Wide-field Contact Research Articles

A Useful Method for the Practice of Pneumatic Retinopexy: Slit-Lamp Laser Photocoagulation through the Gas Bubble.

This study aimed to demonstrate the laser retinopexy method through the gas bubble under a slit-lamp biomicroscope using a wide-field contact lens to treat rhegmatogenous retinal detachment (RRD) with pneumatic retinopexy (PR) and report its anatomical and functional results. This single-center, retrospective case series included RRD patients treated with PR using sulfur hexafluoride (SF6). The demographics, preoperative factors, and anatomical and functional outcomes were collected from the patient files. The single-procedure success rate of PR at postoperative 6th months was 70.8% (17/24 eyes), and the final success rate after secondary surgeries was 100%. The BCVA was better in the successful PR eyes at postoperative 3rd (p = 0.011) and 6th month (p = 0.016) than in failed eyes. No single preoperative factor was associated with PR success. The single-procedure success rate of PR using the laser retinopexy method through the gas bubble with a wide-field contact lens system seems comparable to the PR literature.

Imaging the pediatric retina: An overview.

Recent decade has seen a shift in the causes of childhood blinding diseases from anterior segment to retinal disease in both developed and developing countries. The common retinal disorders are retinopathy of prematurity and vitreoretinal infections in neonates, congenital anomalies in infants, and vascular retinopathies including type 1 diabetes, tumors, and inherited retinal diseases in children (up to 12 years). Retinal imaging helps in diagnosis, management, follow up and prognostication in all these disorders. These imaging modalities include fundus photography, fluorescein angiography, ultrasonography, retinal vascular and structural studies, and electrodiagnosis. Over the decades there has been tremendous advances both in design (compact, multifunctional, tele-consult capable) and technology (wide- and ultra-wide field and noninvasive retinal angiography). These new advances have application in most of the pediatric retinal diseases though at most times the designs of new devices have remained confined to use in adults. Poor patient cooperation and insufficient attention span in children demand careful crafting of the devices. The newer attempts of hand-held retinal diagnostic devices are welcome additions in this direction. While much has been done, there is still much to do in the coming years. One of the compelling and immediate needs is the pediatric version of optical coherence tomography angiography. These needs and demands would increase many folds in future. A sound policy could be the simultaneous development of adult and pediatric version of all ophthalmic diagnostic devices, coupled with capacity building of trained medical personnel.

Suitability of Different Observational Lenses for Viewing the Macular Area Through Multifocal Intraocular Lenses in a Model of the Human Eye.

PurposeMultifocal intraocular lenses (IOLs) can potentially affect the intraoperative view of the retina. We investigated the suitability of different lenses for viewing the macular area through two multifocal intraocular lenses in a human eye model.MethodsThis study compared the image quality of graduated index (0.1 mm) in a model eye when viewed through refractive or diffractive multifocal IOLs with a meniscus or flat contact lens, and a wide field 60 diopter non-contact lens or wide field contact lens (Super Macula®).ResultsImages acquired through the meniscus contact lens or flat contact lens via the central optical zone of the refractive multifocal IOL or the diffractive multifocal IOL were well focused. However, images viewed through these lenses near the center were warped and out of focus. All images viewed through a wide-field 60 diopter non-contact lens at the central optical zone and near the center were slightly out of focus. All images viewed through the Super Macula at the central optical zone and near the center were well focused.ConclusionA wide field contact lens (Super Macula®) made it possible to obtain clear images of the macular area at multiple focal points through refractive or diffractive multifocal IOLs.

Wide-Field Imaging with NAVILAS Laser System

Purpose: to study the potential of wide-field imaging with NAVILAS laser system.Material and methods. In this study we included patients diagnosed with indirect ophthalmoscopy as having one of the follows: diabetic retinopathy (6 eyes), central retinal vein occlusion (5 eyes), choroidal melanoma (3 eyes), rhegmatogenous retinal detachment (4 eyes), and peripheral chorioretinal degeneration (10 eyes). Using NAVILAS 532 laser system and a wide-field contact lens (HR Wide Field (VOLK)) a wide-field central image and a panoramic (consisted of 4 to 6 images) images were obtained in all patients. Fundus images were evaluated according to their diagnostic value versus indirect ophthalmoscopy and wideness of the viewing angle versus standard color fundus photography (55°). In each patient within a single session were obtained: 1) a central fundus image and 2) panoramic image (4-field and in dynamic mode). In a subgroup of patients with central retinal vein occlusion and lattice retinal degeneration, we studied the ability of simultaneous laser photocoagulation wide-field imaging.Results. A single field images obtained with NAVILAS allows to visualize up to 130.3 ± 9.6° of the eye fundus while four-field and dynamic acquisition up to 150.1 ± 8.9° and 171.3 ± 17.0°, respectively. Representative findings of diabetic retinopathy, central retinal vein occlusion, choroidal melanoma, rhegmatogenous retinal detachment, and peripheral lattice degeneration were identified in all cases. Insufficient visualization was found for “snail track” degeneration because the subtle retina and choroid changes were hardly seen on the low magnified image. In 4 patients with lattice retinal degeneration and 3 patients with central retinal vein occlusion within a single session, both wide-field imaging and laser photocoagulation were performed. Surgical goals were achieved in all cases.Conclusion. Wide-field imaging with NAVILAS laser system demonstrated high potential in the documentation of the most widely spread eye fundus disease the and represents an adequate alternative for wide-field fundus cameras. Aside from wide-field imaging this approach also allows for simultaneous laser photocoagulation in entire eye fundus including far peripheral retina.

Panoramic view of human corneal endothelial cell layer observed by a prototype slit-scanning wide-field contact specular microscope

PurposeTo observe the most peripheral region of the corneal endothelial cell (CEC) layer as long as optically recordable by use of a prototype slit-scanning wide-field contact specular microscope and produce...

Digitalization of a Wide Field Contact Specular Microscope

Objectives: Non-contact specular microscopes (SM) have a very small field of observation (usually 0.1 mm2). This constitutes a major limitation when accurate and extended assessment of the corneal endothelium is needed, for instance during clinical trials or difficult diagnosis. Previous contact SM had the advantage of a wide field thanks to the use of an applanating cone but none of the old commercial devices passed the stage of digitalization. This paper aims at upgrading a wide field contact SM with a digital camera and dedicated software in order to combine wide field with the advantages of non-contact SM.Materials and methods: The digital device was composed of an acquisition unit consisting in a contact Konan Specular SP5500 equipped with a digital camera Canon EOS 6D and a Linux-based computer. Image processing uses segmentation algorithms (Gestalt theory and watershed with markers).Results: The device acquired wide field (0.5 mm2) highly contrasted images. The software provided cell boundaries and statistics: endothelial cell density, coefficient of variation of cell area and percentage of hexagonality. Contact SM images significantly increased the sampling of endothelial cells and consequently the reliability of endothelial quality analysis.Conclusion: The digital contact SM is not destined to compete with commercial non-contact SM but is an exceptional device for reference centers. It will allow obtaining accurate and reproducible endothelial qualification for specific studies.

Upgrading wide field contact specular microscope

PurposeNon‐contact specular microscopes (SM) developed 25 years ago highly facilitated image acquisition while eliminating contaminations risk. Nevertheless their very small field of observation (SM Topcon SP2000: 0.1 mm2) constitute major limitations for the assessment corneas.AimTo upgrade a wide field contact SM with a digital camera and dedicated software.MethodsThe original camera film was replaced by a digital camera (Canon EOS 6D with full‐frame 35 mm sensor) connected to a computer. The new camera was fixed on the SM (Konan SP5500, ×40 zoom) with 3D print custom adaptor and uses its optics. After acquisition of wide field images (0.6 mm2), they were processed using a segmentation algorithm (watershed with markers method). Software, using several libraries (ITK, OpenCV, Qt, MySQL), has been developed allowing the acquisition of images (camera control), image processing, and storage of results in a database.ResultsA segmented image showing only cell borders in black over white background and document which presents ECD number (1000 cells counted) and cell's characteristics showing quality of cells (regarding their size). Stored in a database, these results are available for operators.ConclusionsThe upgraded wide field contact SM counts a great number of cells. Consequently, it estimates the ECD with less bias than other methods. Also, it can be used for the assessment of heterogeneous endothelium like in Fuchs corneal endothelial diseases for which noncontact SM are obviously unsuited. GRANT: ANR 2012 CORIMMO project.

Miniaturized high-resolution wide-field contact lens for panretinal photocoagulation.

Background and objectiveWe describe a miniaturized lightweight high-refractive-index panretinal contact lens for diagnostic and therapeutic visualization of the peripheral retina.Instrument designThe miniaturized high-resolution wide-field contact lens includes three optical elements in a light (15 g) and miniaturized (16 mm footplate, 24 mm external aperture, and 21 mm vertical height) casing contributing to a total dioptric power of +171 diopters. This lens provides up to 165° visualization of the retina for diagnostic and therapeutic applications while allowing easier placement due to its miniaturization.ConclusionThis new lens (50% lighter and 89% smaller) improves upon earlier contact lenses for visualization of the peripheral retina.

Experience Using the Heidelberg Retina Angiograph 2 with a Wide-Field Contact Lens System in Diabetic Retinopathy Cases

Introduction:HRA (Heiderberg Retina Angiograph) 2 uses a confocal scanning laser system which can provide high quality digital images but its imaging field is only 30°at most. HRA2 with a wide-field contact lens system allows an imaging field of up to 150°.Methods:We examined the advantages and disadvantages of HRA2, with a wide-field contact lens, for the evaluating diabetic retinopathy (DR).Results:HRA2 was beneficial for obtaining images of the entire retina simultaneously, without missing peripheral retinal non-perfusion and neovascularization. On the other hand, clear images connot be acquired in cases with media opacities such as corneal dystrophy, cataract and asteroid hyalosis, or in those with yellow tinted IOL.Conclusions:HRA2 with a wide-field contact lens is useful for visualizing peripheral retinal lesions in DR cases.

Quality of Image of Grating Target Placed in Model of Human Eye With Corneal Aberrations as Observed Through Multifocal Intraocular Lenses

To evaluate the quality of the image of a grating target placed in a model eye viewed through multifocal intraocular lenses (IOLs). Laboratory investigation. Refractive (NXG1 or PY60MV) or diffractive (ZM900 or SA60D3) multifocal IOLs were placed in a fluid-filled model eye with human corneal aberrations. A United States Air Force resolution target was placed on the posterior surface of the model eye. A flat contact lens or a wide-field contact lens was placed on the cornea. The contrasts of the gratings were evaluated under endoillumination and compared to those obtained through a monofocal IOL. The grating images were clear when viewed through the flat contact lens and through the central far-vision zone of the NXG1 and PY60MV, although those through the near-vision zone were blurred and doubled. The images observed through the central area of the ZM900 with flat contact lens were slightly defocused but the images in the periphery were very blurred. The contrast decreased significantly in low frequencies (P<.001). The images observed through the central diffractive zone of the SA60D3 were slightly blurred, although the images in the periphery were clearer than that of the ZM900. The images were less blurred in all of the refractive and diffractive IOLs with the wide-field contact lens. Refractive and diffractive multifocal IOLs blur the grating target but less with the wide-angle viewing system. The peripheral multifocal optical zone may be more influential on the quality of the images with contact lens system.

Transpupillary thermotherapy (TTT) for age-related macular degeneration (AMD) – Is it time to say good-bye?

Abstract Purpose To evaluate the effectiveness of transpupillary thermotherapy (TTT) for the closure of classic and occult subfoveal choroidal neovascularization (CNV) and to discuss whether TTT is a useful treatment modality for age-related macular degeneration (AMD). Materials and methods The present paper is a retrospective review of the clinical results from a patient group which was treated with TTT in the University Eye Clinic in Mainz. From January 2000 to December 2002, a total of 20 eyes of 20 patients with subfoveal CNV (due to AMD in 16 eyes, due to pathologic myopia in 4 eyes) received TTT. The procedure was delivered using an infrared diode laser at 810 nm, equipped with a modified slit-lamp adapter with an adjustable beam width of 1.2, 2.0 and 3.0 mm. The spot size was selected so that the treatment beam entirely encompassed the lesion. For a 3 mm spot size, up to 800 mW was delivered to the treatment area using a wide-field contact lens. Power was adjusted in such a way that a barely detectable, light-gray appearance of the lesion was seen after 60 s. Patients were seen in follow-up at 6–8 weeks and re-treatment was considered at 12 weeks postoperatively, if persistence or worsening in the leakage of the lesion was observed. Results Twenty eyes with subfoveal CNV were treated with TTT and the healing process was followed for at least 6 months. After an average of 2.5 treatment sessions in 14/20 eyes, a rapid decline of CNV activity was observed with resolution of subretinal fluid accompanied by reduction of central scotoma and a significant relief of metamorphopsia. Four eyes with classic subfoveal CNV, due to pathologic myopia, showed closure of the CNV and no visual loss (more than 2 lines) in all cases. In the 16 eyes with occult subfoveal CNV in AMD, closure of the neovascular membrane was achieved in 10/16 eyes leading to a visual stabilization (within 2 lines) during the 6 months follow-up. Six of 16 eyes with AMD became legally blind despite repeated TTT treatment sessions (mean: 4.6 sessions; range: 3–6 sessions). A loss of central vision was due to persistence of macular leakage accompanied by choroidal bleeding, atrophy of the retinal pigment epithelium or progressive subfoveal fibrosis. Conclusion The results from this retrospective study demonstrate that occlusion of the neovascular membranes could be observed after TTT for subfoveal CNVs in AMD, as well for highly myopic eyes. Review of the literature shows that the success rate of TTT in AMD (60% after 6 months) is in accordance with the natural progression of occult CNVs in AMD.

Scanning Laser Ophthalmoscopy and Angiography With a Wide-Field Contact Lens System

To perform fluorescein and indocyanine green angiography for large or peripheral chorioretinal structures using a contact lens system that provides a 5-fold increase in the field of view of a confocal scanning laser ophthalmoscope (SLO). Separate handheld contact and noncontact ophthalmoscopic lenses were manually aligned with the optical axis of a confocal SLO to demonstrate the feasibility of wide-field SLO angiography. An integrated, wide-field contact lens system was then designed and constructed to increase the SLO's 10 degrees , 20 degrees , and 30 degrees imaging fields to 50 degrees , 100 degrees , and 150 degrees , respectively. Simultaneous fluorescein and indocyanine green angiography was performed with the integrated, wide-field contact lens system for more than 50 patients with disorders that affect their peripheral retina and choroid. Retinal and choroidal abnormalities, including neovascularization and capillary nonperfusion, are easily detected and documented well beyond the range of conventional fundus cameras and SLOs. Peripheral retinal and choroidal hemodynamics can be readily observed and recorded. A confocal SLO has adequate resolution for clinically useful reflectance and angiographic imaging even when its field size is increased 5-fold by a wide-field contact lens system. Dynamic and static wide-field angiography can be performed without the limitations of manual or computer-automated photomontages. Peripheral retinal conditions can be studied and recorded to confirm observations from indirect ophthalmoscopy and to facilitate retinal photocoagulation and vitreoretinal surgery.

Small-size pediatric vitrectomy wide-angle contact lens

Purpose We describe a new wide-field vitrectomy contact lens specifically designed to facilitate pediatric vitreoretinal surgery. Design Experimental study, instrument description. Methods A wide-field contact two-piece glass vitrectomy lens was designed with the largest diameter of 13.6 mm and a contact diameter of 7.00 mm, sacrificing only the more tilt-sensitive parts of the optics in order to reduce its physical size. Results Laboratory measurements in a model eye demonstrated a 61-degree binocular field of view, a 94-degree static field of view, and a maximum 129-degree field of view. Image magnification was 0.50×. No complications were linked to the use of this instrument, and the need to exchange for another lens was never encountered in 10 cases. The two-piece glass construction enabled this lens to be sterilized in an autoclave or sterilized by any other instrument sterilization technique. Conclusion The instrument successfully fulfilled the purpose of its design, providing at the same time an excellent wide field of view and ample space for the surgeon, performing well in 10 pediatric vitreoretinal cases (8 cases of retinopathy of prematurity; 2 cases of traumatic eye injury). Its loose two-piece design rendered it suitable for all sterilization techniques.

Evaluation of Glutaraldehyde and Povidone Iodine for Sterilization of Wide-Field Contact Vitrectomy Lenses

Wide-field vitrectomy contact lenses are currently sterilized with ethylene oxide gas, and other lenses with autoclaving. To maintain a large inventory or possibly run the risk of loss of lens quality with repeated autoclaving, glutaraldehyde 2% and povidone iodine 5% solution were evaluated as possible sterilizing agents. Ethylene oxide presterilized lenses were contaminated with known concentrations (10(5) organisms/mL) of bacteria (S. epidemidis, P. aeruginosa, B. subtilis), and fungi (A. flavus, C. albicans) for 5 minutes. The test lenses were treated with glutaraldehyde or povidone iodine for 5, 10, 30, 60, and 120 minutes, and controls with sterilized water for a similar duration. Following treatment, both test and control lenses were sampled with sterile cotton swabs. The swabs were cultured for bacteria (tryptone soya broth 48 hours), and fungi (Saubourd's dextrose broth 5 days). The culture was negative for both glutaraldehyde- and povidone iodine-treated lenses against all organisms at all time points except B subtilis, which needed 120 minutes treatment. Two hours contact time with glutaraldehyde 2% or providone iodine 5% can sterilize vitrectomy contact lenses against common bacteria and fungi without affecting lens quality.

Inadvertent corneal burn by using indirect wide-field contact lenses and different laser beam delivery systems during experimental fundus photocoagulation.

At fundus photocoagulation by using a wide-field indirect contact lens, the laser radiant exposure may be increased at the anterior segment of the eye. We examined the likelihood of producing inadvertent corneal burn by using parfocal and sharped edge defocus laser delivery systems with various indirect contact lenses. The two laser delivery systems were used with four lenses of different viewing angles during fundus photocoagulation in a total 44 eyes of rabbits. By using the lenses, the parfocal system increased corneal radiant exposure more than did the sharped edge defocus system. By using the Widefield PRP 165 lens of the widest viewing angle, there was no difference between the two systems in the corneal burns produced. Some indirect contact lenses used in combination with the parfocal system caused inadvertent corneal burns more readily than did the same lenses in combination with the sharped edge defocus system.

Finding the Retinal Hole in the Pseudophakic Eye With Detachment

The recently developed wide-field indirect contact lenses, recommended and used for pancoagulation of the retina posterior to the equator, have proved to be unexpectedly advantageous for finding retinal breaks anterior to the equator in the pseudophakic eye. Through a 6-mm pupil, it is possible with some ocular rotations, tilting of the lens, and scleral depression to bring into view the retina anterior to the equator and frequently the ora serrata. We found or confirmed 45 small retinal breaks anterior to the equator in 24 retinal detachments in pseudophakic eyes with the wide-field indirect contact lens. The indirect contact lens eliminates the blur that occurs when viewing through the edge of the intraocular lens, and its image suffers less interference from lens and capsular opacities.

In Vivo Specular Microscopy of Edematous Human Corneal Epithelium with Light and Scanning Electron Microscopic Correlation

A wide-field contact specular microscope was used to examine and to photograph the corneal epithelium in 35 eyes with chronic corneal edema. Seven of the patients subsequently underwent corneal transplantation allowing for correlation of the in vivo findings with the light and electron microscopic appearance. The early findings on specular microscopy included loss of the clear superficial epithelial cell outlines with easy dislodgement of these cells and a fine pattern of edema outlining basal cells. Individual cellular edema and fluid-filled cysts occurring at various epithelial layers and subepithelially appeared with worsening swelling. Subepithelial connective tissue and anamalous basement membrane were present at later stages.