Hypotony maculopathy: improvement of visual acuity after 7 years.

PURPOSE: To describe a 79-year-old Caucasian male with a history of hypotony maculopathy for 7 years after cataract extraction with subsequent recovery of normal intraocular pressure and improvement of visual acuity. METHODS: Interventional case report. The patient developed an intraocular pressure ranging from 0 to 5 mm Hg after cataract surgery. He developed hypotony maculopathy, and the visual acuity declined to 20/200. On evaluation 7 years later, a superior cyclodialysis cleft was detected and treated with the argon laser. RESULTS: Closure of the cleft with argon laser was successful. The intraocular pressure stabilized at 17 to 20 mm Hg, and the visual acuity improved to 20/30. CONCLUSION: The development of hypotony maculopathy leads to impairment of visual acuity. This case demonstrates that visual acuity can improve after resolution of the maculopathy even after several years of hypotony.

Clinical experience of trabeculotomy for the surgical treatment of aniridic glaucoma.

OBJECTIVE: The purpose of this study is to determine the efficacy of initial trabeculotomy in the patient with aniridic glaucoma. DESIGN: Clinical charts were reviewed. PARTICIPANTS: Twenty-nine eyes of 16 patients with aniridia were studied. INTERVENTION: Glaucoma surgery was performed. As an initial procedure, trabeculotomy was performed in 12 eyes, other surgery was performed in 17 eyes (trabeculectomy, 5; goniotomy, 5; other, 7). MAIN OUTCOME MEASURES: Success was defined as an intraocular pressure (IOP) of 21 mmHg or lower, and no further surgery was performed. RESULTS: Ten (83%) of 12 eyes obtained IOP control after first (6 eyes) or second (4 eyes) trabeculotomy with a mean follow-up period of 9.5 years. Five eyes maintained visual acuity of 20/40 to 20/200. No serious complications were found after trabeculotomy. Three (18%) of 17 eyes were controlled with the first glaucoma surgery other than trabeculotomy (goniotomy, trabeculectomy, trabeculectomy combined with trabeculotomy, and Molteno implant). Good IOP control was obtained in 8 (47%) of 17 eyes after several surgeries with a mean follow-up period of 10.4 years. Four of 17 eyes became phthisical. CONCLUSION: This study suggests that trabeculotomy is the preferred initial operation for uncontrolled glaucoma with aniridia.

Endoscopic diode laser cyclophotocoagulation with a limbal approach.

BACKGROUND AND OBJECTIVE: Endoscopic diode laser cyclophotocoagulation with a limbal approach was reviewed retrospectively. The delivery system and procedure used as well as the role of this procedure in the management of glaucoma are discussed. PATIENTS AND METHODS: An 810-nm pulsed continuous-wave diode laser capable of 1.2-W output was used. The maximum treatment area is 7 to 8 clock hours with a single limbal incision. Generally, 800 mW were used for less than 1 second, for a total of 0.8 J per treatment. RESULTS: Eight eyes of 6 patients were treated. The mean follow-up time for each procedure was 3.2 months (range 1 to 8 months) and for each eye was 5.1 months (range 2 to 8 months). Pre- and postoperative intraocular pressures were determined. Postoperative inflammation was the most common complication. CONCLUSION: One reason for the failure of transscleral cyclophotocoagulation, particularly in congenital glaucoma, may be displacement of the ciliary processes. This displacement does not permit the indirect treatment to reach the appropriate area. Because endoscopic laser cyclophotocoagulation allows direct visualization, treatment can be accurately applied to individual ciliary processes.

Update on the subconjunctival THC:YAG (holmium) laser sclerostomy Ab externo clinical trial: a 4-year report.

BACKGROUND AND OBJECTIVE: This is a follow-up report on 103 THC:YAG (holmium) sclerostomies ab externo performed on 87 eyes of 81 patients. PATIENTS AND METHODS: The patients received pulse energies of 0.06 to 0.13 J (mean total energy 4.4 +/- 3.3 J, range 0.6 to 17.1 J). RESULTS: The estimated success rates with or without medication, and allowing a second procedure, were 44% at 2 years and 36% at 4 years. The mean preoperative intraocular pressure (IOP) was 29.7 +/- 11.4 mm Hg, and the mean postoperative IOP in the successful patients was 13.6 +/- 4.6 mm Hg (P < .01). Hypotony and iris incarceration were the most frequent early complications. CONCLUSIONS: Although holmium laser sclerostomy is a relatively straightforward procedure and offers some advantages over standard trabeculectomy in select cases, it currently has a number of drawbacks that limit its use.

A high prevalence of occludable angles in a Vietnamese population.

PURPOSE: To assess the prevalence of occludable angles in a Vietnamese population. METHODS: The authors retrospectively reviewed the angle status in 482 Vietnamese patients who presented to a general ophthalmology practice. All angles were graded by a glaucoma specialist according to the Shaffer method. Patients were excluded if they had known glaucoma or narrow angles, or a history of trauma or intraocular surgery. RESULTS: A total of 29.5% of all patients surveyed and 47.8% of those 55 years of age or older had grade 0 to 2 angles. In the Framingham study, 3.8% of white patients 55 years of age or older had grade 0 to 2 angles. Of the patients in our study population, 8.5% had grade 0 to 1 angles and were considered at high risk for occlusion. CONCLUSIONS: Vietnamese patients have a much higher prevalence of narrow angles and a greater risk of angle-closure glaucoma than white patients.

Trabeculectomy with intraoperative sponge 5-fluorouracil.

PURPOSE: To retrospectively assess the outcome of trabeculectomy surgery performed using intraoperative sponge 5-fluorouracil (5-FU) (50 mg/ml). METHODS: Trabeculectomy with intraoperative sponge 5-FU was performed on 140 eyes of 119 patients. The reduction in intraocular pressure (IOP), the number of supplementary postoperative injections, and any treatment complications were noted. RESULTS: The mean preoperative IOP was 25.7 +/- 8.6 mmHg. The mean postoperative IOP was 12.5 +/- 5.7 mmHg with a mean IOP reduction of 52 percent (P < 0.0001). One hundred twenty-one (86.4 percent) eyes required no postoperative glaucoma medications, with the mean number of glaucoma medications dropping from 2.5 +/- 1.1 before operation to 0.3 +/- 0.8 after operation (P < 0.001). One hundred five eyes received a mean of 5.3 +/- 2.7 postoperative 5-FU injections. There was no significant difference in final IOP or success rate between low- and high-risk eyes, but high-risk eyes seemed to require supplementary postoperative 5-FU. Corneal epithelial damage arose in 52 (37 percent) eyes and correlated strongly with postoperative 5-FU supplementation. CONCLUSION: Intraoperative sponge 5-FU is a reasonably safe and effective adjunct to trabeculectomy surgery.

Intracellular calcium in cultured rabbit oviduct epithelial cells.

Oviduct fluid is the medium in which fertilization and early embryonic development occur but little is known about the ionic basis of fluid secretion or its control. Since calcium ions (Ca2+) are involved in the mechanism of secretion in other epithelia, the intracellular calcium concentration ([Ca2+]i) was measured in single, rabbit oviduct epithelial cells in primary culture using the fluorescent dye Fura-2. The resting [Ca2+]i was constant (115 nM) in cells cultured for 2-7 days. Ion substitution experiments demonstrated the presence of a Na+/Ca(2+)-exchange system in the plasma membrane, whereas influx through channels was found to have only a minor role maintaining the resting [Ca2+]i. The addition of dibutyryl cAMP (db cAMP) induced two types of response: the first was an increase in [Ca2+]i, dependent on the presence of extracellular Ca2+, and the second was a zero response. Extracellular ATP induced a transient increase in [Ca2+]i owing to the release of Ca2+ from intracellular stores and Ca2+ entering the cell across the plasma membrane. It is proposed that these effects may be due to the presence of two types of cell in culture-the ciliated and non-ciliated (secretory type) oviduct epithelial cells.

Human Fallopian tubal epithelial cells in vitro: establishment of polarity and potential role of intracellular calcium and extracellular ATP in fluid secretion.

A pure population of human Fallopian tubal epithelial cells has been isolated by enzyme digestion, grown in primary culture and used to explore the biochemical basis of oviduct fluid secretion. Confluence was achieved in 3-7 days. Immunocytochemical labelling for cytokeratins indicated that the cells were epithelial in nature and formed extensive desmosomal contacts, producing a polarized layer in culture. By growing the cells on collagen-impregnated filters, a small transepithelial electrical potential difference could be recorded, with the apical side of the cells negative with respect to the basal side. In addition, the consumption of glucose and the appearance of lactate were greater on the basal than on the apical side of the cells. Because intracellular Ca2+ ([Ca2+]i) is well established as a signal transduction agent in epithelial fluid secretion, the effect of a wide range of agonists on [Ca2+]i in isolated tubal epithelial cells was studied using Fura-2. The only agent which induced a change in [Ca2+]i was extracellular ATP. The transients induced were dependent on both intracellular and extracellular calcium. ATP added to the basal side of the cells of the polarized layer induced a transient increase in the potential difference. The data are consistent with a potential role for extracellular ATP in the regulation of human tubal fluid formation.

Long-term results of noncontact transscleral neodymium:YAG cyclophotocoagulation.

PURPOSE: To determine the long-term efficacy of noncontact transscleral neodymium:YAG (Nd: YAG) cyclophotocoagulation. METHODS: A retrospective analysis was made of 167 patients (173 eyes) with intractable glaucoma treated with noncontact Nd:YAG cyclophotocoagulation between December 1987 and November 1993, reviewing the treatment parameters, complications, and pre- and posttreatment intraocular pressure (IOP). The IOP was compared using a Student's t test, and the results were subjected to a Kaplan-Meier life-table analysis. Success was defined as an IOP of 22 mmHg or lower in the absence of phthisis and without having undergone any additional surgical procedures. RESULTS: Mean follow-up was 30.5 +/- 22.8 months. Mean preoperative IOP was 40.0 +/- 12.9 mmHg. Mean postoperative IOP was 19.8 +/- 11.4 mmHg (P < 0.05). The mean number of treatment sessions was 1.8 +/- 1.3 (range, 1-8) with 95 eyes (55%) having only one treatment. Kaplan-Meier survival analysis showed a probability of continued success at 3 years of approximately 73% and at 5 years of 45%. Complications included loss of two or more lines of Snellen visual acuity or one or more categories in the low-vision range (40%), phthisis (6.9%), epithelial defects (1.9%), and hyphema (0.6%). CONCLUSION: This study suggests that Nd:YAG transscleral cyclophotocoagulation provides a useful long-term reduction of IOP in eyes with advanced or complicated glaucoma, but there is a significant risk of visual loss associated with the procedure.

Human tubal fluid: formation and composition during vascular perfusion of the fallopian tube.

A vascularly perfused preparation of the Fallopian tube has been developed as a model to study the formation and composition of human tubal fluid. An artery serving the tube was cannulated and perfused at a rate of 0.7 ml/min for 1 h with Medium 199 supplemented with bovine serum albumin, heparin and antibiotics. A cannula was also inserted into the lumen. Light and scanning electron micrographs of control and perfused tubes showed that the epithelial lining was intact after perfusion. Tubal fluid was collected in 13 out of 19 experiments. Fluid could always be collected from patients who were in the follicular phase of their ovarian cycle. The mean rate of appearance was 48 microliters/h. The glucose, lactate and pyruvate concentrations in the tubal fluid, as assessed by fluorescence microanalysis, were 0.53, 8.58 and 0.17 mM respectively. There were no correlations between metabolite concentration and the length of perfusion, cannulation time, patient's age or condition. This technique provides a controlled method with which to access and examine human tubal fluid and will allow the physiology of both healthy and diseased tubes to be studied.

The regulation of rabbit oviduct fluid formation.

The control of the formation of rabbit oviduct fluid and its relationship to the secretion of chloride ions has been studied using an in vitro vascularly perfused preparation. Fluid was produced at a rate of 43.41 microliters h-1 in oviducts from rabbits in oestrus. The rate was increased by isoprenaline and tetraethylammonium, decreased by dibutyryl cAMP, dihydro4,4'diisothiocyanatostilbene-2,2'-disulfonic acid (H2DIDS), and propranolol, while amiloride had no effect. H2DIDS induced a small decrease and isoprenaline a small increase in vascular to lumen Cl- flux but propranolol and dibutyryl cAMP had no effect. Oviducts from pseudopregnant animals treated with hCG three days before the experiment produced significantly less fluid than did those from rabbits in oestrus, but there was no difference in vascular to lumen Cl- flux. The concentration of K+ in oviduct fluid formed in vitro was more than three times higher than in the vascular perfusate. The ability of adrenergic agents to influence the formation of rabbit oviduct fluid could have clinical implications in the prevention or treatment of female infertility due to blockage of the Fallopian tubes and might also be useful in enhancing the secretory activity of oviduct cells maintained in co-culture with early embryos.

Update of the subconjunctival THC:YAG (holmium) laser sclerostomy ab externo clinical trial: 30-month report.

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create 93 thermal sclerostomies ab externo in 81 glaucomatous eyes of 76 patients. Pulse energies of 80 to 120 mJ were used, with a repetition rate of 5 pulses per second. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Estimated probability of success was 0.66 at 12 months and 0.57 up to 30 months. The mean intraocular pressure in the successful cases was 12.8 +/- 4.0 mm Hg.

Use of primary cultures of rabbit oviduct epithelial cells to study the ionic basis of tubal fluid formation.

A pure population of rabbit oviduct epithelial cells was isolated and grown as a polarized monolayer on collagen-impregnated filters in primary culture. The cells were shown to be epithelial by immunocytochemical staining. The cells were mounted in a modified Ussing chamber which enabled ion transport across the cells to be studied. There was a net flux of Cl- in a basal to apical direction which was reversed by 1 mmol dibutyryl cyclic AMP l-1 (cAMP). A small but consistent transepithelial electrical potential difference (p.d.) of 0.86 mV was recorded with the apical side of the cells negative with respect to the basal. Adrenaline added to the basal side of the cells induced large transient increases in p.d. across the monolayer, involving both alpha and beta receptors. Adrenaline also induced a small increase in basal to apical Cl- transport across the cells. It is proposed that adrenergic agonists and cAMP modulate rabbit oviduct fluid formation in part via an effect on transepithelial chloride transport.

Subconjunctival THC:YAG ("holmium") laser thermal sclerostomy ab externo. A one-year report.

BACKGROUND: Laser sclerostomy can be performed in a less-invasive manner than standard filtering surgery. Longer wavelengths in the infrared range have water-absorptive characteristics that facilitate perforation of the sclera. The goal was to perform laser sclerostomy ab externo to avoid intraocular instrumentation and minimize conjunctival trauma. METHODS: A thulium, holmium, chromium-doped:YAG (THC:YAG) crystal laser was used to create thermal sclerostomies in 49 glaucomatous eyes of 46 patients. The laser is a long-pulsed (300-microsecond), compact, self-contained, solid-state laser operating in the near infrared (2.1 microns). Energy was delivered via a specially designed 22-gauge (712-microns) optic probe that emits energy at a right angle to the long axis of the fiber. Pulse energies of 80 to 120 mJ were used. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Subconjunctival 5-fluorouracil (5-FU) injections were administered in 46 eyes. Success was defined as an intraocular pressure (IOP) of less than or equal to 22 mmHg with or without medications. For eyes in which preoperative IOP was less than or equal to 22 mmHg, success was defined as a decrease in IOP of greater than or equal to 30%. RESULTS: Estimated probability of success allowing for one retreatment was 0.75 at 6 months and 0.68 at 12 months. Mean IOP of successful cases was 13.3 mmHg at both 6 and 12 months. Twelve cases failed within the initial 6 months, and two additional cases failed by 12 months. CONCLUSION: THC:YAG ("holmium") laser thermal sclerostomy is an alternative to other full-thickness filtration procedures. Further evaluation and understanding will define its ultimate role in glaucoma management.

Measurement of intracellular calcium and pH in avian neural crest cells.

1. Intracellular pH (pHi) and calcium (Cai2+) were studied in freely migrating neural crest cells and in closely packed non-migrating cells derived from avian neural tubes in vitro, using the fluorescent dyes 2,3-dicyanohydroquinone (DCH) and Indo-1 to measure pHi and Cai2+ respectively. 2. In freely migrating crest cells the pHi was approximately 0.2 pH units more alkaline and Cai2+ 90 nM lower than in closely packed cells. 3. Experiments to establish the cellular mechanisms regulating pHi in isolated neural crest cells demonstrate the presence of Na(+)-H+ exchange in 66% of the cells and Na(+)-HCO3(-)-dependent pHi-regulating mechanisms in all cells examined. 4. Interactions between pHi and Cai2+ were examined. pHi was altered using either NH4Cl pulses resulting in small changes in Cai2+ or using a weak acid and base (propionate and trimethylamine), which produced a fall and a rise in Cai2+ respectively. 5. Exposure to Ca2(+)-free media caused a lowering of Cai2+ and induced a transient acidification. 6. Application of BAPTA-AM (50 microM), a cell-permeant analogue of EGTA, resulted in a fall in Cai2+ and an intracellular acidification. 7. Co2+ and La3+ (2 mM) each induced a reversible fall in Cai2+ that was accompanied by intracellular acidification. These data suggest the presence of a transmembrane flux of Ca2+ in the resting cells. 8. It would appear that the mechanisms influencing Cai2+ and pHi are linked. This idea is discussed in terms of possible mechanisms and roles for Ca2+ and pH as modulators of neural crest cell behaviour.

Relationship between intracellular pH (pHi) and calcium (Cai2+) in avian heart fibroblasts.

Measurements of pHi and Cai2+ were made in single isolated avian heart fibroblasts using the fluorescent dyes 2,3-dicyanohydroquinone (DCH) and Indo-1. The resting level of Cai2+ is in part maintained by an influx of Ca2+ from the external medium. This flux was reduced in the absence of Ca0(2+) or by adding 2 mM LaCl3 or CoCl2 to the bathing medium; however, it was insensitive to calcium channel blockers nifedipine and verapamil. BAPTA (25 microM), a calcium chelator, also reduced Cai2+. Changes in Cai2+ brought about by any of these methods were found to be accompanied by an intracellular acidification. Experiments were carried out altering pHi using trimethylamine, propionate, and ammonium chloride to determine whether pHi could influence Cai2+. It was found that an intracellular acidification induced a fall in Cai2+ and any rise in pHi induced a rise in Cai2+. These results suggest a direct interaction between Cai2+ and pHi. Various models are described which may account for the experimental observations. The findings are discussed in terms of the possible roles for pHi and Cai2+ and their interactions to influence cell motility and adhesion.

Interactions between intracellular pH and calcium in single mouse neuroblastoma (N2A) and rat pheochromocytoma cells (PC12).

Intracellular pH (pHi) was measured at the tips of extending neurites and in the corresponding cell bodies of single cultured mouse neuroblastoma (N2A) and rat pheochromocytoma cells (PC12) using the fluorescent dye 2,3-di-cyanohydroquinone (DCH). It was observed that pHi at the tip of an extending neurite was consistently 0.2-0.3 pH units higher than pHi in the cell body. Experiments performed on whole cells to establish the types of cellular mechanism which could be responsible for such regional differences demonstrate the presence of Na+-H+ exchange and Cl- HCO3- exchange in these cells. Since regional variations in Ca2i+ have been reported between neurites and the cell body, experiments were performed to examine the possible interactions between pHi and Ca2i+. Intracellular calcium was measured using the fluorescent Ca2+-sensitive dye Indo-1. An increase in pHi, on application of NH4Cl, resulted in a transient elevation of Ca12i+. On subsequent acidification, on removal of NH4Cl, there was a further transient increase in Ca2i+. These changes in Ca2i+ were also present in solutions with low calcium suggesting that Ca2i+ is mobilized from within the cell. The results are discussed in terms of possible mechanisms whereby the extension and retraction of cell processes could be influenced by Ca2i+ and modulated by pHi.