Motion perimetry identifies nerve fiber bundlelike defects in ocular hypertension.

OBJECTIVE: To determine whether patients with ocular hypertension (OHT) have elevated motion perimetry thresholds. DESIGN: Motion perimetry uses a customized computer graphics program to detect the ability to identify a coherent shift in position of 50% of dots in a defined circular area against a background of fixed dots. Motion size threshold is defined as the smallest circular area in which dot motion is detected. Subjects respond by touching the area of the computer monitor with a light pen where motion stimuli are perceived. Reaction times (milliseconds) to stimuli and localization error (number of pixels from target center) are also obtained for each trial. SETTING: University hospital ophthalmology clinic. PATIENTS OR OTHER PARTICIPANTS: Twenty-seven patients with OHT and 27 age-matched normal subjects. One eye was tested in each subject. MAIN OUTCOME MEASURES: Random dot motion stimuli size thresholds and total deviation probability plot data, reaction times, and spatial localization errors. RESULTS: The patients with OHT had more abnormal test points in the total deviation probability plot analysis compared with the controls (P < .001, chi 2). The abnormal test points were concentrated in the superior and inferior nasal regions. Six subjects had nerve fiber bundlelike defects to motion stimuli. Six subjects (5 overlapping with the probability plot analysis) had abnormal glaucoma hemifield test results. The patients with OHT also had significantly greater localization errors. CONCLUSION: Motion threshold perimetry may be a more sensitive method to detect visual field abnormalities in OHT than conventional automated perimetry.

Visual field defects after macular hole surgery.

PURPOSE: To describe a group of patients with dense visual field defects following macular hole surgery. METHODS: Nine (7%) of 125 patients reviewed noted onset of dense visual field defects following uncomplicated vitrectomy with gas-fluid exchange for the treatment of macular hole. Patient records were reviewed to investigate the etiology of these defects. RESULTS: Eight (89%) of nine eyes that had surgery for macular hole developed dense, wedge-shaped visual field defects in the temporal periphery. One eye had an inferonasal wedge-shaped defect extending to fixation. Seven (78%) of nine eyes had generalized or focal narrowing of the retinal arteriole extending into the area of retina corresponding to the visual field defect, and five (56%) of nine eyes developed mild to moderate segmental nasal optic disk pallor. Postoperative fluorescein angiography disclosed one eye with delayed filling of the retinal arteriole extending into the area of retina corresponding to the visual field defect. Vitrectomy specimens showed no evidence of nerve fiber layer or internal limiting membrane in eight (89%) of nine eyes. CONCLUSIONS: Visual field defects can occur following vitrectomy and gas-fluid exchange for macular hole. The most common visual field defect is dense and wedge-shaped and involves the temporal visual field. Although unclear, the etiology may involve trauma to the peripapillary retinal vasculature or nerve fiber layer during elevation of the posterior hyaloid or during aspiration at the time of air-fluid exchange, followed by compression and occlusion of the retinal peripapillary vessels during gas tamponade.

A study of aqueous humor dynamics in keratoconus.

Clinical observations suggest that patients with keratoconus have lower intraocular pressures, on average, than normal subjects. Our purpose was to determine whether differences in aqueous production and outflow facility could account for differences in intraocular pressure between a group of patients with keratoconus and a group of normal, age-matched control subjects. Aqueous humor dynamics were determined by the use of fluorophotometry in one eye of seven patients with keratoconus and ten age-matched normal subjects. Intraocular pressure was measured by applanation tonometry. Keratoconus patients had a statistically significant lower mean intraocular pressure than normal control subjects (11.3 +/- 1.6 mmHg vs. 16.6 +/- 2.8 mmHg, P = 0.0004). The difference in mean intraocular pressure remained significant even after correcting for possible errors in applanation tonometry due to thin corneal stroma. There was no difference in mean aqueous humor flow rates in the keratoconus patients as compared to controls (2.29 +/- 0.53 microliter min-1, P = 0.73). The mean apparent outflow facility was 0.21 +/- 0.07 microliter min-1 mmHg-1 for keratoconus patients compared to 0.14 +/- 0.03 microliter min-1 for controls (P = 0.02). Lower mean intraocular pressure in keratoconus patients appears to be due to increased outflow facility as compared to normal subjects.

Tenon's cyst formation after trabeculectomy with mitomycin C.

One hundred eyes of 100 patients in whom Tenon's cysts (TCs) developed in the early postoperative period following trabeculectomy with mitomycin C were retrospectively studied to determine their incidence, possible risk factors associated with their development, and the clinical course of the patients in whom they occurred. The incidence of TC formation was 29/100 (29%). Significantly more cysts developed in the men than in the women. There were no significant differences between those patients in whom TCs developed and those in whom they did not in terms of age, race, type of preoperative medications, mean preoperative intraocular pressure (IOP), prior argon laser trabeculoplasty, prior trabeculectomy, prior Tenon's cyst formation, or prior cataract surgery. The 29 patients in whom a Tenon's cyst developed had a mean follow up of 22.0 +/- 12.9 weeks, with a mean IOP at the last examination of 14.2 +/- 6.3 mm Hg (as compared with 20.7 +/- 8.3 mm Hg at the time of diagnosis). One patient required a repeat trabeculectomy with mitomycin C. Two patients required bleb needling, subsequent TC excision, and eventual seton placement. Of the remaining 26, 14 (54%) required no glaucoma medication for IOP control, 11 (42%) required one, and 1 (4%) required two.

Combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy with mitomycin C.

PURPOSE: We evaluated the effectiveness of combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy with mitomycin C in patients with coexisting cataract and glaucoma. METHODS: We conducted a retrospective review of the records of 21 consecutive patients who had combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy with mitomycin C. Patients were selected for the combined procedure on the basis of the degree to which intraocular pressure was controlled, toleration of medical therapy, degree of glaucomatous optic nerve damage, and extent of visual impairment because of cataract. Nine (43%) of the 21 patients had previous incisional surgery and were at high risk of surgical failure. All patients had at least six months' follow-up. Sixteen (76%) of 21 patients had at least one year of follow-up. RESULTS: The mean preoperative intraocular pressure was 20.8 +/- 5.0 mm Hg (range, 13 to 35 mm Hg), which decreased to a mean postoperative intraocular pressure of 15.1 +/- 3.1 mm Hg (range, 9 to 21 mm Hg) as measured at last follow-up (P = .0002). The intraocular pressure was controlled between 6 and 21 mm Hg) in all patients at last follow-up. Seventeen (81%) of 21 patients had a best-corrected visual acuity of 20/40 or better at last follow-up. No patient had a decrease in visual acuity after surgery. Fifteen (71%) of 21 patients were using no antiglaucoma medications at last follow-up. Four of the remaining six patients were using one medication, and two were using two medications. A hyphema (less than 1.0 mm) was seen in seven (33%) of 21 patients and was the most common postoperative complication. No patient had a postoperative wound or bleb leak or a shallow anterior chamber. No patient developed symptomatic hypotony. CONCLUSIONS: The glaucoma triple procedure with adjunctive mitomycin C appears to be a safe and effective surgical technique for treating selected patients with coexisting cataract and glaucoma.

Quantitation of iris transillumination defects in eyes of patients with pigmentary glaucoma.

Iris transillumination defects may be important markers of disease severity and/or disease activity in patients with pigmentary glaucoma. We present a simple method for quantitation of iris transillumination defects using infrared iris transillumination videography and computerized image analysis. Three observers independently made multiple measurements of percent iris transillumination (the percentage of visible iris that transilluminates) from three standard images using the technique. The interobserver coefficient of variation was 20.35, 6.55, and 8.01%, respectively, for mild, moderate, and marked iris transillumination. The intraobserver coefficient of variation was much smaller for each image, measuring 4.11, 3.23, and 2.38%, respectively, for mild, moderate, and marked iris transillumination. To exemplify the utility of the technique, a single observer measured percent iris transillumination for both eyes of a group of 13 consecutive patients with asymmetric pigmentary glaucoma. There was a significant correlation between the amount of iris trapsillumination and the severity of glaucoma in the eyes of these patients.

Mifepristone blocks specific glucocorticoid receptor binding in rabbit iris-ciliary body.

Mifepristone is a specific glucocorticoid receptor antagonist that has been shown to lower intraocular pressure modestly when applied topically to rabbit eyes. We evaluated the ability of mifepristone to block specific in vitro glucocorticoid receptor binding of the labeled agonist triamcinolone acetonide in cytosol isolated from rabbit iris-ciliary body tissue. A 500-fold molar excess of nonradioactive mifepristone completely blocked specific binding of triamcinolone acetonide to glucocorticoid receptors in the iris-ciliary body cytosol. Additionally, specific binding was blocked in a dose-dependent fashion over a range of 0.005-fold to 500-fold molar excess of mifepristone. Mifepristone's effect on intraocular pressure may be due to its ability to antagonize glucocorticoid receptor-mediated effects in ocular tissues.

Palpebral fissure responses to topical adrenergic drugs.

We measured the magnitude and time course of the increase in palpebral fissure width in ten normal volunteers in response to direct-acting (2.5% phenylephrine, 1% apraclonidine) and indirect-acting (10% cocaine, 1% hydroxyamphetamine) topical adrenergic drugs given in one eye. The increase in the palpebral fissure width of the treated eye was compared to the width of the untreated, control eye during a period of 60 minutes after each drug was administered. The difference in fissure width (asymmetry) between the treated and untreated eyes increased significantly for all drugs during the three- to 60-minute time period after treatment. There was no significant difference in the maximum eyelid effect among the adrenergic drugs tested. The drugs exerted their maximum effect by 30 minutes in 39 of the 40 trials (97.5%). The direct-acting drugs tended to exert their effect more quickly than the indirect-acting drugs. Our results demonstrate the expected increase in palpebral fissure width in response to topical adrenergic drugs in normal eyes. This information will provide a basis for evaluating Müller's muscle and its sympathetic innervation in patients with blepharoptosis.

Phenylephrine prodrug. Report of clinical trials.

The authors evaluated the mydriatic effect of phenylephrine oxazolidine prodrug, a lipophilic sympathomimetic that undergoes hydrolysis to phenylephrine as it passes through the cornea and aqueous humor. Double-masked clinical trials were performed randomizing 66 healthy subjects to receive either the silicone vehicle as a placebo, 10% viscous phenylephrine hydrochloride (HCl), or prodrug in 0.25%, 0.50%, or 1.0% concentrations. A mean horizontal pupillary diameter of 8.8 mm was achieved in 30 minutes in those receiving 1% prodrug versus 6.5 mm obtained at 30 minutes with 10% viscous phenylephrine HCl. Statistically, this difference was highly significant at P less than or equal to 0.0001. There were minimal systemic or ocular adverse effects from any preparation.

Ocular findings in Turcot syndrome (glioma-polyposis).

Turcot syndrome is a hereditary condition characterized by multiple, adenomatous gastrointestinal polyps associated with neuroepithelial tumors of the central nervous system. The authors examined a patient with Turcot syndrome who had multiple regions of congenital hypertrophy of the retinal pigment epithelium (CHRPE) with areas of surrounding hypopigmentation in the fundi of both eyes. Multiple, bilateral patches of CHRPE have been reported in patients with familial adenomatous polyposis and Gardner syndrome. This finding is thought to be a sensitive and specific clinical marker for these conditions and useful for predicting the presence and development of colorectal polyposis. Our findings provide further evidence that familial adenomatous polyposis, Gardner syndrome, and Turcot syndrome may be related conditions representing the variable phenotypic expression of a single, autosomal dominant genetic disorder. Children and young adults with multiple patches of CHRPE and a family history of adenomatous polyposis may be at increased risk for the development of central nervous system tumors as well as gastrointestinal polyps.

Use of infrared videography to detect and record iris transillumination defects.

We have developed a technique of detecting and recording iris transillumination defects using an infrared sensitive video camera. This method is useful for assessing the loss of posterior iris pigment in patients with the pigmentary dispersion syndrome and pigmentary glaucoma. Some patients with no transillumination defects on slit-lamp examination were noted to have discrete defects on infrared videography. This technique is a rapid, convenient, and reproducible method of permanently recording posterior iris pigment changes. These high-quality video images can then be followed to determine the natural course and the results of therapy in these patients.