Wide angle viewing field systems in vr surgery
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Transcript of Wide angle viewing field systems in vr surgery
Wide Angle Viewing Field Systems in VR Surgery
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Vitreous Surgery requires the help of Special devices to clearly visualize the Retina and Vitreous.
Contact Type :VPFS ( Vitreous Panfundoscope)CWF (Contact wide field System)AVIS (Advanced Visual Instrument system)ROLS (Reinverting Operating lens system) - Clarivit - HRX (Volk Optical)Non Contact Type : - BIOM (Binocular IDO) – (Oculus) - MERLIN –(Volk Optical ) - EIBOS (Erect Indirect Binocular IDO)- - OFFISS (TOPCON) - RESIGHT (Carl Zeiss) - Peyman –
Wessels- Landers Dr Rajvin Samuel Ponraj Fellowship
Sankara Eye Hospital Pammal
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Hand Held Irrigating Contact lenses Neutralize High Convergence of Corneal
Curvature to focus on Retina , Vitreous. 3 types of Lenses: - Plano concave lenses with a view of 20
degrees- Biconcave lenses with view of 30 degrees- Prism lenses with meridonial view of 60
degrees
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Hands Free Contact Lens (Landers System) OLIV-WFHands free contact lenses were introduced
by Landers and co workers which were stabilized onto the cornea with the help of a sewn-on limbal ring (stainless steel )
Too tight – corneal folds,break suture midway of surgeryToo loose- decentration of lensBleeding can obscure view of surgeon.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Plano concave lens – core vitrectomyLanders biconcave lens – visualization in air
filled eye (90 D Lens – 25 deg angle field)Machemers magnifying lens – surface
details on posterior pole (28-30 deg angle field)
Peyman wide field lens –equatorial portionTolentino 20 degree prism – peripheryTolentino 30 degree prism – extreme
periphery
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Disadvantages: - Limited field of view - Peripheral Retina seen only with
Indentation - Lens alignment problems -Air Bubble/ Blood film coming beneath Lens
System -Poor visualization in Small pupils and Fluid –
gas exchange
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Conventional Viewing SystemAdvantages: Lower Cost Non – Inverted Image Less learning curve for Surgeon Excellent resolution
Disadvantages : View compromised with Corneal opacity,
Lenticular haze and Small pupils.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
OPTICS OF CONVENTIONAL VITREOUS SURGERYA Plano-concave contact lens made of polymethylmethacrylate Refractive index of 1.488 and a concave
posterior surface radius of curvature of 7.7 mm is used
Refractive power of the anterior surface 48.8 D to -14.5 D and the fundus is easily
visualized
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Principle of Indirect OphthalmoscopyTo make the eye highly Myopic by placing a
strong Convex lens in front of it.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Wide Angle Viewing SystemsContact and Non Contact - Both provide Panaromic View up to Ora
serrata and enhances the safety and efficiency of Surgery
- Problems of High Cost - Inverted image is unsuitable - Bulky and long learning Curve - Distortion of Anatomy interferes with
Quality of Fundus image.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Wide Angle Viewing SystemsContact Non ContactAdvantagesImage resolution and stereopsis better
No intraoperative Corneal trauma
Eliminates corneal aberrations & limits the number of reflecting surfaces
Good view during Fluid air exchange
Wider field of view- Less need of Ocular rotation
Good view - small pupils and irregular corneas
DisadvantagesPoor view in case of corneal or lens opacity/ haze
Poorer image resolution and depth perception
Chance of corneal deformation Learning curve - moreChange in IOP
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
OPTICS OF CONVENTIONAL CONTACT LENSES The first component (inferior lens) –acrylic
contact lens concave posterior surface. Power of 4 D.
The second component (superior lens) -biconvex aspherical image-forming, high refractive index glass lens 0.5 mm anterior of the contact lens element and an effective
power of 150 D in air.
Real, inverted, aerial retinal image anterior to the image forming lens system.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Optics in Air Filled Eye
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Posterior surface of the lens becomes strongly refractive
(64 D) Total refractive power of the eye increases
from 59 to 102 DField of View is 130 deg.Microscope eye piece should be moved
closer to Patients eyes.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Oculus BIOM & SDI-Stereoscopic Diagonal Inverter.
Requires SDI to invert the indirect image from BIOM to a conventional upright image (Internalised Prismatic system Foot pedalled & Automatic ) (Near Zero Light Escape) Easily adaptable to microscopes, sterilised easily Field of view = 70, 90, 110
degrees
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Peyman-Wessels-Landers 132 D Upright Vitrectomy Lens
Wide field Upright images without invertor (Internalised prisms).
Operating Table mounted system ,Can be attached to any microscope
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
The OSVS-U132-2 is a non-contact vitrectomy lens system designed with a flexible arm for positioning wide-angle lenses, which easily swings in and out of the surgical field. The OSVS (clamps) attaches to the wrist rest or surgical bed, freeing the surgeon and assistant to perform tasks other than holding the lens. When used with the Ocular Peyman-Wessels-Landers 132 Diopter Upright Vitrectomy Lens (OUV-132-2), the system allows the surgeon to work in the vitreous with an upright, non-reversed image under panoramic viewing conditions
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
OFFISS- Topcon OMS-800Optical fibre free Intravitreal Surgery systemIncorporated illumination , No need of Light
probeCan perform Bimanual surgical techniques.Working distance is more ,hence less chance
of lens touching cornea.Higher cost as the whole system including the
microscope must be bought.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
EIBOS Erected Image Binocular microscopeIncorporates Inverter and indirect systems in one piece. Inverter cannot be used independently.Incorporates Spring balanced safety – elevation of the Unit if Lens comes in contact with the eye.Field of View = 100,125 degrees.90,132 D Lenses
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Resight 700 from Carl ZeissCan hold two lenses simultaneosuly - 127 deg lens for Wide Angle field - 60 deg lens for High resolution Macular
lens
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Contact Types VPFS ( Vitreous Panfundoscope)CWF (Contact wide field System)AVIS (Advanced Visual Instrument system)ROLS (Reinverting Operating lens system)
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Vitreous PanfundoscopeModified Rodenstock panfundoscopeField of view = 130 – 150 degNeed of SDI. Inverted image.Easy introduction of instruments without
disturbing lens.Hand held stabilized and heavy compared
to other lenses.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Contact Wide field lensesInverted image , Need of SDIField of View = 120-130 degreeHeld by handle or Standard lens ringLighter and smaller than VPFL
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Advanced Visual Instrument SystemAVI stereo inverter2 miniature contact lenses
68 and 130 degree field of viewsHand held by assistant or self retaining
ring
Smaller,lighter, allows easy manipulation of lens
Allows visualization of fundus through small pupil or air filled eye.
Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal
Reinverting Operating Lens System
Single element reinverter prism design to correct the inverted image.
Super Macula lens -60 degMini Quad lenses -127 degMini Quad XL lenses – 134 degDyna – 156 deg