V.A. Shah

TTO utility scores measure quality of life in patients with visual morbidity due to diabetic retinopathy or ARMD

PURPOSE To evaluate the utility scores in patients with varying degrees of visual morbidity due to diabetic retinopathy or ARMD. METHODS Patients with vision =20/40 in one eye due to diabetic retinopathy or ARMD were enrolled. Utility scores were measured by the time trade-off (TTO) method after stratifying the patient population with visual impairment in the better eye (group 1, 20/20 to 20/40; group 2, 20/50 to 20/100; group 3, 20/200 to no light perception). RESULTS Sub-group analysis revealed that subjects in group 1 were willing to give up a median of 1 year as compared to 3 years by the subjects in group 3 for perfect bilateral visual acuity (P < 0.05). The median utility score was 0.94 for group 1, 0.96 for group 2 and 0.80 for group 3. While the utility scores for groups 1 and 2 were comparable (P > 0.05), there was a significant difference in the utility scores between groups 1 and 3 and between groups 2 and 3 (P < 0.05). There was no significant effect on the utility scores of age, educational level or prior ocular surgery. CONCLUSION Substantial visual loss secondary to diabetic retinopathy or ARMD is associated with a significant decrease in utility scores. However, TTO scores were not sensitive enough to demonstrate a difference between subjects with mild (group 1) and moderate (group 2) visual loss in the better eye secondary to diabetic retinopathy or ARMD.

Management of vitreous loss during cataract surgery under topical anesthesia with transconjunctival vitrectomy system.

Purpose A new technique to manage posterior capsular rupture with vitreous prolapse into the anterior chamber during phacoemulsification under topical anesthesia using the sutureless self-sealing 25-gauge transconjuctival vitrectomy system. Method In the event of vitreous prolapse into the anterior chamber, the corneal wound is sutured and cleared of vitreous. A trans conjunctival 25-gauge sclerotomy through the pars plana is made. The high speed 25-guage trans-conjunctival vitrectomy system (TVS-25) under topical anesthesia is introduced and vitrectomy is performed to clear the anterior chamber of vitreous. An anterior vitrectomy is also done. A foldable intraocular lens is subsequently inserted. Results The vitrectomy is performed in a closed chamber maintaining normal intraocular pressure. The high-speed cutter exerts minimal traction on the vitreous. The accessibility to vitreous improves through the pars plana route ensuring more complete removal of the vitreous and restoration of normal anatomy. Topical anesthesia avoids the risks of globe perforation, retrobulbar hemorrhage, and prolonged postoperative akinesia of the eye. Conclusions The 25-gauge pars plana incision is small and self-sealing. This makes the procedure fast, effective, painless and safe.

Intravitreal Dexamethasone Effectively Reduces Postoperative Inflammation After Vitreoretinal Surgery

BACKGROUND AND OBJECTIVE Corticosteroids remain the mainstay for control of ocular inflammation after vitreous surgery. A controlled, randomized, prospective study was performed to evaluate the effectiveness of a single intravitreal injection of dexamethasone phosphate on postoperative inflammation after simple vitreous surgery in patients with proliferative diabetic retinopathy and macular pucker. PATIENTS AND METHODS Aqueous cell flare intensity was measured preoperatively and on days 1, 10, and 90 in 56 consecutive patients who underwent vitreous surgery for proliferative diabetic retinopathy and macular pucker. Subjects were consecutively randomized to two groups: 400 microg of intravitreal dexamethasone (treatment group) or no dexamethasone (control group) RESULTS Before surgery, cell and flare intensity was similar in both groups. Flare intensity was significandy lower at 10, 30, and 90 days in the proliferative diabetic retinopathy treatment group (P < .05). CONCLUSION Intravitreal dexamethasone significantly alleviates postoperative inflammation after vitreous surgery and is a useful adjunct.

Self-stabilizing wide-angle contact lens for vitreous surgery.

Purpose To describe a new self-stabilizing modification for the wide-angle contact lens for vitreoretinal surgery. Design A standard wide-angle contact lens with the radius of curvature of 7.7 mm is modified with addition of four footplates to facilitate stability and centration. Method A drop of viscoelastic material is placed between the lens and the cornea. This induces negative suction, which helps to retain the lens in position and allows dynamic viewing of the retina. Conclusion This specially designed lens reduces the need for a skilled assistant to stabilize the contact lens. It provides a stable, well-centered view of the peripheral fundus during vitreous surgery.

Small-gauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification.

This technique manages vitreous prolapse associated with posterior capsule rupture during phacoemulsification by performing small-gauge pars plana vitrectomy with a sutureless, self-sealing incision performed in a closed chamber, maintaining normal intraocular pressure. A high-speed cutter exerts minimal traction on the vitreous. Accessibility to the vitreous through the pars plana is better, ensuring more complete removal of the vitreous and restoration of normal anatomy.

Newly designed self-retaining contact lens for vitreous surgery

PURPOSE Development of a new self-retaining acrylic contact lens for vitreous surgery. DESIGN A standard -60 diopters plano concave lens with the radius of curvature 6.7 mm (less than the cornea curvature) was modified with addition of four foot plates to facilitate stability and centration. METHODS A drop of viscoelastic material placed between lens and cornea induces negative suction and helps retain the lens in position. CONCLUSIONS This specially designed lens eliminates the need for suturing on the sclera or dependence on the assistant to provide placement. It provides a stable well-centered view of the fundus during vitreous surgery.

Suction-Assisted One-Piece Self-Retaining Wide-Angle Contact Lens for Vitrectomy

Introduction: We have developed a suction-assisted one-piece self-retaining wide-angle contact lens for vitrectomy. Design: The wide-angle contact lens is a one-piece lens without the case, making it lightweight. The contact inferior surface is enhanced by four quadrant plate extensions. A metal housing is attached to the side of the plate extension with an opening at the inferior surface. A negative suction device is attached to the housing of the lens. Method of Use: A drop of viscoelastic is placed between the lens and the cornea. Suction created by a syringe device holds the contact lens on the cornea. Conclusion: This specially designed lens is lightweight and eliminates the need for a skilled assistant to stabilize the contact lens. It provides a stable well-centered view of the peripheral fundus during vitreous surgery.

Evaluation of web-based annotation of ophthalmic images for multicentric clinical trials

An Internet browser-based annotation system can be used to identify and describe features in digitalized retinal images, in multicentric clinical trials, in real time. In this web-based annotation system, the user employs a mouse to draw and create annotations on a transparent layer, that encapsulates the observations and interpretations of a specific image. Multiple annotation layers may be overlaid on a single image. These layers may correspond to annotations by different users on the same image or annotations of a temporal sequence of images of a disease process, over a period of time. In addition, geometrical properties of annotated figures may be computed and measured. The annotations are stored in a central repository database on a server, which can be retrieved by multiple users in real time. This system facilitates objective evaluation of digital images and comparison of double-blind readings of digital photographs, with an identifiable audit trail. Annotation of ophthalmic images allowed clinically feasible and useful interpretation to track properties of an area of fundus pathology. This provided an objective method to monitor properties of pathologies over time, an essential component of multicentric clinical trials. The annotation system also allowed users to view stereoscopic images that are stereo pairs. This web-based annotation system is useful and valuable in monitoring patient care, in multicentric clinical trials, telemedicine, teaching and routine clinical settings.

Two-Piece, Dual-Purpose Comprehensive Contact Lens for Vitreous Surgery

Purpose: To describe a dual-purpose lens that can be used both as a planoconcave direct-image lens and wide-angle lens. This lens provides good resolution, is autoclavable and self-stabilizing. Design: New instrument design. Method: This lens has two components (lenses): the inferior element is a modification of the standard, self-stabilizing planoconcave, one-piece acrylic lens with 4 footplates and is used in a similar manner; the superior part is a biconvex glass lens in a high-temperature-resistant plastic casing. The superior plastic casing is screwed on the inferior lens to convert it into a wide-angle lens. The lens is used as a self-stabilizing, planoconcave or wide-angle lens and is sterilized by autoclaving. Result: The planoconcave direct-image inferior lens gives a high-resolution image with a field of view of 20°. The wide-angle lens on assembly of the inferior and superior parts gives a static field of view of 80° and a dynamic field of view of 98°. Conclusion: The two-piece dual-purpose contact lens is an inexpensive substitute for both planoconcave and traditional wide-angle lens without compromising the stability and quality of the fundus image.

Liquid Crystal Display Microperimetry in Idiopathic Subretinal Fibrosis

A 46-year-old woman presented with a history of decreased vision. On examination, best-corrected visual acuity was 20/30 in both eyes. Fundus evaluation of the right eye revealed subretinal fibrosis of the macula involving the fovea. The fundus of the left eye was normal. Fluorescein angiography confirmed the diagnosis. At 10 months of follow-up, the patient was asymptomatic and the visual acuity was stable at 20/25 in both eyes. Liquid crystal display microperimetry showed comparable retinal sensitivity in both eyes (P> .05). However, the right eye revealed unstable fixation compared to the left eye. Idiopathic subretinal fibrosis should be considered in the differential diagnosis of patients with subretinal fibrosis. Liquid crystal display microperimetry is a useful tool in evaluating these patients.