Wide angle viewing field systems in vr surgery

Surgical retina

1. Wide Angle Viewing Field Systems in VR Surgery Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

2. Vitreous Surgery requires the help of Special devices to clearly visualize the Retina and Vitreous. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

3. 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

4. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

5. 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

6. Hands Free Contact Lens (Landers System) OLIV-WF Hands 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 surgery Too loose- decentration of lens Bleeding can obscure view of surgeon. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

7. Plano concave lens – core vitrectomy Landers 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 portion Tolentino 20 degree prism – periphery Tolentino 30 degree prism – extreme periphery Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

8. 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

9. Conventional Viewing System Advantages: 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

10. OPTICS OF CONVENTIONAL VITREOUS SURGERY A 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

11. Principle of Indirect Ophthalmoscopy To make the eye highly Myopic by placing a strong Convex lens in front of it. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

12. Wide Angle Viewing Systems Contact 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

13. Wide Angle Viewing Systems Contact Non Contact Advantages Image 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 Disadvantages Poor view in case of corneal or lens opacity/ haze Poorer image resolution and depth perception Chance of corneal deformation Learning curve - more Change in IOP Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

14. 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

15. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

16. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

17. Optics in Air Filled Eye Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

18. Posterior surface of the lens becomes strongly refractive (64 D) Total refractive power of the eye increases from 59 to 102 D Field of View is 130 deg. Microscope eye piece should be moved closer to Patients eyes. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

19. 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

20. Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

21. 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

22. 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

23. OFFISS- Topcon OMS-800 Optical fibre free Intravitreal Surgery system Incorporated illumination , No need of Light probe Can 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

24. EIBOS Erected Image Binocular microscope Incorporates 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

25. Resight 700 from Carl Zeiss Can 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

26. 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

27. Vitreous Panfundoscope Modified Rodenstock panfundoscope Field of view = 130 – 150 deg Need 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

28. Contact Wide field lenses Inverted image , Need of SDI Field of View = 120-130 degree Held by handle or Standard lens ring Lighter and smaller than VPFL Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal

29. Advanced Visual Instrument System AVI stereo inverter 2 miniature contact lenses 68 and 130 degree field of views Hand 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

30. Reinverting Operating Lens System Single element reinverter prism design to correct the inverted image. Super Macula lens -60 deg Mini Quad lenses -127 deg Mini Quad XL lenses – 134 deg Dyna – 156 deg Dr Rajvin Samuel Ponraj Fellowship Sankara Eye Hospital Pammal