Choriocapillaris atrophy after submacular surgery in presumed ocular histoplasmosis syndrome.
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Adult↗
Biomedical subjects
L V Del Priore
Publications and source records attributed to L V Del Priore.
Retinal pigment epithelial repopulation in monkeys after submacular surgery.
BACKGROUND: Transplantation of retinal pigment epithelium may be a treatment for retinal diseases, such as age-related macular degeneration and hereditary macular degeneration. Before transplantation studies are undertaken, questions concerning repopulation of retinal pigment epithelial cells in situ and photoreceptor repair after submacular surgery need to be addressed. METHODS: We removed the retinal pigment epithelium from Bruch's membrane in the macaque monkey in the macula and outside the vascular arcades. This model allowed the study of in situ retinal pigment epithelium regrowth and photoreceptor repair for 9 months following débridement. RESULTS: Fluorescein angiography revealed a window defect in the area of denuded retinal pigment epithelium. Histologic studies revealed repopulated nonpigmented retinal pigment epithelial cells in the denuded areas in both the early and late periods. At 9 months, the repopulated retinal pigment epithelium was associated with repaired, normal-appearing photoreceptor outer segments. Retinal pigment epithelium regrowth was observed only if Bruch's membrane was intact. CONCLUSIONS: Repopulation of retinal pigment epithelium in the adult primate can occur rapidly and can support the repair of damaged photoreceptors following submacular surgery.
Animals↗
Débridement of the pig retinal pigment epithelium in vivo.
OBJECTIVE: To study the morphologic effects of surgical débridement of the retinal pigment epithelium (RPE) in an animal model. METHODS: A pars plana vitrectomy was performed in the domestic pig, and a neurosensory retinal detachment was created by injecting the calcium-chelating agent edetic acid (commonly referred to as ethylenediaminetetraacetic acid or EDTA) into the subretinal space through a retinotomy. Twenty minutes later, the RPE was débrided by gently brushing Bruch's membrane with a soft-tip silicone catheter. Dissociated RPE was aspirated from the subretinal space, and the retina was reattached with a fluid-gas exchange. RESULTS: Light microscopic analysis confirmed that Bruch's membrane was devoid of native RPE and the choriocapillaris was morphologically intact immediately after débridement. Photoreceptor outer segments were disrupted and foreshortened immediately after RPE débridement. One to 4 weeks later, a layer of hypopigmented RPE covered most of the previously débrided areas of Bruch's membrane. The choriocapillaris was intact in areas of Bruch's membrane that were repopulated by hypopigmented RPE, and remained intact 12 weeks after débridement. Some regions of Bruch's membrane near the retinotomy remained devoid of RPE for more than 4 weeks after débridement. The choriocapillaris was atrophic and there was extensive disruption of the outer retinal layers in these areas. CONCLUSIONS: The RPE healed in most areas after surgical débridement of the RPE in the experimental animal. Atrophy of the choriocapillaris was present in areas of poor RPE healing near the retinotomy.
Animals↗
Transretinal membrane formation in diffuse unilateral subacute neuroretinitis.
BACKGROUND: Diffuse unilateral subacute neuroretinitis (DUSN) is characterized by unilateral visual loss with vitreous inflammation, optic disc swelling, and the presence of gray-white lesions in the deep retina, and can be associated with intraocular nematode infection. To date, no cases of transretinal membrane formation in DUSN have been reported. METHODS: A 22-year-old woman was examined for a 2-week history of unilateral decreased vision and neuroretinitis. A subretinal nematode was identified and a diagnosis of DUSN was made. The nematode was destroyed with laser photocoagulation. An epiretinal membrane and traction retinal detachment persisted and the membrane was removed surgically, at which time it was noted to be transretinal, passing through a full-thickness retinal defect into the subretinal space. Laser photocoagulation was performed with the argon green laser (400 mW, 400 microns, 100 msec). Subsequent removal of the epiretinal portion of the transretinal membrane was performed via a pars plana approach. The membrane was studied by transmission electron microscopy (TEM). RESULTS: The laser photocoagulation was successful in destroying the nematode. Partial resolution of the neurosensory detachment resulted in marked improvement in visual acuity. The membrane consisted of a pauicellular collagenous stroma with scattered fibroblasts and mononuclear inflammatory cells. CONCLUSION: Removal of membranes affecting the macula may be of benefit in selected patients with DUSN.
Acute Disease↗
Surgery for subfoveal membranes in myopia, angioid streaks, and other disorders.
OBJECTIVE: A retrospective analysis of patients who underwent surgical removal of subfoveal neovascular membranes caused by factors other than age-related macular degeneration (AMD) and presumed ocular histoplasmosis syndrome (POHS) was performed. METHODS: 17 eyes (16 patients) were identified in which subfoveal neovascularization was caused by myopic degeneration (5 eyes), angioid streaks (5 eyes of 4 patients), idiopathic neovascularization (4 eyes), punctate inner choroidopathy (1 eye), multifocal choroiditis (1 eye), or candida chorioretinitis (1 eye). RESULTS: Visual acuity remained stable after surgery in 10 of 17 eyes (59%), improved by 2 or more Snellen lines in 6 eyes (35%) and decreased in 1 eye (6%). Preoperative visual acuity was 20/80 or better in only 1 of 17 eyes (6%), but 5 of 17 eyes (29%) achieved postoperative visual acuity of 20/80 or better. Intraoperative and postoperative complications included peripheral retinal tears (1 eye), peripheral rhegmatogenous retinal detachment (1 eye), and mild cataract formation (1 eye). Subretinal neovascularization recurred after surgical removal in 4 eyes, 2 of which underwent repeat surgery. CONCLUSION: Visual acuity remained stable or improved in 94% of eyes after surgical removal of subfoveal neovascularization, but postoperative visual acuity better than 20/80 was achieved in a minority of eyes.
Adolescent↗
Retinopathy in African Americans and whites with insulin-dependent diabetes mellitus.
BACKGROUND: The development and progression of diabetic retinopathy in African Americans with insulin-dependent diabetes mellitus is not known. METHODS: Two hundred subjects with insulin-dependent diabetes mellitus with duration of diabetes 16 years or less at first visit were studied; 58 were African Americans and 142 were whites. All had gradable stereoscopic color fundus photographs (seven standard fields) from at least two visits (mean time between first and second visit was 4.1 years). Subjects with hemoglobinopathy or proliferative retinopathy or subjects who had evidence of treatment for proliferative retinopathy at first visit were excluded. Masked grading of photographs was conducted using the modified Airlie House classification scheme. RESULTS: African Americans were older, heavier, had higher systolic blood pressure (all P < .05), and marginally higher hemoglobin A1 (HbA1) values (P = .06) than the whites at first visit. African Americans had a lower rate of two steps or more progression from preexistent retinopathy (19%) than whites (43%). Progression to proliferative retinopathy or treatment was similar by race. Multivariate analysis predicting development oe progression of retinopathy, while controlling for length of follow-up, found higher HbA1 (odds ratio [OR] = 2.15), longer duration of insulin-dependent diabetes mellitus (OR = 1.69), higher serum creatinine concentration (OR = 1.59), and white race (OR = 2.62) to be independent risk factors. CONCLUSIONS: These data suggest a previously unsuspected reduction in the adjusted risk for development and progression of retinopathy in African Americans. The reason for this apparently reduced risk are not known.
Adolescent↗
Histopathologic examination of vascular patterns in subfoveal neovascular membranes.
BACKGROUND: Subfoveal neovascular membranes cause significant visual loss in age-related macular degeneration (AMD) and the ocular histoplasmosis syndrome. The frequency of post-laser treatment persistence or recurrence of subfoveal membranes in AMD is as high as 51%. The reason for the high incidence of failure after laser treatment is unknown. The authors performed a histopathologic study of subfoveal membranes to determine the distribution of blood vessels within the neovascular complex, and to see if the blood vessel pattern would provide insight into the reason for laser treatment failure. METHODS: The authors used light microscopy to examine serial sections of subfoveal membranes from six patients (4 with AMD, 2 with the ocular histoplasmosis syndrome). The data from this examination were used to create detailed two-dimensional vascular maps of each membrane. RESULTS: The authors found that subfoveal membranes from patients with AMD and the ocular histoplasmosis syndrome, whether occurring de novo or after laser treatment, have a nonuniform distribution of blood vessels, and that large areas which include the membrane margin may be avascular. CONCLUSIONS: Using current laser treatment protocols, it is likely that avascular or poorly perfused peripheral areas of the neovascular complex would be left untreated after laser photocoagulation. Partial treatment of the neovascular complex may contribute to the high rate of post-laser treatment persistence or recurrence of subfoveal membranes.
Aged↗
Laser photocoagulation and fluid-gas exchange for recurrent macular hole.
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Aged↗
Trigeminal schwannoma as a cause of chronic, isolated sixth nerve palsy.
We treated two patients with trigeminal schwannomas, each of whom had an isolated, ipsilateral, abducens nerve palsy. Both patients initially had normal computed tomographic scan results and no neurologic signs of trigeminal nerve dysfunction. Trigeminal dysfunction did not develop until several years after the initial sixth nerve palsy, at which time a repeat examination disclosed the schwannoma. Accurate detection of a trigeminal schwannoma requires a careful clinical examination and appropriate neuroimaging studies. When such studies give normal results, they should be repeated if symptoms worsen or if new symptoms develop.
Abducens Nerve↗
Response of pig retinal pigment epithelium to laser photocoagulation in organ culture.
Laser photocoagulation was applied in vitro to organ culture exoplants of porcine retinal pigment epithelium (RPE) attached to Bruch's membrane. Four-millimeter-round buttons of eye wall containing RPE, choroid, and sclera were treated with 25 spots from the argon blue-green laser using 300 mW of power, a 500-micron spot size, and 0.1-s duration. Laser photocoagulation disrupts individual RPE cells acutely and lifts damaged RPE cells from Bruch's membrane. Treated areas become covered with irregular mounds of RPE cells within seven days. The acute damage and subsequent repair of the RPE in organ culture mimic the response of the RPE following laser photocoagulation in vivo. Thus, the morphologic response of the RPE to laser photocoagulation is an intrinsic property of this tissue that does not depend on the presence of the overlying retina.
Animals↗
Intraocular pressure measurement after pars plana vitrectomy.
The ability of various tonometers to measure intraocular pressure (IOP) accurately after pars plana vitrectomy was determined by using Schiøtz, Goldmann, and Digilab pneumatic tonometers before and after the procedure in 47 eyes. Seventeen of these eyes underwent intraoperative fluid-gas exchange and had an intravitreal gas bubble on the first postoperative day. The Schiøtz tonometer underestimated the Goldmann IOP by more than 10 mmHg in 6 (35%) of 17 eyes after vitrectomy with intravitreal gas and 4 (13%) of 30 eyes without intravitreal gas. The Digilab tonometer did not underestimate the Goldmann IOP by more than 10 mmHg in any eye postoperatively. However, the Digilab tonometer underestimated the Goldmann IOP by more than 5 mmHg in 3 (18%) of 17 eyes after vitrectomy with intravitreal gas and two (7%) of 30 eyes without intravitreal gas.
Adult↗
Morphology of pig retinal pigment epithelium maintained in organ culture.
Exoplants of porcine retinal pigment epithelium (RPE) attached to Bruch's membrane, choroid, and sclera were maintained in organ culture for up to four weeks. Four-millimeter round buttons of eye wall that contained RPE, choroid, and sclera were trephined from freshly enucleated pig eyes and incubated at 37 degrees C in Eagle's minimum essential medium with 10% fetal calf serum. The RPE cells remained as a monolayer for at least four weeks in organ culture, and individual RPE cells became taller and dome shaped. The RPE cells retained several prominent ultrastructural features, including apical microvilli, intracellular melanosomes and mitochondria, and intercellular tight junctions. Since the cellular substratum can exert important influences on cell behavior, the ability to maintain RPE cells attached to Bruch's membrane provides a new in vitro tool for studying the metabolic activity of this tissue and its response to external stimuli, including laser photocoagulation.
Animals↗
Neodymium: YAG and argon laser iridotomy. Long-term follow-up in a prospective, randomized clinical trial.
Neodymium:YAG (Nd:YAG) and argon laser iridotomies were compared in a prospective, randomized clinical trial of 43 patients with bilateral chronic pupillary-block glaucoma. All patients had one eye randomly assigned to argon and the fellow eye assigned to Nd:YAG laser treatment. Follow-up ranged from 20 to 42 months. Iridotomy closure was not observed in Nd:YAG-treated eyes, but nine (21%) argon iridotomies required retreatment. Visual loss due to progression of laser-induced lens or corneal damage was not observed in any eye. Nine (21%) argon-treated eyes and eight (19%) Nd:YAG-treated eyes required laser trabeculoplasty for further intraocular pressure (IOP) lowering after iridotomy. Five (12%) argon-treated and two (5%) Nd:YAG-treated eyes required intraocular filtration surgery for long-term IOP control, but this difference was not statistically significant. There were no significant long-term differences between these treatment modalities.
Adult↗
Long-term follow-up of neodymium: YAG laser angle surgery for open-angle glaucoma.
Seventy-nine eyes (61 patients) with open-angle glaucoma and uncontrolled intraocular pressure (IOP) of 23 mmHg or more despite maximal tolerated medical therapy and prior argon laser trabeculoplasty (75 eyes) were treated with neodymium: YAG (Nd: YAG) laser angle surgery and followed for at least 1 year. Ten pulses of 10 mJ were applied to the midtrabecular meshwork over 40 degrees in the most visible portion of the angle. The IOP was controlled successfully (less than or equal to 22 mmHg) in 60 eyes (76%) 1 month after treatment and in 36 of 78 eyes (46%) 1 year after treatment. Long-term complications included two eyes with advanced glaucoma that lost central fixation despite good IOP control after treatment.
Aluminum Silicates↗
Fluorescence light microscopy of F-actin in retinal rods and glial cells.
The actin cytoskeleton of rod photoreceptors and glial cells in toad retina has been directly viewed using fluorescence microscopy of cells labeled with a potent phallotoxin that specifically binds to F-actin. The three-dimensional organization of this cytoskeletal protein consists of actin filaments, which course through the inner segment and end at the tips of the calycal processes surrounding the base of the outer segment. A transverse layer of actin staining is also observed at the base of rod outer segments in the region where new discs are formed. At the level of the external limiting membrane, evidence has been found for rings of actin within the glial cells that surround the photoreceptors. These actin rings form a structural meshwork in which photoreceptor cells are embedded.
Actins↗
The Jackson cross cylinder. A reappraisal.
The Jackson cross cylinder is a frequently used but poorly understood tool for clinical refraction. A critical analysis of the principles of cross cylinder testing reveals several important features which should be understood for the proper use of this device. For example, a rarely discussed shortcoming of the cross cylinder is that it can fail to detect even large amounts of ocular astigmatism in certain situations. A little-known advantage of the cross cylinder, on the other hand, is its use in refining cylinder power at an incorrect axis. This particular property of the cross cylinder is useful when the correcting cylinder axis must be rotated toward 90 degrees, 180 degrees, or toward the old axis. The cross cylinder can be used to determine the optimal cylinder power for this new axis setting. Guidelines are also considered for the appropriate step sizes in axis rotation that should be used in cylinder axis refinement.
Astigmatism↗
Vanadate, tungstate and molybdate activate rod outer segment phosphodiesterase in the dark.
Anionic activation of rod outer segment phosphodiesterase by vanadate, molybdate and tungstate is demonstrated. Comparisons are made to adenylate cyclase, which is known to be activated by vanadate and molybdate but not by tungstate. In view of the differences in anionic activation between these two important enzymatic regulators of intracellular cyclic nucleotide metabolism, it is possible that tungstate can be used as a selective probe for the effects of phosphodiesterase activity in photoreceptors and other cells. The known electrophysiological stimulation of Limulus photoreceptors by these anions is also interpreted in light of our results. If anionic production of quantum bumps in Limulus photoreceptors is mediated by changes in cyclic nucleotides, then the electrophysiological response of Limulus photoreceptors to tungstate may indicate a role for phosphodiesterase rather than adenylate cyclase in mediating light-induced cyclic nucleotide alterations in this cell.
3',5'-Cyclic-GMP Phosphodiesterases↗