Yasser Helmy Mohamed

Role of apoptosis in eyelid development.

The upper and lower eyelids fuse together during development and then reseparate. The mechanism of reseparation of the eyelids is still unclear, although many reports agree that keratinization has a major role in lid separation. We applied apoptotic detection methods with ultrastructural features to examine the process of lid separation in rats. We confirmed that the eyelids fused on the 18th day of gestation. At this stage, cellular excrescences appeared from the external and conjunctival surfaces overlying the junctional zone, and the junctional zone consisted of epidermal cell clumps with wide intercellular spaces. From the 18th to the 20th day of gestation, many apoptotic cells appeared in the junctional zone and in the cellular excrescences. In these tissues, TUNEL-positive cells and immunohistochemically stained macrophages were found at this stage. We conclude that apoptosis may eliminate external and conjunctival cellular excrescences to make both surfaces smooth and continuous across the junctional zone. Apoptosis may also play a major role in providing space for proliferation of newly organized epidermal cells without wide intercellular spaces. Subsequent keratinization extends onto epidermal and conjunctival sides of the junctional zone until separation of the lids is complete.

Acute corneal toxicity of latanoprost with different preservatives

Abstract Purpose: To investigate the corneal toxicity of Xalatan and three latanoprost generics using transepithelial electrical resistance (TER) and scanning electron microscopy (SEM). Methods: Corneal TER changes after a 60-s exposure to Xalatan (latanoprost 0.005% preserved with 0.02% BAC), and latanoprost generics (Latanoprost PF BAC free, Latanoprost Nitten SB containing sodium benzoate and Latanoprost Towa containing 0.01% BAC with sodium chloride polysorbate 80 as additive) were measured in living rabbits. Corneal damage was also examined by SEM. Hank’s balanced salt solution (HBSS) was used as a control. Results: There was a significant decrease in the corneal TER after exposure of the cornea to Xalatan (p < 0.01) and all latanoprost generics (p < 0.01: Latanoprost PF, p < 0.05: Latanoprost Nitten SB, Latanoprost Towa) as compared to HBSS. All latanoprost generics showed less TER decrease in the corneal TER as compared to Xalatan (p < 0.01). SEM revealed that superficial cells of Xalatan-treated corneas were damaged and exhibited degenerated microvilli. Conversely, the superficial cells of corneas exposed to HBSS or all latanoprost generics appeared normal and had normal microvilli under SEM examinations. Conclusion: The corneal toxicity of Xalatan is greater than that of latanoprost generics. Xalatan contains 0.02% BAC, which may be responsible for the corneal toxicity.

Less Invasive Corneal Transepithelial Electrical Resistance Measurement Method

PURPOSE To evaluate acute corneal permeability changes after instillation of benzalkonium chloride (BAC) using a newly developed in vivo less invasive corneal transepithelial electrical resistance (TER) measurement method in animals and humans. METHODS We previously developed an in vivo method for measuring corneal TER using intraocular electrodes in animals. This method can be used to precisely measure the decline of the corneal barrier function after instillation of BAC. To lessen the invasiveness of that procedure, we further refined the method for measuring the corneal TER by developing electrodes that could be placed on the surface of the cornea and in the conjunctival sac instead of inserting them into the anterior chamber. Corneal TER changes before and after exposure to 0.02% BAC were determined in this study using the new device in both rabbits and humans. RESULTS There was a significant decrease in the corneal TER after exposure of the cornea to 0.02% BAC solution in both rabbits and humans (P<.01). The results of this new less invasive method agreed with those of formerly established anterior chamber methods in rabbit experiments. CONCLUSION This new less invasive corneal TER measurement method enables us for the first time to measure TER of the human cornea, allowing safe and reliable investigation of the direct effect of different eye drop treatments on the corneal epithelium.

Success Rates of Vitrectomy in Treatment of Rhegmatogenous Retinal Detachment

Aim. To investigate the anatomical success rates of pars plana vitrectomy (PPV) after primary rhegmatogenous retinal detachment (RRD). Methods. This retrospective study was conducted between December 2008 and October 2014 at Nagasaki University Hospital. The preoperative data recorded included the lens status, location of the retinal tear, whether a tear was visualized, presence of multiple tears, macula status, presence of peripheral lattice retinal degeneration, and best-corrected visual acuity (BCVA). The primary outcome measures were anatomical (primary and final) and functional success (visual acuity better than 6/60). Results. This study evaluated 422 eyes of 411 patients with a mean age of 57.7 ± 11.2 years. The single-operation reattachment rate (primary anatomical success) was 89.8%. The final anatomical success rate was 100% after 2–6 operations (mean = 3.14 ± 1.03). Functional success rate after the primary reattachment operation was 96.7%, while it was 97.2% at the end of the follow-up. Multiple logistic regression analysis of the possible risk factors for the primary anatomical failure showed a significant relation with the 25 G instruments (P = 0.002) and the presence of multiple tears (P = 0.01). Conclusion. The primary anatomical success of PPV for primary uncomplicated RRD was 89.8% and the final anatomical success rate was 100%.

First experience of nDASEK with heads-up surgery: A case report

Purpose: To report a case of non-Descemet Stripping Automated Endothelial Keratoplasty (nDSAEK) using heads-up surgery. Case/Intervention: The case was a 72-years-old man who had history of left eye blunt trauma since childhood. One year ago, the patient was diagnosed to have left posttraumatic bullous keratopathy. The patient underwent lt nDSAEK by using the heads-up three-dimensional (3D) system last July. The surgery was performed with a Rescan 700 surgical microscope (Carl Zeiss), which is integrated with intraoperative optical coherence tomography (iOCT) system. During surgery, the surgeon and audience wore 3D passive polarized glasses. A 42 inch high-definition (HD) display and 2 HD cameras (Sony) were used. With this 3D system, the nDSAEK procedure before the graft insertion into the anterior chamber was easy especially with available high magnification. Also, using iOCT of the system enables the surgeon to detect any residual fluid at the donor graft–recipient interface and locate its place to be drained. The only disadvantage of the system was the difficulty in the detection of nDSAEK graft depth in the anterior chamber, which required frequent focus change during the surgery. Although the surgeon frequently adjusted the focus for clear stereoscopic view of the graft, he did not feel any eye strain or discomfort. All other steps of the procedure were performed without any problem and postoperative course of the patient was good. Conclusion: Using heads-up surgery for performing anterior segment surgeries is encouraging and promising.

Acute Corneal Toxicity of Diquas.

Aim: This study aimed to investigate acute corneal toxicity of commercially available diquafosol 3% ophthalmic solution (Diquas®), which contains C12 benzalkonium chloride (BAC) as a preservative. Methods: Corneal transepithelial electrical resistance (TER) changes after a 60-second exposure to Diquas® (diquafosol 3% preserved with 0.0075% C12 BAC); 0.0075% C12 BAC and 0.0075% C12, C14, C16 BAC mixture were measured in living rabbits. Corneal damage was also examined by scanning electron microscopy (SEM). Hanks balanced salt solution (HBSS) was used as a control. Results: Diquas® and 0.0075% C12 BAC did not produce any significant decrease in the corneal TER as compared to the HBSS control eyes. There was a significant decrease in the corneal TER after exposure of the cornea to the 0.0075% C12, C14, C16 BAC mixture (p < 0.01). SEM revealed that the superficial cells of the corneas exposed to the 0.0075% BAC mixture were damaged and exhibited degenerated microvilli. Conversely, the superficial cells of corneas exposed to Diquas® or 0.0075% C12 BAC appeared normal and had normal microvilli under SEM examinations. Conclusion: The acute corneal toxicity of Diquas® is less than that of the 0.0075% BAC mixture. Diquas® preserved with 0.0075% C12 BAC did not show acute corneal toxicity.

Corneal Erosion With Pigments Derived From a Cosmetic Contact Lens: A Case Report.

Purpose: To report a case of corneal erosion with pigments derived from a cosmetic contact lens (CCL). Methods: A 29-year-old woman complained of foreign body sensation after wearing CCL. Slit-lamp examination of her left eye revealed corneal erosion with yellow pigment at its edges. The surface of the CCLs was examined using the rub-off test and scanning electron microscopy (SEM). An elementary analysis using SEM with energy-dispersive x-ray (SEM-EDX) was also performed. Results: On the back surface of the CCL, the pigments easily came off during the rub-off test. An SEM examination found exposed pigments with needle-like construction on the back surface. SEM-EDX revealed the presence of carbon, oxygen, iron, titanium, and chlorine in the pigments. Conclusion: Direct contact between the bare pigments on a CCL and the corneal surface can cause corneal damage.

Safety of Intravitreal Injection Guide

Purpose: To evaluate the safety of our developed intravitreal injection guide. Methods: Retrospective review of all case notes for consecutive patients treated with intravitreal anti-vascular endothelial growth factor (VEGF) injections at the Department of Ophthalmology, Nagasaki University Hospital in Japan between January 2013 and December 2014. We included all patients who had at least 1 intravitreal anti-VEGF injection done within the study period. Data collected included demographics, indications of intravitreal anti-VEGF injections, type of injected drug, usage of intravitreal guide, experience of physicians, and any complication that occurred during or after the procedure. Results: The study included 256 patients (154 males and 102 females) who underwent 992 intravitreal anti-VEGF injections from January 2013 until December 2014. The mean age of the patients was 70.8 ± 11.3 years. Of total injections, 907 (91.44%) were done using the intravitreal guide, 60 (6.04%) were done without using the guide, and only 25 (2.52%) injections were not determined. Local complications include 1 (0.1%) case uveitis, 1 (0.1%) case retinal tear, and 1 (0.1%) case amaurosis fugax. There were no major complications as cataract, retinal detachment, and endophthamitis. No systemic complication was encountered. All complications occurred in the guide group without statistically significant difference in comparison to without guide group (P = 1.0). All complications were related to experienced group without significant difference in comparison to limited experienced group (P = .28). Conclusion: We conclude that the process of intravitreal injection with our developed intravitreal injection guide is safe and easy even for limited experienced physicians.

Visual outcomes and prognostic factors in open-globe injuries

BackgroundOcular trauma is an important cause of visual loss worldwide. Improvements in our knowledge of the pathophysiology and management of ocular trauma during the past 30 years, in conjunction with advances in the instrumentation and techniques of ocular surgery, have improved the efficacy of vitreoretinal surgery in injured eyes. The aim of the current study was to determine the visual outcomes and prognostic factors of open-globe injuries in the Japanese population.MethodsRetrospective study of 59 eyes of 59 patients presented with open globe injuries between September 2008 and March 2014 at Nagasaki University Hospital was conducted.Demographic factors including age, gender, and clinical data such as cause of injury, presenting visual acuity (VA), location of injury, type of injury, lens status, presence of intraocular foreign body, types of required surgeries, and final VA were recorded. According to the classification of Ocular Trauma Classification Group, wound location was classified into three zones. Chi-square test was used to compare presented data.ResultsOut of the 59 patients, 46 were placed in the Light Perception (LP) group, and 13 were placed in the No Light Perception (NLP) group. Work-related trauma was the most common cause (27 eyes) followed by falls (19eyes). Work-related trauma was common in males (P = 0.004), while falls was significantly common in females (P = 0.00001). Zone III injuries had statistically significantly poor prognostic factor compared to other zones (P = 0.04). All cases of NLP group (100%) presented with rupture globe. Poor VA at first visit (P = 0.00001), rupture globe (P = 0.026), history of penetrating keratoplasty (PK) (P = 0.017), retinal detachment (RD) (P = 0.0001), vitreous hemorrhage (VH) (P = 0.044), and dislocation of crystalline lens (P = 0.0003) were considered as poor prognostic factors.ConclusionPoor VA at first visit, rupture globe, zone III injuries, history of penetrating keratoplasty, RD, VH, and dislocation of crystalline lens were found to be poor prognostic factors. PPV had a good prognostic value in open globe injuries associated with posterior segment involvement.

Evaluation of retinal blood flow before and after panretinal photocoagulation using pattern scan laser for diabetic retinopathy

ABSTRACT Purpose: Laser speckle flowgraphy (LSFG) can measure blood flow in the ocular fundus. We analyzed the relationship between retinal blood flow and panretinal photocoagulation (PRP) in diabetic retinopathy. Methods: This retrospective observational study examined the eyes of 35 patients with proliferative diabetic retinopathy (PDR) or non-PDR (NPDR). PRP was performed using a pattern scan laser. Using LSFG, blood flow was evaluated as the mean blur rate (MBR) or the relative flow volume (RFV). We also evaluated MBR in the vessels of the optic nerve head (MBR-V), RFV at the first retinal artery (RFV-A), and RFV at the first retinal vein (RFV-V) before bifurcation. Blood flows were measured prior to treatment initiation, during each PRP session, and after PRP. Results: The total number of laser spots created was 4258 ± 461. Regression of neovascular activity at 6 months after PRP occurred in 29 (82.85%) eyes. MBR-V significantly decreased to 83.9 ± 16% (p = .0039), 79.3 ± 21% (p = .0001), and 73.5 ± 26% (p = .0001) after the first, second, and third PRP treatment sessions. MBR-V was also reduced to 75.0 ± 25% (p = .0001), 75.0 ± 25% (p = .0001), and 80.3 ± 22% (p = .0001) at 1, 3, and 6 months following PRP. During and at 6 months after the PRP treatments, RFV-A and RFV-V were also significantly reduced (p< .01). Conclusions: During and after PRP treatments using pattern scan laser, retinal blood flow was reduced. Retinal blood flow may be an auxiliary measurement for effectively evaluating PRP or PDR.