The relationship between macular cell layer thickness and visual function in different stages of glaucoma.

PURPOSE: To determine whether there were differences in the structure-function relationship between early and advanced glaucoma, and study the association between thickness of discrete macular cell layers, the thickness of the retinal nerve fiber layer, and visual field sensitivity. METHODS: In all, 71 eyes of 50 subjects (28 glaucoma patients and 22 normal control subjects) were included. Thickness of macular retinal nerve fiber layer (mRNFL), macular inner retinal layer (mIRL), and macular outer retinal layer (mORL) were measured from Stratus optical coherence tomography macular scans, using our previously published segmentation algorithm. Visual sensitivity loss was determined by mean deviation (MD) using Humphrey Visual Field Analyzer. The mean thickness for each layer from the normal control subjects, early, and advanced glaucoma groups was compared. In addition, a mixed model analysis was used to explore the relationship between structure-function, allowing for possible interaction with glaucoma stage. RESULTS: The mean mRNFL thickness in early and advanced glaucoma patients was significantly less than measurements in normal subjects (P<0.01). The mean mIRL thickness in advanced glaucoma was significantly less than normal subjects (P=0.04). The mean mORL thickness in early and advanced glaucoma was not statistically significant different from that of normal subjects (P>0.8). There was no statistically significant difference in macular structure-function relationship between the two glaucoma groups (P>0.05). Mean mIRL thickness was significantly associated with MD (P=0.04). CONCLUSION: There was no significant difference in macular structure-function relationship between early and advanced glaucoma groups. Combined data from both glaucoma groups indicated that mIRL thickness was associated with visual sensitivity loss.

Recurrent hyphema in an aphakic child: Swan syndrome.

In 1973, Swan described 3 patients who developed hyphema months to years after uncomplicated cataract surgery. He noted focal vascularization from an ingrowth of episcleral vessels at the cataract wound site, resulting in recurrent intraocular bleeding. Swan syndrome has been reported following intracapsular cataract extraction, extracapsular cataract extraction (including clear corneal incisions), iridocyclectomy, and glaucoma filtering procedures. Patients typically present with sudden painless blurred vision, often upon awakening, which may or may not be preceded by physical strain or trauma. Other patients are asymptomatic and diagnosed with hyphema or anterior chamber red blood cells on routine examination. The hyphema often resolve spontaneously, making later diagnosis difficult. Gonioscopic visualization of the abnormal wound vessels is necessary for diagnosis. Without active bleeding, however, the fibrovascular tuft may be easily overlooked. We report a case of Swan syndrome in a 16-month-old boy after cataract extraction was performed. To our knowledge, Swan syndrome has not been reported in the pediatric population. Children represent a significant proportion of patients undergoing anterior segment surgery and Swan syndrome should be considered in the differential diagnosis of hyphema in this population.

Comparison of contrast sensitivity, visual acuity, and Humphrey visual field testing in patients with glaucoma.

PURPOSE: To investigate the relationship between large-letter contrast sensitivity, high-contrast visual acuity, and visual field defects in patients with glaucoma. METHODS: Patients with a diagnosis of glaucoma, glaucoma suspect, or ocular hypertension whose visual acuity was 20/40 (logMAR = 0.3) on better were included in the study. Visual acuity was measured using the Lighthouse visual acuity charts. Contrast sensitivity was measured using the Pell-Robson (PR) chart. The mean depression (MD) score from the most recent Humphrey visual field was used to quantify the visual field defect. RESULTS: A total of 120 eyes were studied. The PR contrast sensitivity score correlated more strongly with the MD of the visual field (r = .589, P < .001) than did the logMAR visual acuity (r = .193, P = .035). When just the eyes with open-angle glaucoma were considered (N = 54), the correlation was even greater for the PR score (r = .638). In ocular hypertensive eyes (N = 25), the correlations to PR and logMAR were not that different (r = .394 for PR, r = .303 for logMAR). Pseudophakic eyes did not show as strong a correlation (r = .335) as did phakic eyes (r = .591). CONCLUSION: For glaucomatous eyes with visual acuity of 20/40 or better, a decrease in the contrast sensitivity correlates with increased visual field loss. We speculate that this decrease in contrast sensitivity in glaucoma patients may account for their complaints of poor vision despite normal or near normal visual acuity.

The role of medical therapy in the rank order of glaucoma treatment.

There is no consensus as to how treatment of open-angle glaucoma should be initiated. Medical therapy, laser trabeculoplasty, and filtration surgery each have their advocates as the best modality for initial treatment. The advantages and disadvantages of these three options are discussed here. It is pointed out that there may not be a single answer as to how to begin treatment. Patient factors such as age, general health, and stage of glaucoma as well as various socioeconomic and technologic factors may lead to different recommendations for different patients. At present, most patients with open-angle glaucoma are started on medical therapy. beta-Blockers are used most commonly as the initial drug of choice, but latanoprost and brimonidine are now being recommended by many as alternate first-line therapy.

Ocular amyloidosis and secondary glaucoma.

OBJECTIVE: To report the clinical and histopathologic findings in two cases of secondary glaucoma associated with amyloidosis. DESIGN: Two case reports. METHODS: Retrospective review of clinical findings, course, and treatment of the two patients. The histopathologic findings from available biopsy material were also reviewed. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), visual field changes, and surgical outcome. RESULTS: The first case describes a 76-year-old woman with orbital amyloidosis who developed gradual unilateral elevation of IOP that was poorly responsive to medical therapy and underwent filtration surgery. Episcleral venous pressure was elevated on the affected side, and histopathologic analysis of the conjunctival tissue confirmed perivascular amyloid deposits, further suggesting raised episcleral venous pressure to be a possible mechanism of glaucoma. The second case describes a 47-year-old white woman with familial amyloid neuropathy with a transthyretin cys-114 mutation. The association of glaucoma with this mutation has not been described previously. Persisting elevation of IOP in one eye was initially responsive to topical antiglaucoma medications but eventually required filtration surgery. Amyloid particles were found in the aqueous and on the lens surface. Histopathologic analysis of the aqueous and sclerectomy specimens demonstrated amyloid, suggesting outflow obstruction as a possible mechanism of glaucoma. Conjunctival buttonholing complicated filtration surgery in both cases, and the leaks eventually resolved with good control of IOP. CONCLUSIONS: Amyloid associated with glaucoma may involve different pathophysiologic mechanisms. The elevated IOP may not respond well to medical therapy. Cautious surgical manipulation of the conjunctiva is warranted in these cases.

Long-term follow-up of initially successful trabeculectomy.

OBJECTIVE: The purpose was to study the long-term outcomes of primary trabeculectomies that were successful at 1 year. DESIGN: A retrospective study of patients with various types of glaucoma who had trabeculectomies that were successful at 1 year and who had a follow-up of at least 10 years. PARTICIPANTS: There were 40 patients (40 eyes) who had primary trabeculectomies that were successful at 1 year and who had a follow-up range of 10 to 21 years. INTERVENTION: Control of intraocular pressure (IOP) and disease progression was evaluated at 5, 10, and 15 years and at the last obtainable follow-up. MAIN OUTCOME MEASURES: Successful control of IOP was defined as IOP less than 21 mmHg or a reduction of 33% if preoperative IOP was less than 21 mmHg. Successful control of disease progression was defined as stable cup-disc ratios determined by examination, or color photographs or both, as well as stable visual fields. RESULTS: If an eye was considered successful by IOP at 1 year, the probability of successful control of IOP was 82% at 5 years and 67% at 10 and 15 years. If an eye was considered successful by IOP at 1 year, the probability of successful control of disease progression at 5 years was 77%, at 10 years 61%, and at 15 years 48%. If an eye did not require further glaucoma surgery at 1 year, the probability that it still would not need further surgery at 5 years was 90%, at 10 years 75%, and at 15 years 67%. Forty percent of eyes had cataract extraction by the time of last follow-up examination. CONCLUSIONS: Loss of IOP control and progression of glaucomatous damage occurs over time despite initial success at 1 year.

The role of brimonidine in the treatment of open-angle glaucoma.

At present, medical therapy is the first line of attack against primary open-angle glaucoma. beta-blockers, miotics, sympathomimetics, carbonic anhydrase inhibitors, and prostaglandins have been used with varying degrees of success. The alpha 2-agonists, clonidine, apraclonidine, and now brimonidine are powerful inhibitors of aqueous humor production, thereby lowering intraocular pressure (IOP) in these patients. Brimonidine is emerging as a potential first-line therapy for primary open-angle glaucoma, with a peak IOP-lowering efficacy comparable to that of timolol, but without timolol's adverse cardiopulmonary side effects. Brimonidine promises to be an important new drug to help meet the therapeutic challenges faced by ophthalmologists in treating glaucoma.

Should patients with anatomically narrow angles have prophylactic iridectomy?

In this set of articles, the authors outline methods and criteria for determining which patients with anatomically narrow angles should have laser iridectomy to prevent acute angle-closure glaucoma.

Management of bleb leaks after glaucoma filtering surgery. Use of autologous fibrin tissue glue as an alternative.

PURPOSE: To study the nature of bleb leaks after contemporary glaucoma filtering surgery as well as to evaluate various treatment modalities, including autologous fibrin tissue glue (AFTG) prepared in a modified manner. METHODS: Patients who presented to a Glaucoma Service during a 1-year period with a postoperative bleb leak were studied. Evaluation of various treatment modalities, including AFTG, was performed. RESULTS: Thirty-five episodes of bleb leaks were encountered in 25 eyes of 22 patients in a 1-year period. There was no statistically significant association between late or early leaks and the age or the race of the patient, previous eye surgery, or the use of antimetabolites at the time of filtering surgery. Eleven (31.4%) of the leaks were refractory to nonsurgical treatment modalities, 8 or them being of the late type. Successful healing of the leaks was obtained in 9 of the 12 episodes in which AFTG was used. However, there were no statistically significant differences between AFTG and the other treatment modalities. CONCLUSION: Bleb leaks are a common complication of contemporary glaucoma filtering surgery. Various nonsurgical and surgical modalities can be used in the treatment. In early as well as late bleb leaks, AFTG offers an alternative nonsurgical treatment and is at least as efficacious and may, in some ways, be superior to other nonsurgical modalities of treatment.

Long-term results of trabeculectomy in eyes that were initially successful.

A number of published case series provide short-term and intermediate success rates for the surgical treatment of glaucoma with trabeculectomy. There is little information, however, regarding long-term outcomes that extend beyond 10 years. Therefore, we conducted a retrospective study to determine the long-term outcome of eyes that had successful trabeculectomy surgery at 1 year (IOP < 21 mmHg, or lowering by 33% if preoperative IOP was < 21 mm Hg) and had been followed up for at least 10 years. We found 40 such eyes. With respect to IOP control, 83% were still considered to be successful at 5 years, 73% at 10 years, but only 42% at 15 years. Ten percent required additional glaucoma surgery by 5 years, 25% by 10 years, and 58% by 15 years. Forty percent of the eyes had cataract surgery by the time of the last follow-up examination. It appears that there is a significant late failure rate of trabeculectomy in eyes that were initially successful.

Glaucoma after congenital cataract surgery.

OBJECTIVES: To study eyes that manifested glaucoma after congenital cataract surgery and to identify factors that might lead to better diagnosis and treatment of such glaucoma. DESIGN: A retrospective review of patients treated for glaucoma that developed after congenital cataract surgery. RESULTS: Sixty-four eyes of 38 patients were studied. Open-angle glaucoma was the more frequent type of glaucoma (51 eyes, 79.7%). Glaucoma was diagnosed a mean interval of 12.2 years after cataract surgery, but it could occur at any time from months to decades after the cataract surgery. Medications alone were successful in intraocular pressure control in 21 (63.6%) of 33 eyes, and additional surgical procedures resulted in successful intraocular pressure control in 11 of 14 eyes in which they were performed. CONCLUSION: The authors cannot predict in which eyes glaucoma will develop after surgery for congenital cataracts. Once detected, the glaucoma can be treated successfully in the majority of cases. Careful follow-up, including examinations with the patient sedated or anesthetized as needed, is required.

The effects of glaucoma filtering surgery on the variability of diurnal intraocular pressure.

The results of this study indicate that filtration surgery reduces the mean diurnal IOP, the range of diurnal variation, and the day-to-day variability. The effect on the range is proportionally greater than on the other two parameters. Further study will be required to determine whether this selective effect makes surgical reduction of IOP any more effective in the prevention of further glaucomatous visual field damage than other therapeutic methods that lower mean IOP to the same degree.

Can the concentration of timolol or the frequency of its administration be reduced?

BACKGROUND: There is evidence that the ocular hypotensive effect of topical beta-blockers persists for at least 24 hours once beta-blockade has been achieved. In previous studies, the highest concentration of drug generally has been used for this purpose. METHOD: Home tonometry was performed with a self-tonometer by 14 patients to study the intraocular pressure (IOP) reduction of 0.5% timolol administered once daily in the morning or in the evening and of 0.25% timolol administered in the morning. The study was masked and included washout periods before and between the different regimens. At the end of each treatment period, the IOP was monitored five times daily for 3 days. RESULTS: No significant difference in mean reduction of IOP was found between the morning instillation of once daily 0.5% timolol compared with evening instillation of 0.5% timolol. In addition, there was no statistically significant difference in the mean IOP reduction between once daily administration of 0.25% versus 0.5% timolol. CONCLUSION: This study indicates that a lower concentration of timolol maleate used once daily may achieve maximum IOP reduction. The time of the single administration appears not to make any difference.

Individual variability in the diurnal intraocular pressure curve.

BACKGROUND: Reduction of intraocular pressure (IOP) is a primary goal of most glaucoma treatments. However, because the IOP varies during the day, single measurements performed in an ophthalmologist's office do not necessarily provide information on the peak level and fluctuation of the IOP. METHODS: Home tonometry was performed to gain more information on the nature of the diurnal IOP curves and on their variability. One hundred seventy-six patients with open-angle glaucoma (OAG), 55 subjects with ocular hypertension (OHT), and 18 control individuals measured their IOP five times daily at home for 4 to 8 consecutive days using a self-tonometer. RESULTS: Well-defined diurnal IOP variations were observed in all three groups with a predominance of curves with morning or mid-day maxima. Erratic IOP curves without a diurnal rhythm were present in OHT (22%) and OAG (16%) patients but not in control subjects. Differences between the curves of the two eyes of an individual were frequent in OHT (33%) and OAG (36%) patients but not in control subjects (6%). Finally, the majority of OHT (72%) and OAG (66%) patients showed a difference in their diurnal curve patterns on repeat home tonometry performed months apart. CONCLUSION: The authors indicate that it is difficult to rely on one eye as a control for the other. They also indicate that changes in IOP observed in the office at different visits often may be due to a shift in the type of diurnal curve rather than to a true change in the mean IOP. Monitoring of the diurnal IOP may be necessary in some cases if the clinician relies, even partially, on the level of IOP when making a decision on patient management.

Follow-up of angle-closure glaucoma suspects.

One hundred twenty-nine patients thought to be at risk for developing angle-closure glaucoma underwent a baseline examination, which included gonioscopy, refraction, anterior chamber pachymetry, ultrasound biometry, and an angle-closure provocative test. Patients were then followed up with no treatment. Mean follow-up was 2.7 years with a range up to six years. Twenty-five patients developed angle closure in at least one eye during the follow-up period, but in most (17 of the 25 patients), the angle closure was nonacute (that is, no clinical signs or symptoms and no increase in intraocular pressure). None of the test factors studied showed a high sensitivity or positive predictive accuracy in detecting the eyes that later developed angle closure.

High incidence of sympathetic ophthalmia after contact and noncontact neodymium:YAG cyclotherapy.

BACKGROUND: Two cases of sympathetic ophthalmia occurring after noncontact neodymium:YAG (Nd:YAG) cyclotherapy have previously been reported. In each case, the patient had undergone filtering surgery in the exciting eye. Although in each case Nd:YAG cyclotherapy was the last surgery performed, the inciting event of sympathetic ophthalmia was unclear. METHODS: The authors studied three additional patients who developed sympathetic ophthalmia after Nd:YAG cyclotherapy for glaucoma. RESULTS: Two patients developed sympathetic ophthalmia 4 months after noncontact Nd:YAG cyclotherapy, and 1 patient developed sympathetic ophthalmia 18 months after contact Nd:YAG cyclotherapy. All patients had previous cataract extractions but no filtering surgery in the exciting eye. Clinical features included chronic iridocyclitis, choroidal folds, Dalen-Fuchs nodules, and optic disc edema. Combining these cases with the two previously reported cases, the incidence of sympathetic ophthalmia at our institution thus far is 5.8% (4 of 69) and 0.67% (1 of 150) after noncontact and contact Nd:YAG cyclotherapy, respectively. CONCLUSIONS: The incidence of sympathetic ophthalmia after Nd:YAG cyclotherapy is high compared with other ocular procedures. The clinician should vigilantly monitor patients after Nd:YAG cyclotherapy and report additional cases that may have occurred at other institutions.