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David J Apple

Publications and source records attributed to David J Apple.

At least 55 records · Page 3Linked to original sources
PubMed2003

Cataract treatment in the beginning of the 21st century.

PURPOSE: To describe the principles upon which present day cataract treatment success resides. DESIGN: Literature review and collective experience of the authors. RESULTS: Surgical removal remains the standard treatment for cataract now and in the foreseeable future. Ultrasound cataract removal with a foldable "in-the-bag" intraocular lens with a truncated edge treated for dysphotopsia best correlates with core treatment principles, as we now understand them. Improving refractive results is an important trend. The worldwide burden of this problem is immense. CONCLUSIONS: While results for treatment of cataracts are excellent today, improvements in safety and refraction precision are needed. Other approaches are desperately needed to stem the worldwide tide of cataract related ocular dysfunction.

Cataract↗
PubMed2003

Scanning electron microscopic and histologic evaluation of the AcrySof SA30AL acrylic intraocular lens. Manufacturing quality and morphology in the capsular bag.

PURPOSE: To evaluate the properties of the AcrySof(R) SA30AL (Alcon Laboratories, Inc.) single-piece foldable posterior chamber intraocular lens (IOL). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Two nonimplanted clinical-quality AcrySof IOLs were examined by gross, light, and scanning electron microscopy (SEM). In addition, 2 eyes implanted with this IOL obtained post-mortem, the first such eyes accessioned in our laboratory and the first described to date, were examined using the Miyake-Apple posterior photographic technique and by histologic sections. RESULTS: Scanning electron microscopy of the SA30AL IOL showed excellent surface finish. The edge of the optic was square (truncated) and had a matte (velvet or ground-glass) appearance, a feature that may minimize edge glare and other visual phenomena. A well-fabricated square or truncated optic edge was demonstrated. Miyake-Apple analysis revealed that the SA30AL IOL showed appropriate fit and configuration within the capsular bag. Histologic correlation of the IOL's square edge and its relation to the capsular bag and adjacent Soemmering's ring were noted. CONCLUSIONS: The AcrySof SA30AL IOL is a well-fabricated lens that situates well in the capsular bag. The truncated optic and its relationship to adjacent structures show a morphological profile that has been shown to be highly efficacious in reducing the rate of posterior capsule opacification.

Acrylates↗
PubMed2003

Viscoanesthesia. Part I: toxicity to corneal endothelial cells in a rabbit model.

PURPOSE: To evaluate the toxicity of a solution combining sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to the rabbit corneal endothelium. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Each rabbit cornea was excised, and the endothelium was exposed to 1 of the following solutions for 20 minutes: viscoanesthetic solution (0.5%, 1.0%, or 1.65% lidocaine in sodium hyaluronate 1.5%; 5 corneas each), sodium hyaluronate 1.5% (n = 5), balanced salt solution (BSS(R)) (n = 5), mitomycin-C 0.02% (n = 2), dextran 15% (n = 2), or distilled water (n = 2). The endothelium was then stained with trypan blue and alizarin red. Two corneas were stained immediately after excision. Cell morphology and damage to the corneal endothelium were analyzed by microscopic examination. RESULTS: The endothelium in the corneas of the viscoanesthetic groups was comparable to that in the sodium hyaluronate 1.5% and the BSS groups and to the corneas not exposed to any solution. In some areas of the 1.0% and the 1.65% viscoanesthesia groups, the corneal endothelial cells presented irregular intercellular borders. Staining with trypan blue, which indicates cellular damage, was observed in some linear areas corresponding to corneal folds in all groups. The folds were probably caused during manipulation for corneal excision and staining. The corneal endothelium was destroyed in the mitomycin group. In the dextran and distilled-water groups, morphological alterations probably resulting from osmotic changes were observed. CONCLUSIONS: The 3 concentrations of viscoanesthetic solutions appeared to be safe to rabbit corneal endothelium.

Acetates↗
PubMed2003

Viscoanesthesia. Part II: toxicity to intraocular structures after phacoemulsification in a rabbit model.

PURPOSE: To investigate the toxicity of a solution that combines sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to intraocular structures. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Phacoemulsification was performed in both eyes of 29 rabbits. They were divided into 3 groups; in each group (n = 7), 1 viscoanesthetic solution was used before capsulorhexis. After irrigation/aspiration, 0.2 mL of the solution was purposely left in the capsular bag. In 1 rabbit in each group, the solution was injected into the vitreous cavity through a posterior capsulorhexis. In 8 rabbits used as controls, balanced salt solution (BSS(R)) (n = 4) or sodium hyaluronate 1.5% (n = 4) was injected into the vitreous cavity. Enucleations were performed 15, 30, and 60 days postoperatively. Histological sections were cut and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson trichrome stains. RESULTS: Light microscopic evaluation of the eyes enucleated after 15, 30, and 60 days in the study and control groups showed similar findings in intraocular structures such as the ciliary body and retina. No evidence of an inflammatory reaction, cell necrosis, or cell degeneration was observed in the histological sections. CONCLUSIONS: The use of viscoanesthesia during phacoemulsification appeared to be safe, with no histologic abnormalities observed with the 3 lidocaine concentrations. The efficacy of the anesthetic effects of these solutions will be addressed in clinical trials.

Anesthetics, Local↗
PubMed2003

Viscoanesthesia. Part III: removal time of OVD/viscoanesthetic solutions from the capsular bag of postmortem human eyes.

PURPOSE: To investigate and evaluate the removal time of various ophthalmic viscosurgical device (OVD)/viscoanesthetic solutions containing sodium hyaluronate 1.5% with different concentrations of lidocaine (0.5%, 1.0%, and 1.65%). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Six postmortem human eyes were prepared per the Miyake-Apple posterior video technique. Capsulorhexis, hydrodissection/delineation, and nuclear emulsification were performed, followed by thorough cleaning of the capsular bag using an irrigation/aspiration (I/A) tip. The time and ease of removal of 4 solutions from the capsular bag were evaluated. The solutions were Ophthalin Plus (sodium hyaluronate, 15 mg/mL) and sodium hyaluronate 15 mg/mL mixed with lidocaine 0.5%, lidocaine 1.0%, and lidocaine 1.65%. The solutions were dyed with fluorescein to enhance visualization. After the capsular bag was filled with 1 of the solutions, a posterior chamber intraocular lens was implanted. The solution was then aspirated using an automated I/A device set at 250 mm Hg of aspiration. The time required to remove most and then all the material was recorded. RESULTS: The mean time required for removal of most of the Ophthalin Plus, viscoanesthesia 0.5%, viscoanesthesia 1%, and viscoanesthesia 1.65% solutions was 8.7 seconds +/- 2.1 (SD), 7.7 +/- 1.1 seconds, 9.7 +/- 0.6 seconds, and 6.3 +/- 1.5 seconds, respectively (P =.1). The mean time to remove all the solutions was 21.3 +/- 3.2 seconds, 19.7 +/- 2.5 seconds, 18.3 +/- 3.2 seconds, and 15.7 +/- 2.1 seconds, respectively (P =.166). No subjective difference in viscosity or consistency was found among the solutions. CONCLUSIONS: The addition of lidocaine to the OVD solution did not significantly alter the viscosity or consistency of the solution or change its removal time from the capsular bag.

Anesthetics, Local↗
PubMed2003

Diffuse lamellar keratitis: evaluation of etiology, histopathologic findings, and clinical implications in an experimental animal model.

PURPOSE: To induce diffuse lamellar keratitis (DLK) and investigate the potential causative agents in an animal model. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: In 70 eyes of 35 Dutch Belted rabbits, a corneal flap was cut and the interface randomly exposed to 1 of 7 substances: Pseudomonas aeruginosa endotoxin, 1 of 2 Staphylococcus aureus exotoxins, meibomian gland secretion, povidone-iodine 10%, Palmolive Ultra soap, and Klenzyme soap. Slitlamp examinations were performed 1, 3, 5, and 7 days postoperatively. The DLK was staged from 1 to 4. On day 7, the rabbits were killed and the eyes enucleated and processed for histopathologic examination. RESULTS: At the end of the study, 54 eyes (46 exposed, 8 control) were available for evaluation. The 8 eyes studied concurrently in the control group remained clear and did not show interface inflammation. Thirty-one of 46 eyes (67%) treated with the various test substances developed DLK. The highest DLK rates were found with the cleaning soap Palmolive Ultra (100%; P =.022) and P. aeruginosa lipopolysaccharide endotoxin (90%; P =.026). CONCLUSIONS: Interface inflammation was consistently induced in the animal model. All 7 agents caused DLK in at least some eyes. The histopathologic evaluation showed the morphologic profile of the marked inflammatory cellular reaction that occurred in almost all the specimens.

Animals↗
PubMed2003

Retrospective evaluation of intraocular lenses in adults younger than 60 years.

Data from the U.S. Food and Drug Administration, the American Academy of Ophthalmology's National Eyecare Outcomes Network, and Storm Eye Institute databases were analyzed for short- and long-term safety and efficacy outcomes of intraocular lens (IOL) implantation in adults younger than 60 years and 60 years and older. Statistical analyses for significance were performed where appropriate. A comprehensive literature review was conducted to identify safety and efficacy outcomes and their relationship to patient age at the time of implantation. Analyses established that the performance of IOLs in adults younger than 60 years was comparable to that in adults older than 60 years and supported the use of IOLs in the younger adult population.

Adult↗
PubMed2003

Corneal flap complications in refractive surgery: Part 2: postoperative treatments of diffuse lamellar keratitis in an experimental animal model.

PURPOSE: To induce diffuse lamellar keratitis (DLK) and investigate a prophylactic treatment with pharmacological agents. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Charleston, South Carolina, USA. METHODS: In 100 eyes of 50 Dutch Belted rabbits, a nasal corneal flap was cut and the interface inoculated with Pseudomonas aeruginosa lipopolysaccharide endotoxin (n = 50) or Palmolive Ultra soap (n = 50). The eyes were randomly assigned to treatment with a mast-cell stabilizer, a nonsteroidal antiinflammatory drug (NSAID), a fluoroquinolone antibiotic agent, a corticosteroid, or left without treatment as a control. Slitlamp examinations and photographs were performed 1, 3, 5, and 7 days postoperatively, and DLK was graded by a masked observer from 0 (no DLK) to stage 4. RESULTS: At the end of the study, 80 eyes were available for evaluation. Ninety-four percent of the untreated eyes developed DLK compared to 56% of eyes treated with NSAIDs and 63% of eyes treated with steroids (P<.05, Fisher exact test). The DLK rates with the mast-cell stabilizer and fluoroquinolone antibiotic agent were 86% and 76%, respectively. The DLK incidence in the latter 2 groups was not significantly different from that in the control eyes (P>.05, Fisher exact test). CONCLUSIONS: Postoperative prophylactic treatment with NSAIDs and corticosteroids led to a statistically significantly lower incidence of postoperative DLK. The study demonstrated that corticosteroids and NSAIDs can be used to treat DLK after LASIK. While steroids are a generally accepted treatment for DLK, NSAIDS may offer an additional potent modality.

Animals↗
PubMed2003

Corneal flap complications in refractive surgery: Part 1: development of an experimental animal model.

PURPOSE: To report the outcome, learning curve, and complication rates of an experimental animal model for corneal flaps in refractive surgery. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Charleston, South Carolina, USA. METHODS: Corneal flaps with a nasal or a temporal hinge were created in 190 eyes of 95 Dutch Belted rabbits using the Automated Corneal Shaper microkeratome (Bausch & Lomb Surgical). Diffuse lamellar keratitis (DLK) was induced by inoculating the corneal interfaces with 1 of 7 substances. Postoperatively, the eyes were examined with a slitlamp. Special emphasis was placed on corneal flap complications and the relationship between slipped flaps and hinge position and/or inoculation agent. RESULTS: A good corneal flap was achieved in 174 eyes (92%). The eyes with a nasal hinge had a lower incidence of slipped flaps (14%) than eyes with a temporal hinge (37%) (P =.02). CONCLUSION: With the animal model described, corneal flaps were created in a precise and reproducible way in more than 90% of eyes. Nasal hinged flaps showed less postoperative displacements than temporal hinged flaps and are adequate for further study.

Animals↗
PubMed2003

Implantation of a single-piece, hydrophilic, acrylic, minus-power foldable posterior chamber intraocular lens in a rabbit model: clinicopathologic study of posterior capsule opacification.

PURPOSE: To compare the extent of posterior capsule opacification (PCO) after implantation of a standard-power biconvex Centerflex intraocular lens (IOL) and a newly introduced biconcave high-minus-power Centerflex design in rabbit eyes. SETTING: The Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, and the David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA. METHODS: Twelve rabbits had phacoemulsification and implantation of 2 foldable single-piece hydrophilic acrylic Centerflex posterior chamber IOLs. The right eyes received a standard-power (+21.00 diopters [D]) biconvex-optic lens and the left eyes, a minus-power (-7.00 D) biconcave-optic IOL. Formation of PCO was evaluated 3 weeks after surgery using the Miyake-Apple posterior photography technique. Histological sections from each globe were prepared to analyze capsular bag status and assess postsurgical intracapsular lens epithelial cell (LEC) proliferation, especially ingrowth of LECs across the visual axis. The data were analyzed using the Kruskal-Wallis 1-way analysis of variance for nonparametric measurements and the Mann-Whitney rank sum test. RESULTS: There was no significant difference in Soemmering's ring formation between the 2 IOL models. The biconcave minus-power IOL showed significantly lower central and peripheral PCO scores than the biconvex standard-power lens (P<.05). Pathological evaluations revealed that the effective site of blockage of LECs was at the truncated optic edge of both lenses, even in the presence of retained and/or regenerative cortical material. CONCLUSIONS: This study confirms the efficacy of a truncated IOL optic in helping reduce the incidence of PCO. Both IOL designs have optic geometries that create clear-cut barrier effects. However, the biconcave minus-power IOL, which has a thicker, square, truncated optic edge with a ridge that encircles the periphery of the optic for 360 degrees, appears to have an enhanced barrier effect, especially at the optic-haptic junction. This further minimizes the ingrowth of migrating LECs toward the visual axis.

Acrylic Resins↗
PubMed2003

Pharmacologic prevention of posterior capsule opacification: in vitro effects of preservative-free lidocaine 1% on lens epithelial cells.

PURPOSE: To assess the in vitro effectiveness of preservative-free lidocaine 1% in removing lens epithelial cells (LECs) from the anterior capsule and to evaluate the effect of lidocaine on the LECs. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Eight rabbits (16 eyes) were used in the study. After the rabbits were killed, the eyes were enucleated and divided into 2 groups. In Group 1 (n = 8 eyes), LECs were exposed to preservative-free lidocaine 1% or balanced salt solution (BSS) for 1, 2, or 5 minutes. The anterior capsules were then stained with trypan blue and alizarin red. Photomicrographs of each capsule were taken and analyzed for LEC damage. In Group 2 (n = 8 eyes), hydrodissection was performed with 1 of the agents, followed by phacoemulsification and cortical cleanup. The LEC attachment to the anterior capsule was evaluated by histopathology. RESULTS: Anterior capsule fragments irrigated with BSS showed no LEC nuclear staining; ie, no direct toxic effect. In those irrigated with preservative-free lidocaine 1%, the LECs showed mild toxicity; some cells showed blue nuclear staining. After hydrodissection with lidocaine, the capsules were almost free of LECs; after hydrodissection with BSS, the capsules showed a normal layer of LECs attached to the anterior capsule. CONCLUSIONS: Preservative-free lidocaine 1% may help diminish the amount of live LECs by facilitating cortical cleanup, by loosening the desmosomal area of cell-cell adhesion with decreased cellular adherence, or by a direct toxic effect. The use of this agent may help prevent posterior capsule opacification.

Anesthetics, Local↗
PubMed2003

Sir Nicholas Harold Ridley. He changed the world, so that we might better see it.

Cataract surgery with intraocular lens (IOL) implantation has become the most common and most successful of all operations in medicine. Sir Harold Ridley's first cataract extraction with implantation of an IOL marked the beginning of a major change in the practice of ophthalmology. Millions of patients worldwide have benefited from Sir Ridley's invention, and are likely to continue to derive benefit from this device. However, the development of the IOL was not without its share of ups and downs. Sir Harold Ridley, the inventor of IOL, died at the age of 94, on 25 May 2001, and ophthalmology lost one of its greatest and most influential practitioners. We are happy that he lived to enjoy the fruits of his labour--to see the amazing improvements and the expansive growth that evolved in the cataract-IOL technique, from early and unsatisfactory operations in previous decades, to the superb results attainable today. The invention of the IOL has not been just the addition of one new form of treatment, but rather, Sir Harold's tiny disc-shaped sliver of plastic has changed the world so that our patients may better see it. This article presents a brief biographical sketch of Sir Harold and lists his major inventions and contributions to ophthalmology.

Cataract Extraction↗
PubMed2003

The "demise" of diagnostic and research ocular pathology: temporary or forever?

PURPOSE: Several authorities have documented a significant decrease in support for modern eye pathology/pathology research laboratories. Indeed, many laboratories have closed or suffered marked cutbacks. The purpose of this report is to ask why this is so and to seek a possible means for reversing this trend. METHODS: Observations from the senior author's experience and a case from author's facility are analyzed. RESULTS: There are several reasons for ocular pathologists' difficulties, such as financial problems, lack of vision, personality conflicts, and problems with the departmental administration. Until recently, most research and development in several subspecialty fields of ophthalmology, including biodevices research, has been done primarily by engineers and in-house workers in industry. This precludes proper independent, nonbiased control and guidance from academia. Most ocular pathologists have not participated in this relatively new and wide-open field. CONCLUSIONS: We suggest a new realm of activity for today's newly trained ocular pathologists. Based on personal experience of two decades of fruitful collaboration with industry, we believe that ocular pathologists are uniquely trained to apply their expertise to various new fields of research that most pathologists today have not utilized. An important example is research on clinicopathological aspects of implantable biodevices. In addition, support and oversight should be provided by the major ophthalmic societies, such as the American Academy of Ophthalmology, in order to retain (even regain) control over this field. This is mandatory in order to control the safety and efficacy of new drugs and devices being introduced almost daily. Only then can clear differentiation between profit and patient welfare be achieved as potentially dangerous devices and techniques are let loose on the market. The field of "routine, descriptive" eye pathology is severely wounded and will return only in an attenuated fashion. In general, full-time support for ocular pathologists will not be possible unless they seek extra support from the private sector, engage in a concurrent clinical practice, or are supported by an endowed chair (a wonderful alternative).

Financing, Government↗
PubMed2002

Analysis of elements of interlenticular opacification.

PURPOSE: To report the histopathologic and ultrastructural features of three cases of interlenticular opacification (ILO) between piggyback intraocular lenses. DESIGN: Interventional case series with clinicopathologic correlation. METHODS: Three pairs of acrylic piggyback lenses were explanted due to decrease in visual acuity associated with ILO. Lenses were evaluated with gross and light microscopic examinations in all cases. The anterior lens in one case was examined with scanning electron microscopy and energy dispersive x-ray spectroscopy. RESULTS: The material opacifying the interlenticular space was composed mostly of retained/regenerative cortical material in all cases. From the peripheral interface towards the central interface, the opacifying material changed as the interlenticular space was progressively narrower. The material attached to the peripheral interface, where the interlenticular space was wider, was very thick. At the midperipheral interface, the thick cortical material was broken into multiple globules due to liquefactive degeneration. At the paracentral zone, compression of the globules formed a flat, compact layer of an amorphous material. At the central interface (contact zone), almost no material could be found between the piggyback lenses. CONCLUSIONS: Analyses of ILO cases where all the components of the opacifying material were in situ allowed us to confirm that the pathogenesis of this complication is similar to that of posterior capsule opacification; thus, careful removal of lens epithelial cells and cortical material is mandatory in piggyback implantation.

Acrylic Resins↗
PubMed2002

Evaluation of neodymium:yttrium-aluminum-garnet capsulotomies in eyes implanted with AcrySof intraocular lenses.

PURPOSE: As of December 31, 2000, the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy rate for the Alcon AcrySof intraocular lens (IOL) as measured in our database was 3.3%. This was the lowest of any IOL model used in the United States. Only 12 of 361 cases required treatment. We analyzed possible surgical reasons that may have been responsible for the posterior capsule opacification (PCO) in this small group. Special attention was given to the three surgical factors that we had previously identified as being important for PCO reduction: (1) quality of cortical clean up, (2) type of haptic fixation, and (3) continuous curvilinear capsulorhexis (CCC) size and shape. DESIGN: Comparative autopsy tissue analysis. PARTICIPANTS: Three hundred sixty-one human eyes obtained postmortem with Alcon AcrySof IOLs, accessioned between January 1995 and December 2000 from Lions Eye Banks. METHODS: The eyes were evaluated by the Miyake-Apple posterior photographic technique. MAIN OUTCOME MEASURES: The area and intensity of Soemmering's ring and type of fixation were studied in 361 eyes. The size and shape of the CCC and relation of the CCC edge to the IOL's optic rim were analyzed in 168 eyes. RESULTS: The amount of Soemmering's ring formation was significantly larger in the group of IOLs requiring Nd:YAG capsulotomy (Nd:YAG group). The not in-the-bag fixated IOLs required more Nd:YAG capsulotomies. Although the trend was clear, the number of specimens was not large enough to acquire statistical significance. The Nd:YAG group showed a highly significant difference compared with the No Nd:YAG group with regard to the amount of clock hours of the CCC edge on the optic rim's surface (P < 0.001). Mean CCC diameters were significantly larger in the Nd:YAG group (P < 0.05). CONCLUSIONS: The amount of Soemmering's ring correlates with the quality of cortical clean up. Cells within the Soemmering's ring are the direct precursors of PCO. This study confirms our previous laboratory studies and the clinical assumption that the incidence of PCO and thus the need for Nd:YAG capsulotomy is correlated with the cortical clean up. A second clinical assumption, that poor IOL fixation increases the risk of PCO, is also strongly suggested in this study. This study also verifies the relation of the CCC to PCO and the Nd:YAG laser, namely that a relatively small CCC without tears is best to prevent this complication. Use of a high-quality IOL combined with diligent attention to these three surgical factors should lower further the incidence of PCO.

Acrylic Resins↗