^{International Conference and Expo on} Optometry and Vision Science October 20-22, 2016 Rome, Italy

Biography:

Prof.Antonio Carlos Centelhas is head of ophthalmology of CRMED Ministery of Health, Nise da Silveira Hospital , Rio de Janeiro, Brazil Ex- Professor of ABC University , SãoPaulo, Brasil and Gama Filho University, Rio de Janeiro, Brazil. Prof. Centelhas is international advisory board Of Delhi Journal of Ophthalmology,New Delhi, India. Panelist in many Congress and Universities ( EUA )

Abstract:

Introduction: The TransPRK (transepithelial photo refractive Keratectomy) by Amaris 750S a SCHWIND technology is a refractive procedure with no-contact surgery. Corneal epithelium is removed by the laser without manual interference. It brings more acuity and perfect de-epithelization.

Method: We treated and studied in three years, 452 eyes of 224 patients, 96 males and 128 females. The average degree of spherical refraction was -3.70 DE and cylindrical refraction was -0.75. We used 1% tetracaine hydrochloride as anesthesia and mitomicin-c 0,01% for 25 minutes or more; contact lens after the application; and drops of moxifloxacin hydrochloride 0,5 for antibiotic therapy. In the post-operatory we used moxifloxacin hydrochloride 0,5-4 drops a day for 7 days, trometamol cetorolac 0,45%-4 drops a day for 7 days and carmellose sodium and sodium hyaluronate for 1 month.

Results: We had 96,3% with 20/20 in the end of two eyes of study and 6 eyes presented a little manifestation of haze. 93% had epithelial regeneration in 3 days after surgery and all patients in 5 days. 96,3 % showed a spherical refraction target of 0,48 and a cylindrical refraction of 0.5 degrees. The corneal architectural structure became preserved and we had to pay attention when we had diameters below 9.5 mm which may occur due to overcorrection in the results. The results modified with a little between 12 to 24 months. The dry eye occurred in 72% of patients in the first month and kept with the same incidence of all population after 3 months of the surgery.

Conclusion: The TransPRK showed an excellent and safe procedure with 96,3% of good results of myopia and astigmatism .We need to observe the development of dry eye in the 3 months of post–operatory.

Biography:

Bonnie Molloy PhD, CRNA has been practicing anesthesia for 33 years and has been studying Post-operative visual loss (POVL) and conducting research in this field since 2005. She completed her Doctoral dissertation in 2010 in the Development of the Molloy/Bridgeport Anesthesia Observation Scale (MBOS) correlating rising intraocular pressure (IOP) to observations in eyelid and conjunctival edema (chemosis) during steep trendelenburg (ST) surgical procedures and became an Associate Member of the American Academy of Ophthalmology at that time. She has published practice interventions in pursuit of normalizing IOP and has established a protocol that can be used by all anesthesia caregivers. 

Abstract:

Following a case of postoperative visual loss (POVL) in the steep trendelenburg (ST) position at our institution, IOP measurements were taken during laparoscopic surgery. IOP was observed to rise overtime with increases (4-5 times baseline). While monitoring we observed eyelid edema and degrees of conjunctival edema and correlated findings to rising IOP. We trialed a preventive supine intervention that significantly impacted increase in IOP and may prevent future POVL events since current literature cites retinal cell ganglion dysfunction as a result of even brief (30-40minute) acute increases in IOP. Additionally, increased peri-orbital swelling and venous congestion secondary to trabecular meshwork dysregulated pressure dependent outflow may produce a low perfusion state in the eye, via a compartment syndrome mechanism. Cosopt™ eye drops were trialed (carbonic anhydrase inhibitor/beta adrenergic blocker). Prevention of IOP rising above 40 mmHg was the goal since 45-55mmHg IOP was determined to bea critical threshold in POVL incidents. The literature cites the importance of early IOP reduction since optic nerve ischemia may lead to visual loss. The purpose of these four studies was to: 1) Develop an observation scale (MBOS) correlating to the rising IOP, 2) Evaluate a Peri-operative and 3) Preventive intervention with Cosopt™ eye drops and 4) A comparative intervention where head was elevated mid procedure so as to reduce the rising IOP trend. Studies have provided significant results and valuable findings in determining when IOP is elevated, in lieu of direct tonometry and all interventions have arrested the IOP escalating trend. This symposium will provide a venue for illustration and education of these findings in pursuit of ophthalmic safety.

Biography:

Maitreyee Roy is a Senior Lecturer and a Deputy Director of Optics & Radiometry Laboratory at the School of Optometry and Vision Science, University of New South Wales, Australia. She is responsible for teaching geometric, physical and visual optics in the optometry and vision science degrees. She was awarded her PhD from School of Physics at the University of Sydney. She is an accomplished Optical Physicist with broad experience in government and academic institutions with strong R&D background particularly in optical metrology, 3D optical imaging and nanoparticle metrology. She holds numerous memberships with optical societies nationally and internationally. 

Abstract:

Blue blocking lenses are being marketed to protect retinas against hazardous blue light allegedly linked to age related macular degeneration without restricting the wavelengths that may be related to melatonin suppression and sleep quality. Any lenses that transmit some wavelengths more than others have the potential to affect color vision significantly. The purpose of this study was two-fold: Firstly, to determine the reduction in the blue dose hazard for several blue control lenses currently for sale. Secondly, to determine whether color vision perception is affected by the use of blue blocking lenses. Five (5) blue blocking lenses of various brands and 1 clear control lens were evaluated for their spectral transmittance and the blue hazard dose reduction. Color perception was assessed using 3 tests: The Cambridge Color Test, the Color Assessment & Diagnosis test and the Farnsworth-Munsell 100 Hue test. Young adults (18 to 35 years) with normal color vision and normal ocular health undertook the tests through 3 brands of blue blocking lenses and 1 clear lens as a control. The lenses were presented in randomized order to minimize fatigue and learning effects. Blue hazard dose reductions varied across the different brands of blue blocking lens (range 15 to 43%). However, no significant differences in color discrimination on any of the tests were found for any of the lenses used. 

Biography:

Faraz Farooq Saleem has completed his BSc in Optometry from Glasgow Caledonian University in 2004. He obtained his Post-graduate Legal Diploma from BPP Law School, London in 2007 and Post-graduate Diploma in Legal Practice for Solicitors from University of Hertfordshire in 2011. While studying Law, he concurrently built experience as a Refractive Laser and IOL Optometrist for Optical Express, and has served as a Senior Lead Optometrist Manager for Ultralase and Optimax. He is currently a Lead Optometrist at Specsavers, Oxford as well as the Local Ophthalmic Committee’s GRRS Clinical Governance Lead (Glaucoma Referrals Scheme).

Abstract:

The practitioner undertakes a duty of care, operating within a legal framework designed to afford investigative freedom to differential diagnosis within an ever-increasing litigious mise-en-scene. The characteristics which define this duty and breach of, strongly include the developing concept of consent but reach beyond civil responsibility and into the criminal sphere (with the advent of the first gross negligence manslaughter verdict in the UK). A practitioner’s judgment in this field is almost always incomplete until a series of tests have been completed. With this in mind, the role can provide a challenge in reaching a conclusion without negligently abusing the patient or the duty thereby. This article will seek to provide a practical approach in fulfilling the duty of care with care.

Biography:

Nguyen Duc Trong, MD achieved Specialist 1 certification of Ophthalmology (equivalent to Master degree), refraction certification at the Eye Hospital of Ho Chi Minh city. Furthermore, he obtained Ortho-K license fitting from Fargo and Paragon Company. He is currently working at HYEC as an Ophthalmologist, specialized in ocular surface disease. He has experience in fitting Ortho-K nearly for two years

Abstract:

Aim/Purpose: The purpose of this study is to report refractive error changes and visual outcome of number of patients using Cornea Refractive Therapy.

Methods: This is a single-center retrospective descriptive study of 40 patients (80 eyes) including 11 male and 29 female, mean age 14.53±2.84, wearing Fargo overnight Ortho-K contact lenses from May 2014 to February 2016.

Results: The result shows mean uncorrected visual acuity (UCVA) at distance of pre-treatment is 1.22±0.17 logMAR; post-treatment one week, one month and three months are 0.23±0.0.25 logMAR, 0.19±0.23 logMAR 0.19±0.24 logMAR respectively. Mean spherical equivalent refractive error (SER), mean spherical power (SP), mean astigmatism (AS) of pre-treatment are -5.52 ±2.26D (from -2.00D to -10.88D), -4.96±2.08D, -1.12±0.94D appropriately. Mean SER; mean SP, mean AS of three months post-treatment are -0.62±1.11D, -0.17±0.93D, -0.90±0.64D. There are statistically significant changes in UCVA (p<0.0001), SER (p<0.0001), SP (p<0.0001), AS (p=0.01) at three months post-treatment compared with pre-treatment. There are no statistically significant difference of UCVA and SER at one month and three months.

Conclusion: In conclusion, visual acuity and refractive error improve significantly and achieve stability after one month treatment of wearing Ortho-K lenses.

Biography:

Jeremy A Ciano has a high end, concierge concept office, RevolutionEYES as well as a pediatric focused satellite office, Little Eyes. As a student he was able to receive honors both in the tennis court as well as in the classroom at King's College. He is a graduate of the Pennsylvania College of Optometry in 2001. As a Lecturer, he has presented lectures in over 20 states at nearly 100 venues. He has published many articles in medical and business journals. He has also assisted over 40 practices through his consulting work around the United States.

Abstract:

Sports vision and training can become a cornerstone of your practice. Energizing both your patient base as well as your staff, this is an exciting aspect of Optometry that you will enthusiastically embrace. There are so many great aspects of sports vision that many patients and Optometrists aren’t even aware of. The focus of this lecture will be to enlighten the practitioner about the new, exciting and unique ways to differentiate your practice while helping your patients achieve new athletic heights which they never realized to be possible. During this lecture we will focus on the basics of sports vision, techniques of implementation, and the mentality shift one need to become successful in this growing and exciting aspect of Optometry. 

Biography:

Katherine Schuetz has completed her Doctorate from the Indiana University School of Optometry in 2000. She has practiced Family Optometry for the past 16 years, and has specialized in Pediatrics, Orthokeratology and Contact Lenses. She and her partner Dr. Ciano provide vision screenings for over 1200 elementary school students every year, and she also volunteers her time doing exams at a free local health clinic for low-income patients. 

Abstract:

The incidence of myopia has increased by staggering amounts over the past 50 years. As practitioners see more pediatric cases of myopia, we have to think about the future risks these patients may experience as high myopes. This lecture will discuss the incidence of myopia in different areas of the world, how myopia is being identified in younger children, and how to slow the progression of myopia worldwide. With some areas in Asia showing over 90% myopia in patients of 18 years and above, we must address this alarming trend. We have 3 treatments currently at our disposal: Orthokeratology, soft multifocal contact lenses, and atropinization. The benefits and risks of all 3 modalities will be discussed, citing multiple studies.

Biography:

Jeremy A Ciano has a high end, concierge concept office, RevolutionEYES as well as a pediatric focused satellite office, Little Eyes. As a student he was able to receive honors both in the tennis court as well as in the classroom at King's College. He is a graduate of the Pennsylvania College of Optometry in 2001. As a Lecturer, he has presented lectures in over 20 states at nearly 100 venues. He has published many articles in medical and business journals. He has also assisted over 40 practices through his consulting work around the United States.

Abstract:

In addition to help the owner, doctors, and staff understand basic business principles, business metrics increases the quality of medical care you can provide to your patients. Business metrics are a great way to inject fun, excitement, and enthusiasm into your place of work. This will not be a boring hour on graphs and charting, but rather, it will be a high energy journey through team building exercises to help the staff embrace the value of metrics both personally and professionally. The addition of team and individual metric games will bring great unity, pride, and a sense of accomplishment when implemented properly. Casting a vision for the office, watching that vision become a reality, and enjoying the hard work together as a team is a rewarding journey that pays dividends to the owner, the team and the patients being treated.

Biography:

Daniel Valverde Solis is an Optometrist at the Faculty of Medical Sciences University of Guayaquil and a Fellow in Universidad Interamericana of Puerto Rico. He is continuing his education in Optometry Clinic and Pediatric, The New England College of Optometry Boston, USA. He has done his Diploma and Master’s in Management in Higher Education Unit Graduate Research and Development from University of Guayaquil, and has done his PhD from Atlantic International University Higher Education Honolulu, USA

Abstract:

Optometry in the world, is on track to reach the fourth level of care provided by the WCO, universities must raise their academic level of training to transmit the necessary knowledge to approach the treatment of anterior ocular segment. The retina is a vital part of the visual process and if your primary care is not done properly, it is precisely at this point that optometrists can contribute quickly and timely. It doesn’t need more than 3 to 5 minutes to emphasize on the diagnosis of the retina. With help of a direct ophthalmoscope, we can look for the diagnosis, as ophthalmoscope being a basic tool we can not only give a primary diagnosis but can also do preventive work, without inflicting the laws in force, because we not only say but confirm optometry as the first barrier against blindness.

Biography:

Amir Asharlous is a PhD candidate in Optometry and Vision Science at Mashhad University of Medical Sciences. He is a Professor at Optometry department of Iran University of Medical Sciences. He has completed more than 10 research programs and has published more than 6 papers in reputed journals of Optometry and Ophthalmology

Abstract:

Purpose: To investigate rule similarity (iso rule and aniso rule) and symmetry patterns (direct and mirror) in the astigmatism axes of fellow eyes in bilateral astigmatisms.

 Methods: Refractive outcomes of 160608 subjects aged from 10 to 80 years old (mean 39.2±15.4) including 53.7% (86230) females were analyzed. Minimum astigmatism magnitude in both fellow eyes was considered 0.25 diopter (D).

Results: The prevalence of iso rule bilateral astigmatism was 82.9%. Mean aniso-astigmatism was 0.31±0.4D and 85.2% of our subjects had lowered than 0.50 D cylindrical anisometropia. The median values of absolute difference in the axes of the fellow eyes were 10 and 20 degrees under the mirror and direct symmetry models, respectively. 68% in mirror model and 47.1% in direct model were within 15 degrees of exact symmetry point. The symmetry patterns did not show any significant difference between various magnitudes of spherical ametropia. The astigmatisms with higher magnitudes were shown stronger symmetries than the lower astigmatisms.

 Conclusion: According to our findings, the majority of bilateral astigmatisms are iso rule. This rule similarity becomes less prevalent with increasing age. The iso rule pattern is more common in individuals having higher magnitudes spherical ametropia. Both mirror and direct symmetry are common in the astigmatism axes of fellow eyes and the mirror pattern is predominant. Both of symmetry models are stronger in the higher magnitudes of bilateral astigmatisms. 

Biography:

Asma A A Zahidi is currently in the second year of her PhD at the School of Optometry and Vision Sciences, Cardiff University, under the supervision of Dr. J Margaret Woodhouse and Professor Jonathan T Erichsen. Her research interests are Infantile Nystagmus, Pediatric Optometry and Visual Impairment

Abstract:

One of the challenges of performing eye movement recording (EMR) in young children is maintaining their attention while performing the visual tasks. Thus, the type of stimulus used during the EMR can play an important role in obtaining good quality eye position data. Traditional stimuli used in eye movement recording in adults are geometric shapes, such as a cross or a black dot, which are usually small in size. The purpose of using stimuli with such characteristics is to reduce the variability of eye position in the EMR data. However, these types of stimulus have few details and do not grab the attention of very young children. For these reasons, it has been suggested that a larger and more complex image might be better at attracting the child’s attention. Increasing the size and amount of details of a stimulus, however, may adversely affect the quality of data obtained in an EMR of patients with infantile nystagmus (IN). Therefore, the present experiment aims to compare the quality of EMR data of patients with IN using two different types of stimulus: animated and non-animated. Five adults with IN performed the eye movement recording. The stimulus used was 10 cartoon images of animated and non-animated animals, respectively. Each stimulus was presented in two different sizes (2º and 4º) at the center of a computer screen for 3 seconds. The quality of the data in terms of the amount of noise for each stimulus was then assessed. The findings obtained from this experiment enabled us to choose the stimulus type and size that is most suitable during eye in movement recording children with IN of different age groups.

Biography:

Abstract:

Pterygium is a common tumor-like ocular disease, which may be related to exposure of chronic ultraviolet (UV) radiation. Though the standard treatment for pterygium is surgical intervention, the recurrence of pterygium is high when no effective inhibitory drug is used after surgery. Rosmarinic acid (RA) is a polyphenol antioxidant, which has many biological activities including anti-UV and anti-tumor. This study was to examine the inhibiting effects of RA on pterygium epithelial cells (PECs). The inhibitory effect of RA on the cytotoxicity of the PECs was determined by the MTT reduction assay. Intracellular ROS (reactive oxygen species) levels were measured using a fluorescent probe, DCFH-DA (2’,7’-dichlorofluorescin diacetate). The levels of superoxide dismutase (SOD) and catalase (CAT) were measured as indexes of antioxidant activities. Western blot analysis was used to determine the protein expression of Nrf2, HO-1, NQO1 and apoptosis associated proteins. RA significantly reduced the cell viability of the PECs. Treatment with RA could remarkably increase the Nrf2 protein expression levels in nucleus, HO-1 and NQO1 protein expression levels, and activities of SOD and CAT. As the result, intracellular ROS levels in PECs were decreased. In addition, the induction of extrinsic apoptosis on PECs by RA was also associated with the increasing of Fas, FADD, TNF-α and caspase 8 protein expression levels. Moreover, the induction of PECs intrinsic apoptosis cell death through up-regulation of cytochrome c, Bax and caspase 9, down-regulation of Bcl-2 and inactivation of pro-caspase 3. Our study demonstrated that RA could inhibit the viability of the PECs via regulation the extrinsic and intrinsic apoptosis pathway. Therefore, RA may have potential for pterygium therapeutic medication.

Biography:

Amila Sampath Chandrasekera has completed the certificate of ophthalmic assistance in 2011 and completed diploma in optometry in 2015 form academy of Vision Care Optical Services Sri Lanka. He has presented oral and poster presentations in academic and international level poster and won the second place for best poster award in International conference in Clinical and Experimental Ophthalmology 2015. Currently, he is practicing at the retinal and glaucoma diagnostic unit at Vision Care Optical Services PVT LTD head office Sri Lanka.

Abstract:

Aim: Objective of this study is to find the effect of off-the-visual axis retinoscopy on objective refractive measurement in routine clinical practice.

Material & Methods: Study was based on 450 subjects, with age range – 15-30 years; male were 225 and female were 225, and the study was conducted from 01.03.2015-25.4.2016; 150 myopes>(-3.00Ds/-1.00dc), 150 hyperopes > (+3.00Ds/-1.00dc), 150 emmetopes were selected for the study. Spherical refractive error +/- 3.00Ds and cylindrical error - 1.00Dc and the subjects with ocular pathology and strabismus are excluded. Retinoscopy was carried out in +/- 0.12 steps on visual axis (0 degrees) and at 5⁰,10⁰,15⁰,20⁰ off the visual axis. Targets were selected from snellen chart and presented isolated optotpes are of 6/60 letter size and the letters are attached to a mirrored wall at different eccentricities at a distance of 3 meters from the subject.

Results: Mean cylindrical error on off-the-visual-axis alignment was -0.32D,-0.40D,-0.51D,-0.72D at 5⁰,10⁰,15⁰, 20⁰ of eccentricity respectively which is statistically significant (p= 0.001).Group wise comparisons for mean cylindrical change in emmetropes and hyperopes statistically significant for different eccentricities from the visual axis with P value of 0.001, 0.003 & 0.367respectively. The mean spherical equivalent refractive error is -0.46,-0.55,-0.64,-0.56,-0.68 at 0, 5, 10, 15 and 20 degrees respectively and not statistical significant with p value of 0.98.

Conclusion: Off the axis refractions, even at small degrees of eccentricities resulted in significant errors in refractions.

Biography:

Amila Sampath Chandrasekera has completed the Certificate of Ophthalmic Assistance in 2011 and has done his Diploma in Optometry in 2015 form Academy of Vision Care Optical Services Sri Lanka. He has presented oral and poster presentations in Academic and international level poster presentation and has won the second place for Best Poster Award in International conference on Clinical and Experimental Ophthalmology 2015. Currently, he is practicing at the Retinal and Glaucoma Diagnostic Unit at Vision Care Optical Services Pvt. Ltd., Sri Lanka.

Abstract:

Objectives: To determine the relationship between macula pigment optical density and visual performances (foveal sensitivity, contrast sensitivity, visual acuity and color vision) in patients with drusen maculopathy. To determine the relationship between MPOD and drusen maculopathy and to evaluate the awareness of patients according the condition.

Materials: Descriptive cross sectional study was done with 1500 patients with age ranging from 40-50 for duration of 14 months. Data was recorded by carrying out a questionnaire including demographic profile, visual acuity, foveal sensitivity- Humphrey field analyzer, contrast sensitivity- LEA contrast acuity chart, color vision- Ishiharas’ test, Thickness of macula and presence of drusen measured by Cirrus 4000 spectral domain optical coherence tomography and macula pigment optical density by Zeiss Visucam 500.

Methods: AMD was graded to 3 stages by the presence of 15 or more macular drusen >63 μm and all were again divided in to 3 sub-groups according to MPOD levels.

Results: Mean MPOD levels in 1600 subjects; Stage-1 mean MPOD- 0.41, Stage-2 -0.31 and Stage-3 -0.17. Mean foveal sensitivity was low range-MPOD group =11dB (p=0.0013), mid-range=16dB (p=0.0019) and high-range=26dB (p=0.0041). Mean contrast sensitivity was low-range=25% (p=0.0003), mid-range=5% (p=0.0042) and high-range=2.5% (p=0.0048). Mean stereo acuity was low-range=nil, mid-range=480sec of arc (p=0.0005) and high-range=120 sec of arc (p=0.0012). Color vision was low-range=2/24 plates (defected) (p=0.02), mid-range=20/24 plates (excluding vanishing plates) (p=0.082) and high-range=24/24 plates (p=0.0041). Visual acuity was low-range=6/36^+/-2(p=0.021), mid-range=6/18^+/-2(p=0.032) and high-range=6/9^+/2(p=0.048). Patients awareness score was 7/7=10pt, 7/6=0pt, 7/5=12pt, 7/4=8pt, 7/3=15pt, 7/2=16pt, 7/1=34pt and 7/0=1105pt.

Conclusion: People aged 40-65 drusen maculopathy was found with a significant relationship of decreasing macula pigments (lowering MPOD values), as a result of it they are at a considerable risk of decreasing visual performances. 

Biography:

Monika Czaińska is an Optometrist and a PhD candidate from Adam Mickiewicz University in Poznań, Poland. She is interested in Binocular Vision, Vision Therapy and motor deficits in subjects with Binocular Disorders.

Abstract:

Introduction & Aim: Interocular suppression is a common visual disorder in anisometropic and strabismic patients, however still little is known about the neuronal mechanisms of this disorder. The aim of the study was to explore cortical activation in subjects with interocular suppression related to strabismus.

Method: In this study, 24 young subjects with corrected refractive errors were examined: 12 subjects with normal visual acuity and stereopsis (GN) and 12 subjects with strabismus (with strong interocular suppression and stereoblind) (GS). Cortical activity was measured with 64 active channels (QuickAmp128). Reversed checkerboard patterns (box size 15’) were presented with a frequency of 0.79 Hz. Three different visual conditions: Dominant eye (DE), non-dominant eye (NDE) and both eyes (BE) were tested in two groups: GN vs. GS. To examine mechanism of interocular cortical event-related potentials (ERPs) were analyzed.

Results & Conclusions: Subjects with strabismus presented lower cortical activity compared to normal (smaller amplitudes of ERPs) in the area of extrastriate cortex (components P1, P2), both during binocular viewing and monocular one. It may prove a general intercortical inhibition in strabismic subjects. In strabismus, P2 component was marginal, what may suggest visual-processing deficits in the neural way between primary visual cortex and higher regions of brain. It can also imply weaker representation of objects and shapes in visual memory.

Biography:

Monika Wojtczak-Kwaśniewska is a PhD candidate from Adam Mickiewicz University of Poznań, Poland. She is interested in neuronal aspects of Binocular Vision, especially the Eye Movements. She is an Optometrist and a Vision Therapist

Abstract:

Eye movements may be elicited reflexively by stimuli appearing in visual periphery, and voluntarily by endogenous cognitive control processes. Although the neural circuits of saccades are well understood, it is still difficult to identify clearly the differences between reflexive and volitional vergences. The aim of this study was to increase our understanding of volitional eye movement preparation by measuring cortical activation related to different two types of pure saccades and pure vergences. Nine LEDs were located at eye level on three isovergent circles at near (20 cm) middle (35cm) and at far (1 m) distance. The eccentricity of the lateral LEDs was 10º for all distances. The subject was instructed to look at the target LED in accordance with the indication (color of the middle LED) as quickly and precisely as possible. The electroencephalogram was registered from 64 active electrodes (brain products). The differences between vergences and saccades were observed 120 ms before the eye movement. Both, convergence and divergence evoked significantly more positive ERP than saccade on C1/C2 channels. Moreover, on the frontal lateral areas (F7/F8) registered potential associated with convergence was more negative than for saccade. On temporo-parietal region (TP7/TP8) ERP was in turn, more negative for saccade than for convergence.

Just before the eye movement ERP for saccade was also more negative than for vergences on temporo-parietal areas, whereas divergence was more negative than saccade on the frontal area (AF3/4, AF7/8, F1/F2, F3/F4 and F7/F8). The obtained results suggest that preparation of different types of volitional eye movements is characterized by different neural circuitries, where vergences, particularly divergence caused strong response of frontal areas, whereas saccade engaged central, temporo-parietal and parieto-occipital areas.

Biography:

Maitreyee Roy is a Senior Lecturer and a Deputy Director of Optics & Radiometry Laboratory at the School of Optometry and Vision Science, University of New South Wales, Australia. She was awarded her PhD in Physical Optics from School of Physics at the University of Sydney. She is an accomplished Optical Physicist with broad experience in government and academic institutions with strong R&D background particularly in optical metrology, 3D optical imaging and nano-particle metrology. One of her major contributions was to demonstrate the fundamental principle of geometric phase in optics and its achromatic nature, which has opened up new insights in to broadband interferometry with application ranging from biological systems, electronics to astronomy. 

Abstract:

Purpose: Holographic refraction is a quick and accurate way to measure spherical refractive error of the human eye. However, holograms use coherent illumination, and how this lighting interacts with vision during subjective measurements is still poorly understood. The purpose of this study is to evaluate the accommodation of young subjects while looking at multiple diverging targets (MVT) in a hologram.

Method: Healthy subjects (n=31) with spherical refractive-error were asked to look into the holographic MVT and report the clearest characters as well as nearest target that is just recognizable. These are a measure of the eye’s refractive state and the amplitude of accommodation, respectively. Subjects were separated into younger (mean=22 years, SD=7) and older (mean=54 years, SD=8) age groups, and the amplitude of accommodation measured with the hologram was subjected to a Student t-test to determine whether there was a difference in accommodation between the two age groups. The refractive state of the eye measured with the hologram was compared to conventional spherical subjective refraction using a paired t-test and Bland-Altman’s method.

Results: Accommodation was found to be similar between the younger group (mean=1.75 D, SD=1.34 D) and older age group (mean=1.72 D, SD=1.40 D) with the mean difference of 0.02 D being non-significant (p=.97). Subjects were also found to have an average lead of accommodation of 0.68 D (SD=0.76 D) when looking at the holographic MVT. When using the hologram to measure refractive state of the eye, the 95% level of agreement between the holographic method and conventional method was found to be from -0.75 D to 2.11 D.

Conclusions: When attempting to measure subjects’ amplitude of accommodation using the hologram, the hologram appears to inhibit accommodation resulting in the reduced ability to recognize near characters. When given ample time to observe the holographic MVT to measure the refractive state of the eye, most subjects exhibited a slight lead of accommodation, resulting in poor agreement with conventional methods.