ASAhmed Sherif

Ahmed Sherif

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Ahmed Sherif has a total of 46 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Longitudinal Ocular Surface Changes in Women with Polycystic Ovary Syndrome Receiving Hormonal or Ovulation-Induction Therapy: A Prospective Cohort Study

    by Mohamed S. Emam, Ahmed Sherif, Mohamed R. Khedr, Malak I. ElShazly, Ayah Marrie

    Ocular surface disease, including dry eye disease and meibomian gland dysfunction, is highly prevalent among women of reproductive age and significantly affects visual comfort and quality of life.1...

  • Open Access

    A Masking Effect: A Case of Initial Presentation of Ulcerative Colitis After Discontinuing Growth Hormone Therapy

    by Onyinye Ugonabo, M'HAmed Turki, Dane Stewart, Ahmed Sherif, Xavier Villa

    Background: The inflammation and repair of the intestinal mucosa in inflammatory bowel disease (IBD) involve a complex interplay between innate, adaptive immune responses, and hormones. This may explain the relapsing clinical course of the disease.Methods: We present the first reported case of a patient presenting their initial flare of ulcerative colitis immediately after discontinuing growth hormone (GH) therapy, suggesting treatment with GH or growth factors may prevent the development of IBD.Results: This is a case of a 13-year-old female with a history of GH deficiency, presenting with an 8-week history of abdominal pain, blood-stained diarrhea, and fecal calprotectin greater than 8000 mcg/g, 2 weeks after discontinuing GH therapy. The patient subsequently underwent an esophagoduodenoscopy and colonoscopy with biopsies showing histological features consistent with ulcerative colitis.Conclusions: The finding of withdrawing GH or growth factors therapy potentially unmasking IBD in this patient raises a question of whether growth factors can inhibit the development of IBD and suggests beneficial effects of treatment with GH or growth factors as adjuvant therapy for IBD.

  • Open Access

    Failure to Thrive in a Middle-Aged Female: A Case of Congenital Incomplete Pancreas From a Rare Genetic Defect

    by Onyinye Ugonabo, Turki Mohamed, Murad Kheetan, Ahmed Sherif

    Hepatocyte nuclear factor-1 beta (HNF1B) gene is predominantly expressed in the liver, kidney, lung, genitourinary tract, and pancreas. It is an important transcription factor that regulates pancreas development. Mutation or absence of this gene is rare and can cause incomplete pancreatic development known as the agenesis of the dorsal pancreas. This rare genetic abnormality is associated with other disorders like maturity-onset diabetes of the young, abnormal liver function tests, genitourinary tract malformation, pancreatitis, and renal cysts. Diagnosing this genetic abnormality is difficult, especially in patients presenting with symptoms specific to only one system. Management is based on disease manifestation and involves a multidisciplinary approach. Our case describes a 51-year-old female with poorly controlled diabetes mellitus and Mullerian duct anomalies who presented with abdominal pain, fatigue, dizziness, and electrolyte derangement. Contrast-enhanced computed tomography (CECT) of the abdomen showed a multicystic kidney and a pancreatic head with a missing body and tail. Further workup revealed an HNF1B mutation.


  • Open Access

    Endoscopic stricturotomy with pulsed argon plasma and balloon dilation for refractory benign colorectal strictures: a case series

    by Saad Emhmed Ali, Avinash Bhakta, Robert-Marlo Bautista, Ahmed Sherif, Wesam Frandah

    Endoscopic stricturotomy with pulsed argon plasma and balloon dilation for refractory benign colorectal strictures: a case series Saad Emhmed Ali, Avinash Bhakta, Robert-Marlo Bautista, Ahmed Sherif, Wesam Frandah


  • Open Access

    Contralateral Eye Study of Topography Guided versus Q Value Adjusted Photorefractive Keratectomy in Myopia and Myopic Astigmatism

    by Rania E Gad, Mohamed Hosny, Rania A Ahmed, Ahmed M Sherif, Yehia Salah Eldin

    Purpose of the Study: To compare visual outcome, higher order aberrations (HOAs) of topography guided and Q value adjusted ablation in the fellow eye of patients undergoing photorefractive keratectomy (PRK) for the correction of myopia and myopic astigmatism. Methods: Prospective randomized controlled interventional clinical study. The eyes of 52 patients undergoing PRK for myopia and astigmatism were included, that is, 104 eyes in total. In each patient, eyes were randomly allocated to group I: one eye received topography guided PRK using Contoura ablation software, or group II: the other eye received Q value adjusted PRK using Custom Q ablation software. Follow-Up: Six months. Results: At the end of 6 months, LogMAR UDVA was − 0.04 ± 0.12 and − 0.05 ± 0.11 (p = 0.688), while LogMAR CDVA was − 0.06 ± 0.09 and − 0.06 ± 0.1 in group I and group II, respectively (p = 0.972). Both groups showed a progressive oblate shift with time. This oblate shift was insignificantly less in group I by Topolyzer at 6mm, 15° and 30° at 6 months (p = 0.102, p = 0.138, p = 0.245, respectively). Topolyzer identified a significant difference between the change in coma and trefoil in both groups at 6 months (p< 0.001 and p = 0.001, respectively). This was caused by the significant worsening of coma in group II (p< 0.001) and the significant improvement of trefoil in group I (p = 0.007). No significant difference was found between groups in the change of ISV or ABR (p = 0.955 and 0.982, respectively). Ablation depth is a significant predictor of ΔQ at 6mm, 15° and 30° (p = 0.009, 0.039 and 0, respectively). No significant difference was found in the Strehl ratio or contrast sensitivity, although they were insignificantly better in group I (p = 0.785 and p = 0.745, respectively). Conclusion: TG PRK and CQ PRK yielded similar results regarding UDVA, CDVA, MRSE, safety, predictability and contrast sensitivity. Both groups showed a progressive oblate shift, which was less in the TG group but the difference was statistically insignificant. TG PRK showed significantly improved trefoil HOA as compared to CQ PRK.


  • Open Access

    Study of Demarcation Line Depth in Transepithelial versus Epithelium-Off Accelerated Cross-Linking (AXL) in Keratoconus

    by Yehia Salah, Kholoud Omar, Ahmed Sherif, Sarah Azzam

    Aim. This is a prospective interventional clinical trial to assess the depth of the demarcation line in transepithelial versus epithelium-off accelerated corneal cross-linking (AXL) in keratoconus patients. Methods. This prospective clinical trial was conducted on 40 eyes of 20 patients. Each patient had transepithelial AXL in one eye and epithelium-off AXL in the contralateral eye applying UVA light with an irradiance of 45 mW/cm2 for 2.4 minutes and 30 mW/cm2 for 4 minutes. The depth of the demarcation line was measured using anterior segment OCT (Topcon 3D OCT-2000) one month postoperative for both eyes. Results. The demarcation line was patchy in 50% of the transepithelial AXL eyes, the other half showing a demarcation line at a mean depth of 183 ± 41.6 μm. In the epithelium-off AXL technique, the demarcation line was well defined in all cases with a mean depth of 219 ± 27.3 μm. There was a statistically significant difference in corneal demarcation line depth between transepithelial and epithelium-off techniques ( = 0.008 and < 0.05). The shallower demarcation line in the transepithelial group suggests that it is less effective. Conclusion. Based on the depth of the demarcation line, the cross-linking effect of epi-off AXL seems more efficacious than after transepithelial AXL. The future will show if the biomechanical effect will be sufficient to stop progression of keratoconus similarly after standard CXL. This trial is registered with NCT04045626.


  • Open Access

    Effect of Reformation of the Anterior Chamber by Air or by a Balanced Salt Solution (BSS) on Corneal Endothelium after Phacoemulsification: A Comparative Study

    by Alahmady Hamad Alsmman, Mohammed Ezzeldawla, Amr Mounir, Ashraf Mostafa Elhawary, Osama Ali Mohammed, Mahmoud Farouk, Ahmed Mohamed Sherif

    Aim. To study the effect of reformation of the anterior chamber by air or by a balanced salt solution, after smooth phacoemulsification on the corneal endothelial count and morphology. Methods. A prospective interventional nonrandomized comparative study included 500 eyes of 500 patients with age range between 50 and 60 years, prepared for cataract surgery and presented to the Ophthalmology department of Sohag University Hospital in the period from October 2016 to May 2017. Corneal endothelial morphology and count were examined, and the results were recorded for all cases before the surgery. Patients were divided into two groups, and both groups were diagnosed with grade 2 cataract and underwent uncomplicated phacoemulsification performed by well-trained surgeons. At the end of the surgery, group 1 was subjected to a reformation of the anterior chamber via a balanced salt solution (BSS) injection while group 2 was subjected to a reformation of the anterior chamber via air injection. Corneal endothelial morphology and count were evaluated in the first and 3rd month postoperatively. Results. The study included 500 patients (250 in each group), 220 males (44%) and 280 females (56%) with no significant statistical age differences. Both preoperative and postoperative (3 months after the operation) recorded parameters of the corneal endothelium did not show any significant statistical differences. The cumulative dissipated energy was recorded, for all cases of both groups, during phacoemulsification with no significant statistical differences (P=0.7). Conclusion. There is no difference between the effect of reformation of the anterior chamber after phacoemulsification, using air or using a BSS injection, on the corneal endothelial count and morphology.


  • Iris reconstruction using artificial iris prosthesis for management of aniridia

    by Yehia S. Mostafa, Amr A. Osman, Dina H. Hassanein, Ashraf M. Zeid, Ahmed M. Sherif

    Purpose: To discuss the limitations and benefits of the BrightOcular prosthetic artificial iris device in management of aniridia associated with aphakia or cataract. Methods: This is a retrospective study including 5 eyes of 4 patients who underwent implantation of the BrightOcular iris prosthesis (Stellar Devices) for total or partial aniridia. The cases included 2 eyes of 1 patient with congenital aniridia associated with congenital cataract and 3 eyes with traumatic aniridia: 1 with subluxated cataractous lens and 2 with aphakia. In all cases, the iris prosthesis was implanted after a 3-piece acrylic intraocular lens was implanted. We evaluated the clinical course with a minimum follow-up period of 6 months, the intraoperative and postoperative complications, and the cosmetic satisfaction of patients. Results: All patients had improved uncorrected distance visual acuity and best-corrected distance visual acuity. All patients had a transient corneal edema that resolved within the first postoperative week. Only the patient with congenital aniridia had a permanent increase in intraocular pressure and developed a band keratopathy throughout a 2-year follow-up period. The prosthesis was well-centered in all eyes except for one case that required scleral suture fixation after 3 months. All patients had a satisfactory cosmetic appearance. Conclusions: BrightOcular iris prosthesis is a safe and useful tool to correct aniridia associated with pseudophakia or aphakia. Being foldable, it is easy to be implanted through a small incision and placed in the ciliary sulcus without sutures when properly sized. Cosmetic results are satisfactory. Sizing methods should be improved.


  • Open Access

    Intraoperative Corneal Thickness Changes during Pulsed Accelerated Corneal Cross-Linking Using Isotonic Riboflavin with HPMC

    by Ahmed M. Sherif, Nihal A. El-Gheriany, Yehia M. Salah El-Din, Lamiaa S. Aly, Amr A. Osman, Michael A. Grentzelos, George D. Kymionis

    Purpose. To evaluate corneal thickness changes during pulsed accelerated corneal cross-linking (CXL) for keratoconus using a new isotonic riboflavin formula.Methods. In this prospective, interventional, clinical study patients with grades 1-2 keratoconus (Amsler-Krumeich classification) underwent pulsed accelerated (30 mW/cm2) CXL after application of an isotonic riboflavin solution (0.1%) with HPMC for 10 minutes. Central corneal thickness (CCT) measurements were taken using ultrasound pachymetry before and after epithelial removal, after riboflavin soaking, and immediately after completion of UVA treatment.Results. Twenty eyes of 11 patients (4 males, 7 females) were enrolled. Mean patient age was26±3(range from 18 to 30 years). No intraoperative or postoperative complications were observed in any of the patients. Mean CCT was507±35 μm (range: 559–459 μm) before and475±40 μm (range: 535–420 μm) after epithelial removal (P<0.001). After 10 minutes of riboflavin instillation, there was a statistically significant decrease of CCT by 6.2% from475±40 μm (range: 535–420 μm) to446±31 μm (range: 508–400) (P<0.005). There was no other statistically significant change of CCT during UVA irradiation.Conclusions. A significant decrease of corneal thickness was demonstrated during the isotonic riboflavin with HPMC application while there was no significant change during the pulsed accelerated UVA irradiation.


  • Open Access

    One-Year Results of Simultaneous Topography-Guided Photorefractive Keratectomy and Corneal Collagen Cross-Linking in Keratoconus Utilizing a Modern Ablation Software

    by A. M. Sherif, M. A. Ammar, Y. S. Mostafa, S. A. Gamal Eldin, A. A. Osman

    Purpose.To evaluate effectiveness of simultaneous topography-guided photorefractive keratectomy and corneal collagen cross-linking in mild and moderate keratoconus.Methods. Prospective nonrandomized interventional study including 20 eyes of 14 patients with grade 1-2 keratoconus that underwent topography-guided PRK using a Custom Ablation Transition Zone (CATz) profile with 0.02% MMC application immediately followed by standard 3 mw/cm2UVA collagen cross-linking. Maximum ablation depth did not exceed 58 μm. Follow-up period: 12 months.Results.Progressive statistically significant improvement of UCVA from0.83±0.37logMAR preoperative, reaching0.25±0.26logMAR at 12 months (P<0.001). Preoperative BCVA (0.27±0.31logMAR) showed a progressive improvement reaching0.08±0.12logMAR at 12 months (P=0.02). MeanKmax reduced from48.9±2.8to45.4±3.1 D at 12 months (P<0.001), meanKmin reduced from45.9±2.8 D to44.1±3.2 D at 12 months (P<0.003), mean keratometric asymmetry reduced from3.01±2.03 D to1.25±1.2 D at 12 months (P<0.001). The safety index was 1.39 at 12 months and efficacy index 0.97 at 12 months.Conclusion. Combined topography-guided PRK and corneal collagen cross-linking are a safe and effective option in the management of mild and moderate keratoconus.Precis. To our knowledge, this is the first published study on the use of the CATz ablation system on the Nidek Quest excimer laser platform combined with conventional cross-linking in the management of mild keratoconus.