Incidence and indications for pars plana vitrectomy following the treatment of posterior uveal melanomas in Scotland.

BACKGROUND: Globe-sparing treatments such as plaque brachytherapy, local or endoresection, and proton beam therapy (PBT) are the treatments of choice for posterior uveal melanoma. However, both early and late complications can arise from these techniques, including vitreous haemorrhage (VH) and retinal detachment (RD). Choroidal melanomas in Scotland are managed by a single unit, the Scottish Ocular Oncology Service (SOOS). METHODS: Indications and outcomes from surgery were analysed for patients undergoing vitrectomy following treatment for uveal melanoma in the SOOS between 1998 and 2013. RESULTS: Seventeen from 715 cases (2.4%) required vitrectomy, of which 8/445 (1.8%) followed plaque brachytherapy, 7/43 (16.3%) combined local resection and brachytherapy, and 2/227 (0.9%) PBT. Case notes were reviewed for 16/17 cases, with surgery indicated for VH in 10 (63%), RD in 5 (31%), and combined VH/RD in 1 (6%). The median interval from initial tumour treatment to vitrectomy was 5.8 months (range 10 days to 8.8 years). Ten (63%) required early vitrectomy (within 6 months), of which the majority (70%) followed combined resection/brachytherapy. Six (37%) required late vitrectomy (after 6 months), of which all were non-clearing VH following plaque brachytherapy, with proliferative retinopathy in 4/6 (67%), and tumour recurrence in 2/6 (33%). Overall vision improved in 8 eyes (50%), remained the same in 2 (12.5%), and deteriorated in 6 (37.5%). CONCLUSIONS: Early vitrectomy was most commonly indicated for RD following local resection, and late vitrectomy for VH due to radiation retinopathy. The majority of patients undergoing vitrectomy gained or maintained vision.

Spatial localization after different types of retinal detachment surgery.

PURPOSE: To compare the effect on spatial localization of two different forms of surgery for primary rhegmatogenous retinal detachment. METHODS: Two groups of 30 patients (one group undergoing conventional external scleral-buckling procedures, the other undergoing vitrectomy procedures) were recruited. They pointed at targets appearing on a computer touchscreen without being able to see their hands, while viewing targets with the non-surgically treated eye. The sizes of the horizontal pointing errors were recorded on three separate occasions: before surgery, on the first postoperative day, and approximately 10 days later. RESULTS: On the first postoperative day a significant change in localization of 2.9 +/- 0.9 degrees [SD]) was observed in the scleral-buckling group, compared with 1.3 +/- 0.6 degrees in the vitrectomy group. These changes resolved by the second postoperative assessment. CONCLUSIONS: These results, particularly in patients in the scleral-buckling group in whom greater manipulation of the extraocular muscles inevitably occurs, are consistent with an alteration in the extraretinal eye position information that is used in spatial localization. This is likely to be a consequence of modified efference copy and/or extraocular muscle proprioception.

Motility and binocularity outcomes in vitrectomy versus scleral buckling in retinal detachment surgery.

BACKGROUND: Ocular motility defects and loss of binocularity are well-recognised problems following retinal detachment surgery. It is presumed that scleral buckling is primarily responsible for these effects. The increasing use of vitrectomy in the management of retinal detachment might be expected to reduce the incidence of these defects. METHOD: Two groups of patients presenting with primary uncomplicated rhegmatogenous retinal detachments were examined following a single surgical repair. The first group underwent vitrectomy (n = 17), the second group, scleral buckling/external surgical techniques (n = 23). RESULTS: Heterotropia was present in 24% (n = 4) of the vitrectomy group and 30% (n = 7) of the "external" group, with suppression reported clinically in 8 of these and diplopia by the other 3. While ocular movements were frequently full (vitrectomy 59%, external 61%), restricted vertical movements were observed in 35% of the vitrectomy group and 26% of the external group, with horizontal and general restrictions being rare (6% and 13% respectively). True motor fusion was more common for the external group (44%) than the vitrectomies (24%), while superimposition was more frequent in the vitrectomies (64%; external 39%). The latter was achieved only with correcting prisms in 18% of vitrectomies and 9% of the external group. The remainder did not demonstrate any potential for binocularity. Visual symptoms were more frequent among the vitrectomy group, with aniseikonia and torsion significantly more common. CONCLUSIONS: The findings confirm that ocular motility problems are not exclusive to scleral buckling, with the incidence being similar in both groups. Slinging of the extraocular muscles and the accompanying dissection, resulting in the 'fat adherence syndrome', must be considered as contributory factors. The visual deficits which inevitably occur as the result of retinal detachment seem to play a more major role in the disruption of binocularity in these cases.

Linkage of a medium sized Scottish autosomal dominant retinitis pigmentosa family to chromosome 7q.

Retinitis pigmentosa is a group of hereditary retinopathies which is both clinically and genetically heterogeneous. Autosomal dominant (ADRP), autosomal recessive (ARRP), and X linked recessive (XLRP), as well as digenic forms of inheritance have been reported. ADRP has been linked to 3q, 6p, 7p, 7q, 8cen, 17p, 17q, and 19q. Three unrelated ADRP families have been reported to show linkage to 7q. We tested a Scottish ADRP family with microsatellite markers mapping within the 7q31-q35 region, and found three markers (D7S487, D7S514, D7S530) showing statistically significant evidence of linkage. A maximum two point lod score of 3.311 at 0% recombination was obtained for D7S514.

How much blame can be placed on laser photocoagulation for failure to attain driving standards?

One hundred consecutive patients who underwent bilateral pan-retinal photocoagulation (PRP) for proliferative diabetic retinopathy were assessed in accordance with the UK Driver and Vehicle Licensing Agency (DVLA) guidelines. Visual acuity was documented, and visual fields were assessed using the Esterman test. Among the 30% of patients who failed to reach the visual standards required for a driving licence, three groups were identified: those who failed to attain either the required binocular visual acuity (n = 4), or visual fields (n = 9), or both (n = 17). Previous studies reveal a large variation in DVLA field test failure following PRP treatment for proliferative diabetic retinopathy. Our results show a 19% failure rate solely attributable to treatment, which is at the lower end of previously reported studies (20-80%). The reasons for this discrepancy are discussed. We conclude that modern treatment procedures for proliferative diabetic retinopathy may be undertaken with the knowledge that in the majority of cases a patient's driving licence is unlikely to be revoked.

Rhodopsin mutations in a Scottish retinitis pigmentosa population, including a novel splice site mutation in intron four.

Retinitis pigmentosa (RP) is the name given to a group of disorders, both clinically and genetically heterogeneous, that primarily affect the photoreceptor function of the eye. Mutations in the genes encoding for rhodopsin, RDS-peripherin, or the beta subunit of the cGMP phosphodiesterase enzyme can be responsible for the phenotype. In this study the rhodopsin gene has been screened for mutations in a panel of RP individuals and five different sequence changes have been detected to date in three dominantly inherited and two unclassified families. One of these, a base substitution in the 3'UTR, has not yet been confirmed as disease specific, while three missense substitutions have previously been reported and are likely to be responsible for the phenotype. The fifth change, a base substitution at the intron 4 acceptor splice site, represents a novel mutation and is assumed to be the causative mutation.

Pathology of hereditary retinal degeneration associated with hypobetalipoproteinemia.

BACKGROUND: The clinical features and previously unreported ocular pathology in a case of heterozygous hypobetalipoproteinemia (HBL) associated with a pigment epitheliopathy are documented. Night blindness developed in a white woman with familial heterozygous HBL (cholesterol and low-density lipoprotein levels < 5% of normal) at 51 years of age. Ophthalmoscopy showed bilateral symmetric depigmentation at the posterior pole with pigment clumping and pavingstone configuration in the periphery. By the time the patient died, at 75 years of age, vision had deteriorated to hand motions. METHODS: One eye was removed 2 hours postmortem for light and electron microscopic study. RESULTS: The photoreceptors were absent, and the outer nuclear layer was replaced by glial cells throughout most of the retina, but there was some focal photoreceptor preservation in isolated regions. The outstanding feature was a massive deposition of basal linear deposit which was calcified in segments and which contained macrophages and the processes of glial cells: trilaminar bodies and melanin granules were identified in the macrophages. The remaining retinal pigment epithelial cells contained melanin but very little lipofuscin: intraretinal migration was minimal. CONCLUSIONS: The authors postulate that the pigment epitheliopathy associated with HBL is an abiotrophy in which photoreceptor discs are unable to regenerate due to locally disordered metabolism resulting from or acting in concert with the pigment epitheliopathy.

An increased incidence of apolipoprotein E2/E2 and E4/E4 in retinitis pigmentosa.

Previous studies from our laboratory have shown that retinitis pigmentosa (RP), a family of hereditary retinal degenerations, is often accompanied by abnormal levels of cholesterol or polyunsaturated fatty acids. The requirement of the retina for n-3 fatty acids is well known, and a defect in the supply of these lipids (e.g., by apolipoproteins) could affect the course of the disease. The present study confirms and extends a report on apolipoprotein E (apo E) isoforms in German RP patients [Jahn, Oette, Esser, Bergmann, and Leiss, (1987) Ophthalmic Res. 19, 285-288] which showed a tenfold increased frequency of the E2/E2 phenotype compared to the average German population. In our study, apo E phenotypes were determined in the probands of 100 Scottish RP families. The findings revealed a 4-fold increase in the incidence of E2/E2 and an 8-fold increase in E4/E4 compared to a Scottish control population. These increases were statistically significant at the P < 0.05 and P < 0.01 levels, respectively. To investigate the possibility that some of these apparent E2/E2 or E4/E4 phenotypes might actually be new apo E mutations, we examined the behavior of the apo E on sodium dodecyl sulfate-polyacrylamide gels (E2 migrates anomalously) and on isoelectric focusing gels following cysteamine modification of cysteines. These studies showed that two RP patients possibly had new apo E mutations, though amino-terminal sequence analysis revealed no changes in the sequence of the first 19 residues; further sequence analysis is obviously warranted.

Diagnostic and counselling difficulties using a fully comprehensive screening protocol for families at risk for tuberous sclerosis.

Tuberous sclerosis (TS) results from an autosomal dominant gene which exhibits variable expression and reduced penetrance. Although there are well established diagnostic criteria for TS, examination of first degree relatives can cause diagnostic criteria for TS, examination of first degree relatives can cause diagnostic problems with consequent difficulties in genetic counselling. Using an extensive, non-invasive protocol consisting of skin examination with Wood's lamp, cranial CT scan, specialist ophthalmological and dental examination, skeletal survey, and echocardiography, we have examined 56 first degree relatives of persons with TS. These consisted of 40 parents and seven sibs from 25 sporadically affected families and nine persons from seven multigeneration families. In seven of the apparently sporadically affected families, three mothers had echocardiographical findings consistent with one or more rhabdomyoma. In another, the mother's renal ultrasound showed evidence of single cysts in both kidneys. In a fifth family, the father had suggestive but not diagnostic features of TS on the cranial CT scan and skeletal survey. In the sixth family, the mother was found to have atypical calcification on CT scan. In a seventh instance a sib from a two generation family had echocardiographical evidence of a rhabdomyoma. Even though the proband in three of the sporadically affected families presented with fits, developmental delay, and depigmented patches, and therefore did not strictly fulfil the diagnostic criteria for TS, two mothers were found to have evidence of rhabdomyomata on echocardiography and the brother of the third had typical depigmented patches. Although the presently accepted diagnostic criteria for TS may not allow one to make a definitive diagnosis of TS in these relatives, we recommend that an extensive screening protocol be used to examine first degree relatives and that caution be used in counselling apparently unaffected members of families at risk for TS.

Visual performance in pseudophakia with standard and ultraviolet-absorbing intraocular lenses: a preliminary report.

There is currently considerably interest in the vulnerability of the pseudophakic eye ultraviolet light. Contrast sensitivity was measured in patients receiving UV-absorbing and standard posterior chamber intraocular lenses (IOLs) and in normal age-matched observers. The results suggest that in the relative short-term there is no difference in visual performance with either type of IOL. Modulation Transfer Function studies on 3 batches of IOLs (2 standard and 1 UV-absorbing) showed slight variations in optical performance within and between batches. Spectral sensitivity testing demonstrated increased macular protection from short wave-length blue light by the crystalline lens when compared with both types of IOL.

Ophthalmic findings in very low birth weight children.

Recent advances in neonatal intensive care have led to a much improved survival rate in very low birth weight infants (under 1,500 g). A group of such children was examined and found to have a low incidence of serious visual or general handicap, but severe retrolental fibroplasia (RLF) affects a significant number.

Optic chiasmal radionecrosis.

Four patients (3 acromegalics, 1 chromophobe adenoma) out of a total of 87 patients with pituitary tumors treated with irradiation are presumed to have developed optic chiasmal radionecrosis. It would appear very difficult, if not impossible, to predict those patients at greatest risk of this complication due to individual variations in sensitivity to radiation.

Plasma lipid abnormalities in retinitis pigmentosa and related conditions.

Plasma samples obtained from 69 fasting retinitis pigmentosa (RP) patients and 110 controls were assayed for cholesterol, triglycerides, lipoproteins, and fatty acids. It was found that many RP patients were hyperlipidaemic compared to their spouses and siblings, as well as compared to unrelated controls. This hyperlipideaemia was particularly severe in men over 35 years of age, and in hemizygotes in X-linked families. In contrast, hypocholesterolaemia was observed in albipunctate retinal dystrophy. Plasma fatty acid titres were, in general, similar in RP patients and controls; however, patients in three families (two X-linked, one autosomal dominant) showed a significant reduction in docosahexaenoic acid (C22:6) compared to their unaffected relatives. These various plasma lipid abnormalities may reflect disorders in lipid metabolism which also may lead to retinal dystrophy.