Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 15th International Congress on Vision Science and Eye London, UK.

Day 2 :

Keynote Forum

John L Barbur

University of London, UK

Keynote: Color vision in normal aging, congenital deficiency and retinal disease

Time : 09:00-09:45

OMICS International Vision Science and Eye 2017 International Conference Keynote Speaker John L Barbur photo

John Barbur is a Professor of Optics and Visual Science at Applied Vision Research Centre at City, University of London. He combines fundamental vision science with applied and clinical research, which underpins a long record of research achievement and wider impact. He works on camouflage for the royal signals and radar establishment led to insights into the processing of luminance and color signals that have important applications in color vision assessment. These and other studies led to the development of several Advanced Vision and Optometric Tests (AVOT), initially for research studies and later for more precise assessment of vision in visually-demanding environments such as aviation and rail transport. The CAD (Color Assessment and Diagnosis) is now used throughout the world to assess pilots, firefighters, seafarers, police officers and air traffic controllers.


Significant advances in understanding the genetics of color vision make it possible to account for a great deal of the observed variability in both normal trichromats and in congenital color deficiency. Advancements in shading evaluation systems additionally yield within subject variability and hence more accurate assessment of both red/green (RG) and yellow/blue (YB) chromatic sensitivity with reliable classification of the subject's class of color vision (i.e., normal trichromatic color vision, deutan-, protan- or tritan-like and acquired deficiency). The severity of color deficiency can also be quantified more accurately with reliable separation of RG and YB loss leading to clear distinction between congenital and acquired loss. A third element that has contributed to the recent flurry of interest in color vision is the availability of reliable data that describe the effect of normal aging on RG and YB chromatic sensitivity. Such advances have made color vision assessment more attractive as a diagnostic tool for early detection of diseases of the retina such as age-related macular degeneration (AMD) and glaucoma and systemic diseases that can

also affect visual function such as diabetes. The outcome of conventional tests of color vision will be reviewed and data that describe the variability observed within normal trichromats and in subjects with congenital deficiency will be presented. This improved understanding has significant effects on color assessment and the establishment of minimum color vision requirements within visually-demanding occupational environments. Studies that led to color vision changes as a result of normal ageing and the application of these to early detection of acquired loss of chromatic sensitivity will be discussed. Finally, results of extensive, clinical studies designed to detect the earliest changes in color vision in diabetes, glaucoma and AMD will also be presented.

  • Colour Vision | Ocular Oncology | Dry Eye


Douglas Borchman

University of Louisville, USA

Session Introduction

Samer Hamada

The Eye Clinic London, UK

Title: Dry eye disease: Challenges and opportunities

Samer Hamada, MD, is an ophthalmologist and cornea surgeon performing eye surgeries at his practice, the Eye Clinic London. With nearly two decades' experience, Mr. Hamada is recognised as a leading expert in the field of cataract, refractive lens exchange (RLE) and corneal surgeries, and is frequently asked to lecture at international eye conferences. He has performed thousands of cataract surgeries and RLE surgeries using the latest technological advancements in ophthalmology.Mr. Hamada offers laser cataract surgery with the option of artificial lenses, called intraocular lenses (IOLs), to replace the natural eye lens that has been clouded by a cataract. These IOLs are used for the restoration of near, intermediate and far vision. He is one of the very few eye surgeons who offer trifocal intraocular lens implants. Patients who prefer to be less dependent on glasses or contact lenses, even without a significant amount of clouding due to cataracts, could choose laser or non-laser RLE, both of which are very similar to cataract surgery.


Dry eye disease is becoming a challenging disease. The more we know about aetiology the more it becomes difficult to manage it. Understanding the pathology is important in treatment pathways. Another challenge is the mismatch between signs and symptoms. Moreover, psychological effects of dry eye on patients’ emotional status are often ignored. I will discuss my approach to patients with dry eye and how to make the best outcomes of dry eye patients. A systematic approach including focus on signs and symptoms will be discussed. Finally, I will go through the current and future modalities of treatment.


Petar Markov is currently pursuing his PhD at Cardiff University as part of a joined project between the Schools of Optometry and Vision Sciences, Biosciences and Engineering. He completed his Master’s thesis at Institute of Genetics and Molecular and Cellular Biology (IGBMC) in Strasbourg, France. Having background in Molecular biology and Biophysics, respectively, his Bachelor and Master degrees at Sofia University benefits his investigation of the role of ocular fibroblasts in determining tissue biomechanics in healthy and diseased eyes. He is also a member of the Cardiff Institute of Tissue Engineering and Repair (CITER).


Statement of the Problem: Over 300 million people worldwide are affected by vision impairment. Thus, extensive research efforts are being directed towards developing new and improved treatments. The sclera (white of the eye) is vital for healthy vision because it maintains the eye’s structural stability and shape, properties which are compromised in prevalent conditions such as myopia and glaucoma. To better comprehend the disease mechanisms, we aim to create biomechanical computer models of the eye that incorporate physiological data on both the scleral cell cytoskeletal and extracellular matrix (ECM) components. Specifically, we targeted the scleral region bordering the optic nerve, a key region in glaucoma and myopia development.

Methodology & Theoretical Orientation: We required specimens from closely-matched young adult age because body physiology slows down with time. This is particularly problematic when dealing with human tissues. Therefore, we compared several mammal species to find a suitable human analogue. Wide-angle X-ray scattering (WAXS) was used to map the scleral collagen orientation and distribution, while multi-photon microscopy provided clarity on the depth profile. The geometry of the eyeball was acquired from video motion capture imaging of specimens that were inflated under simulated eye pressure. Planned experiments include studies of fibroblast cytoskeletal reorganization under simulated eye pressure (mimicking glaucoma).

Findings: After comparing 11 mammal species, our results revealed that the peripapillary sclera of the bovine has a tissue structure closely resembling that of humans, including the important annular structure

around the optic nerve, which is vital for its mechanical support. Furthermore, we have optimized protocols for bovine fibroblasts, which will be used to study their pressure-controlled mechanotransduction pathways.

Conclusion & Significance: ECM and cytoskeletal structural information will be used along with geometric data to create integrated models of the eye for driving future scleral-targeted treatments for glaucoma and myopia.


Fawzia Bardag-Gorce has been studying ocular surface disease for the last six years, and has published and co authored six peer-reviewed publications in this
field. She began her research on the treatment of limbal stem cell deficiency using Cultured Autologous Oral Mucosa Epithelial Cell Sheet (CAOMECS). During these six years, and under her supervision and guidance, her lab has successfully completed pre-clinical studies related to the efficacy and safety of CAOMECS cell-based therapy. She is currently directing a new study approved by the Institutional Research Board in which subjects are being recruited for the human oral mucosal epithelial cell sheet characterization. The long-term goal of this study is to regenerate corneal epithelium in patient with severe ocular surface diseases using autologous oral mucosa epithelial cell sheet grafts.


PURPOSE: This study focuses on characterizing proteasomes in corneal epithelial cells (CEC) and in cultured autologous oral
mucosal epithelial cell sheets (CAOMECS) used to regenerate the ocular surface.

METHODS: Limbal stem cell deficiency (LSCD) was surgically induced in rabbit corneas. CAOMECS was engineered and grafted
onto corneas with LSCD to regenerate the ocular surface. RESULTS: LSCD caused an increase in inflammatory cells in the ocular
surface, an increase in the formation of immunoproteasomes (IPR), and a decrease in the formation of constitutive proteasome
(CPR). Specifically, LSCD-diseased CEC (D-CEC) showed a decrease in the CPR chymotrypsin-like, trypsin-like and caspase-like
activities, while healthy CEC (H-CEC) and CAOMECS showed higher activities. Quantitative analysis of IPR inducible subunit (B5i,
B2i, and B1i) were performed and compared to CPR subunit (B5, B2, and B1) levels. Results showed that ratios B5i/B5, B2i/B2 and
B1i/B1 were higher in D-CEC, indicating that D-CEC had approximately a two-fold increase in the amount of IPR compared to
CAOMECS and H-CEC. Histological analysis demonstrated that CAOMECS-grafted corneas had a re-epithelialized surface, positive
staining for CPR subunits, and weak staining for IPR subunits. In addition, digital quantitative measurement of fluorescent intensity
showed that the CPR B5 subunit was significantly more expressed in CAOMECS-grafted corneas compared to non-grafted corneas
with LSCD.

CONCLUSION: CAOMECS grafting successfully replaced the D-CEC with oral mucosal epithelial cells with higher
levels of CPR. The increase in constitutive proteasome activity is possibly responsible for the recovery and improvement in the treated
corneas. Supported by Emmaus Life Sciences Inc.


Yan Ning Neo is an Ophthalmology Registrar in North London. He attended University of Edinburgh with a full undergraduate scholarship and graduated with multiple awards and prizes, including an external grant by the Royal College of Surgeons and Physicians Glasgow to carry out ophthalmology research at Harvard University. During his undertaking of an Ophthalmology Academic Foundation Programme in Scotland, he was rewarded few national research awards and prizes, including FaME Best Junior Doctor Award, TASME UK Young Educator Prize and Novartis Academic Bursary etc.


We sought to report the long-term visual and treatment outcomes in a whole-population, orthoptic-delivered pre-school visual screening (PSVS) programme in Scotland and their associations with socioeconomic backgrounds and home circumstances. Retrospective case review was conducted on 430 children who failed PSVS. Outcome measures included best corrected visual acuity (BCVA) and proportion of amblyopia based on severity (mild, moderate and severe), binocular vision (BV) (normal, poor and none), ophthalmic diagnosis and treatment modalities. Parameters at discharge were compared to those at baseline, and were measured against Scottish Index of Multiple Deprivation (SIMD) and Health Plan Indicator (HPI), which are indices of deprivation and status of home circumstances. The proportion of children with amblyopia reduced from 87.1% at baseline to 27.2% at discharge (p<0.001). 81.3% had good BV at discharge compared to 33.5 at baseline (p<0.001). Association between final BCVA and BV is significant (p<0.001). Children from more socioeconomically deprived areas (OR 2.01, p=0.003) or adverse family backgrounds (OR 3.40, p=0.002) were more likely to attend poorly and become lost to follow-up. Children from worse home circumstances were five times more likely to have residual amblyopia (OR 5.33, p<0.001) and three times more likely to have poor/no BV (OR 3.23, p<0.001) than those from better home circumstances. Orthoptic-delivered PSVS is effective and feasible for the early detection and treatment of childhood amblyopia. Children from unstable homes are more likely to have poorer visual outcomes.


Samer Hamada, MD, is an ophthalmologist and cornea surgeon performing eye surgeries at his practice, the Eye Clinic London. With nearly two decades' experience, Mr. Hamada is recognised as a leading expert in the field of cataract, refractive lens exchange (RLE) and corneal surgeries, and is frequently asked to lecture at international eye conferences. He has performed thousands of cataract surgeries and RLE surgeries using the latest technological advancements in ophthalmology.Mr. Hamada offers laser cataract surgery with the option of artificial lenses, called intraocular lenses (IOLs), to replace the natural eye lens that has been clouded by a cataract. These IOLs are used for the restoration of near, intermediate and far vision. He is one of the very few eye surgeons who offer trifocal intraocular lens implants. Patients who prefer to be less dependent on glasses or contact lenses, even without a significant amount of clouding due to cataracts, could choose laser or non-laser RLE, both of which are very similar to cataract surgery.


Cataract surgery is becoming a refractive surgery. The requirements of our patients are changing and most of our patients are looking for glasses independence after cataract surgery. Refractive lens exchange has increased in our practice due to expanding awareness among patients about refractive options past the age of 45. The key elements to success are choosing the most suitable patients, perfect planning, knowledge of available technologies and appreciating the differences so choice to meet patients requirements and life style, surgical techniques, measuring outcomes, and auditing.c



Purpose: To assess the learning curve in the initial 100 cases of cataract surgery performed using the femtosecond-laser-assisted-cataractsurgery
(FLACS) by experienced cataract surgeons without prior experience with the femtosecond laser platform.

Setting: Tertiary care eye hospital in South India.

Methods: First 100 consecutive eyes undergoing FLACS were prospectively studied to understand the docking time, number of docking attempts, problems encountered during docking and complications attributable to docking. Phacoemulsification performed after the femtosecond laser was also studied for complications, need for additional instrumentation and total time required for surgery. Comparison between two operating surgeons was also made.

Results: One hundred eyes of 91 participants were included in the analysis. The mean age of participants was 57.8+8.2 years and 68% were men. Surgery was performed by the SMO in 56 eyes and by the JMO in 44 eyes. Successful docking of the femtosecond laser was recorded in 70% eyes at the first attempt. Most of the remaining eyes underwent successful docking at the second attempt. The commonest causes for failure of docking were inadequate suction, air bubble at the docking interface, failed patient registration and eye movement post docking. Seven patients had pre-dock miscellaneous errors such as undetected patient interface, insufficient rise of the table height and
pre-treatment error, which occurred due to inadequate tightness of the patient interface attachment. Only one patient experienced loss of suction during the laser delivery because of sudden movement in the middle of the procedure. The mean time taken for successful docking was 9.3+6.4 minutes. Total time for phacoemulsification surgery across the study period was 12.9+6.2 minutes. Keratome was required to open the corneal incision in 18% eyes. Similarly, 6% eyes showed anterior capsular tags, when the capsulorhexis was uncovered and only one of these evolved into a radial capsular tear. Two eyes with mature cataract had significant miosis after laser, which dilated well with intracameral adrenaline. Only one eye experienced zonular dialysis. There were no other complications during surgery including posterior capsular rupture and vitreous loss. Six eyes had persistent subconjunctival hemorrhage in the first post-operative day and 25 eyes had corneal edema in the first post-operative day, all of which resolved within 1 week of surgery. Eight patients had IOP spike (>21 mmHg) in the first postoperative day, out of which 7 resolved spontaneously and one patient required topical timolol for one-month duration. At 6 weeks follow up, 79% eyes attained UCDVA of 20/20, 19% had UCDVA of 20/30 and only 2 eyes had 20/40. All eyes had BCDVA of 20/20. When surgeries were divided into quartiles (Table 1), a significant reduction was seen in docking time between the first 25 eyes and the remaining 75 eyes. Similarly, successful 1st docking attempts significantly improved from 36% in the first quartile to 80% in the 4th quartile. Three attempts were required in 2 eyes (one in 1st and 3rd quartile) and 4 attempts were required in 1 eye in the first quartile. Additionally, the need to use a keratome to open the corneal incision showed time trends across quartiles. When surgeries were divided into deciles (i.e. groups of 10 each), docking time reduced significantly after the first 30 cases. Similarly, the proportion of successful docking at 1st attempt shows a trend to improve from 1st to 10th decile. The average number of docking attempts per case was 1.44, which improved with learning from 1.6 in the first decile to 1.3 in the last decile. No other significant differences were observed between the deciles. Comparison between the two operating surgeon showed that the senior surgeon performed phacoemulsification surgery significantly faster than the junior, however, he required using the keratome in significantly more number of eyes.

  • Visual Neuroscience | Vitreo-retinal | Diabetic Retinopathy | Visual Impairment | Vision and Cognition


Rajamani Lakshminarayanan

Singapore Eye Research Institue, Singapore

Session Introduction

Rajamani Lakshminarayanan

Singapore Eye Research Institute, Singapore

Title: Rational Design of Cell-selective Antimicrobial Peptides


The evolution of antibiotic-resistant pathogens pose significant threat to human health and healthcare systems and account for considerable economic burden world-wide. In particular, the Gram-negative bacteria adapted sophisticated machineries that can overcome all the available pathways targeted by current antibiotics. Agents that target cytoplasmic membranes of prokaryotes are attractive alternatives for combating antimicrobial resistance owing. Cationic antimicrobial host defense peptides have been shown to elicit rapid bactericidal action by targeting cytoplasmic membrane of the bacteria, but their cytotoxicity for mammalian cells limited their therapeutic potential. Our preliminary investigations that the cationic polymer ε-polylysine has superior cellselectivity
than isomeric α-polylysine. Based on this preliminary data, we replaced α-lysine residues in prolific pore forming peptide, melittin from bee venom, with ε-lysine residues and determined their cell selectivity. Melittin elicited toxic effect on both microbial as well as mammalian cells confirming its poor cell selectivity. However, substitution of N-terminal α-lysine with ε-lysine residues increased the cell selectivity while C-terminal substitution did not alter the properties. Multiple substitution of ε-lysyl residues enhanced the cell selectivity significantly. Two such peptides displayed excellent antimicrobial activities against MRSA, vancomycinresistant enterococci, antibiotic-resistant P. aeruginosa, carbapenem-resistant enterobacteriacae and azole-resistant Candida spp strains. The modified melittin peptides display rapid bactericial properties and slightly weaker pore-forming properties than melittin
while non-cytotoxic for mammalian cells. We further confirmed the enhanced cell selectivity upon -lysylation in mastoparan B, the antimicrobial peptide present in harnet’s venom. Together, these results establish the rational modification of multifunctional hostdefense peptides by -lysylation with improved cell selectivity.


She graduated from Istanbul University, Istanbul School of Medicine in 1997. She has completed her residency in Istanbul Universtiy, Cerrahpasa School of
Medicine, Department of Ophthalmology in 2002. She has worked in Turkish Diabetes Hospital since 2002. She has held the position of Medical Retina Specialist and Deputy Chief Physician in Dünyagöz Hospital between 2005-2016. She coordinated the initiation of the long-term partnership of Orbis which is a branch of the World Health Organisation and Dünyagöz Hospital Group. She is the ophthalmology consultant of telemedicine systems of GSM operators in Turkey. She coordinated the bionic eye treatment initiation (Argus II Retinal Implant) in Turkey, also incorporating the Frankfurt World Eye Hospital in Germany as a scientific committee and board member of Dünyagöz Foundation and Turkish Medical Academy. She initiated the projects Dunyadiyabet and Athletic Eye Health in order to contribute to ‘Retina Awareness’ as a clinical scientist to prevent the loss of resources that would be used for keeping patients healthy. She has been invited contribute to the Turkish Olympic Committee and is working with the Turkish Paralympic Committee. She aims that the eye would be a symbol for the preventive
medicine globally, starting from athletes.


Retinitis pigmentosa is a degenerative eye disease that causes progressive loss of vision. In RP, there is irreversible degeneration of the outer retina (the photoreceptors) while the inner retinal cells (bipolar cells, retinal ganglion cells) and visual pathway downstream remain intact. Affected people suffer from progressive visual loss which can be profound: 0.5% of people with RP above the age of 45 have no light perception and 25% have ≤1/10 vision in both eyes. A person who suffers with sight loss can experience difficulties relating to maintaining their independence, social isolation, activities of daily living and issues around financial support. Loss of visual field is associated with a decrease in physical mobility and difficulties in adjusting being blind. Treatment options for RP, other than for the associated cataract and macular oedema, are limited. Treatment is mainly aimed at slowing disease progression.
The Argus II system is intended to treat patients at the most advanced stages of RP, for whom there are no other treatment options. It is the only CE-marked and FDA-approved option that can restore vision for end-stage RP patients. The epiretinal prosthesis: Argus II system The Argus II system works by bypassing damaged retinal cells and electrically stimulating retinal ganglion cells, creating visual perceptions (percepts) of light. This is the first example of a system, or any therapy, that has demonstrated improved visual function
in the extremely low-vision range (NLP to HM) in this population. Insertion of an epiretinal prosthesis aims to restore perception of light, movement and shapes by surgically implanting an array of electrodes onto the retina The epiretinal prosthesis has two key components: The eye implant and the external camera system, comprising an eyeglass-mounted video camera and a small patientworn computer (video processing unit, VPU) When the implant is on, the video camera in the patient’s glasses records real-time images and sends them to the VPU. The VPU converts the images into data that are sent back to the glasses and are then wirelessly transmitted to the episcleral receiver unit, which in turn relays the data to the electrode array Electrical impulses are produced which bypass damaged photoreceptors and stimulate the remaining retinal cells. Visual information is then transmitted by the optic nerve to the brain, creating a visual perception. Patient selection must be careful and rigorous and the patient should be counselled to have realistic expectations: if the patient’s expectations of the system are not fulfilled, the patient may stop using the system. To maximise the likelihood that patients receive benefit from the Argus II system, they should be motivated and willing to receive the
recommended training and visual rehabilitation.

Prasanth Gireesh

Aravind Eye Hospital, India

Title: Prasanth Gireesh


The most challenging step in sutureless scleral fixation of intraocular lens (SFIOL) is exteriorization of haptics. The conventional handshake technique has a learning curve since it involves intraocular handing over of haptics from one forceps to another. Here, we describe “extraocular needle-guided haptic insertion technique” (X-NIT), a novel technique of exteriorizing haptics that totally eliminates intraocular manipulations. This method involves sequential introduction of two bent 26-gauge needles through the sclera (pars
plicata zone) into the eye which are brought out through a sclerocorneal wound. The intraocular lens haptics are threaded through these needles and exteriorized. Nineteen consecutive patients underwent surgery by this technique. There were no intraoperative complications. The mean best-corrected visual acuity (BCVA) of these patients at 1-month follow-up was 0.5 ± 0.3 (logarithm of the minimum angle of resolution) with 18 of 19 eyes showing one or more lines of improvement in BCVA. X-NIT is a safe, easy, costeffective, and highly reproducible technique, especially for beginners.
Key words: Aphakia, extraocular, scleral fixation of intraocular lens, extraocular needle-guided haptic insertion technique Scleral fixation of intraocular lens (SFIOL) surgery has come a long way since its inception. Conventionally, suture fixation of the intraocular lens (IOL) was practiced. Then, came sutureless SFIOL surgery to avoid suture-related problems.[1] Various techniques exist to secure the exteriorized haptic of the IOL.[1-5] However, exteriorization of the haptics in the first place is a challenging step. The conventional handshake technique has a learning curve since it involves intraocular handing over of haptics from one forceps to another. This step becomes particularly difficult in the setting of small pupil or corneal scar. Here, we describe extraocular needleguided haptic insertion technique (X-NIT), a minimally traumatic, easy, and quick method of exteriorizing the IOL haptics during SFIOL implantation.

Results: All surgeries were performed by a single surgeon (PB) on 19 eyes of 19 patients. Table 1 shows demographic and preoperative data. The mean best-corrected visual acuity preoperatively was 0.5 ± 0.3 logarithm of the minimum angle of resolution (LogMAR) units which improved by one or more lines postoperatively in all, but one eye that had preexisting corneal pathology. Table 2 summarizes the visual outcome of our patients. Intraoperative complications such as haptic slippage, IOL drop, and intraocular rebound of leading haptic were not encountered. Postoperative complications such as serous choroidal detachment, wound leak, IOL decentration, or retinal detachment were not encountered. Transient corneal edema occurred in three patients, dispersed vitreous hemorrhage in one patient, and postoperative hypotony in another, all of which resolved by the end of the first postoperative week

Nadejda Bocheva

Institute of Neurobiology, Bulgaria

Title: Contextual modulation in motion direction processing


Statement of the Problem: Contextual modulation is a common phenomenon observed at different levels of the visual system. It mainly represents the modulation of neuronal response from stimuli outside the receptive field and is often described as centersurround interactions. Diverse motion phenomena are related to center-surround interactions in visual information processing. Typically, changes in sensitivity are observed at short stimulus presentation times, while at longer presentation times more often the perceived motion direction and speed are biased. In the present study a large set of stimulus parameters were chosen with the aim to obtain indirect information on the potential contributions of center-surround interactions, tuned and/or untuned normalization and neuronal correlation in motion processing on the perceived motion at longer duration.

Methodology & Theoretical Orientation:
In six experiments we studied the effects of the size of the central region, the total contrast, the motion speed, the motion direction of the surround and the relative orientation of the elongated elements in the stimulus with respect on the motion trajectory on the perceived motion direction of the center in a center-surround configuration. The observers had to determine whether the direction of the central patch moved to the left or to the right of the vertically downward direction. Findings: The surround motion significantly affected both the precision and the sensitivity to the motion direction in the central region. In most cases, the sensitivity is lower when the surround moved in a direction orthogonal to the reference axis or at ±45° of it. The highest sensitivity to motion direction in the central region was observed when the surround moved upwards along the reference axis (at about 180° away from the motion direction of the center). The size of the central region has little effect on the performance, while the effect of the contrast varies depending on the other stimulus characteristics. The deviation of the motion trajectory from elements’ orientation had various effects depending on the contrast of the configuration and the size of the central region. Conclusion & Significance: The observed
effects could hardly be explained by the changes in sensitivity of single neurons due to the presence of surrounding motion. They suggest cooperative activity at the population level in orientation and motion encoding and at different levels of dynamic information processing. The potential functional significance of the observed effects will be discussed



Aim: Aim of this study is to investigate LEDGFp52 regulation of primary neurite number and length, mRNA production and protein expression of Thy1 of rat retinal ganglion cells.

Methodology & Theoretical Orientation: Primary RGCs were isolated and cultured. After 36 h in culture, LEDGFp52(2.0×10-4 g/L) and Ab-LEDGF(2.5×10-4 g/L) were added into cultures of RGCs; pAd-LEDGFp52 (2.5×10-4 g/L) and siRNA-LEDGFp52 (6.0×10-4 g/L) were transfected into RGCs. After 12, 24, 36, 48, 72 and 96 h, in culture changes in neurite number and length were investigated using contrast phase microscopy, and an IPP image analysis. The Thy1 mRNA production and proteins expression were assayed after 24, 48, 72 and 96 h in culture using RT-PCR and immunofluorescence, respectively.

Findings: The primary neurite numbers on single RGCs in the +LEDGF treatment groups were not significantly different, but the neurite length was much longer and Thy1 mRNA production and proteins expression were much more than the control group, meanwhile, the number and length of primary neurites on single RGCs in the Ab-LEDGF group were significantly less than the control group at 72 and 96 h, and Thy1 mRNA production were much less than the controls at all the time points, however, its proteins expression was just less than controls at 24 h. After transfecting with pAd-LEDGFp52, the number of neurites were significantly increased at 72 and 96 h, their lengths were significantly increased at all the time points but 24 h compared to control group, moreover, Thy1 mRNA production and proteins expression were much more than the control group at all the time points. However, the introduction of siRNA-LEDGFp52 significantly decreased the number at all the time points but 24 h and the length of neurites was shorter compared to the controls. Similarly, Thy1 mRNA productions were significantly down-regulated at all the time points and proteins expressions were significantly down-regulated at all the time points but 96 h.

Conclusion & Significance: RGC neurite growth and Thy1 expression can be controlled by the LEDGFp52. The LEDGFp52 may be beneficial to RGCs in vitro, and Thy1 levels are closely related to RGCs growth.


Senior Vitreo-retinal consultant at the Jordanian Hospital in Amman. Fayyad graduated from Rome University (La Sapienza) in 1976, and completed his residency program in ophthalmology at the same university between 1977 and 1981 with honors. He then traveled to Canada and completed a two year fellowship program in clinical Retina, at the department of ophthalmology at Ottawa University. He served at the Jordanian ministry of health hospitals and the King Hussein Medical Center as well as at the Jordan University Hospital.An examiner at the Jordanian Board of Ophthalmology. Fayyad is involved in training ophthalmologists in Vitreo-retinal surgery.


Key points

What is bi-manual surgery?

We use both upper ports as active ones i.e. we utilize the upper left port to insert active instruments (like cutters, forceps and scissors). However, we need a light source to substitute for the endo-illuminator.


Proliferative diabetic retinopathy

Rhegmatogenous retinal detachment

RD complicated with PVR


Dislocated lens/ IOL



Better surgical control

Reduced frequency of instruments change during surgery and less iatrogenic complications

Reduce overall time of surgery

Difficult cases become more amenable to surgery

Minimize need for an assistant

Chandelier Lights

My preference is to use a 2 twin lights to eliminate the need to reposition the fiber and minimizes the shadow seen with single-fiber chandelier endo-illumination because the illumination comes from 2 different directions.

Advantages of Chandelier

The working distance for light irradiation is important, and holding the light probes as far away from the retina as possible increases safety.

The self-retaining nature of chandelier endoilluminators frees up my hand from holding a light probe, allowing true bimanual manipulation during surgery.


Bimanual approach is the safest and the most effective approach in the management of complicated diabetic vitrectomies.