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Biomedical subjects

D J Apple

Publications and source records attributed to D J Apple.

At least 55 records · Page 3Linked to original sources
PubMed2001

Complications of cataract and refractive surgery: a clinicopathological documentation.

PURPOSE: To present selected complications of keratorefractive and phakic intraocular lens (IOL) surgery and a series of IOLs that required explantation because of various postimplantation opacification of the IOL optic. METHODS: Two specimens obtained after keratorefractive surgery, 2 phakic IOLs, and a total of 23 explanted IOLs from cases in which postimplantation opacification of the IOL optic had occurred were studied. These included 6 Bausch and Lomb (B&L) Hydroview H60 M designs, 9 Medical Developmental Research (MDR) SC60B-OUV designs, and 24 IOLs with rigid PMMA optics that had been implanted in the 1980s and early 1990s. Of the latter, 8 required late explantation because of decreased visual acuity. Analyses performed included gross and light microscopic evaluation, histochemical staining, electron microscopy, and energy-dispersive spectroscopy. RESULTS: We provide examples of 3 postrefractive surgery complications: (1) fungal keratitis after LASIK, (2) post-LASIK corneal decompensation, and (3) cataract formation after implantation of phakic posterior chamber IOLs. Regarding the IOL optic opacities, classifications of 3 types are described: (1) a surface calcification of the B&L Hydroview IOL; (2) diffusion of calcium into the substance of the optic of the hydrophilic "acrylic" SC60B-OUV MDR foldable IOL design, sometimes leading to total opacification of the IOL optic and also its haptics; (3) a distinct pattern of intraoptical opacification with rigid PMMA designs that we term a snowflake degeneration. This term is based on the clinical and pathologic appearance of the individual lesions. Each snowflake lesion represents a focal breakdown of PMMA material as opposed to deposition of exogenous material. CONCLUSIONS: Analysis of complications of refractive surgery represents a new field of ocular pathology. The clinicopathological reports presented here provide an overview of selected complications after refractive surgery. We also help define 3 newly recognized, clinically significant conditions based on postoperative IOL optic opacification. The calcification processes noted on the 2 modern foldable designs studied here (B&L and MDR lenses) need further review by the manufacturers in order to reassess production processes, especially in terms of polymer selection, manufacturing techniques, and other factors required to produce a safe and effective lens. Any lens not meeting today's high standards should not be marketed. The important fact in recognizing the snowflake complication of PMMA IOLs as described here is to alert surgeons about the nature of the lesion so that they will not alarm patients or require extensive and unnecessary testing in trying to determine its pathogenesis. There is no reason why successful explantation cannot be performed in cases where severe visual decrease or loss has occurred.

Calcinosis↗
PubMed2000

Induction of cataracts of varying degrees of hardness in human eyes obtained postmortem for cataract surgeon training.

PURPOSE: To report a method of inducing nuclear cataracts of varying degree of hardness using intralenticular injection of the Karnovsky solution. METHODS: Twelve postmortem human eyes were prepared according to the Miyake-Apple posterior video technique. After performing capsulorhexis and hydrodissection/delineation, 0.2 ml of the Karnovsky solution was injected into the lens nucleus of the eyes. Manual extracapular cataract extraction techniques and various two-handed phacoemulsification maneuvers were then practiced at various time intervals after the injection. RESULTS: Uniform nuclear cataracts with varying degrees of hardness were successfully induced in all globes. The optimum dose of the Karnovsky solution and time for induction of nuclear hardness of grade 3 (ideal for practicing two-handed phacoemulsification maneuvers) were 0.2 ml and 15 minutes, respectively. CONCLUSION: The Karnovsky solution can be successfully used for the induction of hard, uniform nuclear cataracts for learning/practicing extracapular cataract extraction and phacoemulsification.

Cataract↗
PubMed2000

Postoperative deposition of calcium on the surfaces of a hydrogel intraocular lens.

OBJECTIVE: To report clinical, pathological and histochemical features of 5 Hydroview intraocular lenses (IOLs) explanted from five patients who had visual disturbances caused by postoperative deposits on the lens surfaces. DESIGN: Noncomparative small case series with clinicopathologic and histochemical correlations. PARTICIPANTS: Five hydrophilic IOLs explanted from five different patients. All patients presented with decreased visual acuity and glare circa 12 months after uneventful phacoemulsification and IOL implantation, associated with a red-brown granularity on the optical surfaces of the IOLs. METHODS: The lenses were explanted, fixed in buffered formaldehyde and examined by gross and light microscopy. MAIN OUTCOME MEASURES: Staining of the IOLs with 1% alizarin red and with the von Kossa method (both stains for calcium). Two additional IOLs were also stained and included as controls. RESULTS: The optical surfaces of all five IOLs were covered by a layer of irregular granular deposits, composed of multiple fine, translucent spherical-ovoid granules. The deposits stained positive for calcium in all cases. No deposit or positive staining was observed on the IOLs haptics. Staining of the control IOLs was also negative. CONCLUSION: This is the first histopathological report of calcified deposits on the surfaces of this hydrogel IOL model. Further studies on other similar cases with this lens should be done to determine the incidence and possible mechanisms of this phenomenon.

Aged↗
PubMed2000

The South Asian cataract management study: complications, vision outcomes, and corneal endothelial cell loss in a randomized multicenter clinical trial comparing intracapsular cataract extraction with and without anterior chamber intraocular lens implantation.

OBJECTIVE: To determine clinical outcomes of primary intracapsular cataract surgery with and without implantation of anterior chamber lenses. DESIGN: A multicenter randomized clinical trial. PARTICIPANTS: One thousand two hundred twenty-nine male and female patients 40-75 years of age with senile cataract. METHODS: Study patients were recruited from screening eye camps and outpatient clinics. Randomization to the two treatment groups was performed after screening for predetermined inclusion and exclusion criteria. Demographics, visual acuity, intraocular pressures, and corneal endothelial cell data were recorded before surgery and at 6 weeks, 12 months, and 24 months after surgery. Monitoring of the study was secured by a standardized image documentation procedure on all patients using the IMAGEnet digital imaging system. Analysis of corneal endothelial cell images was performed with the Cell Soft software (Topcon Corporation, Japan). MAIN OUTCOME MEASURES: Visual acuity and central corneal endothelial cell loss. RESULTS: The patients were randomized to intraocular lens (IOL; n = 616) and no IOL (n = 613) implantation. Surgical complications were reported in 177 (14.4%) patients (IOL = 14.8%; no IOL = 14.0%). The most frequent complication observed was vitreous loss which occurred in 10.3% of eyes (IOL = 11.2%; no IOL = 9.5%). At the final examination (2 years after surgery), 88% of the operated eyes had a best corrected vision of 6/18 or better (IOL = 88.8%; no IOL = 86.6%). Analysis of corneal endothelial cell data showed a small but significantly greater cell loss 6 weeks after surgery in eyes with IOL compared with those without IOL, but no overall difference was found between the treatment groups in the long term follow-up. CONCLUSIONS: The findings indicate that there is a rationale for the use of anterior chamber intraocular lenses in primary intracapsular cataract surgery.

Adult↗
PubMed2000

Anterior capsule opacification: a histopathological study comparing different IOL styles.

OBJECTIVE: To compare the degree of anterior capsule opacification (ACO) in human eyes obtained post-mortem containing various rigid and foldable posterior chamber intraocular lens (PC-IOL) designs. DESIGN: Comparative autopsy tissue study with clinicopathologic correlations. MATERIALS: Four hundred sixty human globes containing the following PC-IOL styles were analyzed: (1) one-piece polymethylmethacrylate (PMMA) optic-PMMA haptic (n = 50), (2) one-piece silicone-plate IOL, large hole (n = 40), (3) one-piece silicone-plate IOL, small hole (n = 67), (4) three-piece PMMA optic-PMMA/Prolene haptic (n = 51), (5) three-piece acrylic optic-PMMA haptic (n = 96), (6) three-piece silicone optic-PMMA haptic (n = 24), (7) three-piece silicone optic-polyimide haptic (n = 40), and (8) three-piece silicone optic-prolene haptic (n = 92). TESTING: The globes were sectioned in the equatorial plane for gross examination and then processed through paraffin; sectioned, and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome stains; and examined by light microscopy. MAIN OUTCOME MEASURES: Anterior capsule opacification was scored in each eye by grading the histologic sections from 0 to III, according to the amount (thickness) of proliferative tissue and cells measured in sagittal sections on the inner surface of the anterior capsule at the capsulorhexis margin. RESULTS: The difference among the eight groups was significant (P < 0.0001). Mean ACO scores were highest with the large and small hole one-piece silicone-plate lenses (1.77 +/- 0.86 and 1.28 +/- 0.77, respectively). The lowest mean score was observed in the group of three-piece acrylic optic-PMMA haptics lenses (0.51 +/- 0.52). CONCLUSIONS: Our results confirm previous clinical observations that the rate of ACO is relatively high with plate-haptic silicone IOLs. The lowest rate was noted with the three-piece acrylic optic-PMMA haptic IOL. The IOL design and IOL material are significant factors in the development of ACO.

Cataract↗
PubMed2000

Dye-enhanced cataract surgery. Part 1: anterior capsule staining for capsulorhexis in advanced/white cataract.

PURPOSE: To evaluate anterior capsule staining using 3 dyes to perform continuous curvilinear capsulorhexis (CCC) in postmortem human eyes with advanced/white cataract. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: In experimental closed-system surgery, CCC was performed in 12 postmortem human eyes with cataract after the anterior capsule was stained with 3 capsule dyes (fluorescein sodium 2%, indocyanine green [ICG] 0.5%, and trypan blue 0.1%). Two commonly used techniques for capsule staining were also compared: staining within an air bubble and intracameral subcapsular injection of dye. RESULTS: In all globes, CCC was uneventful using the 3 dyes and with both techniques. With the intracameral subcapsular injection, the dye remained trapped in the subcapsular space in contact with the posterior surface of the anterior capsule, allowing enough time to perform any maneuver. The staining provided by ICG, at the concentration used, was slightly superior to that of the other dyes. Leakage of fluorescein sodium into the vitreous cavity was seen using the Miyake-Apple posterior video/photographic technique. CONCLUSION: Intracameral subcapsular injection of ICG allowed the easiest recognition of the capsular flap by staining the posterior surface of the anterior capsule and without leaking into the vitreous cavity.

Cadaver↗
PubMed2000

Dye-enhanced cataract surgery. Part 3: posterior capsule staining to learn posterior continuous curvilinear capsulorhexis.

PURPOSE: To evaluate the use of 2 dyes for staining the posterior capsule to enhance visualization during posterior continuous curvilinear capsulorhexis (PCCC). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Indocyanine green 0.5% (ICG) and trypan blue 0.1% were used to stain the posterior capsule for performing PCCC in 8 human eyes obtained postmortem. The eyes were prepared according to the posterior video technique of Miyake-Apple. After CCC and hydrodissection/delineation were performed, the nucleus was carefully delivered by hydroexpression. Cortical cleanup was completed by irrigation/aspiration. The posterior capsule was stained by instilling 1 microdrop of ICG (4 eyes) or trypan blue (4 eyes) in the capsular bag. A PCCC was then performed by 2 independent surgeons (4 eyes/surgeon) not familiar with this technique. Each surgeon also performed PCCC in 2 eyes without the use of dye. RESULTS: Both dyes facilitated the performance of PCCC after staining the otherwise transparent posterior capsule. It was easier to differentiate the stained posterior capsule flap from the underlying transparent anterior hyaloid phase of the vitreous. In addition, optic capture of an intraocular lens, with or without anterior vitrectomy, was easily accomplished because of the enhanced visualization by posterior capsule staining. CONCLUSIONS: Posterior capsule staining can be successfully used to learn and perform the PCCC procedure, combined with optic capture, anterior vitrectomy, or both.

Cadaver↗
PubMed2000

Dye-enhanced cataract surgery. Part 2: learning critical steps of phacoemulsification.

PURPOSE: To use capsule dyes to enhance visualization to learn and perform various critical steps of the phacoemulsification procedure in a laboratory setting using postmortem human eyes. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Indocyanine green 0.5% (ICG) and trypan blue 0.1% were used to enhance visualization for performing critical steps of phacoemulsification in 8 human eyes obtained postmortem. All eyes were prepared according to the Miyake-Apple posterior video technique. After a continuous curvilinear capsulorhexis (CCC) was made, the dyes were used to enhance visualization for hydrodissection, hydrodelineation, and various maneuvers for nuclear emulsification and cortical cleanup. In 8 eyes, all the aforementioned steps were performed without using dye (control group). RESULTS: Both dyes helped enhance visualization during the critical steps of phacoemulsification. The use of a dye solution instead of balanced salt solution (BSS) for hydrodissection/delineation helped localize the complete plane of cleavage between the capsule and cortex and the nucleus-epinucleus complex. During various nuclear sculpting maneuvers, the use of dye helped visualization of the position of the phaco tip and its relation to the posterior capsule. It also helped localize remaining cortical fibers, facilitating complete cleaning of the capsular bag. CONCLUSIONS: Dye-enhanced cataract surgery was useful in learning various critical steps of phacoemulsification in a wet laboratory setting.

Cadaver↗
PubMed2000

Opacification of piggyback IOLs associated with an amorphous material attached to interlenticular surfaces.

PURPOSE: To report the pathological and ultrastructural features and interval surgical management of an atypical case of opacification between piggyback intraocular lenses (IOLs). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, and Nature Coast EyeCare Institute and Surgery Center, Perry, Florida, USA. METHODS: Opacification between 2 acrylic piggyback lenses was observed 16 months after implantation, with decreased best corrected visual acuity and a hyperopic shift. Elschnig pearls were observed in the peripheral interface between the lenses, and the central interface was occupied by an amorphous material. The pearls were surgically aspirated, but attempts to remove the central material were unsuccessful. The lenses were explanted and sent to the laboratory. Staining with hematoxylin and eosin (H&E), examination under a light microscope, and scanning electron microscopic analysis were performed. RESULTS: The surfaces of the anterior IOL were relatively clear. The amorphous material, mostly attached to the center of the anterior surface of the posterior IOL, was homogeneously stained with H&E. No cell nucleus was observed in this region. Scanning electron microscopy showed that the IOL edge presented a smooth, regular surface relatively free of deposits. The most central region was covered by an irregular layer of an amorphous compact material with some cracks, fissures, or both on its surface. CONCLUSIONS: Although the exact composition of the material between the lenses could not be established, hypotheses were advanced to understand the pathological mechanism associated with this condition. This case is different from those in previous reports of opacification composed of cortex and cells between piggyback IOLs.

Acrylates↗