Vitreo-retinal surgery in sickle cell disease [abstract]

Sickle cell disease is the commonest haemo-globinopathy. The gene is present in about 8 percent of Afro-American and 10 percent of Afro-Jamaican. Severe ocular complications of this condition include proliferative retinopathy, vitreous haemorrhages, and retinal detachment ultimately leading to blindness in a number of cases. There are not many reports of vitreo-retinal surgery in the literature dealing with cases. This is a report of 28 vitero-retinal surgeries in 20 eyes of 19 patients with sickle cell eye disease. Four eyes had surgery for viterous haemorrage, 16 for retinal detachment. All four eyes with vitreous haemorrage had successful pars plana vitrectomy (PPV) with full restoration of full potential vision. Eight of 16 eyes had successful retinal detachment surgery. Four eyes had pneumatic retinopexy with one unsuccessful result. Five eyes had scleral buckles with four having successful results, and six had bad results and one was unchanged. Six of ten eyes that had pars plana virectomy for retinal detachment had bad results. The unsuccessful cases were difficult ones with extensive proliferative vitero-retinopathy and long-standing retinal detachment. (AU)

New classification of peripheral retinal vascular changes in sickle cell disease

The systemic complications of homozygous sickle cell disease (SS) are more severe than in sickle cell haemoglobin C (SC) disease, and yet visual loss due to proliferative retinopathy is more common in the latter. This anomaly is unexplained. It is believed that proliferative disease occurs in response to closure of the peripheral retinal vasculature, yet a systematic longitudinal survey of the peripheral retinal vascular bed has not been undertaken. In the Jamaica Sickle Cohort study all subjects are scheduled to receive annual ocular examination and fluorescein angiography. The results have now been analysed in subjects with SS and SC disease using a new classificaton system based on a comparison of the peripheral retinal vascular bed with that recorded in the cohort with normal haemoglobin (AA) genotype. The vascular patterns could be classified as qualitatively normal (type I) or abnormal (type II). An abnormal vascular pattern was identified more commonly with age, in a significantly larger proportion of subjects with SC than SS disease, and was associated with the development of proliferative disease. In order to establish the dynamics of change, the angiograms were analysed in the 18 subjects (24 eyes) who developed proliferative disease. It is shown that qualitatively normal vascular pattern may be retained despited loss of capillary bed and posterior displacement of the vascular border. A border which is qualitatively abnormal does not revert to normal, and once abnormal, continuous evolution may occur before development of proliferative lesions. The peripheral border of the retinal vasculature was too peripheral to photographed in 13 of the 24 eyes before it becoming qualitatively abnormal. It is concluded that a normal border, if posterior, results from gradual modification of the capillary bed and indicated low risk of proliferative disease. A qualitatively abnormal vascular border occurs as a radical alteration of retinal perfusion in subjects in whom little modification of the vascular bed occurred before the event, and signal risk of proliferative disease. This classification system is useful in identifying the likelihood of threat to vision in young Jamaicans with sickle cell disease, and the higher frequency of proliferative retinopathy in SC can be explained by the higher prevalence of a qualitatively abnormal peripheral retinal vasculture (AU)

Laser photocoagulation for proliferative retinopathy in sickle haemoglobin C disease

The effect of sectoral, scatter laser photocoagulation on proliferative sickle retinopathy (PSR) was investigated by reviewing florescein angiograms of 88 sickle cell-haemoglobin C patients enrolled in a controlled, randomised trial. Follow-up was for a median period of 2.9 years. Complete infarction of all PSR in an eye occurred in 7 of 74 treated eyes and 2 0f 60 control eyes. Treatment resulted in significantly greater regression (decrease in number and size of PSR lesions) in eyes of patients aged <25 years at enrollment but not in eyes of patients> or = 25 years at enrollment. Infarction of the individual PSR lesions was significantly more common in treated eyes. Treated PSR was significantly more likely to infarct if small (< 15 degrees circumferential involvement) and if flat rather than elevated. New PSR was significantly less likely to develop in treated eyes.

Retinal changes in sickle cell/hereditary persistence of fetal haemoglobin syndrome

We describe for the first time retinal changes in sickle cell/hereditary persistence of fetal haemoglobin syndrome, which is a rare and benign disorder. The changes are qualitively similar to retinal disease seen with sickle haemoglobin and sickle C haemoglobin, but are mild (AU)

Central retinal artery occlusion without retrobulbar hemorrhage after retrobulbar anaesthesia

Four patients had central retinal artery occlusions after retrobulbar anaesthesia with lidocaine HCl was administered before photocoagulation. One of these four had two separate episodes of closure. Only one had permanent visual loss and none had evidence of retrobulbar hemorrhage. Each patient had a severe hematologic or vascular disorder. We think that direct trauma to the central retinal artery behind the globe, the pharmacologic or compressive effects of the injected solution,or both caused the occlusions in these patients. (AU)