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Photo demonstration of quality of vision with intact posterior capsule
Photo demonstration of quality of vision with intact posterior capsule John J. Alpar, M.D. James J. Spurlock, Ph.D. Amarillo, Texas
ABSTRACT The patient presented in this paper had a clinically clear but optically disturbing posterior capsule. The patient was able to visualize transparent refractive anomalies in the posterior capsule and the fine structure of a cataractous lens. Key Words: extracapsular cataract extraction, glare, posterior capsule, visual handicap
Since the rebirth of extracapsular cataract extraction, clinicians have become increasingly aware that a clear posterior capsule, even with 20/20 visual acuity in the controlled office environment, does not mean good quality vision. Undulations in the capsule may induce a Maddox rod effect or tension lines; small islands of thickening in the capsule may produce glare with decreased "real" vision (sunny days, light reflection from clouds, headlights at night). Although new methods and instruments for evaluating visual acuity are available (Millerl, Browning2 , contrast sensitivity tests 3), the majority of ophthalmologists still rely on the Snellen chart and base their decision on Snellen visual acuity and slitlamp examination. Some perform a capsulotomy (or neodymium: YAG capsulectomy) when the patient complains of disturbed vision. This communication is based on observations made by one of us OJS) in the photographic laboratory some months subsequent to cataract extraction. The experiment was devised to illustrate how a patient may visualize transparent refractive anomalies in the posterior capsule, and indeed may also visualize the fine structure of a cataractous lens. CASE REPORT On November 16, 1979, the patient had an extracapsular cataract extraction with irrigation and aspiration of the cortex, polishing of the posterior capsule, Reprint requests to John J. Alpar, M.D., 15 Medical Drive, Amarillo, Texas 79106-4186 .
and in-the-bag implantation of a +19 diopter (D) Binkhorst two-loop lens. The lens was secured to the iris with a 10-0 polypropylene suture. The patient achieved a visual acuity of 20/20 and had a clear posterior capsule with a +50 - 1 0 axis 98 correction. After a few months, the patient's vision began to deteriorate. During this time, while using a grain focuser (a simple 20x microscope) in the photographic laboratory, we observed that the bright field of view was overlaid with irregular shadow-like structures that were not part of the grain structure of the photographic film. An examination of the optical system and some experimentation led to the conclusion that the "clear" posterior capsule contained granular structures that were refracting light randomly, resulting in shadows being cast on the retina. These structures were visualized by the observer when a point source of light was placed at or slightly within the focal point of the lens as shown in Figure l.
POSTERIOR CAPSULE
Fig. 1.
RETINA
(Alpar) Point source of light is placed at or slightly within the focal point of the lens.
Light, which emerges from the lens in parallel rays, was refracted and thereby scattered by the transparent anomalies of the posterior capsule. This resulted in shadows being cast on the retina. A node in the optical path of the grain focuser provided the point light source for the original observation. The effect on visual acuity is precisely that produced by a diffusion disc used occasionally to soften a photographic image. Such a disc consists of a clear refractive pattern ground or embossed on a clear disc, which is otherwise an optical flat. This pattern refracts light into the shadows of the image, thereby reducing contrast, producing a slight halo around bright objects, and degrading fine detail resolution. Figure 2 shows the light pattern cast on the retina with no diffusion disc in place. (A few lens imperfections are visible.) Figure 3 shows the pattern formed with a Rollei diffusion disc consisting of concentric rings ground into the glass. Figure 4 shows the pattern formed with a Zeiss diffusion disc consisting of micro lenses embossed on an optical flat of plexiglass. Such anomalies, either refractive or opaque, may be self-visualized by using a point light source made from a penlight that is covered with aluminum foil in which a
AM INTRAOCULAR IMPLANT SOC J - VOL 11, JULY 1985
393
Fig. 2. (Alpar) Light pattern cast on retina with no diffusion disc in place.
Fig. 3.
(Alpar) Pattern formed with Rollei diffusion disc.
very small pinhole has been pricked. In a dimly lit room, this light source is slowly and carefully brought near the eye. A round bright field (the pupillary opening) appears with the shadowed anomalies of capsule or lens. This system enabled the patient to visualize transparent refractive anomalies in the posterior capsule that were not visible to the external observer. Indeed, Figure 5 shows the patient's eye with a pupil slightly dilated prior to the interruption of the posterior capsule. The lens is in the capsular bag and the optical axis appears to be completely clear. 394
Fig. 4.
(Alpar) Pattern formed with Zeiss diffusion disc.
Fig. 5.
(Alpar) Patient's eye with pupil slightly dilated prior to interruption of posterior capsule.
In addition, the system allowed the patient to visualize the fine structure of the cataractous lens in the unoperated eye. I believe this unique demonstration put together by a patient who had a clinically clear, but optically disturbing, posterior capsule supports a statement by Dr. Worst: "A clear capsule is no guarantee for optical performance. " REFERENCES 1. Miller D , Nadler MP, LeClaire J, Weiss SM: A new clinical glare tester in assessment of corrected aphakia. In : Emery JM,
AM INTRAOCULAR IMPLANT SOC J-VOL 11, JULY 1985
Jacobson AC, eds, Current Concepts in Cataract Surgery. Selected Proceedings of the Seventh Biennial Cataract Surgical Congress. New York, Appleton-Century-Crofts, 1982, pp 257262 2. Downing JJ, Smith JA: Glare acuity in pseudophakia and aphakia. In: Emery JM, Jacobson AC, eds, Current Concepts in Cataract Surgery. Selected Proceedings of the Eighth Biennial Cataract Surgical Congress. Norwalk, Conn, AppletonCentury-Crofts, 1984, pp 194-197 3. Faulkner W: Predicting acuities in capsulotomy patients: Interferometers and potential acuity meter. Am Intra-Ocular Implant Soc] 9:434-437, 1983
New techniques of viscosurgery with phacoemulsification
J.
Elliott Blaydes, M.D. Karl J. Fritz, Ph.D., M.D. J.A. Fogle, M. D. Bluefield, West Virginia
ABSTRACT Sodium hyaluronate is a valuable aid for phacoemulsification and intraocular lens insertion. Procedures such as anterior capsulotomy, polishing the capsule, lens adjustment, incision closure, and conversion to planned extracapsular cataract extraction are facilitated when sodium hyaluronate is used. A new method of removing it from the eye is presented. Key Words: anterior capsulotomy, phacoemulsification, planned extrilcapsular surgery, sodium hyaluronate, viscosurgery, wound closure
The use of a viscoelastic material, sodium hyaluronate (Healon ®), in anterior segment surgery was first suggested in 1979 (E.A. Balazs, M.D., D. Miller, M.D., R. Stegmann: Viscosurgery and the use ofNahyaluronate in intraocular lens implantation. Presented at the International Congress and First Film Festival on Intraocular Implantation, Cannes, France, May 1979). Cataract extraction, primary and secondary intraocular lens (IOL) implantation, corneal transplantation, and trauma surgery have all benefited from this material. Variants of these operations using Healon ® have also been discussed. 1,2,3 Healon ® provides a physiological buffer between tissues and instruments, making it especially useful for phacoemulsification techniques and IOL insertion. We have routinely used Healon ® in cataract extraction for more than three years. During this time we have performed well over 2,000 cataract extractions. In most cases, posterior chamber IOLs were implanted Presented at the U.S. Intraocular Lens Symposium, Los Angeles, California, April 1984. Reprint requests to J. Elliott Blaydes, M.D., The Blaydes Foundation, P.O. Box 1380, Bluefield, West Virginia 24701. AM INTRAOCULAR IMPLANT SOC J-VOL 11, JULY 1985
395
ABSTRACT The patient presented in this paper had a clinically clear but optically disturbing posterior capsule. The patient was able to visualize transparent refractive anomalies in the posterior capsule and the fine structure of a cataractous lens. Key Words: extracapsular cataract extraction, glare, posterior capsule, visual handicap
Since the rebirth of extracapsular cataract extraction, clinicians have become increasingly aware that a clear posterior capsule, even with 20/20 visual acuity in the controlled office environment, does not mean good quality vision. Undulations in the capsule may induce a Maddox rod effect or tension lines; small islands of thickening in the capsule may produce glare with decreased "real" vision (sunny days, light reflection from clouds, headlights at night). Although new methods and instruments for evaluating visual acuity are available (Millerl, Browning2 , contrast sensitivity tests 3), the majority of ophthalmologists still rely on the Snellen chart and base their decision on Snellen visual acuity and slitlamp examination. Some perform a capsulotomy (or neodymium: YAG capsulectomy) when the patient complains of disturbed vision. This communication is based on observations made by one of us OJS) in the photographic laboratory some months subsequent to cataract extraction. The experiment was devised to illustrate how a patient may visualize transparent refractive anomalies in the posterior capsule, and indeed may also visualize the fine structure of a cataractous lens. CASE REPORT On November 16, 1979, the patient had an extracapsular cataract extraction with irrigation and aspiration of the cortex, polishing of the posterior capsule, Reprint requests to John J. Alpar, M.D., 15 Medical Drive, Amarillo, Texas 79106-4186 .
and in-the-bag implantation of a +19 diopter (D) Binkhorst two-loop lens. The lens was secured to the iris with a 10-0 polypropylene suture. The patient achieved a visual acuity of 20/20 and had a clear posterior capsule with a +50 - 1 0 axis 98 correction. After a few months, the patient's vision began to deteriorate. During this time, while using a grain focuser (a simple 20x microscope) in the photographic laboratory, we observed that the bright field of view was overlaid with irregular shadow-like structures that were not part of the grain structure of the photographic film. An examination of the optical system and some experimentation led to the conclusion that the "clear" posterior capsule contained granular structures that were refracting light randomly, resulting in shadows being cast on the retina. These structures were visualized by the observer when a point source of light was placed at or slightly within the focal point of the lens as shown in Figure l.
POSTERIOR CAPSULE
Fig. 1.
RETINA
(Alpar) Point source of light is placed at or slightly within the focal point of the lens.
Light, which emerges from the lens in parallel rays, was refracted and thereby scattered by the transparent anomalies of the posterior capsule. This resulted in shadows being cast on the retina. A node in the optical path of the grain focuser provided the point light source for the original observation. The effect on visual acuity is precisely that produced by a diffusion disc used occasionally to soften a photographic image. Such a disc consists of a clear refractive pattern ground or embossed on a clear disc, which is otherwise an optical flat. This pattern refracts light into the shadows of the image, thereby reducing contrast, producing a slight halo around bright objects, and degrading fine detail resolution. Figure 2 shows the light pattern cast on the retina with no diffusion disc in place. (A few lens imperfections are visible.) Figure 3 shows the pattern formed with a Rollei diffusion disc consisting of concentric rings ground into the glass. Figure 4 shows the pattern formed with a Zeiss diffusion disc consisting of micro lenses embossed on an optical flat of plexiglass. Such anomalies, either refractive or opaque, may be self-visualized by using a point light source made from a penlight that is covered with aluminum foil in which a
AM INTRAOCULAR IMPLANT SOC J - VOL 11, JULY 1985
393
Fig. 2. (Alpar) Light pattern cast on retina with no diffusion disc in place.
Fig. 3.
(Alpar) Pattern formed with Rollei diffusion disc.
very small pinhole has been pricked. In a dimly lit room, this light source is slowly and carefully brought near the eye. A round bright field (the pupillary opening) appears with the shadowed anomalies of capsule or lens. This system enabled the patient to visualize transparent refractive anomalies in the posterior capsule that were not visible to the external observer. Indeed, Figure 5 shows the patient's eye with a pupil slightly dilated prior to the interruption of the posterior capsule. The lens is in the capsular bag and the optical axis appears to be completely clear. 394
Fig. 4.
(Alpar) Pattern formed with Zeiss diffusion disc.
Fig. 5.
(Alpar) Patient's eye with pupil slightly dilated prior to interruption of posterior capsule.
In addition, the system allowed the patient to visualize the fine structure of the cataractous lens in the unoperated eye. I believe this unique demonstration put together by a patient who had a clinically clear, but optically disturbing, posterior capsule supports a statement by Dr. Worst: "A clear capsule is no guarantee for optical performance. " REFERENCES 1. Miller D , Nadler MP, LeClaire J, Weiss SM: A new clinical glare tester in assessment of corrected aphakia. In : Emery JM,
AM INTRAOCULAR IMPLANT SOC J-VOL 11, JULY 1985
Jacobson AC, eds, Current Concepts in Cataract Surgery. Selected Proceedings of the Seventh Biennial Cataract Surgical Congress. New York, Appleton-Century-Crofts, 1982, pp 257262 2. Downing JJ, Smith JA: Glare acuity in pseudophakia and aphakia. In: Emery JM, Jacobson AC, eds, Current Concepts in Cataract Surgery. Selected Proceedings of the Eighth Biennial Cataract Surgical Congress. Norwalk, Conn, AppletonCentury-Crofts, 1984, pp 194-197 3. Faulkner W: Predicting acuities in capsulotomy patients: Interferometers and potential acuity meter. Am Intra-Ocular Implant Soc] 9:434-437, 1983
New techniques of viscosurgery with phacoemulsification
J.
Elliott Blaydes, M.D. Karl J. Fritz, Ph.D., M.D. J.A. Fogle, M. D. Bluefield, West Virginia
ABSTRACT Sodium hyaluronate is a valuable aid for phacoemulsification and intraocular lens insertion. Procedures such as anterior capsulotomy, polishing the capsule, lens adjustment, incision closure, and conversion to planned extracapsular cataract extraction are facilitated when sodium hyaluronate is used. A new method of removing it from the eye is presented. Key Words: anterior capsulotomy, phacoemulsification, planned extrilcapsular surgery, sodium hyaluronate, viscosurgery, wound closure
The use of a viscoelastic material, sodium hyaluronate (Healon ®), in anterior segment surgery was first suggested in 1979 (E.A. Balazs, M.D., D. Miller, M.D., R. Stegmann: Viscosurgery and the use ofNahyaluronate in intraocular lens implantation. Presented at the International Congress and First Film Festival on Intraocular Implantation, Cannes, France, May 1979). Cataract extraction, primary and secondary intraocular lens (IOL) implantation, corneal transplantation, and trauma surgery have all benefited from this material. Variants of these operations using Healon ® have also been discussed. 1,2,3 Healon ® provides a physiological buffer between tissues and instruments, making it especially useful for phacoemulsification techniques and IOL insertion. We have routinely used Healon ® in cataract extraction for more than three years. During this time we have performed well over 2,000 cataract extractions. In most cases, posterior chamber IOLs were implanted Presented at the U.S. Intraocular Lens Symposium, Los Angeles, California, April 1984. Reprint requests to J. Elliott Blaydes, M.D., The Blaydes Foundation, P.O. Box 1380, Bluefield, West Virginia 24701. AM INTRAOCULAR IMPLANT SOC J-VOL 11, JULY 1985
395