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Biomedical subjects

A M Brooks

Publications and source records attributed to A M Brooks.

At least 37 records · Page 2Linked to original sources
PubMed1996

Noninvasive closure of a persistent cyclodialysis cleft.

BACKGROUND: A persistent post-traumatic cyclodialysis cleft can result in substantial visual loss due to subchoroidal effusion and macular folds with hypotony. A method of closure is needed. PATIENTS AND METHODS: After other methods had been tried, the authors used transscleral YAG laser cyclophotocoagulation in three consecutive patients with 20 applications in two rows of ten applications, 2 to 3 mm behind the limbus, at a power setting of 6 J, with a defocus setting of 9. RESULTS: The cleft was closed with restoration of normal intraocular pressure and recovery of visual function in all patients. CONCLUSION: Transscleral YAG laser cyclophotocoagulation is a simple, effective, noninvasive method of closing a persistent traumatic cyclodialysis cleft, which may make invasive surgical closure unnecessary.

Adult↗
PubMed1996

A clinical trial of MK-507, Trusopt, for raised intraocular pressure--the Australian experience.

BACKGROUND: Since the introduction of carbonic anhydrase inhibitors, a topical preparation has been sought to avoid the complications of systemic medication while retaining the effect of lowering intraocular pressure. Recently, a topical carbonic anhydrase inhibitor, MK-507, has been found superior to others and introduced for multicentre clinical trial. PATIENTS AND METHODS: As part of an international multicentre trial, we compared MK-507 with beta blockers for one year in 20 patients with raised intraocular pressure, both as monotherapy and in combination. RESULTS: Twelve patients with a mean peak pressure of 31.9 +/- 6.8 mmHg (range, 22 to 49 mmHg) off all medication received MK-507. After two weeks, mean peak pressure was 24.7 +/- 6.1 mmHg (range, 14 to 41 mmHg)--a 22.6% fall in pressure. Six of these patients had a mean peak pressure of 27.8 +/- 6.4 mmHg (range, 21 to 41 mmHg), a fall of 19.2% from day one and were given timolol as add-on therapy. This resulted in a fall to 19.1 +/- 2.8 (range, 15 to 24 mmHg) at year one, a fall of 31.3% after add-on. Four patients on timolol and four on betaxolol gave similar falls in pressure with an additional fall when MK-507 was used as add-on therapy. CONCLUSIONS: MK-507 demonstrated its effectiveness as an ocular hypotensive agent in this trial of patients with an unusually high rise in pressure. It showed a hypotensive effect roughly equivalent to beta blockers. It is likely that either a topical carbonic anhydrase inhibitor or a cardioselective beta blocker will be the medication of first choice in newly diagnosed glaucoma.

Administration, Topical↗
PubMed1996

Disorders of perfusion of the anterior segment of the eye.

BACKGROUND: We have investigated the vascular perfusion of a wide variety of conditions of the anterior segment using fluorescein angiography. METHODS: The conditions were classified and findings reported according to the system set out below. Patients underwent full ocular examination. Fluorescein angiography of the anterior segment was carried out when indicated to investigate iris atrophy and neovascularisation. Specular microscopy of the corneal endothelium was used to detect changes in this tissue. RESULTS: The hypoperfusion was variable in degree and accompanied by varying degrees of iris hypoplasia and atrophy with neovascularisation. The degree of neovascularisation depended upon its rapidity of development, the pre-existing state of vascular perfusion and the underlying pathological condition. CONCLUSIONS: Hypoperfusion with resultant ischaemia and neovascularisation is common in conditions of the anterior segment. An understanding of the changes is valuable in treating many conditions affecting the anterior segment. The changes observed may also occur elsewhere in the physical system and may be a significant part of the ageing process, either as scattered, disparate processes or as part of a general disease process.

Acute Disease↗
PubMed1996

Comparison of Fastpak with full-threshold 24-2 glaucoma field tests.

BACKGROUND AND OBJECTIVES: The authors noted an underestimation of the mean deviation for field testing using the Fastpak (Humphrey Instruments, San Leandro, CA) strategy, and set out to define the extent of this difference. PATIENTS AND METHODS: Sixty-seven eyes of 35 glaucomatous patients were examined. Patients received full-threshold 24-2 tests before and after the Fastpak strategy was used, each test on a different day. For some patients, another full-threshold test was performed using a different birth date in order to obtain a result uninfluenced by prior data. RESULTS: The mean deviation (MD) was significantly underestimated by Fastpak compared with the full-threshold tests. The time taken for Fastpak was almost identical to that taken for full-threshold tests. Short-term fluctuation (SF) appeared to have very little reliability statistically, and, consistent with this, there was a greater concordance among pattern standard deviation (PSD) data than among corrected pattern standard deviation (CPSD) data. CONCLUSION: Fastpak was an effective method for charting the visual field, but did so with greater variation than full-threshold tests. It significantly underestimated the MD, and this was not a fatigue effect. Fastpak was no faster than full-threshold testing in advanced glaucoma. CPSD was a less consistent reading than PSD in these glaucomatous patients.

Aged↗
PubMed1995

Excimer laser filtration surgery.

PURPOSE: In order to remove precisely scleral tissue overlying Schlemm's canal with minimal trauma as an outpatient procedure under local anesthetic, we used a VisX Twenty/Twenty excimer laser. METHODS: We performed excimer laser filtration in three enucleated pig eyes, seven enucleated human eyes, and seven eyes of seven patients with severe glaucoma. Precise ablation to Schlemm's canal was confirmed by scanning electron microscopy in the enucleated eyes. For the patients, a local anesthetic was used, and a custom-made holder was used to mobilize the conjunctiva and fix the eye. RESULTS: A functional sclerostomy was obtained with 1,780 to 5,965 pulses, using a 2 x 1-mm slit. In our mean follow-up of nine months (range, six to 12 months) the excimer laser filtration technique achieved controlled filtration in five of seven patients and minimized conjunctival trauma. One patient subsequently underwent cataract extraction. CONCLUSIONS: This study indicates that excimer laser filtration is an effective technique for achieving filtration in glaucoma. It may reduce the complications of glaucoma filtration surgery, particularly the incidence of shallow anterior chamber postoperatively, as it leaves the trabecular meshwork intact.

Aged↗
PubMed1995

Congenital fibrosis of the vertically acting extraocular muscles. A new group of dominantly inherited ocular fibrosis with radiologic findings.

BACKGROUND: The authors studied a family with a form of congenital fibrosis of the extraocular muscles different from any group previously reported. METHODS: A careful examination was done of all affected and all, except one, unaffected members of a family of 15 members extending over three generations. The authors performed computed tomography on five affected and four unaffected family members. RESULTS: All affected family members showed complete loss of vertical ocular movement but largely free horizontal movement except for variable restriction of adduction in some members. A variable degree of ptosis was present, ranging from gross to nil, but with poor levator function and an absent Bell phenomenon in all affected members. All affected members showed superficial keratopathy, many with corneal scarring. Ocular alignment showed considerable variation. Refractive error and amblyopia also were variable. Computed tomographic scan indicated reduction in size of the extraocular muscles, particularly the superior recti with intracranial ventricular asymmetry in three of five patients examined, and abnormality in shape of the eye globes in two patients. CONCLUSIONS: The findings indicate a new group best described as dominantly inherited congenital fibrosis of the vertical-acting extraocular muscles, which is part of the syndrome of congenital ocular fibrosis. Computed tomographic scanning suggested that the clinical picture was produced by changes present in the orbit, but intracranial ventricular asymmetry also was present in some patients and asymmetry of the eye globes in others.

Adult↗
PubMed1994

The significance of anterior chamber depth in Fuchs' corneal dystrophy and cornea guttata.

It is sometimes claimed that a relationship exists between Fuchs' dystrophy and angle closure glaucoma and that this is an indication for the simultaneous performance of keratoplasty and cataract extraction in patients with Fuchs' dystrophy. If such a relationship exists, then the anterior chamber depth in Fuchs' dystrophy should resemble that in angle closure glaucoma and a significant degree of cornea guttata might be expected to be common in angle closure glaucoma. In 88 patients with angle closure glaucoma we found that the anterior chamber depth was significantly shallower than in cornea guttata or Fuchs' dystrophy for acute (p < 0.001), chronic (p < 0.002) or incipient angle closure glaucoma (p < 0.001). Cornea guttata and Fuchs' dystrophy were very infrequent in these patients with angle closure, only two having cornea guttata and one Fuchs' dystrophy. These results do not support a relationship between angle closure glaucoma and Fuchs' dystrophy or cornea guttata and do not justify performing combined cataract surgery and keratoplasty in all cases of cornea guttata or Fuchs' dystrophy undergoing keratoplasty. Each case should be assessed on its merits and combined surgery should be reserved for patients shown to have a shallow anterior chamber or significant cataract.

Acute Disease↗
PubMed1994

The long-term results of fistulising trabeculotomy in chronic open-angle glaucoma.

BACKGROUND: Fistulising trabeculotomy has been used for nearly 20 years to combine the minimally invasive surgery of trabeculotomy with production of a subconjunctival fistula. METHODS: The canal of Schlemm was unroofed 2mm on one side of a 3mm half-thickness scleral flap. A trabeculotomy probe was passed about 30 degrees along the canal on the opposite side and rotated into the anterior chamber. RESULTS: Of 99 eyes of 74 patients, 35 eyes of 25 patients were available for follow-up at 10 or more years. The mean IOP was 14 +/- 4 mmHg (range 7 to 23 mmHg) from a preoperative IOP of 29 +/- 8 mmHg (17 to 60 mmHg). Results in 44 similar patients undergoing trabeculectomy and 44 undergoing fistulising trabeculotomy were very similar at five-year follow-up. CONCLUSION: Fistulising trabeculotomy was effective for lowering intraocular pressure with a low complication rate and a large area of subconjunctival fistulisation.

Adolescent↗
PubMed1994

Long-term results with argon laser trabeculoplasty.

The long-term effectiveness of argon laser trabeculoplasty (ALT) is still questioned. In order to assess the long-term effect of ALT in our hands we reviewed the results of 102 patients who underwent ALT nine to 11 years ago. Thirty eyes of 22 patients were still available for follow-up at 9.5 years, having a fall in intraocular pressure (IOP) from 23 +/- 7 mmHg (range, 15 to 44 mmHg) before treatment to 17 +/- 4 mmHg (10 to 30 mmHg) at 9.5 years. A mean field loss of 39% +/- 29% in 21 eyes with IOP controlled in a range of 15 mmHg or less progressed another 5% +/- 4% additional loss. In eight eyes whose IOP could not be controlled below 20 mmHg a mean field loss of 10% +/- 24% sustained an additional 22% +/- 24% loss. Pressure control in the range of 16 to 20 mmHg gave intermediate results for progression of field loss. Argon laser trabeculoplasty with adjunctive medical therapy continues to lower IOP long term, but IOP control at 15 mmHg or less optimally slows field loss.

Adolescent↗
PubMed1994

Hypoperfusion of the iris and its consequences in anterior segment pigment dispersal syndrome.

The effects of changes in iris perfusion in anterior segment pigment dispersal syndrome (ASPDS) were examined by iris fluorescein angiography in 29 patients (20 men and 9 women; mean age, 49 +/- 14 years; range, 29 to 77 years). All showed hypoperfusion, with mild to moderate microneovascularization. There was a significant relationship between the degree of hypoperfusion and pigment scatter (P < .05), and between the level of intraocular pressure (IOP) and angle pigmentation (P < .01). No statistically significant relation was found between hypoperfusion and iris leak, nor between the level of IOP and iris hypoplasia, hypoperfusion, leakage of dye, pigment scatter, or iris processes. These findings suggest that iris hypoplasia and hypoperfusion are the underlying causes of ASPDS with a congenital etiology.

Adult↗
PubMed1993

Laser trabeculoplasty--argon or diode?

It is important to compare the pressure-lowering effect of the recently introduced diode laser with that of the argon laser currently used for trabeculoplasty, since there is a considerable difference in their wavelengths. In 50 consecutive eyes of 50 patients argon laser trabeculoplasty (ALT) produced a fall from 23 to 18 mmHg at three months compared with a fall from 23 to 19 mmHg at three months with diode laser trabeculoplasty (DLT). This difference was not statistically significant. Comparing the magnitude of the fall in intraocular pressure (IOP) in these two groups of 50 eyes, 28 patients achieved a fall of 5 mmHg or more with ALT and 17 with DLT and this difference was significant (chi 2 1df = 4.04, P < 0.05). Comparing 23 paired fellow eyes which both needed laser trabeculoplasty, those treated with ALT achieved a fall from 22 to 17 mmHg compared with a fall from 22 to 19 mmHg with DLT and this difference was statistically significant (T = 53.5, P < 0.02, Wilcoxon matched-pairs signed rank test). These results suggest that the pressure lowering effect of DLT is comparable to that of ALT, but ALT is somewhat more effective as shown by a greater fall in IOP after ALT than DLT in fellow eyes of the same patient. In the unpaired eyes the number of falls of 5 mmHg or more was significantly greater with ALT than DLT, although the mean fall was not statistically different between the two groups.

Adult↗