Myopia and unexpected intraocular pressure elevations after neodymium-YAG capsulotomy.
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Adult↗
Biomedical subjects
R K Parrish
Publications and source records attributed to R K Parrish.
Fluorouracil (5-FU) and cytarabine (ara-C) inhibition of corneal epithelial cell and conjunctival fibroblast proliferation.
We evaluated the antiproliferative properties of fluorouracil (5-FU) and cytarabine (ara-C) in a tissue culture model of rabbit corneal epithelial cells and conjunctival fibroblasts. Cells were treated with fluorouracil or cytarabine for five days. Corneal epithelial cell proliferation was inhibited to 50% of control proliferation by 0.6 mg/L of fluorouracil or 30 micrograms/L of cytarabine. Proliferation of conjunctival fibroblasts was inhibited to 50% of control by 0.5 mg/L of fluorouracil or 50 micrograms/L of cytarabine. The antiproliferative effect of 10 mg/L of fluorouracil was not blocked by thymidine. The inhibition of proliferation produced by 100 or 1,000 micrograms/L of cytarabine was blocked by 2'-deoxycytidine at concentrations of 10(-5) M and 10(-4) M, respectively. The antiproliferative effects of fluorouracil and cytarabine appear similar for both cell types. Blockage of cytarabine-related ocular toxic effects may be possible with 2'-deoxycytidine.
Animals↗
Acute elevations of intraocular pressure following Nd:YAG laser posterior capsulotomy.
We performed applanation tonometry preoperatively, hourly for the first four postoperative hours and on the first postoperative day in 66 eyes after Nd:YAG laser posterior capsulotomy in order to determine the nature of the acute intraocular pressure (IOP) elevation and the risk factors involved. Forty-one percent of eyes developed an intraocular pressure greater than 30 mmHg and 14% greater than 40 mmHg. The IOP spike occurred on the second postoperative hour in 35% of eyes. Patients with controlled glaucoma prior to capsulotomy had a significantly lower mean IOP rise than patients without glaucoma. Eyes with posterior chamber IOLs were less likely to develop an IOP greater than 30 mmHg than were aphakic eyes without IOLs. There was no correlation between the laser energy or the size of the capsulotomy and the IOP rise.
Cataract Extraction↗
Neodymium: YAG laser posterior capsulotomy: visual acuity outcome and intraocular pressure elevation.
A Q-switched neodymium: YAG laser was used to perform 67 posterior capsulotomies in 67 patients. A clear visual axis was produced in all the eyes. The visual acuity improved by one or more Snellen lines in 90% of the eyes, and the final visual acuity was 20/40 (6/12) or better in 78% of the eyes. Cystoid macular edema developed in two patients after capsulotomy. Increases in intraocular pressure were most prevalent in the early postoperative period. No significant correlation was found between the acute pressure rise and the laser energy used, a previous history of glaucoma or the presence of an intraocular lens. After 6 months of follow-up none of the eyes showed a permanent pressure elevation.
Aphakia, Postcataract↗
5-Fluorouracil toxicity to the ocular surface epithelium.
The antimetabolite, 5-fluorouracil (5-FU), has been used to control proliferation of retinal pigment epithelial cells and fibrocytes, and is currently the subject of a multicenter clinical trial of its value in the control of scarring after glaucoma operations. To evaluate possible ocular surface toxicity, the effect of 5-FU on the mitotic rate and differentiation of the ocular surface epithelium in rabbits was measured. 5-FU was instilled into eyes with 10-mm diameter central epithelial wounds and into nonwounded eyes at a dose of 9 mg per day for 4 days. Saline treated control wounded eyes healed within 4 days (n = 5) while 40% (4 of 10) of the 5-FU treated wounded eyes had defects at 4 days. The normal mitotic rate of the corneal epithelium was 1.0 +/- 0.3 (n = 4) tritiated thymidine labeled cells per 100 basal corneal epithelial cells after 2.5 hr incubation. Saline treated control wounded eyes had an increased mitotic rate, 7.1 +/- 1.3 (n = 5) labeled cells per 100 basal corneal epithelial cells after 2.5 hr incubation. Topical 5-FU decreased both of those rates to about 1% of normal. The normal conjunctival epithelial mitotic rate was 1.8 +/- 0.4 (n = 4) labeled cells per 60 basal cells after per 2.5 hr incubation. This rate was the same in wounded eyes, but was decreased in eyes treated with 5-FU. Thus, 5-FU (9 mg/day topically) has serious toxic effects to ocular surface epithelium which must be carefully considered if this drug is to be used clinically.
Animals↗
Static and kinetic visual field testing. Reproducibility in normal volunteers.
The SD of static visual threshold ranges from 0.12 log units near fixation to 0.41 log units 30 degrees from fixation. Among 60 points tested, most persons have at least one point that tests 0.5 log units less sensitive than the adjacent points, simulating a scotoma 0.5 log units deep. With automated kinetic perimetry, the SD of isopter position is 2.6 degrees to 5.5 degrees, with the greatest variation appearing in the temporal field where the slope is flatter and the isopters are more peripheral. More than 10% of the points show an inward deviation of 5 degrees or more compared with their neighboring points. Retesting of the deviant points is required to distinguish an artifact caused by variable responsiveness from true localized defects. Judgments about progression also require that the accuracy of the isopter position or threshold determination be taken into account.
Adult↗
Delayed nonexpulsive suprachoroidal hemorrhage.
Eight cases of delayed nonexpulsive suprachoroidal hemorrhage occurred after filtering operations in aphakic eyes. Sustained hypotonia resulting in serous choroidal detachments, scleral infolding, or both was observed prior to the hemorrhage in seven of the eight eyes. The prognosis was related to the extent of the hemorrhage and possibly to whether or not surgical drainage was performed. Only one of the five patients with massive hemorrhages recovered visual acuity better than hand motions; that patient had undergone prompt surgical drainage of the suprachoroidal blood.
Aged↗
Trabeculectomy in young patients.
The results of 117 trabeculectomies performed on 98 patients under the age of 50 years were reviewed. The success rate in primary glaucomas (29/39, 74%) was considerably higher than in secondary glaucomas (24/50, 48%) or in developmental glaucomas (6/17, 35%). Only one (9%) of 11 trabeculectomies performed for neovascular glaucoma was successful. Trabeculectomies for secondary glaucomas were significantly more often successful in eyes that had not undergone previous surgery. None of the six trabeculectomies performed on patients under the age of ten years controlled the intraocular pressure. Of the 45 trabeculectomies performed on patients aged 10 to 29 years, 17 (38%) were successful. Of the 66 trabeculectomies performed on patients aged 30 to 49 years, 43 (65%) were successful. The success rates among black, white, and hispanic patients were similar. The ability to identify patients at high risk for failure of trabeculectomy may be of value in guiding the surgical management of glaucoma.
Adolescent↗
Trabeculectomy in aphakic eyes.
One hundred twenty-seven trabeculectomies performed on aphakic eyes at the Bascom Palmer Eye Institute (BPEI) between 1972 and 1982 were reviewed. Forty-five cases were excluded from data analysis: 28 in eyes with confounding conditions, such as neovascular glaucoma; ten with follow-up of less than six months; and seven that were the second or third trabeculectomy performed at the BPEI in six eyes. Of the remaining 82 trabeculectomies in 82 eyes: 32 (39%) were categorized as successes (eyes that achieved an intraocular pressure of less than or equal to 21 mmHg with medication or less than or equal to 25 mmHg without medication); eight (10%) were categorized as qualified failures (eyes that had an intraocular pressure of greater than 21 mmHg despite medication or greater than 25 mmHg without medication); and 42 (51%) were categorized as complete failures (eyes that underwent further glaucoma surgery, had further glaucoma surgery recommended, or lost light perception). In the 20 eyes of the patients younger than 50 years of age, only one (5%) was categorized as a success; while in the 62 eyes of the patients 50 years of age or older, 31 (50%) were categorized as successes.
Adolescent↗
5-fluorouracil and glaucoma filtering surgery: I. An animal model.
Failure of a glaucoma filtering procedure commonly results from scarring at the surgical site. Fibroblasts play an important role in the scarring process. 5-fluorouracil is an antimetabolite capable of inhibiting fibroblast proliferation. We tested the ability of 5-fluorouracil to inhibit cicatrization at the filtering site in an experimental model. Posterior lip sclerectomies were performed in each eye of ten normal owl monkeys. Postoperatively, one eye of each animal received subconjunctival injections of fluorouracil and the fellow eye received saline injections in a randomized, masked fashion. Two animals died of undetermined causes. None of the control eyes developed blebs, but six of the eight treated eyes in surviving animals developed blebs. The difference between intraocular pressures in fluorouracil-treated and control eyes was statistically significant (P less than 0.05). Signs of ocular toxicity included persistent corneal epithelial defects and delayed healing of the conjunctival incision. These results are considerably more favorable than those previously reported with experimental filtering procedures in non-human primates. Pharmacologic modulation of wound healing may decrease the risk of failure of filtering operations.
Animals↗
5-fluorouracil and glaucoma filtering surgery. II. A pilot study.
5-Fluorouracil (5-FU) was injected subconjunctivally after glaucoma filtering surgery in a pilot study of eyes with poor surgical prognoses. Twenty-seven (79%) of the 34 aphakic eyes with glaucoma achieved an intraocular pressure (IOP) of less than or equal to 21 mmHg (range of follow-up on nonreoperated eyes, 91 -468 days). Nine (69%) of 13 eyes with neovascular glaucoma achieved an IOP of less than or equal to 21 mmHg (range of follow-up on nonreoperated eyes, 120-379 days). Eight (89%) of nine phakic eyes with glaucoma following unsuccessful filtering procedures achieved an IOP of less than or equal to 21 mmHg (range of follow-up on nonreoperated eyes, 134-394 days). Visual acuities remained within one line of their preoperative levels or improved in 32 (94%) of the 34 aphakic eyes with glaucoma, eight (62%) of the 13 eyes with neovascular glaucoma, and six (67%) of the nine phakic eyes with glaucoma following unsuccessful filtering procedures. Postoperative corneal epithelial defects occurred in 45% of the cases. Conjunctival wound and conjunctival needle tract leaks were observed in 41% of the cases, but only one eye required wound revision. No other serious side effects that we attributed to 5-FU were observed. It seems that postoperative subconjunctival 5-FU increases the likelihood of achieving IOP control following filtering surgery in eyes with poor surgical prognoses; however, a randomized clinical trial is necessary to confirm this.
Adolescent↗
Surgical therapy of traumatic hyphema.
The usual management of traumatic hyphemas in our institution has been to avoid or delay surgery until absolutely demanded by the clinical course. Despite this, most (73%) of our in-patients with total hyphema underwent surgery before leaving the hospital. In those who required surgery, 43% developed corneal staining. Optic nerve damage occurred in half of the patients whose surgery was performed eight or more days after the hyphema occurred, but was absent in those undergoing earlier surgery. The usual procedure used in this series was a trabeculectomy with iridectomy and gentle irrigation of the anterior chamber, and no surgical complications occurred. We believe that surgery, being relatively safe, should be performed early in cases of total hyphema unless the elevated intraocular pressure is controlled medically and spontaneous resolution is clearly imminent. For cases in which surgery is nearly inevitable, we suggest that earlier surgery might reduce the incidence of optic nerve damage and corneal staining.
Adolescent↗
Evaluation of local anesthesia agents using a new force-sensitive lid speculum.
Three commonly used injection anesthetics, bupivacaine .75%, mepivacaine 2%, and lidocaine 2% were evaluated for onset, completeness and duration of akinesia following modified O'Brien facial nerve block, using a new force-sensitive lid speculum. All three agents provided facial akinesia that was profound within six minutes of the time of injection. The onset and the depth of anesthesia were roughly the same with all three agents. However, bupivacaine induced akinesia of greatest duration, lasting up to six hours, the time of final measurement in this study. Akinesia produced by mepivacaine was adequate for about 90 minutes, and lidocaine for 15-30 minutes. A newly-described force-sensitive speculum was utilized in this study. It is an effective instrument for measuring completeness of akinesia, and may have clinical usefulness.
Anesthetics, Local↗
Fundamentals in focus. Ocular emergencies.
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Emergencies↗
Neovascular glaucoma following central retinal vein obstruction.
The results of a prospective clinical and fluorescein angiographic study of 155 patients with central retinal vein obstruction (CRVO) were analyzed to identify risk factors contributing to the subsequent development of iris neovascularization (NVI) and neovascular glaucoma (NVG). Of 144 untreated eyes, 20% developed NVG. The eyes were classified as having either an ischemic or a hyperpermeable type of CRVO according to the extent of retinal capillary nonperfusion demonstrated by the initial fluorescein angiogram. The risk of developing NVG was found to be approximately 60% in those eyes with extensive retinal ischemia. None of the 22 eyes with an ischemic CRVO treated with panretinal photocoagulation (PRP) prior to the onset of NVI developed NVG.
Adult↗
Ocular toxoplasmosis and visual field defects.
We studied 34 patients with peripapillary lesions secondary to toxoplasmosis. All patients had visual field defects corresponding to interruption of the nerve fiber layer of the retina. The extent of visual field loss increased with proximity to the disk.
Adult↗
Wound healing in glaucoma filtering surgery.
Successful glaucoma filtering surgery is characterized by the passage of aqueous humor from the anterior chamber to the subconjunctival space, which results in the formation of a filtering bleb. Aqueous in the subconjunctival space may then exit by multiple pathways. Bleb failure most often results from fibroblast proliferation and subconjunctival fibrosis. Factors associated with an increased risk of bleb failure include youth, aphakia, active anterior segment neovascularization, inflammation, previously failed glaucoma filtering surgery, and, possibly, race. Several surgical and pharmacologic techniques have recently been introduced to enhance success in eyes with poor surgical prognoses. To elucidate the scientific rationale of these methods, we summarize the process of wound healing after glaucoma filtering surgery and describe postoperative clinical and histopathologic features, factors which may affect success, and specific methods to improve surgical success.
Adrenal Cortex Hormones↗
Treatment of hypotony maculopathy after trabeculectomy.
BACKGROUND AND OBJECTIVE: To determine if resuturing of the scleral flap to increase IOP in the post-trabeculectomy eye is an effective treatment of hypotony maculopathy. PATIENTS AND METHODS: The medical records of nine consecutive patients who developed visual acuity loss after trabeculectomy related to hypotony maculopathy were reviewed to determine factors that contribute to successful restoration of visual acuity. The average age of the patients was 50 years and average refractive error was -4.25 diopters (D). Mean Snellen visual acuity dropped from 20/25 to 20/200 after the onset of hypotony. RESULTS: Six of nine eyes recovered visual acuity to within one line of initial level after treatment of the hypotony. Four of these six eyes underwent resuturing of the scleral flap to reverse the excess filtration within 6 months of the onset of hypotony maculopathy. Five of these six patients had final vision of 20/30 or better. The mean phakic preoperative refractive error in these six eyes was -2.25 D, compared with a mean refractive error of -8.50 D in the three eyes with persistent visual loss (P = 0.002). After reversal of the hypotony, the average peak intraocular pressure in the six eyes with visual recovery was 33 mm Hg, compared with an average peak IOP of 7 mm Hg in the three eyes with persistent visual loss. (P = 0.015) CONCLUSION: Although reversal of the hypotony maculopathy in six eyes was associated with a few weeks of higher than normal IOP, the final IOP was acceptably low. Five of six filtering blebs remained functional with a mean follow-up of 3 years. The final average IOP in the six eyes that were successfully treated was 12.7 mm Hg. In this series of patients, visual acuity was restored to eyes with hypotony maculopathy by increasing the IOP to higher than normal levels.
Adult↗