causes of stromal edema including toxic insult, inflammatory processes, and endothelial dystrophies.

To compare visual outcome of aspheric and spheric intraocular lenses (IOLs) implantation in patients with age-related cataract in terms of visual acuity (VA), contrast sensitivity (CS) and spherical aberration In this prospective randomized interventional study, 59 consecutive cases of senile cataract who had been admitted for cataract surgery to Farabi Eye Hospital, Tehran, Iran between June 2008 and July 2010 were recruited. Patients were randomly assigned to two treatment groups using computerized software; eyes were implanted with either a aspheric or spheric IOLs (Acrylic, Lens Tec Co, Tehran, Iran). Pre and postoperatively, patients underwent complete ocular examination and their uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were measured. Three months after the operation patients were visited to measure spherical aberration and CS. Fifty-two patients with the mean age of 55.7±5.9 years (range, 45-73 years) remained for surgical interventions. Postoperative UCVA and BCVA did not show a significant difference between our two study groups (P=0.124 and 0.400, respectively). Spherical aberration after cataract surgery in pseudophakic situation and pupil diameter of 5 mm was significantly lower in eyes with aspheric IOLs compared to spherical ones (0.22±0.10 vs. 0.30±0.12 µ, respectively, P=0.03). CS in all frequencies was better in aspheric IOLs compared to the spheric ones and except to the frequency of 20 cpd this difference was statistically significant (P<0.05). Although both aspheric and spheric IOLs resulted into a favorable VA, aspheric IOLs lead to better visual performance through a lower spherical aberration and better CS and quality of vision. However intraindividualization of asphericity by individual IOL surface design may be the best future option.

To evaluate the effect of topical diclofenac sodium 0.1% on the corneal epithelial healing after photorefractive keratectomy (PRK) In this prospective randomized double blind clinical trial, PRK was performed on 82 patients. Thirty-three cases of them receiving topical diclofenac four times per day after surgical procedure and 45 patients did not receive this medication as a control group. Patients were compared for corneal epithelial healing after treatment. Statistically significant delayed epithelial healing has been found in the treatment group 24 hours after PRK but corneal reepithelialization has been completed in all patients four days after surgery. Postoperative topical diclofenac used following PRK may delay the epithelial healing.

To investigate the association of primary open angle glaucoma (POAG) and systemic hypertension in patients referred to Farabi Eye Hospital In this case-control study in Farabi Eye Hospital. One hundred patients were selected randomly from POAG patients of glaucoma clinic, Farabi Eye Hospital. Control group consists of 100 patients, candidates for cataract surgery. History of any anti-hypertensive agent consumption was recorded for all participants. A complete set of systemic and ophthalmologic examinations, including several blood pressure measurements, was performed for each subject. Systolic blood pressure above 140 mmHg, diastolic blood pressure above 90 mmHg and/or any history of anti-hypertensive usage in each group were considered as hypertensive status. Diastolic blood pressure was significantly higher in POAG patients than control group (P=0.003). Systolic blood pressure was also higher in POAG patients than control group; however, the difference was only marginally significant (P=0.07). No association between POAG and hypertension was found. POAG was found to have a strong positive association with diastolic blood pressure in our patients.

To compare the outcome of surgery and postoperative complications between using manually dissected cornea in Descemet’s stripping with endothelial keratoplasty (DSEK) and using eye bank automated precut cornea in Descemet’s stripping with automated endothelial keratoplasty (DSAEK) Forty eyes with indication of endothelial keratoplasty (EK) were included in this randomized prospective clinical trial. The eyes were randomly divided into two groups. Donor cornea in one group was dissected with curved blade by the surgeon, while precut cornea from eye bank was used in other group. All surgeries were performed in one center by three surgeons, authors of the article. Patients were followed for 3 months. Baseline parameters and demographic features were not significantly different between the two groups. The most common indication of EK in both groups was pseudophakic bullous keratopathy (PBK) (60%). Endothelial cell loss in DSEK and DSAEK were 51.59% and 50.70%, respectively after 3 months follow-up (P=0.947). Best spectacle-corrected visual acuity (BSCVA) and intraocular pressure (IOP) after surgery and postoperative complications were not significantly different in both groups. Prevalence and intensity of interface opacity was significantly lower in DSAEK group after surgery. BSCVA equal or more than 20/100 was detected in 85% and 75% individuals in DSAEK and DSEK groups, respectively. In conclusion, three months postoperative outcomes of EK were similar in the two groups of precut DSAEK and manually dissected DSEK. Smooth and uniform layer in precut DSAEK leads to lower interface opacity in patients.

To study the effect of phototherapeutic keratectomy (PTK) in the treatment of various superficial corneal pathologies.

We performed a nonrandomized, prospective study on patients who presented with superficial corneal disease and/or poor vision. Fifty eyes were included; recurrent corneal erosion (RCE): 25 eyes, Salzmann’s nodular degeneration: 9 eyes, spheroidal degeneration: 4 eyes, trachoma keratitis scar: 5 eyes, traumatic scar and pseudophakic bullous keratopathy: each one 2 eyes, macular dystrophy, herpetic corneal scar, and band keratopathy each of them 1 eye. All patients were treated with Nidek EC-5000 excimer laser. A central 4- 8 mm ablation zone was determined by opacity diameter. Follow up ranged from 90 days to 20 months; mean 304±165 days for RCE group and 395±197 days for others.

Uncorrected visual acuity (UCVA) improved from mean of 20/50 (logMAR=0.44) and 20/400 (logMAR=1.1) preoperatively to 20/30 (logMAR=0.2) and 20/120 (logMAR=0.78) postoperatively in RCE and opacity groups respectively. Best corrected visual acuity (BCVA) improved from mean of 20/30 (LogMAR=0.22) and 20/200 (logMAR=0.96) preoperatively to 20/25 (logMAR=0.07) and 20/100 (logMAR=0.65) postoperatively in RCE and opacity groups respectively. Recurrent erosion dramatically reduces in RCE group.

PTK can improve UCVA and BCVA in various superficial corneal pathologies and reduce spontaneous corneal erosions but proper case selection is crucial.