dr. amir houshang beheshtnejad

To compare the corneal epithelial thickness along the flat and steep meridians of corneas with low and high toricity.

This was a prospective observational comparative study on healthy subjects with normal corneas seeking preoperative evaluation for refractive surgery at a university‑based hospital. Subjects with up to 2 diopters (D) of corneal with‑the‑rule astigmatism were defined as low corneal toricity (CT), whereas cylinder > two‑dimensional was considered as high CT. The anterior segment optical coherence tomography was conducted to measure the epithelial thickness along the principle meridians of CT over a diameter of 9 mm. At the eye level, outcome variables (corneal and epithelial thicknesses in low‑ and high‑astigmatism groups) were assessed using generalized estimating equation models.

Included were 98 eyes (49 subjects): 46 eyes (23 subjects) with low CT and 52 eyes (26 subjects) with high CT. Two groups were similar with respect to the age (P = 0.82), sex (P = 0.49), and spherical equivalent (P = 0.11). Although the corneal thickness at steep and flat meridians was not different between two groups, high‑CT group had significantly thinner epithelium at inferior 2.5–3.5 and 3.5–4.5 mm zones (P = 0.01 and 0.04) as well as superior 2.5–3.5 mm zone (P = 0.03) along the steep meridian. Two groups were similar with respect to epithelial thickness of flat meridian (all P > 0.05).

The epithelium of steep meridian was thinner in the high‑CT group compared to the low‑CT group.

As a soccer referee or an assistant referee, having perfect visual skills is mandatory, which will help make quick and accurate decisions in the field of the play and during matches; however, this skill is not well studied among referrers. This study aimed to assess the visual skills of referees and assistant referees.

Men’s professional referees and assistant referees working for the Iran football federation were investigated in 2019. The visual skill investigation consists of the evaluation of static visual acuity, color vision, stereoacuity, intraocular pressure, confrontation test, and eye anatomical assessment with slit lamp. The statistical analysis was performed using the SPSS software Version 18.

In this study, 159 men’s professional referees and assistant referees with a mean age of 35.52±5.39 were selected. The results of this study showed that 1.88% of the referees and assistant referees had color blindness dyschromatopsia) and 3.14% of them needed more follow-up examinations. The mean spherical equivalent of examined eyes was -0.42D in the right eye and -0.16 D in the left eye.

Our results showed that referees and assistant referees both had some kind of visual skill deficiencies. As visual skills are among the fundamental skills for success in referees in dynamic sports such as soccer, all of them must undergo visual skill assessments during the precompetition period to avoid any errors in judgment due to visual disturbances.

To evaluate the effect of myopic photorefractive keratectomy (PRK) on color vision, contrast sensitivity and higher order aberrations (HOAs). Patients and

This prospective study was performed on 46 eyes of 23 patients with 3 to 6 diopter of myopia/myopic astigmatism undergoing PRK. Color vision using FransworthMunsell 100 hue test (©2011 X-Rite Inc., Michigan, U.S) and contrast sensitivity using CSV-1000 (Vector Vision, Dayton, OH) were tested preoperatively and 2 and 6 months postoperatively. HOAs were assessed using Zernike analysis map of Pentacam (OCULUS Optikgeräte GmbH, Germany) preoperatively and 6 months postoperatively.

No significant change was observed in color vision following PRK. Contrast sensitivity function was also preserved except for an increase in 12 cycles per degree (cpd) spatial frequency 6 months after surgery (P = 0.04). Total HOAs and primary spherical aberrations (total, anterior and posterior surface) increased significantly (P < 0.001), however, primary coma showed no statistically significant change 6 months after surgery compared to baseline values. Induced total HOAs significantly correlated with change in primary vertical coma and total, anterior, and posterior primary spherical aberration. No significant correlation was found between the changes in contrast sensitivity, color vision and HOAs with the amount of preoperative sphere and cylinder.

PRK with an aspheric profile in moderate myopia/ myopic astigmatism does not affect color vision and contrast sensitivity at 3, 6 and 18 cpd spatial frequencies. It increases total HOAs and spherical aberration, but not coma. It remains a good option for refractive correction of moderate.

To describe a case of chronic graft versus host disease (GVHD) leading to severe dry eye and recurrent corneal perforation in both eyes, its stepwise management and histopathological reports.
Case Report: A 22-year-old woman with a history of thalassemia and subsequent high-dose chemotherapy followed by allogeneic bone marrow transplant (BMT) was referred to Farabi Eye Hospital. Despite aggressive medical and surgical intervention, corneal vascularization in her right eye progressed and led to corneal perforation. Cyanoacrylate glue was applied to seal the perforation, however it recurred. Multilayer amniotic membrane transplantation (AMT) was performed to seal the corneal perforation, which was effective for a short period. Subsequently, the corneal perforation recurred and penetrating keratoplasty was performed. After a few months deep vascularization and descemetocele occurred in the fellow left eye and the patient finally underwent therapeutic lamellar keratoplasty.
Patients with GVHD are at risk of severe dry eye and subsequent corneal vascularization. Recurrent and recalcitrant corneal perforation resistant to cyanoacrylate glue and multilayer AMT may occur. Proper systemic and ocular management alongside close collaboration with the hematologist is strongly recommended to control the condition.

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 a rare case of a patient with hypoparathyroidism presenting with bilateral disc swelling and near mature cataract as her first clinical manifestation Case report: A 23-year-old woman presented with complaint of worsening vision since one year ago and a history of refractory seizures and headache for several years, being under treatment with Lamotrigine 50 mg/daily. Slit-lamp examination revealed significant cataracts on both sides. Red reflex was dull in the right eye and absent in the left side. The intraocular pressure (IOP) measurement was normal in both eyes (16 mmHg). Her fundus examination revealed disc swelling in her right eye and hazy media that obscured fundus examination due to dense cataract in the left eye. The combination of bilateral disc swelling and dense cataracts raised suspicion to hypoparathyroidism. Subsequently, neuroimaging and intracranial pressure (ICP) monitoring was requested along with neuro-ophthalmalogy consultation. The diagnosis was Psedotumor Cerebri. Due to increased ICP, she underwent multiple lumber punctures. Computed tomography (CT) scan showed abnormal signal density in basal ganglia suggestive for presence of calcium depositions, making the diagnosis of hypoparathyroidism more probable. Ensuing laboratory result made the definite diagnosis of hypoparathyroidism. Meanwhile the cataract progressed and the visual acuity (VA) decreased to HM in her both eyes. She underwent cataract extraction and PCIOL implantation. Papilledema resolved and the vision restored to 20/20. Ocular complaints happens very rare in the course of hypoparathyroidism but still it seems rational that this occasionally fatal condition be ruled out by hormonal evaluation for cases of unexplained cataracts, particularly if it is accompanied by disc swelling.

We describe our experience on safety and effectiveness of phacoemulsification in cataract and congenital iris coloboma and point out some specific surgical recommendations aimed to minimize its complications. A prospective case series study was conducted on nineteen consecutive patients with cataract and congenital iris coloboma referred to the Farabi Eye Hospital in Tehran. After primary preoperative evaluations, cataract surgery was performed for each patient. All patients were followed-up for at least six months to determine surgical mid-term outcome. Mean preoperative best corrected visual acuity (BCVA) in the participants was 1.99±0.70 logMAR which was improved to 0.82±0.61 logMAR postoperatively (p<0.001). Mean cell area was increased from 419.0±103.9 µm2 to 656.8±281.6 µm2 after surgery (p=0.001), while endothelial cell density was decreased from 2313.6±474.2 cell/mm2 before surgery to 1361.2±448.2 cell/mm2 after the operation (p<0.001). None of the patients developed corneal decompensation within the follow-up period. Regarding postprocedure complications, vitreous loss was observed in three patients, followed by penetration of dye to vitreous and remnant of the posterior capsule. None of the patients also experienced glare or photophobia and all of them were satisfied with the cosmetic result of their pupils. Based on our experience phacoemulsification with cosmetic repair of the coloboma can be a useful and safe procedure in patients with cataract and congenital iris coloboma.

To assess the safety, efficacy and predictability of photorefractive keratectomy (PRK) [Tissue-saving (TS) versus Plano-scan (PS) ablation algorithms] of Technolas 217z excimer laser for correction of myopic astigmatism In this retrospective study one hundred and seventy eyes of 85 patients (107 eyes (62.9%) with PS and 63 eyes (37.1%) with TS algorithm) were included. TS algorithm was applied for those with central corneal thickness less than 500 µm or estimated residual stromal thickness less than 420 µm. Mitomycin C (MMC) was applied for 120 eyes (70.6%); in case of an ablation depth more than 60 μm and/or astigmatic correction more than one diopter (D). Mean sphere, cylinder, spherical equivalent (SE) refraction, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) were measured preoperatively, and 4 weeks,12 weeks and 24 weeks postoperatively. One, three and six months postoperatively, 60%, 92.9%, 97.5% of eyes had UCVA of 20/20 or better, respectively. Mean preoperative and 1, 3, 6 months postoperative SE were -3.48±1.28 D (-1.00 to -8.75), -0.08±0.62D, -0.02±0.57 and -0.004± 0.29, respectively. And also, 87.6%, 94.1% and 100% were within ±1.0 D of emmetropia and 68.2, 75.3, 95% were within ±0.5 of emmetropia. The safety and efficacy indices were 0.99 and 0.99 at 12 weeks and 1.009 and 0.99 at 24 weeks, respectively. There was no clinically or statistically significant differences between the outcomes of PS or TS algorithms or between those with or without MMC in either group in terms of safety, efficacy, predictability or stability. Dividing the eyes with subjective SE≤4 D and SE ≥4 D postoperatively, there was no significant difference between the predictability of the two groups. There was no intra- or postoperative complication. Outcomes of PRK for correction of myopic astigmatism showed great promise with both PS and TS algorithms.

To evaluate the biomechanical changes of cornea after intracorneal ring segment (ICRS) implantation in keratoconic eyes In this study, 1 or 2 ICRS were inserted in 17 keratoconic eyes. Best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), refraction, and keratometry were evaluated preoperatively and 1 and 3 months after surgery. Corneal hysteresis (CH) and corneal resistance factor (CRF) were also measured preoperatively and postoperatively with ocular response analyzer (ORA). ICRS was inserted in 17 keratoconic eyes (12 patients). Mean UCVA significantly increased from 0.72±0.37 logMAR to 0.54±0.27 logMAR (P=0.027) and 0.46±0.30 logMAR (P=0.01) 1 and 3 months after surgery, respectively. Mean BSCVA increased from 0.41±0.29 logMAR to 0.32± 0.26 logMAR at the end of the 1st month and 0.32±0.27 logMAR at the end of 3rd month postoperatively. These changes were not significant. Spherical equivalent (SE) significantly decreased from -5.64±3.21 Diopter (D) to -3.36±2.74 D (P=0.009) 1 month and -3.51±2.04 D (P=0.002) at the 3 months after surgery. Mean keratometry also significantly decreased from 49.82±4.33 D to 48.10±3.64 D (P=0.010) and 47.40±3.47 D (P=0.003) at 1- and 3- month follow-ups, respectively. Mean CH was 7.48±1.65 mmHg and mean CRF was 5.98±2.06 mmHg, preoperatively. At 1-month follow-up, their values were 7.13±1.56 mmHg and 5.74±1.60 mmHg, respectively. At 3-month follow-up, their values were 7.20±1.23 mmHg and 5.80±1.72 mmHg, respectively. The CH and CRF changes at 1- and 3-month follow-ups were not significant. After ICRS insertion in keratoconic eyes, no significant changes were observed in mean values measured with the ORA at 1- and 3-month follow-ups.

To examine the relationship between retinal nerve fiber layer (RNFL) measurements obtained using scanning laser polarimetry with variable corneal compensation (VCC) and central corneal thickness (CCT) measurements using pentacam in myopic patients

The study included 45 eyes from 45 myopic patients with intraocular pressure (IOP) measurements≤21 mmHg. All participants had normal optic discs and normal standard automated perimetry visual fields. All patients underwent imaging with the GDx VCC and pentacam. We examined the relationship between GDx VCC RNFL measurements and CCT.

Mean spherical equivalent (SE) was -3.65±1.1 D (range: -1.00 to -6.5 D). Mean CCT was 530.9±24.32 µm with a range of 488 to 596 µm. TSNIT (temporal, superior, nasal, inferior, temporal) average, inferior average, superior average, TSNIT standard deviation (SD) and nerve fiber indicator (NFI) were not correlated with CCT. There were no correlations between RNFL thickness and refraction, age, corneal volume and mean keratometry. However, RNFL in patients with CCT≤530 µm was significantly thinner than in those with thick corneas.

RNFL measurements obtained using GDx VCC may not correlate with corneal thickness (CCT) and refraction in myopic patients. Myopic patients with CCT≤530 have thinner RNFL than in those with thick corneas.