Optical coherence tomography of melanocytoma.

PURPOSE: To evaluate the use of optical coherence tomography in differentiating between melanocytoma and choroidal melanoma. METHODS: Case reports. Three consecutive patients with melanocytoma were scanned using optical coherence tomography. RESULTS: Optical coherence tomography showed lesions with a high reflectance signal anteriorly and optical shadowing behind, corresponding to the melanocytomas. The high signal was continuous with the retinal nerve fiber layer, consistent with known growth patterns of melanocytoma. CONCLUSION: Optical coherence tomography may be useful in differentiating melanocytoma from choroidal melanocytic lesions.

Comparison between optical coherence tomography and fundus fluorescein angiography for the detection of cystoid macular edema in patients with uveitis.

PURPOSE: To compare optical coherence tomography (OCT) with fundus fluorescein angiography (FFA) for the detection of cystoid macular edema (CME) in patients with uveitis. DESIGN: Prospective comparative observational series. PARTICIPANTS: One hundred twenty-one eyes of 58 patients with uveitis of varied causes (seven patients were studied twice). TESTING: Patients with suspected CME underwent OCT scanning followed by FFA at the same visit. MAIN OUTCOME MEASURES: Detection and distribution of macular edema. RESULTS: One hundred eight eyes had similar results on both OCT and FFA in that 67 eyes had CME and 41 eyes had no CME. In 10 eyes subretinal fluid was detected on OCT but not FFA. Five of these eyes had CME on FFA but not OCT. Three other eyes had CME that was detected by FFA but not by OCT. Compared with FFA, the OCT sensitivity for detecting CME was 96% (including the eyes with subretinal fluid), and the OCT specificity was 100%. CONCLUSIONS: OCT is as effective at detecting CME as is FFA but is superior in demonstrating axial distribution of fluid.

Natural history of diabetic macular streak exudates: evidence from a screening programme.

BACKGROUND/AIMS: Diabetic retinopathy screening guidelines recommend referral to an ophthalmologist if there is exudate within one disc diameter of the fovea. Many of these patients, however, have resolution of small amounts of exudate without treatment. This study aimed to assess whether patients with minimal streak or dot exudates within one disc diameter of the fovea can be monitored in a screening programme without compromising visual acuity. METHODS: A retrospective review of records and Polaroid photographs obtained by one screening centre over a 10 year period was performed. Outcomes measured were referral rates, alteration of Snellen visual acuity, and the need for macular photocoagulation treatment. RESULTS: 55 patients (74 eyes) fulfilled entry criteria (37 streak and 37 dot exudates). Mean follow up was 56.1 months (range 12-127 months). Twenty five patients (30 eyes) were referred to an ophthalmologist. 13 eyes (17.6%) required macular photocoagulation treatment. Four eyes (5.4%) lost two or more lines of Snellen acuity over the follow up period (three from macular oedema and one from macular ischaemia). There was no relation between the presence or resolution of minimal exudate and visual loss (p>0.2). CONCLUSION: It is appropriate to monitor eyes with streak or dot macular exudates at 6-9 monthly intervals in a screening programme.

Relationship of diabetic microvascular complications to outcome in panretinal photocoagulation treatment of proliferative diabetic retinopathy.

Argon laser panretinal photocoagulation for proliferative diabetic retinopathy was shown in the Diabetic Retinopathy Study and Early Treatment Diabetic Retinopathy Study to reduce the incidence of blindness by 50% with relatively small amounts of treatment. However, some diabetics require much more extensive photocoagulation for control of proliferative disease. We attempted to determine risk factors for poor response to treatment with panretinal photocoagulation (PRP) by studying outcome in relation to the argon laser burn count and the presence of diabetic vascular complications. Sixty-six consecutively treated eyes undergoing PRP were studied, of which 57% showed resolution of new vessels 6 weeks after treatment. This was significantly related to the total amount of laser treatment given (mean no. in regressed eyes 5800 burns, non-regressed 3510 burns; p < 0.05). Renal disease and age (< 50 years) were identified as risk factors for non-regression (p < 0.05); hypertension, neuropathy, duration of disease and insulin dependence had no significant effect on outcome. We conclude that regression of proliferative disease is significantly related to the cumulative total number of laser burns applied and that successful laser photocoagulation in patients with diabetic renal disease requires considerably more treatment than that suggested by earlier studies.

Breakdown of the blood-aqueous barrier after argon laser panretinal photocoagulation for proliferative diabetic retinopathy.

BACKGROUND: Breakdown of the blood-aqueous barrier (BAB) after panretinal photocoagulation (PRP) was measured with a laser flare photometer over a study period of 8 weeks. METHODS: Twenty-five eyes of 25 patients who had no previous photocoagulation and required such treatment for proliferative diabetic retinopathy (PDR) were included in the trial. They received 2000 burns (0.1-second exposure, 200 mu m spot) via a panfunduscope and 500 burns (0.1-second exposure, 500-mu m spot) with a Goldmann lens. Power levels were adjusted to produce a mild blanching of the retina. Only an argon green laser (514 nm) was used. Laser photometry was performed on both eyes at 3, 24, 48, 72, 96, and 168 hours and 8 weeks after laser treatment. RESULTS: Including all of the eyes treated, there was a significant increase in flare value of 3, 24, and 48 hours compared with baseline (Student's t test) but not at 72, 96, and 168 hours or at 8 weeks. Peak values occurred at 24 hours. When blue and brown irides were analyzed separately, there was a significant increase in flare for blue irides compared with baseline levels at 3 and 24 hours, whereas for brown irides the increased flare was sustained at 3, 24, 48, 72, and 96 hours (Student's paired t test). In addition, when the increase in flare value from baseline was compared between blue and brown irides (pooled Student's test), there was a sustained increase at 24, 48, 72, and 96 hours for brown irides compared with blue. Clinically significant uveitis, posterior synechiae, or peripheral anterior synechiae did not develop in any of the patients. CONCLUSIONS: Breakdown of the BAB may occur after PRP, particularly in more heavily pigmented irides. The time course of this suggests that the phenomenon is related directly to laser effects in the anterior segment, although other factors may contribute.

The assessment of clinical investigations: the Greenwich Grading System and its application to electrodiagnostic testing in ophthalmology.

The aim of the study was to describe the Greenwich Grading System, a simple method developed for assessing the value of a clinical investigation, and to investigate its application to electrodiagnostic testing (EDT) in ophthalmology patients. This was done by means of a retrospective case analysis carried out on 95 unselected, consecutive patients referred from a district ophthalmology department for electrophysiological investigation at a regional neurosciences centre. The classification was developed to quantify the effect of EDT on the diagnosis, investigation and treatment in each case. From this, an overall value of EDT in management could be assessed for different groups of patients. It was found that the classification was easy to apply and analyse. EDT was valuable in 80% of patients referred, and was classified as essential or important in 53 (56%) patients. In no patient did EDT adversely affect the clinical outcome. The diagnosis was changed in 7 (7%) patients, and made in 5 (5%). Diagnostic certainty was increased in a further 62 (65%) patients. Other investigations were avoided by performing electrophysiology in 28 (29%) cases. Treatment was initiated in 6 (6%) cases and altered in 8 (8%). It is concluded that the Greenwich Grading System, as applied to EDT in ophthalmology, demonstrated the value of electrophysiological investigation in ophthalmology patients and identified the patient groups which benefit most from testing.

Factors predisposing to postoperative intraocular inflammation.

This prospective study of 123 patients undergoing cataract extraction determined the preoperative and surgical factors predisposing to an exaggerated postoperative inflammatory response. It is important to identify the patients at increased risk of complications requiring additional prophylaxis or more intensive postoperative care, particularly when selecting patients for day case surgery. Previous intraocular inflammation or surgery was the factor most strongly associated with marked inflammation on the first postoperative day (p < 0.01, compared to uncomplicated patients). As a result, patients stayed in hospital an average of one day longer (p < 0.001) and required significantly more steroid drops (p < 0.001). Other factors of significance, but reducing importance were: difficult surgery, non-caucasian race and brown irides. Amongst uncomplicated patients, the difficulty of surgery was most significantly related to a high inflammation score (p < 0.01). Non-caucasian patients stayed in hospital significantly longer than their caucasian counterparts (p < 0.05), and required more steroid drops (p < 0.001). Of caucasian patients, those with brown irides were inpatients for significantly longer than those with blue or hazel (p < 0.05). No other factors studied significantly altered postoperative inflammation: neither the presence of diabetes, nor the technique of cataract extraction.

Studies of the blood-aqueous barrier in diabetes mellitus.

We measured the breakdown of the blood-aqueous barrier in 63 patients with diabetes (126 eyes) by using a laser flare meter. Of 126 eyes, 40 had no retinopathy, 34 had proliferative retinopathy, 24 had regressed proliferative retinopathy, 14 had background retinopathy, and 14 had maculopathy. Eyes were classified into one category only. Mean flare was greater for proliferative retinopathy compared to background retinopathy (P = .0065), no retinopathy (P = .0001), and maculopathy (P = .0189). Flare values were greater for regressed proliferative retinopathy compared to no retinopathy (P = .0118) (paired Student's t-test). Diabetic eyes without demonstrable retinopathy still had higher flare values than control eyes without diabetes. The length of diabetes was greater for those eyes with proliferative diabetic retinopathy (P = .0195), regressed proliferative diabetic retinopathy (P = .0625), and background diabetic retinopathy (P = .006) compared to those with no retinopathy. No significant difference was noted in duration of diabetes for eyes with diabetic maculopathy when compared to those with no retinopathy (P = .5788). Breakdown of the blood-aqueous barrier precedes the development of retinopathy, and the more severe proliferative forms have greater blood-aqueous barrier dysfunction.

Macular ischaemia in posterior uveitis.

The commonest cause of visual morbidity in patients with posterior uveitis is cystoid macular oedema, which usually responds to immunosuppressive treatment. However, a small group of patients do not have a satisfactory visual outcome despite apparently adequate therapy. In a retrospective study of 345 angiograms of 135 patients with active non-occlusive retinal vasculitis 12 patients were identified by independent masked review as showing macular ischaemia on their fluorescein angiograms. Four patients had Behçet's disease, 4 sarcoidosis, and 4 idiopathic retinal vasculitis. Follow-up of these patients for an average of 36 months (range 6-120 months) showed that visual acuity failed to improve in 4 patients and dropped by an average of three lines Snellen in the other 8. We suggest that a poor visual outcome in some patients with posterior uveitis may be predicted by the presence of macular ischaemia on fluorescein angiography and that immunosuppressive therapy should be prescribed with caution in these patients.

Subconjunctival betamethasone is of benefit after cataract surgery.

Following cataract extraction, the intraocular inflammatory response is particularly marked in some patients, who then require more intensive post-operative care. This prospective randomised double-masked controlled trial of 246 patients undergoing cataract extraction assessed the efficacy and safety of a prophylactic subconjunctival injection of betamethasone (Betnesol, Glaxo) in improving the post-operative course. Betamethasone injected subconjunctivally at the end of cataract extraction significantly reduces anterior segment inflammation (p < 0.05) on the first post-operative day. It also reduces the need for additional steroid treatment and in-patient stay (p < 0.05). The benefits are most marked in those patients prone to a greater inflammatory response: especially those with previous intraocular inflammation (p < 0.01), but also those with racial pigmentation or difficult surgery. There was no evidence of adverse effects following betamethasone; in particular there was no endophthalmitis or steroid-induced elevation of intraocular pressure. We therefore conclude that subconjunctival injection of betamethasone is a practical, safe and effective means of improving the quality and efficiency of patient care.

Neovascular response in ischaemic central retinal vein occlusion after panretinal photocoagulation.

Twenty seven eyes treated for ischaemic central retinal vein occlusion with panretinal photocoagulation were reviewed. Prior to laser therapy anterior segment neovascularisation predominated (17 eyes) over posterior segment involvement (6 eyes). After photocoagulation anterior segment new vessels regressed or did not develop in the majority of cases. However, in five eyes previously absent posterior segment neovascularisation occurred. These results suggest that photocoagulation alters but does not eliminate retinal ischemia, thus modulating the neovascular response.

Neovascularisation associated with posterior uveitis.

Twenty-six patients (39 eyes) with retinal neovascularisation associated with ocular inflammation were identified from the retinal vasculitis clinic at St Thomas's Hospital. Eight patients had sarcoidosis, seven patients Behçet's disease, and 11 had idiopathic retinal vasculitis. Twenty-three patients had required systemic therapy to control the inflammation and 11 patients received laser photocoagulation. Fluorescein angiography showed significant capillary closure in 15 eyes and diffuse microvascular leakage in the remaining 24 eyes. All patients had posterior vitreous detachment. The visual prognosis was good despite vitreous haemorrhage being the presenting feature in 22 eyes, and the new vessels resolved in 70% of cases. However, laser treatment was followed by a significant increase in cystoid macular oedema (p less than 0.01). This retrospective study suggests that medical therapy is the first line of treatment in this group of patients. Photocoagulation should be performed when the eye is quiet and should be reserved for patients with recurrent vitreous haemorrhages and significant capillary closure.

Assessment by fluorescein angiography of surgical treatment of occlusive carotid artery disease.

Fundus fluorescein angiography was performed in 10 cases of occlusive carotid artery disease at presentation and after surgery or medical treatment. An improvement in the microcirculation of the retina was observed in 4 cases after carotid endarterectomy and in 1 case after carotid endarterectomy and extracranial-intracranial bypass. Improvement was not observed in 2 cases after extracranial-intracranial bypass alone or in 3 cases in which surgical intervention was not undertaken. Our results suggest that carotid endarterectomy is a more effective procedure than extracranial-intracranial bypass in improving retinal perfusion when compromised by ipsilateral carotid obstruction.

Fluorescein angiography in carotid disease.

Twenty four cases in whom occlusive disease of the carotid artery was proven by digital subtraction angiography or direct carotid arteriography were studied. In five cases venous stasis retinopathy was evident ophthalmoscopically. Fluorescein angiography was abnormal in 19 cases. The abnormalities found were microaneurysms (16 cases); slow arteriovenous transit time (8 cases); macular oedema (8 cases); leakage from the arterioles (3 cases); disc new vessels (4 cases). The differences between this retinopathy and diabetic retinopathy are discussed.

Argon laser iridotomy.

Argon laser iridotomy was successfully performed on 47 out of 52 eyes of 35 patients by the continuous wave argon laser. The technique of argon laser iridotomy is described in detail. A number of complications were observed. The reasons for these are discussed, and measures for the avoidance of complications are suggested.

Retinal branch vein occlusion: a study of argon laser photocoagulation in the treatment of macular oedema.

A control trial is reported which demonstrates that treatment with argon laser photocoagulation to certain patients with macular oedema following a branch vein occlusion does not alter significantly their visual prognosis. It confirms that patients with an intact perifoveal capillary arcade have a better prognosis than those with a broken arcade.

A comparative trial of xenon arc and argon laser photocoagulation in the treatment of proliferative diabetic retinopathy.

We present the results of a randomised study comparing xenon arc and argon laser photocoagulation in the treatment of proliferative diabetic retinopathy. Our results show that when used in the way described below there is no significant difference between the effect of the 2 treatments on optic disc neovascularisation and visual acuity. We also compare the results of peripheral retinal ablation with those of panphotocoagulation in the argon and xenon groups. The results suggest that in some patients peripheral treatment may be sufficient to cause regression of disc neovascularisation.