Showing papers in "Journal of Glaucoma in 1995"

Ability of the heidelberg retina tomograph to detect early glaucomatous visual field loss.

Abstract: SummaryPurposeThe Heidleberg Retina Tomograph provides rapid, reproducible measurements of optic disc topography as well as calculations of disc parameters. We used a stepwise discriminant analysis to determine which parameters were most useful in detecting individuals with early glaucomatous visual

Test/Retest Reproducibility of Color Doppler Imaging Assessment of Blood Flow Velocity in Orbital Vessels

Abstract: Purpose The purpose of this study was to evaluate the test-retest reproducibility of measures of blood flow velocities using color Doppler imaging (CDI) in orbital arteries. Patients and methods Measures of peak systolic velocity, end-diastolic velocity, and resistive index were performed in a group of 15 normal tension glaucoma patients and in 15 healthy subjects using the Siemens Quantum 2000 CDI system with a 7.5 MHz linear probe. After each velocity measure in each vessel, the probe was removed and then replaced to repeat the measurement -2 min later. Results For all subjects, the coefficients of reliability for measures of peak systolic velocity were 12% in the ophthalmic artery, 25% in the central retinal artery, and 19% in a short posterior ciliary artery. For end diastolic velocity, the coefficients were 6%, 11%, and 25%, respectively. The coefficients for resistive index were 4%, 11%, and 38%. Conclusion CDI produces highly reproducible measures in the ophthalmic artery. Measures in the central retinal artery are somewhat more variable but seem reasonably reproducible. Short posterior ciliary measurements were the most variable, suggesting that current methods for assessing these vessels may not be sufficiently reliable.

Evaluation of the effect of aging on the retinal nerve fiber layer thickness using scanning laser polarimetry.

Abstract: SummaryPurposeThe scanning laser polarimeter is a new diagnostic scanning laser instrument that uses the polarizing properties of the retinal nerve fiber layer to measure its thickness in vivo. We first ascertained the measurement reproducibility of this instrument and then evaluated the effects of

Ethnic differences in optic nerve head topography.

Abstract: Purpose To investigate ethnic differences in optic nerve head topography. Methods This is a cross-sectional university-based comparative study of 180 normal subjects (43 African-American, 45 Asian, 48 Hispanic, and 44 white subjects) ages 19–40 years. Optic nerve head parameters including optic disc size, cup-disc ratio, rim area, rim volume, cup volume, and maximal cup depth were measured using a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph). Differences among groups were evaluated using analysis of variance. Results Disc area, cup volume, maximal cup depth, and vertical cup-disc ratio were largest in African-Americans, intermediate in Asians and Hispanics, and smallest in whites; for these parameters the differences between African-Americans and whites were statistically significant. Significant differences were also found between African-Americans and Hispanics for cup volume, and between African-Americans and Asians for vertical cup-disc ratio and maximal cup depth. Rim volume and rim area were not significantly different among the four ethnic groups. Conclusions Ethnic differences in the normal optic nerve are present and should be taken into a ccount when evaluating the optic disc for glaucoma and other optic neuropathies.

Cytoskeletal changes in cultured human glaucoma trabecular meshwork cells.

Abstract: PURPOSE Glucocorticoid treatment of cultured human trabecular meshwork (TM) cells has been shown to reorganize actin microfilaments into cross-linked actin networks (CLANs) and to alter TM cell function. The purpose of the present study is to determine whether similar microfilament structural changes occur in TM cells derived from glaucoma patients. METHODS The microfilament structures of nine different TM cell cultures, derived from four glaucoma patients and from five normal subjects, was examined by epifluorescent microscopy and by whole-mount transmission electron microscopy. The cells were cultured in the absence and presence of dexamethasone (DEX) for 7-14 days. RESULTS The normal TM cell lines and glaucoma cell line TM13 had relatively low levels of cross-linked actin networks in the absence of exogenously added glucocorticoids. In contrast, the glaucoma cell lines TM23, TM36C, and TM48D had high levels of CLANs without the addition of dexamethasone. The addition of 10 M DEX to the culture medium significantly increased CLAN expression in all normal as well as glaucoma TM cell lines. CONCLUSION CLAN formation in glaucoma TM cells or in TM cells exposed to glucocorticoids may be a factor contributing to the generation of ocular hypertension.

Basic sciences in clinical glaucoma: steroids, ocular hypertension, and glaucoma.

Abstract: Glucocorticoids (GC) can regulate aqueous humor outflow and have often been associated with primary open angle glaucoma (POAG). The ocular or systemic administration of glucocorticoids can cause the elevation of intraocular pressure by increasing aqueous humor outflow resistance via morphological and biochemical changes in the trabecular meshwork (TM). The ability of glucocorticoids to induce ocular hypertension is dependent on individual responsiveness, the potency of the glucocorticoid, the route of administration, and the duration of treatment. Glucocorticoid-induced ocular hypertension occurs not only in humans, but also in rabbits, cats, dogs, and nonhuman primates. Glucocorticoids have a multitude of effects on trabecular meshwork cells causing changes in TM protein expression, cytoskeletal organization, extracellular matrix deposition, cell shape, and cell function. Many of these changes in the TM may be responsible for the generation of glucocorticoid-induced ocular hypertension. There have been several reports of increased cortisol levels, altered cortisol metabolism, and differential glucocorticoid responsiveness in patients with ocular hypertension and POAG. However, there is as yet no clear evidence for a causal role between glucocorticoids and primary open angle glaucoma. Finally, there is evidence that a variety of steroids of differing pharmacological steroid classes can lower the elevated intraocular pressure (IOP) in glucocorticoid-induced ocular hypertension and/ or in glaucoma patients. Continued research in the coming years should (a) identify the molecular mechanisms responsible for glucocorticoid-induced ocular hypertension and glaucoma, (b) determine whether glucocorticoids play a role in the pathogenesis of primary open angle glaucoma, and (c) determine the therapeutic utility of anti-glaucoma steroids.

Experience with the baerveldt implant in young patients with complicated glaucomas.

Abstract: PURPOSE Previous studies have suggested that glaucoma shunt implantation may be useful in the management of glaucoma in young patients in whom goniotomy and/or trabeculotomy have failed or are inappropriate. Herein, we describe our initial experience with Baerveldt implantation in young patients with complicated glaucomas. METHODS Charts of all patients with glaucoma who were under 21 years of age, and who underwent Baerveldt implantation between March 1, 1991 and March 1, 1993 with at least a 6-month follow-up (30 eyes of 30 patients) were reviewed retrospectively. RESULTS The patients' ages ranged from 2 months to 20 years (mean, 6.6 +/- 6.4 years) with follow-up of 6-25 months (mean, 15.0 +/- 6.3 months). Intraocular pressure (IOP) was reduced from a preoperative range of 17-78 mm Hg (mean, 35.5 +/- 13.1 mm Hg) to a range of 6-22 mm Hg (mean, 13.5 +/- 4.2 mm Hg) postoperatively. Six- and 12-month life-table success rates (6 +/- IOP +/- 21 without additional glaucoma surgery or devastating complication) were 93% and 86%, respectively. CONCLUSION Baerveldt implantation is a useful approach to the treatment of glaucoma in young patients with complicated glaucomas.

Mitomycin as adjunct chemotherapy with trabeculectomy in congenital and developmental glaucomas.

Abstract: PURPOSE To report on sixty-eight patients (98 eyes) who were trabeculectomized with the use of mitomycin C as adjunctive therapy. METHODS Fifty-six patients (79 eyes) were followed for at least 6 months or had IOP of >21 mm HG or any complications that were considered end point for them. Forty-six were primary congenital glaucoma; one was Sturger Weber disease; five were Axenfeld-Rieger syndrome; two were Peters anomaly; one was congenital glaucoma associated with ectopia lentis and one aniridia. The mean age was 76.06 +/- 81.56 months (range, 1 month to 30 years). RESULTS Fifty-three eyes (67.09%) were considered successful (IOP 21 mm Hg (30.37%), one developed retinal detachment, (1.26%) two developed phthisis (2.53%), eight had flat anterior chamber (10.12%), two vitreous hemorrhage (2.53%), and four choroidal detachment (5.06%). CONCLUSIONS Despite the number of complications, some of them very serious, the use of mitomycin seems to be a reasonable approach in these eyes with very poor surgical prognosis, otherwise candidates for setons.

Correlation of peripapillary retinal height and visual field in glaucoma and normal subjects.

Abstract: PURPOSE: To investigate the relationship between peripapillary retinal height and visual field sensitivity. PATIENTS AND METHODS: Fourteen normal subjects and 25 primary open-angle glaucoma patients were examined using a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph). Visual fields (Humphrey program 24-2) were assessed with both standard achromatic automated perimetry and shortwavelength automated perimetry. The mean peripapillary retinal height was determined for superotemporal (60-90 degrees ), superonasal (91-120 degrees ), inferotemporal (271-300 degrees ), and inferonasal (240-270 degrees ) sectors. Based on Glaucoma Hemifield Test sector definitions, achromatic automated perimetry and short-wavelength automated perimetry fields were divided into each of four distinct regions. RESULTS: Significant differences in disc rim area, rim-disc area ratio, cup volume, and each papillary region were found between glaucoma patients and normal subjects. With both standard achromatic automated perimetry and short-wavelength automated perimetry, significant correlations (p < 0.05) were found between the mean peripapillary retinal height of the inferotemporal, inferonasal, superotemporal, and superonasal sectors and age-adjusted mean deviation of their respective anatomically matched visual field region. In addition, peripapillary retinal height was more highly correlated with ageadjusted mean deviation than disc rim area in glaucoma patients. CONCLUSIONS: We found that peripapillary height, particularly in the temporal region, showed the strongest association with visual field loss in glaucoma patients.

Hypotony following trabeculectomy.

Abstract: OBJECTIVE To determine the risk factors for development of postoperative hypotony and the effects of hypotony on the outcome of surgery in terms of intraocular pressure (IOP) control and final visual acuity in patients who underwent standard trabeculectomy, trabeculectomy with postoperative 5-fluorouracil injections, trabeculectomy with intraoperative mitomycin-C, or trabeculectomy with both antimetabolites. PATIENTS AND DESIGN We retrospectively reviewed the outcome in 155 eyes of 155 patients who underwent standard trabeculectomy (n = 15), trabeculectomy with postoperative 5-fluorouracil injections (n = 81), trabeculectomy with intraoperative mitomycin-C (n = 55), or trabeculectomy with both antimetabolites (n = 4). RESULTS Hypotony developed in 108 (69.6%) eyes (IOP 14 days) in 33 eyes. The positive preoperative factors for the development of prolonged hypotony were young age, myopia, and preoperative use of carbonic anhydrase inhibitor. The mean age of patients in whom prolonged hypotony developed was 57.3 +/- 18.3 years (compare the mean age without prolonged hypotony, 65.3 +/- 14.5 years, p = 0.02). Sixteen of 33 (48%) patients in whom prolonged hypotony developed were myopic (p = 0.02), and 23 of 33 (70%) patients in whom prolonged hypotony developed used preoperative carbonic anhydrase inhibitor (p = 0.07). CONCLUSIONS There was no difference in the incidence of hypotony between patients who received 5-fluorouracil and those who received mitomycin-C. Postoperative hypotony was associated with three types of postoperative complications: shallow anterior chamber, choroidal detachment, and hypotony maculopathy (p = 0.02, 0.000, and 0.05, respectively). Hypotony did not have any effect on the success of surgery in terms of IOP control, but did have an effect on the visual outcome. Fourteen of the 33 patients (42.4%) in whom prolonged hypotony developed had worse visual acuity (p = 0.002); of these cases, four were due to hypotony maculopathy.

Reproducibility of pulsatile ocular blood flow measurements.

Abstract: SUMMARYPurposeLangham adapted the pneumotonometer to provide a waveform of the ocular pulse and using the heart rate derived values for pulsatile ocular blood flow. We have used a new pneumotonometer linked to an ocular blood flow system that has addressed several of the problems encountered with th

Influence of time separation on variability estimates of topographic measurements with confocal scanning laser tomography.

Abstract: Purpose Confocal scanning laser tomography is a new technique with significant potential in the treatment of glaucoma. Before new techniques are widely implemented in clinical practice, factors that affect the variability of measurements should be identified. The purpose of this study was to determine the influence of various time separations between images on test-retest variability of topographic measurements. Subjects and methods Our sample contained 10 healthy subjects whose mean age was 46.30 years (range 25-60 years). For each subject we obtained six sets of three images each with the Heidelberg Retina Tomograph. The images in set 1 were obtained in one sitting, in set 2 separated by 1 h each, in set 3 by 1 day each, in set 4 by 1 week each, in set 5 by 2 weeks each, and in set 6 by 4 weeks each. Results The mean (+/-1 standard deviation) test-retest variability, estimated in terms of the 90% confidence interval, ranged from 55.63 (+/-24.37) mum in set 1 to 64.37 (+/-28.00) mum in set 4. The differences between the variability estimates were not statistically significantly different among the six sets of images. Conclusions Our results show that the short-term and long-term variability of topographic measurements with scanning laser tomography are not different. Since variability was not influenced by images obtained at different sittings, our study suggests that the alignment algorithms used by the Heidelberg Retina Tomograph are robust.

Delayed-onset pneumococcal endophthalmitis after mitomycin-C trabeculectomy: association with cryptic nasolacrimal obstruction.

Abstract: Purpose Delayed-onset endophthalmitis is a well-recognized complication of glaucoma filtering surgery, but, to our knowledge, no previous reports have associated this entity with occult nasolacrimal duct obstruction. Methods A 16-month-old girl developed endophthalmitis 1 month after a mitomycin-C trabeculectomy for congenital glaucoma. A diagnostic pars plana vitrectomy, anterior chamber paracentesis, and injection of intravitreal antibiotics were performed. Results Streptococcus pneumoniae was cultured from the aqueous and vitreous samples. Gradual clearing of the infection was achieved with systemic, intravitreal, and topical antibiotic therapy. Examination following resolution of the infection revealed complete obstruction of the ipsilateral nasolacrimal duct. Conclusions The high incidence of Streptococcus pneumoniae as the causative organism in delayed-onset endophthalmitis following glaucoma filtering surgery may be related, in part, to preexisting lacrimal outflow obstruction. Careful preoperative evaluation with attention to lacrimal outflow disorders is imperative prior to glaucoma filtering surgery, especially in children.

Comparison of a simple ophthalmoscopic and planimetric measurement of glaucomatous neuroretinal rim areas

Abstract: PURPOSE The objective of this study was to compare the measurement of the optic nerve of the glaucomatous neuroretinal rim areas by planimetry and simple ophthalmoscopy. METHODS Studied were 49 randomly selected glaucomatous eyes. Their planimetric measurements of the optic nerve head and the neuroretinal rim were compared with an ophthalmoscopic measurement derived from the projection of the Welch Allyn 5 degrees illuminated cone. Axial length of the eyes was determined. RESULTS Utilizing regression equations, a correlation coefficient of 0.77 with a p value of < 0.0001 was obtained. CONCLUSION The simple ophthalmoscopic estimation of the optic nerve head size and the neuroretinal rim size in glaucomatous patients compared well with the more laborious planimetric techniques and might be helpful in evaluating optic nerve heads for glaucomatous abnormalities.

Surface area of glaucoma implants and perfusion flow rates in rabbit eyes.

Abstract: PURPOSE These experiments were designed to analyze the relationship between glaucoma drainage implant surface area and the physiological function of the surrounding encapsulation. METHODS Three sizes of Baerveldt implants were studied. Commercially available 200 mm devices were trimmed to reduce surface area to 100 and 50 mm (one side), respectively. Five samples of each size of device were studied 3 weeks after implantation in normal rabbit eyes by perfusing the drain tubes in vivo using a micromanometric system allowing precise control of flow rates. Additional eyes were analyzed at 12 weeks. Resistance to flow was calculated using Poiseuille's equation after at least three different flow rate readings for each implant, and a linear regression line was plotted for each eye. Flow rates at the pressures of 10, 15, 20, and 25 mm Hg were standardized by slope calculation and mean flow rate values for each size of implant compared statistically. Calculated flow per unit area (hydraulic conductivity) was calculated for each sized implant. RESULTS The perfusion flow tests demonstrated statistically significant differences for the values of resistance to flow and flow through the implants for the three surface areas tested. The 200 mm implants had higher flow rates and lower resistance values. A statistically significant inverse correlation was found between the surface area of the implant and the resistance to flow (p = 0.0002). A statistically significant direct correlation was also found between the surface area of the implant and the values of flow rates (p = 0.0002) through the capsules. Hydraulic conductivity of the capsules was virtually identical for all three sizes of implants tested. CONCLUSION The results demonstrate a direct relationship between the surface area of glaucoma implants and the filtering capacity of their surrounding capsules.

Postoperative complications and short-term outcome after 5-Fluorouracil or mitomycin-C trabeculectomy

Abstract: PURPOSE This study was performed to compare the postoperative complications between trabeculectomy with 5-fluorouracil injected after surgery and trabeculectomy with mitomycin-C applied intraoperatively. METHODS Retrospective review was done on 77 eyes that had received 5-fluorouracil injections after trabeculectomy, 45 eyes that received mitomycin-C during trabeculectomy, 4 eyes that received both agents, and 15 eyes that received neither agent between January 1991 and July 1992. 5-fluorouracil-treated eyes received a mean of 5 +/- 2.5 subconjunctival injections of 5 mg each (5 mg/0.1 ml). Mitomycin-C-treated eyes received 3-5 min exposure to 0.5 mg/ml mitomycin-C. Several parameters were compared between groups including hypotony defined as intraocular pressure <6 mm Hg. Success was defined as IOP <21 mm Hg with or without medications. Followup averaged 6-12 months. RESULTS Complications including hypotony, loss of visual acuity, choroidal effusion, shallow anterior chamber, cataract progression, hyphema and procedure failure were equivalent between 5-fluorouracil and mitomycin-C-treated groups. CONCLUSIONS Excluding corneal epithelial toxicity that was more common with 5-fluorouracil, the two agents used had similar success and complications during the short followup period.

Antibiotic prophylaxis in eyes with filtration blebs: survey of glaucoma specialists, microbiological study, and recommendations.

Abstract: PURPOSE Bleb-related endophthalmitis is a major late complication of filtration surgery. The purpose of this study was to determine the ophthalmic practic patterns regarding long-term antibiotic prophlaxis in eyes with filtration blebs, and the effect of long-term antibiotic usage on conjunctival bacterial flora. METHODS A mail survey of members of the American Glaucoma Society (AGS) was undertaken. In addition. 41 patients who had filtation surgery and received long-term topical antibiotic therapy in one eye only had conjunctival cultures performed in both eyes. RESULTS Of the responding members of the AGS, only 6% routinely prescribed long-term antibiotic prophylaxis, 28% prescribed therapy in selected cases only, and 66% did not employ antibiotic prophylaxis. Although more physicians than not had observed endophthalmitis in patients not receiving antibiotic therapy, it was evident that antibiotic prophylaxis did not guarantee that endophthalmitis would not develop in a filtered eye. A total of 49 organisms were isolated from the conjunctiva of eyes receiving antibiotic prophylaxis and 52 organisms were isolated from eyes not receiving antibiotic prophylaxis. There was no statistically significant difference in the types of organisms isolated. CONCLUSION Long-term antibiotic prophylaxis does not appear to be a common practice among glaucoma specialists in this country, and it cannot be depended upon as a fail-safe method to prevent bleb-related endophthalmitis. Furthermore, long-term antibiotic usage does not appear to alter the conjunctival flora. Of paramount importance are early detection and treatment of bleb-related infections. Critical in this regard is patient education. Recommendations to minimize the development of endophthalmitis in filtered eyes are reviewed.

Do glaucoma patients use eye drops correctly

Abstract: Purpose To assess how glaucoma patients use their topical medications. Methods 142 subjects were tested before an examiner as to how they used their eyedrops. Results Fifty-six patients (39.4%) used one drop. The number of drops instilled increased with age. The tip of the bottle touched the ocular surface in 78 (54.9%). The proportion of patients whose bottle came into contact with the eye or periocular tissues increased with age. Only four patients (2.8%) closed the treated eye and compressed the medial angle after applying the medication. Conclusions It is important that ophthalmologists instruct their patients on the correct manner of applying topical medication so that the patients can themselves administer the medicine precisely. Such instruction will improve the patients' compliance and quality of life during therapy for glaucoma.

The relation between the reflectance and thickness of the retinal nerve fiber layer.

Abstract: PURPOSE This study examined quantitatively the commonly held assumption that the reflectance of the retinal nerve fiber layer is proportional to its thickness. METHODS The reflectance of the retinal nerve fiber layer of an in vitro vertebrate cyecup preparation was measured with an imaging microreflectometer, an instrument that provided quantitative images of a small retinal area and allowed precise control of the directions of illumination and observation. After an experiment, the eyecup was fixed and embedded for histology. A direct correspondence between the measured images and the histologic sections was established by serial reconstruction of the retinal blood vessel pattern. The thickness of the previously imaged nerve fiber bundles was measured from photomicrographs of the histologic sections. RESULTS The reflectance of the retinal nerve fiber layer was proportional to its thickness in areas where nerve fiber bundles were parallel. When bundles were not parallel, the directional reflectance of the retinal nerve fiber layer caused a failure of proportionality for a single illumination angle. When multiple angles of illumination were used to find the peak reflectance, this peak reflectance was again proportional to the thickness of the retinal nerve fiber layer. CONCLUSION These results indicate that the reflectance of the retinal nerve fiber layer arises from throughout its thickness, and have implications for assessment methods designed to identify the surface of the retinal nerve fiber layer. In addition, they indicate that control of observation geometry may be an important means to reduce variability in clinical assessment systems.

Surface-tension properties of hyaluronic Acid.

Abstract: Purpose The maintenance of flow channels in the trabecular meshwork is dependent, in part, on the patency of the trabecular spaces. Because the amount of hyaluronic acid decreases in the trabecular meshwork of patients with primary open-angle glaucoma, a change in surface tension may be one of the effects of hyaluronic acid on aqueous outflow. Methods The surface-active properties of hyaluronic acid (concentration of 0.156-2.5 mg/ml; molecular weights of 100,000, 500,000, and 4,000,000) in deionized water, Ringer's lactate, Ringer's lactate plus 0.06 mg/ml bovine serum albumin, and mock aqueous solution were tested using the drop volume method. Results At a hyaluronic acid concentration of 0.312 mg/ml, surface tension decreased; at higher concentrations, a further decrease in surface tension was observed. In the presence of Ringer's lactate, the 100,000-MW hyaluronic acid was more active than the 4,000,000-MW hyaluronic acid. In the presence of Ringer's lactate plus bovine serum albumin or mock aqueous solution, the influence of surface tension of the 100,000-MW hyaluronic acid was moderated: with lower hyaluronic acid concentrations, the decline in surface tension was more than with Ringer's lactate, but with higher hyaluronic acid concentrations, the decline in surface tension was less than with Ringer's lactate. At high concentration, hyaluronic acid behaves like a non-Newtonian fluid, becomes more viscous, and may act to "seal" the trabecular space. Conclusions The results of this study indicate that hyaluronic acid possesses surface-active properties, which is just one of several properties of hyaluronic acid that may influence aqueous outflow resistance.

Acute Effect of Topical (beta-Adrenergic Antagonists on Normal Perimacular Hemodynamics.

Abstract: PURPOSE beta-adrenergic antagonists are the most commonly prescribed antiglaucoma medications. The nonselective beta blocker timolol has been shown to either increase or to not affect retinal blood flow, despite the suggestion that the drug may cause vasoconstriction due to its blockade of beta-2 receptors. Other beta blockers with unique pharmacologies may produce different effects on blood flow. We studied the effects of betaxolol (beta-1 selective antagonist), carteolol (nonselective beta-antagonist with intrinsic sympathomimetic activity), and levobunolol (nonselective beta antagonist with intrinsic sympathomimetic activity), and levobunolol (nonselective beta antagonist with active polar metabolite) on perimacular hemodynamics. METHOD On four separate occasions separated by at least 10 days, 16 normal subjects performed measurements of heart rate, blood pressure, IOP, and blue field entoptic simulation assessment of leukocyte velocity and density before and 2 h after instillation of one of the three drugs or an artificial tears placebo. RESULTS IOP was significantly reduced by all three drugs as compared to placebo (p < 0.05, Bonferroni-corrected two-tailed paired t-test). No significant differences were found in heart rate, blood pressure, and perimacular leukocyte velocity or density in any of the treatment conditions as compared to placebo. CONCLUSIONS Betaxolol, carteolol, and levobunolol do not appear to significantly alter perimacular hemodynamics 2 h after administration. The absence of any acute change in hemodynamics despite the drop in IOP suggests normal autoregulation maintained constant blood flow.

Rapid visual recovery and long-term intraocular pressure control after donor scleral patch grafting for trabeculectomy-induced hypotony maculopathy.

Abstract: PURPOSE To report on a 21-year-old man who had persistent hypotony maculopathy eight months after trabeculectomy with mitomycin C. METHODS He was treated by excising the filtering bleb, placing a donor scleral patch graft over the trabeculectomy site, and bringing conjunctiva superior to the previous bleb over the patch graft. RESULTS He had rapid resolution of his hypotony accompanied by an increase in visual acuity from 4/200 preoperatively to 20/80 at one day, and 20/20 at three months postoperatively. He also established and maintained a filtration bleb which kept his intraocular pressure in the mid teens without the use of medication. CONCLUSION Scleral patch grafting may provide rapid resolution of visual loss secondary to hypotony maculopathy.

Trabeculectomy with mitomycin C for normal-tension glaucoma.

Abstract: Purpose A prospective investigation of the postoperative intraocular pressure level, visual function changes, and postoperative complications of trabeculectomy with adjunctive mitomycin C in normal-tension glaucoma. Patients and methods Thirty-one patients (31 eyes) who underwent trabeculectomy with 0.4 mg/ml mitomycin C were studied. The preoperative intraocular pressure of the eyes ranged from 11 to 18 mm Hg with a mean (+/- SD) of 14.1 +/- 1.9 mm Hg. Follow-up examinations were performed at least once a month for 14-35 months (mean: 24.4 months). Results Intraocular pressures decreased to between 4 and 14 mm Hg with a mean (+/- SD) of 8.4 +/- 2.4 mm Hg at the last three follow-up visits. The magnitude of the intraocular pressure reduction ranged from 1 to 10 mm Hg, with a mean of 5.8 mm Hg. Final measurements of postoperative intraocular pressure ranged between 5 and 12 mm Hg in 27 eyes (87%). Visual acuity deteriorated two lines or more in seven eyes, which was caused by cataract. The visual field deteriorated postoperatively in two eyes (6%): their respective postoperative intraocular pressures averaged 9.4 and 7.5 mm Hg. Hypotonous maculopathy developed in three eyes (10%). Conclusions Trabeculectomy with mitomycin C appears to have potential as a treatment modality of choice for normal-tension glaucoma, because a large majority of the patients in the present study achieved an intraocular pressure allegedly beneficial in managing normal-tension glaucoma.

Results of combined phacoemulsification and trabeculectomy in patients with elevated preoperative intraocular pressures.

Abstract: Purpose We evaluated the results of 17 consecutive patients with high intraocular pressures and visually significant cataracts who underwent combined phacoemulsification and trabeculectomy. Methods We individually matched each patient by age, race, and intraocular pressure (trabeculectomy group only) to two control groups: group 1, patients who had combined phacoemulsification and trabeculectomy and whose intraocular pressures were controlled preoperatively (pressure Results One year postsurgery there was no statistically significant difference between study patients and either control group in terms of intraocular pressure (p > 0.05). Moreover, no statistical difference was observed between groups at 1 year postsurgery in number of glaucoma medications, bleb height or extent, anterior chamber depth, or bleb vascularity (p > 0.05). Additionally, both study and control patients had a statistically similar peak pressure the first month following surgery (p > 0.05). Complications were similar among groups. Conclusion This study suggests that patients with chronic open-angle glaucoma and high intraocular pressure may undergo combined trabeculectomy and phacoemulsification and achieve long-term postoperative intraocular control similar to those patients who have trabeculectomy only or a combined procedure and controlled preoperative pressure.

Ophthalmic arterial hemodynamics during isometric exercise.

Abstract: PURPOSE Isometric exercise raises systemic arterial pressure and simultaneously lowers intraocular pressure. Together, these pressor effects increase calculated ocular perfusion pressure and test the capacity for flow and pressure autoregulation in the orbital circulation. METHODS We investigated in 17 young, healthy subjects the effect of isometric exercise on ophthalmic arterial hemodynamics, as measured by color Doppler imaging. Isometric handgrip was maintained for 10 min at 20% maximal force. RESULTS Handgrip predictably raised systolic (114 +/- 2 to 122 +/- 3 mm Hg; p < 0.01), diastolic (69 +/- 2 to 78 +/- 2 mm Hg; p < 0.01), and mean systemic pressures (84 +/- 2 to 93 +/- 3 mm Hg; p < 0.01). Because exercise also reduced intraocular pressure (from 14.2 +/- .5 to 12.2 +/- .4 mm Hg, p < 0.01), calculated ocular perfusion pressure increased from 42 +/- 3 mm Hg before exericse to 50 +/- 3 mm Hg during exercise (p < 0.01). Despite this pressure increase, we found no evidence for exercise-induced vasoconstriction in the ophthalmic artery: peak systolic velocity (PSV) was unaltered by exercise, whereas end-diastolic velocity (EDV) increased (from 5.8 +/- .5 mm/s at rest to 8.4 +/- 1.3 mm/s during exercise; p < 0.01). These velocity changes reduced the calculated resistance index ((PSV - EDV)/PSV) from 0.82 +/- 0.01 at rest to 0.78 +/- 0.02 during exercise (p < 0.05). CONCLUSION Isometric exercise-induced increases in ocular perfusion pressure are apparently associated with reductions in vascular resistance distal to the ophthalmic artery, a result suggesting that ocular blood flow or microvascular pressures may be autoregulated by vascular adjustment proximal to the orbit itself.