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Marianne Cilluffo - One of the best experts on this subject based on the ideXlab platform.

  • p2 purinergic receptor coupled signaling in the rabbit Ciliary Body Epithelium
    Investigative Ophthalmology & Visual Science, 2002
    Co-Authors: Nasser A. Farahbakhsh, Marianne Cilluffo
    Abstract:

    PURPOSE. To identify and characterize P2 purinergic receptors and their signaling pathways in the epithelial cells of the rabbit Ciliary Body. METHODS. Real-time fluorescence ratio imaging of the intact furs-2-loaded nonpigmented Ciliary Body epithelial (NPE) cells of rabbit were used to record changes in the intracellular free calcium concentration ([Ca 2+ ] i ), in response to a number of purinergic agonists and antagonists. The effects of some of these drugs on the inositol phosphate (IP) levels in Ciliary processes were also examined. RESULTS. Adenosine diphosphate (ADP), adenosine triphosphate (ATP), and uridine triphosphate (UTP) dose dependently increased the [Ca 2+ ] i and IP levels. The [Ca 2+ ] i increases induced by ADP and UTP were distinguishable, both kinetically and pharmacologically. The effect of ADP on [Ca 2+ ] i was mimicked by a number of P2Y 1 -selective agonists, and was blocked by three P2Y 1 -receptor-specific antagonists. The [Ca 2+ ] i increases elicited by ADP (or its analogs) and UTP were additive. CONCLUSIONS. Rabbit Ciliary Body Epithelium possesses both P2Y 1 and P2Y 2 metabotropic purinergic receptor subtypes, which differentially use the IP 3 /Ca 2+ second-messenger pathway.

  • ocular panca antigens are expressed in nonpigmented Ciliary Body Epithelium and are conserved in multiple mammalian species
    Ocular Immunology and Inflammation, 2001
    Co-Authors: Hallie Sandusky, Marianne Cilluffo, Jonathan Braun, Lynn K Gordon
    Abstract:

    PURPOSE: pANCA marker autoantiBody is expressed by a subset of patients with anterior uveitis. A recombinantly isolated pANCA monoclonal antiBody, Fab 5–3, identifies ocular expression of corresponding pANCA antigens in human Ciliary Body and retina. In this study, Fab 5–3 was used to explore pANCA antigen expression in ocular tissues of multiple mammalian species and identify the Ciliary Body cell type expressing the pANCA antigen. METHODS: Ocular tissues were obtained from several mammalian species and evaluated for expression of the pANCA (Fab 5–3) antigen(s) using immunohistochemistry and Western analysis of tissue extracts. Additionally, primary cultures of nonpigmented and pigmented rabbit Ciliary Body Epithelium were analyzed for pANCA expression using immunofluorescence and Western analysis. RESULTS: Ocular pANCA (Fab 5–3) antigen expression was observed by immunohistochemistry only in the cytoplasm of retinal ganglion cells and Ciliary Body Epithelium. Retinal antigen expression was conserved in ...

  • nonpigmented cells of the rabbit Ciliary Body Epithelium tissue culture and voltage gated currents
    Investigative Ophthalmology & Visual Science, 1991
    Co-Authors: Marianne Cilluffo, B N Cohen, Gordon L Fain
    Abstract:

    The aqueous humor of the eye is thought to be secreted by the Epithelium of the Ciliary Body. This Epithelium has been difficult to study, in part because of its complicated morphology. The authors attempted to circumvent this difficulty by growing the epithelial cells in tissue culture. A procedure is described for producing pure primary cultures of rabbit nonpigmented Ciliary Body epithelial cells. This procedure was used with whole-cell patch-clamp recording to characterize voltage-activated currents in the nonpigmented cells. These experiments show that most nonpigmented cells contain two kinds of currents: a rapidly activating and inactivating inward current, carried by Na + and blocked by tetrodotoxin (TTX), and a more slowly activating and inactivating outward current, blocked by tetraethylammonium (TEA + ), Ba 2+ , and 4-aminopyridine (4-AP) and presumably carried by K + . Both of these currents have been observed in freshly dissociated cells and in cultures up to 7 days old. The voltagegated currents in Ciliary Body epithelial cells are remarkably similar to those of neurons and raise the possibility that these epithelial cells are capable of spike propagation. Invest Ophthalmol Vis Sci 32:1619-1629, 1991 The Epithelium of the Ciliary Body lies at the inner margin of the eye between the retina and the iris and is thought to be responsible for secreting the aqueous humor. 1 The physiology of this Epithelium has been difficult to study, in part because of its complicated morphology. The Epithelium lies on the surface of the highly invaginated Ciliary processes and is difficult to mount in an Ussing chamber. Furthermore, there are two kinds of epithelial cells which occur in separate layers: the pigmented cells which face the stroma and the nonpigmented, which face the lumen of the posterior chamber. These two cell types have different populations of transport enzymes, receptors, and other proteins. 2 " 6 The cells of these two layers are coupled electrically 7 by an extensive network of gap junctions, both among the cells of each layer and from one layer to the other. 8 This makes it difficult to interpret recordings from intact or semiintact epithelial preparations. 7

  • nonpigmented cells of the rabbit Ciliary Body Epithelium tissue culture and voltage gated currents
    Investigative Ophthalmology & Visual Science, 1991
    Co-Authors: Marianne Cilluffo, B N Cohen, Gordon L Fain
    Abstract:

    The aqueous humor of the eye is thought to be secreted by the Epithelium of the Ciliary Body. This Epithelium has been difficult to study, in part because of its complicated morphology. The authors attempted to circumvent this difficulty by growing the epithelial cells in tissue culture. A procedure is described for producing pure primary cultures of rabbit nonpigmented Ciliary Body epithelial cells. This procedure was used with whole-cell patch-clamp recording to characterize voltage-activated currents in the nonpigmented cells. These experiments show that most nonpigmented cells contain two kinds of currents: a rapidly activating and inactivating inward current, carried by Na+ and blocked by tetrodotoxin (TTX), and a more slowly activating and inactivating outward current, blocked by tetraethylammonium (TEA+), Ba2+, and 4-aminopyridine (4-AP) and presumably carried by K+. Both of these currents have been observed in freshly dissociated cells and in cultures up to 7 days old. The voltage-gated currents in Ciliary Body epithelial cells are remarkably similar to those of neurons and raise the possibility that these epithelial cells are capable of spike propagation.

Gordon L Fain - One of the best experts on this subject based on the ideXlab platform.

  • nonpigmented cells of the rabbit Ciliary Body Epithelium tissue culture and voltage gated currents
    Investigative Ophthalmology & Visual Science, 1991
    Co-Authors: Marianne Cilluffo, B N Cohen, Gordon L Fain
    Abstract:

    The aqueous humor of the eye is thought to be secreted by the Epithelium of the Ciliary Body. This Epithelium has been difficult to study, in part because of its complicated morphology. The authors attempted to circumvent this difficulty by growing the epithelial cells in tissue culture. A procedure is described for producing pure primary cultures of rabbit nonpigmented Ciliary Body epithelial cells. This procedure was used with whole-cell patch-clamp recording to characterize voltage-activated currents in the nonpigmented cells. These experiments show that most nonpigmented cells contain two kinds of currents: a rapidly activating and inactivating inward current, carried by Na + and blocked by tetrodotoxin (TTX), and a more slowly activating and inactivating outward current, blocked by tetraethylammonium (TEA + ), Ba 2+ , and 4-aminopyridine (4-AP) and presumably carried by K + . Both of these currents have been observed in freshly dissociated cells and in cultures up to 7 days old. The voltagegated currents in Ciliary Body epithelial cells are remarkably similar to those of neurons and raise the possibility that these epithelial cells are capable of spike propagation. Invest Ophthalmol Vis Sci 32:1619-1629, 1991 The Epithelium of the Ciliary Body lies at the inner margin of the eye between the retina and the iris and is thought to be responsible for secreting the aqueous humor. 1 The physiology of this Epithelium has been difficult to study, in part because of its complicated morphology. The Epithelium lies on the surface of the highly invaginated Ciliary processes and is difficult to mount in an Ussing chamber. Furthermore, there are two kinds of epithelial cells which occur in separate layers: the pigmented cells which face the stroma and the nonpigmented, which face the lumen of the posterior chamber. These two cell types have different populations of transport enzymes, receptors, and other proteins. 2 " 6 The cells of these two layers are coupled electrically 7 by an extensive network of gap junctions, both among the cells of each layer and from one layer to the other. 8 This makes it difficult to interpret recordings from intact or semiintact epithelial preparations. 7

  • nonpigmented cells of the rabbit Ciliary Body Epithelium tissue culture and voltage gated currents
    Investigative Ophthalmology & Visual Science, 1991
    Co-Authors: Marianne Cilluffo, B N Cohen, Gordon L Fain
    Abstract:

    The aqueous humor of the eye is thought to be secreted by the Epithelium of the Ciliary Body. This Epithelium has been difficult to study, in part because of its complicated morphology. The authors attempted to circumvent this difficulty by growing the epithelial cells in tissue culture. A procedure is described for producing pure primary cultures of rabbit nonpigmented Ciliary Body epithelial cells. This procedure was used with whole-cell patch-clamp recording to characterize voltage-activated currents in the nonpigmented cells. These experiments show that most nonpigmented cells contain two kinds of currents: a rapidly activating and inactivating inward current, carried by Na+ and blocked by tetrodotoxin (TTX), and a more slowly activating and inactivating outward current, blocked by tetraethylammonium (TEA+), Ba2+, and 4-aminopyridine (4-AP) and presumably carried by K+. Both of these currents have been observed in freshly dissociated cells and in cultures up to 7 days old. The voltage-gated currents in Ciliary Body epithelial cells are remarkably similar to those of neurons and raise the possibility that these epithelial cells are capable of spike propagation.

David J Apple - One of the best experts on this subject based on the ideXlab platform.

  • A Comparison of Neodymium:Yttrium Aluminum Garnet and Diode Laser Transscleral Cyclophotocoagulation and Cyclocryotherapy Materials and Methods
    2020
    Co-Authors: Ehud I Assia, Hugh L Hennis, W C Stewart, Ulrich F C Legler, Alan N Carlson, David J Apple
    Abstract:

    The cyclodestructive effects of cyclocryotherapy and of the neodymium:yttrium aluminum garnet (Nd:YAG) and diode laser transscleral cyclophotocoagulation were investigated in phakic and pseudophakic cadaver eyes using a modified Miyake posterior-view technique and light microscopy. Cyclocryotherapy to -80°C was applied with a 2.5-mm diameter tip, 1 and 2 mm from the limbus. Freezing at the Ciliary processes was evident after 10-15 sec and reached a diameter of 3-4 mm by 30 sec. No visible changes were evident grossly in the Ciliary processes, crystalline lens, or intraocular lens. Histologically increased separation of cells was observed. Effective noncontact Nd:YAG and diode laser applications to the Ciliary processes were observed grossly as tissue blanching and shrinking and pigment dispersion. This effect was obtained by aiming 0.5-1.0 mm behind the limbus at a 1-mm defocus using 4 J of energy for the NdrYAG and 1.2 J for the diode laser. The diode laser spot size did not affect the tissue response. No damage was observed in the crystalline or intraocular lens with either type of laser. Histologic changes using both lasers were coagulation necrosis with fragmentation and detachment of the Ciliary Body Epithelium. This study suggested that the gross and histologic thermal effects produced by the diode and Nd:YAG laser were similar in the Ciliary Body. Also, at the time of surgery, these cyclodestructive procedures potentially cause little alteration of the crystalline or intraocular lens. Invest Ophthalmol Vis Sci 32:2774-2778,1991 Cyclodestructive procedures are done in selected patients in whom conventional filtering surgery either previously failed or was not indicated. Over the past several decades, cyclocryotherapy was the cyclodestructive procedure most commonly performed. However, several laser cyclodestructive techniques recently were described, using either the neodymium:yttrium aluminum garnet (Nd:YAG) or semiconductor diode laser energy. In this study, we compared the gross and histologic changes in the Ciliary Body, crystalline lens, intraocular lens, and capsular bag of cadaver eyes, using various treatment parameters of these cyclodestructive techniques. Our results were evaluated using a modified Miyake posterior photographic technique and light microscopy. Materials and Methods Eight eyes, obtained within 36 hr of death, were prepared according to the Miyake posterior photographic technique by transsecting the globe anterior to the equator and filling it with 1% hyaluronic acid. 1 This technique was modified from the method used in previous reports to allow real-time posterior photographic imaging of transscleral cyclodestructive laser applications from a slit-lamp apparatus. In four of the eyes evaluated in this study, the lens nucleus was removed by manual extraction, followed by aspiration of cortical material. A one-piece polymethylmethacrylate posterior chamber intraocular lens 12.5 mm in length with a 6-mm diameter optic was implanted in the capsular bag. Cyclocryotherapy was applied to -80°C with nitrous oxide gas (Frigitronics, Coral Gables, Florida) 1 and 2 mm posterior to the surgical limbus with slight pressure on a 2.5-mm diameter probe tip. Separate applications were done for 1, 2, 4, and 8 min. A Microrupter 2 (Lasag, Eden Prairie, Minnesota) was used for the Nd: YAG transscleral cyclophotocoagulation. This laser has a wavelength of 1064 nm and was used in the thermal mode with a maximum defocus. Laser applications were evaluated that were aimed 0.5, 1, and 2 mm posterior to the surgical limDownloaded from iovs.arvojournals.org on 06/28/201

  • a comparison of neodymium yttrium aluminum garnet and diode laser transscleral cyclophotocoagulation and cyclocryotherapy
    Investigative Ophthalmology & Visual Science, 1991
    Co-Authors: Ehud I Assia, Hugh L Hennis, W C Stewart, Ulrich F C Legler, Alan N Carlson, David J Apple
    Abstract:

    The cyclodestructive effects of cyclocryotherapy and of the neodymium:yttrium aluminum garnet (Nd:YAG) and diode laser transscleral cyclophotocoagulation were investigated in phakic and pseudophakic cadaver eyes using a modified Miyake posterior-view technique and light microscopy. Cyclocryotherapy to -80 degrees C was applied with a 2.5-mm diameter tip, 1 and 2 mm from the limbus. Freezing at the Ciliary processes was evident after 10-15 sec and reached a diameter of 3-4 mm by 30 sec. No visible changes were evident grossly in the Ciliary processes, crystalline lens, or intraocular lens. Histologically increased separation of cells was observed. Effective noncontact Nd:YAG and diode laser applications to the Ciliary processes were observed grossly as tissue blanching and shrinking and pigment dispersion. This effect was obtained by aiming 0.5-1.0 mm behind the limbus at a 1-mm defocus using 4 J of energy for the Nd:YAG and 1.2 J for the diode laser. The diode laser spot size did not affect the tissue response. No damage was observed in the crystalline or intraocular lens with either type of laser. Histologic changes using both lasers were coagulation necrosis with fragmentation and detachment of the Ciliary Body Epithelium. This study suggested that the gross and histologic thermal effects produced by the diode and Nd:YAG laser were similar in the Ciliary Body. Also, at the time of surgery, these cyclodestructive procedures potentially cause little alteration of the crystalline or intraocular lens.

J M Wolosin - One of the best experts on this subject based on the ideXlab platform.

  • ca2 mobilization and interlayer signal transfer in the heterocellular bilayered Epithelium of the rabbit Ciliary Body
    The Journal of Physiology, 1996
    Co-Authors: M Schutte, J M Wolosin
    Abstract:

    1. 'Ratiometric' fura-2 methodology in slice preparations and 'intensitometric' fluo-3 measurements of confocal images were used to simultaneously monitor Ca2+ mobilization in the two distinct, apically joined cell layers which constitute the Ciliary Body Epithelium (CBE): the non-pigmented (NPE) and pigmented (PE) epithelia. 2. Both methods yielded comparable results regarding Ca2+ responses in the syncytium upon stimulation with adrenergic and cholinergic agonists. 3. The alpha 1-adrenoceptor agonist phenylephrine elicited a moderate [Ca2+]i increase in the PE, whereas NPE [Ca2+]i remained unchanged or exhibited a slight diminution. 4. In combination with carbachol, the alpha 2-adrenoceptor agonist brimonidine elicited large Ca2+ increases (> 10-fold) in both the NPE and PE cell layers, even though previous studies indicated the absence of an alpha 2-adrenergic effect on [Ca2+]i in the PE. The onset, as well as the peak of the Ca2+ responses in PE cells frequently exhibited a small delay with respect to adjacent NPE cells. No such time difference was observed between adjacent NPE cells. 5. Pre-incubation of the Ciliary Body in Ca(2+)-free solution under conditions known to elicit overt NPE-PE separation abolished the alpha 2-adrenocholinergic response in the PE. 6. Addition of heptanol to the perfusate, to block gap-junctional communication, caused a small [Ca2+]i decrease in the NPE and a slight increase in PE[Ca2+]i. Subsequently, the Ca2+ mobilization in the Pe in response to the brimonidine and carbachol combination was either blocked or showed a substantial delay. The Ca2+ mobilization in the NPE, in contrast, remained unchanged. 7. We conclude that the heterocellular syncytium exhibits rectificatory behaviour with respect to Ca2+ mobilization; responses originating within the NPE are easily transferred to the PE, while the reverse does not occur.

  • adreno cholinergic modulation of junctional communications between the pigmented and nonpigmented layers of the Ciliary Body Epithelium
    Investigative Ophthalmology & Visual Science, 1996
    Co-Authors: X P Shi, Aldo C Zamudio, Oscar A Candia, J M Wolosin
    Abstract:

    Purpose. Cell-to-cell communications between the epithelial layers of the Ciliary Body may be critical for aqueous humor production. The aim of this study was to identify pharmacologic agents that affect this path. Methods. Whole New Zealand rabbit Ciliary bodies were mounted in Ussing-type chambers with Ca 2+ -free and Ca 2+ -rich Tyrode's in the nonpigmented (NPE; aqueous) and pigmented (PE; serosa) epithelial side hemichambers, respectively. The NPE or the PE were then permeabilized, either selectively to monovalent ions with amphotericin B or nonselectively to small solutes with digitonin. Resultant active transport activities were tracked as short circuit currents (IscS). Results. Permeabilization of the NPE with eidier 10 /JM amphotericin B or 10 /JM digitonin led to an aqueous-to-serosa-positive Isc. This I.* was inhibited by serosal-side ouabain and heptanol, indicating movement of Na + from the permeabilized NPE to the PE by the interlayer junctional path, followed by PE-to-serosa active Na + transport. Permeabilization of the PE with amphotericin B elicited an 1^ in the opposite direction. This I^ was abolished by aqueousside ouabain and by heptanol, consistent with sequential PE to NPE Na + translocation, followed by active, NPE-to-aqueous transport. Acetylcholine, epinephrine, norepinephrine, and the aradrenergic agonist phenylephrine, but not brominidine, an aradrenergic agonist, each caused an approximately 50% reduction of these currents. The inhibitions were fully dependent on serosal-side Ca 2+ and were blocked by one calmodulin inhibitor, trifluoperazine, but not by another, calmidazolium. Conclusions. The above observations provide evidence that cholinergic or aradrenergic activation of the PE causes Ca 2+ - dependent inhibition of the NPE - PE junctional path. A trifluoperazine-sensitive entity, which may be distinct from calmodulin, is involved in the inhibition. Invest Ophthalmol Vis Sci. 1996; 37:1037-1046. Aqueous humor production is thought to involve a functional interplay between the two apically apposed, distinct cell layers that form the Ciliary Body Epithelium, namely, the aqueous-facing nonpigmented (NPE) and the serosal-facing pigmented (PE) epithelia. The two apical membranes are attached tightly by

  • comparative adrenocholinergic control of intracellular ca2 in the layers of the Ciliary Body Epithelium
    Investigative Ophthalmology & Visual Science, 1996
    Co-Authors: M Schutte, C Wang, A Diadori, J M Wolosin
    Abstract:

    PURPOSE Both nonpigmented epithelia (NPE) and pigmented epithelia (PE) of the Ciliary Body are thought to participate in the formation of aqueous humor and its pharmacologic regulation. The aim of this study was to identify the similarities and differences in intracellular Ca2+ ([Ca2+]i) changes in each of the two layers in response to adrenergic and cholinergic inputs. METHODS Incubation of the Dutch belted rabbit Ciliary Body (CB) in low-[Ca2+] solution was used to induce the functional dissociation of the NPE and PE layers from each other. These layers or the intact undissociated CB were loaded with the fluorescent Ca2+ indicator fura-2 and mounted in superfusion chambers for fluorometric measurement of [Ca2+]i. RESULTS In the NPE of the intact CB Epithelium or in the isolated NPE, 10 microM acetylcholine (ACh), 1 microM brimonidine (UK 14304), or 1 microM epinephrine each elicited minimal rises in [Ca2+]i. On the other hand, the combination of either adrenergic drug with ACh resulted in large mobilizations of this cation. The alpha 1-adrenergic agonist phenylephrine was unable to induce Ca2+ mobilization in the isolated NPE and failed to do so in 10 of 12 intact CB specimens. In the isolated PE, both epinephrine and phenylephrine elicited substantial similar [Ca2+]i increases, ACh induced a smaller and slower rise, and the response to its combination with either adrenergic drug was essentially additive. UK 14304 (+/- ACh) had no measurable effect in these cells. CONCLUSIONS Each layer of the CBE exhibits distinct alpha-adrenergic control mechanisms. The NPE contains an alpha 2-adrenergic mechanism highly dependent on the cholinergic tone. The PE, in contrast, contains an alpha 1-adrenergic pathway that operates independently of cholinergic input. This segregation of mechanisms provides a basis for highly complex regulatory responses in the intact, syncytially organized Ciliary Body Epithelium.

  • a vesicular preparation enriched in basolateral membranes from cow Ciliary Body Epithelium
    Current Eye Research, 1991
    Co-Authors: C M Debacker, J M Wolosin
    Abstract:

    A procedure is described for the preparation of a tissue fraction enriched in basal-lateral membranes of the Epithelium of Ciliary Body dissected from abattoir-derived cow eyes. Microscopical methods established the viability of the epithelial cells in the dissected tissue. A two-step homogenization procedure was employed. First, mild trituration with a Potter-Elvehjem tissue grinder was used to release the epithelial cells with minimal disintegration of the stroma and muscle components. Then, complete vesiculation of the released material was induced with a Dounce homogenizer. This material was fractionated through sequential differential and (Ficoll 400) equilibrium density gradient centrifugation steps. The procedure led to the isolation of a fraction enriched 16.8 +/- 5.5 (+/- SE, n = 5) fold in Na(+)+K(+)-ATPase activity with respect to the initial homogenate. Using a method to artificially generate pH gradients it was demonstrated that the preparation contained sealed vesicles and that the membranes of these vesicles exhibited a K+ selectivity consistent with a plasma membrane origin.

W C Stewart - One of the best experts on this subject based on the ideXlab platform.

  • A Comparison of Neodymium:Yttrium Aluminum Garnet and Diode Laser Transscleral Cyclophotocoagulation and Cyclocryotherapy Materials and Methods
    2020
    Co-Authors: Ehud I Assia, Hugh L Hennis, W C Stewart, Ulrich F C Legler, Alan N Carlson, David J Apple
    Abstract:

    The cyclodestructive effects of cyclocryotherapy and of the neodymium:yttrium aluminum garnet (Nd:YAG) and diode laser transscleral cyclophotocoagulation were investigated in phakic and pseudophakic cadaver eyes using a modified Miyake posterior-view technique and light microscopy. Cyclocryotherapy to -80°C was applied with a 2.5-mm diameter tip, 1 and 2 mm from the limbus. Freezing at the Ciliary processes was evident after 10-15 sec and reached a diameter of 3-4 mm by 30 sec. No visible changes were evident grossly in the Ciliary processes, crystalline lens, or intraocular lens. Histologically increased separation of cells was observed. Effective noncontact Nd:YAG and diode laser applications to the Ciliary processes were observed grossly as tissue blanching and shrinking and pigment dispersion. This effect was obtained by aiming 0.5-1.0 mm behind the limbus at a 1-mm defocus using 4 J of energy for the NdrYAG and 1.2 J for the diode laser. The diode laser spot size did not affect the tissue response. No damage was observed in the crystalline or intraocular lens with either type of laser. Histologic changes using both lasers were coagulation necrosis with fragmentation and detachment of the Ciliary Body Epithelium. This study suggested that the gross and histologic thermal effects produced by the diode and Nd:YAG laser were similar in the Ciliary Body. Also, at the time of surgery, these cyclodestructive procedures potentially cause little alteration of the crystalline or intraocular lens. Invest Ophthalmol Vis Sci 32:2774-2778,1991 Cyclodestructive procedures are done in selected patients in whom conventional filtering surgery either previously failed or was not indicated. Over the past several decades, cyclocryotherapy was the cyclodestructive procedure most commonly performed. However, several laser cyclodestructive techniques recently were described, using either the neodymium:yttrium aluminum garnet (Nd:YAG) or semiconductor diode laser energy. In this study, we compared the gross and histologic changes in the Ciliary Body, crystalline lens, intraocular lens, and capsular bag of cadaver eyes, using various treatment parameters of these cyclodestructive techniques. Our results were evaluated using a modified Miyake posterior photographic technique and light microscopy. Materials and Methods Eight eyes, obtained within 36 hr of death, were prepared according to the Miyake posterior photographic technique by transsecting the globe anterior to the equator and filling it with 1% hyaluronic acid. 1 This technique was modified from the method used in previous reports to allow real-time posterior photographic imaging of transscleral cyclodestructive laser applications from a slit-lamp apparatus. In four of the eyes evaluated in this study, the lens nucleus was removed by manual extraction, followed by aspiration of cortical material. A one-piece polymethylmethacrylate posterior chamber intraocular lens 12.5 mm in length with a 6-mm diameter optic was implanted in the capsular bag. Cyclocryotherapy was applied to -80°C with nitrous oxide gas (Frigitronics, Coral Gables, Florida) 1 and 2 mm posterior to the surgical limbus with slight pressure on a 2.5-mm diameter probe tip. Separate applications were done for 1, 2, 4, and 8 min. A Microrupter 2 (Lasag, Eden Prairie, Minnesota) was used for the Nd: YAG transscleral cyclophotocoagulation. This laser has a wavelength of 1064 nm and was used in the thermal mode with a maximum defocus. Laser applications were evaluated that were aimed 0.5, 1, and 2 mm posterior to the surgical limDownloaded from iovs.arvojournals.org on 06/28/201

  • a comparison of neodymium yttrium aluminum garnet and diode laser transscleral cyclophotocoagulation and cyclocryotherapy
    Investigative Ophthalmology & Visual Science, 1991
    Co-Authors: Ehud I Assia, Hugh L Hennis, W C Stewart, Ulrich F C Legler, Alan N Carlson, David J Apple
    Abstract:

    The cyclodestructive effects of cyclocryotherapy and of the neodymium:yttrium aluminum garnet (Nd:YAG) and diode laser transscleral cyclophotocoagulation were investigated in phakic and pseudophakic cadaver eyes using a modified Miyake posterior-view technique and light microscopy. Cyclocryotherapy to -80 degrees C was applied with a 2.5-mm diameter tip, 1 and 2 mm from the limbus. Freezing at the Ciliary processes was evident after 10-15 sec and reached a diameter of 3-4 mm by 30 sec. No visible changes were evident grossly in the Ciliary processes, crystalline lens, or intraocular lens. Histologically increased separation of cells was observed. Effective noncontact Nd:YAG and diode laser applications to the Ciliary processes were observed grossly as tissue blanching and shrinking and pigment dispersion. This effect was obtained by aiming 0.5-1.0 mm behind the limbus at a 1-mm defocus using 4 J of energy for the Nd:YAG and 1.2 J for the diode laser. The diode laser spot size did not affect the tissue response. No damage was observed in the crystalline or intraocular lens with either type of laser. Histologic changes using both lasers were coagulation necrosis with fragmentation and detachment of the Ciliary Body Epithelium. This study suggested that the gross and histologic thermal effects produced by the diode and Nd:YAG laser were similar in the Ciliary Body. Also, at the time of surgery, these cyclodestructive procedures potentially cause little alteration of the crystalline or intraocular lens.