D G Cottrell

Risk factors for strabismus in children born before 32 weeks’ gestation

AIM To investigate risk factors associated with strabismus in children born prematurely. METHODS Prospective study of all children born before 32 weeks’ gestation between 1 January 1990 and 31 December 1991 in a geographically defined population of approximately 3 million in the Northern Region of the United Kingdom. All children were examined aged 2 years by the same ophthalmologist and paediatrician. RESULTS 558 children (98.6% of study group) were examined. Logistic regression showed an increased risk of strabismus in children with cicatricial retinopathy of prematurity (p=0.02), refractive error (p=0.003), family history of strabismus (p<0.0001), and poor neurodevelopmental outcome (p<0.0001), in particular impaired locomotor skills (p=0.008) and hand-eye coordination (p=0.001). Gestational age and regressed acute ROP were not independent risk factors for strabismus (p=0.92 and 0.85 respectively). CONCLUSIONS This study has identified factors which are independently related to strabismus (although not necessarily causative) and others which are related only indirectly. This may contribute both to the management of children born prematurely and to future studies of the aetiology of strabismus.

Retinopathy of prematurity in practice. I: screening for threshold disease

AbstractAims To review an 11-year period of screening for retinopathy of prematurity (ROP) in the north of England by a single ophthalmologist. To identify the gestational ages and birth weights of babies reaching different stages of ROP. To investigate the workload involved in screening to detect threshold ROP, and that the practical outcomes had narrower inclusion criteria for screening. To identify babies treated for threshold disease.Methods During the period August 1987–October 1998, babies were screened according to the national guidelines and the results were prospectively entered onto a computerised database. These data were then systematically reviewed.Results Data were available for 484 babies: 203 (41.9%) developed any ROP, 46 (9.5%) reached stage 3 ROP, and 25 (5.2%) reached threshold and were treated. Data on 425 babies showed them to require an average of 2.3 screening examinations per baby. It took an average of 39 screening examinations to detect one case of threshold ROP. The more premature and lighter birth weight babies required the most examinations. Therefore, restricting the inclusion criteria for screening would only have reduced the total number of screenings modestly and could have allowed us to miss two of our threshold cases who were both of 30 weeks gestational age and >1400u2009g birth weight.Conclusions Screening is time consuming but worthwhile in view of the benefits of treatment. As applied to babies in the north of England, the current national screening criteria are satisfactory. The results of treatment of the babies identified in this study are presented in the accompanying paper.

Triple cycle audit of primary retinal detachment surgery.

Purposeu2003To determine the effect of increasing subspecialisation on the results of retinal detachment surgery in one city.Methodsu2003Three audit cycles over a 10-year period when major subspecialisation and organisational changes were occurring. Retrospective case note reviews of all primary surgery for rhegmatogenous retinal detachments in each of the audit periods. Statistical analyses used contingency table/chi-square methods for comparing all three audits and Fisher’s exact test/mean odds ratio with 95% confidence intervals (CIs) for the Audit 1 vs Audit 3 comparison.Resultsu2003A marked improvement in success rates occurred: primary reattachment rose from 67% in Audit 1 to 87% in Audit 3 (Pu2009=u20090.0004), and final success from 84% to 97% (Pu2009=u20090.0003). There was a dramatic change in operative techniques over the same period: the percentage of vitrectomies increased from 1.5% in Audit 1 to 48% in Audit 3, while that of ‘open’ conventional procedures decreased from 78% to 32%. However, the improvement in anatomical success was not mirrored by an increase in the percentage of patients with 6/12 or better visual acuity postoperatively (55% in Audit 1, 49% in Audit 3; Pu2009=u20090.34, mean odds ratiou2009=u20090.78; 95% CI 0.48–1.2). The percentage of patients with 6/18–6/36 post op visual acuity did increase in Audit 3 (18% in Audit 1; 29% in Audit 3; Pu2009=u20090.03, mean odds ratiou2009=u20091.9; CI 1.1–3.3), and the percentage with 6/60 or worse decreased (27% in Audit 1, 20% in Audit 3; Pu2009=u20090.26, mean odds ratiou2009=u20090.71; CI 0.40–1.2).Conclusionsu2003With increased subspecialisation there has been an increase in anatomical success, but the goal of 100% reattachment is still not being attained. There remains scope for further improvement in anatomical and functional outcomes.

Refractive errors in children born before 32 weeks gestation

Purpose: To document the refractive errors in a cohort of children born before 32 weeks gestation.Methods: All children born before 32 weeks gestation between 1 January 1990 and 31 December 1991 to mothers resident in the Northern Region of the National Health Service were examined at 2 years old (n = 558).Results: Stage 3 or worse retinopathy of prematurity (ROP) was associated with myopia. In those not developing stage 3 or worse ROP, the refractive errors were myopia in 1.5%, hypermetropia >4 dioptres (D) in 5.4%, anisometropia >1 D in 1.1% and astigmatism >1.25 D in 5.7%.Conclusion: The incidence of refractive errors in those not developing stage 3 or worse ROP was similar to that in the general population.

Referral delay and ocular surgical outcome in Terson syndrome.

Background: In Terson syndrome, vitreous hemorrhage can result from intracranial hypertension associated with intracranial bleeding. The vitreous hemorrhage can cause a considerable visual handicap. The aim of this study was to determine the outcome of surgery in patients with Terson syndrome and any delay in referral to an ophthalmologist. Methods: Retrospective case review of 25 eyes of 17 patients undergoing vitrectomy for Terson syndrome. Delay in presentation to an ophthalmologist, intraoperative and postoperative complications, and the final visual acuity were noted. Results: The mean interval between visual symptoms and referral to an ophthalmologist was 5.2 months for the nine unilateral cases and 4.9 months for the eight bilateral cases. Intraoperative complications included retinal break (2) and retinal dialysis (3). Late complications included epiretinal membrane (4), ghost cell glaucoma (1), and cataract (8). Twenty‐two of the 25 eyes achieved a final visual acuity of 20/30 or better. Conclusion: Vitrectomy for vitreous hemorrhage in Terson syndrome is a safe and effective procedure, offering a rapid and prolonged improvement in vision. There is good reason to consider early vitrectomy, particularly when the hemorrhage is bilateral and dense. RETINA 20:374‐377, 2000

Regionalisation of retinopathy of prematurity (ROP) screening improves compliance with guidelines: an audit of ROP screening in the Northern Region of England

AIMS This project was designed to determine whether a coordinated regional strategy can improve the implementation of national guidelines for screening for retinopathy of prematurity (ROP), and to identify causes for failure of compliance. METHODS Retrospective case note audit relating to two periods, 1990–1 and 1994, involving all 17 neonatal intensive care units in the Northern Region of England. Between the two periods, a regional strategy was instituted in an endeavour to improve compliance. Babies born in or admitted to the units during the study periods who were eligible for ROP screening were included. Screening performance was assessed against a standard of 100% compliance with the guidelines. In the second audit period compliance with subsidiary standards was also measured, and reasons for failure were identified. RESULTS Compliance improved from 47% (262/558) in the first audit cycle to 73% (264/360) in the second. Subgroup analysis in this second cycle indicated better compliance (93.3%) in higher risk babies (⩽ 29 weeks gestational age). Babies transferred between units, discharged home before screening, or who failed to qualify for screening on one of the two defined criteria, were more likely to be missed. CONCLUSION A carefully implemented regional approach to screening resulted in a higher uptake for babies most at risk. Simple recommendations are made to achieve further improvement in compliance with the guidelines. The wider implications for screening in other conditions and in other areas and specialties are highlighted.

Bilateral acute retinal necrosis syndrome following herpes simplex type 1 encephalitis.

traction and tears with vitreous traction with or without retinal neovascularisation. Tears and retinal detachment due to traction on neovascular tissue are infrequent. A strong association between BRVO with vitreous haemorrhage and posterior tractional retinal breaks was reported by Joondeph et al. They reviewed 358 cases with BRVO and reported 1.6% incidence of posterior tractional breaks leading to rhegmatogenous retinal detachment in 0.6% of patients. Kir et al reported 3% incidence of retinal breaks and 1.3% of rhegmatogenous retinal detachment. Retinal breaks are almost exclusively found in the distribution of the occluded vessel and often located at or posterior to equator. The most widely accepted hypothesis for pathogenesis of tractional retinal break in BRVO is vitreoretinal traction caused by vitreous contraction following retinal neovascularisation. The influence of laser photocoagulation and/or vitreous haemorrhage resulting in retinal break formation remains controversial. Our case emphasises that vitreous haemorrhage in eyes with BRVO should alert the examiner to closely monitor the situation since traction on neovascular fronds may lead to retinal breaks and consequent retinal detachment.

Haemodynamic responses to subconjunctival mydriatic agents (Mydricaine) used for maintenance of perioperative mydriasis in patients undergoing vitreoretinal surgery.

Purpose To assess the systemic effects of subconjunctival mydriatic agents (Mydricaine).Methods Haemodynamic variables were recorded at baseline and during the first 60 min following subconjunctival injection of Mydricaine and normal saline.Results Statistical analysis of the change in heart rate showed a highly significant difference between the two groups (p > 0.001). There was no significant difference in the effect on systolic or diastolic blood pressure between the two groups.Conclusions We advise extreme caution when using Mydricaine via the subconjunctival route in patients with compromised cardiac function.

Retinopathy of prematurity in practice. II: long-term results following treatment for threshold disease

AbstractObjective To determine the long-term outcome of treatment for threshold retinopathy of prematurity (ROP) in one UK unit.Methods A total of 35 infants diagnosed with threshold ROP were treated by a single ophthalmologist (DGC) between 1987 and 1998. The parents of the 29 surviving patients were contacted; 21 brought their child for special review of acuity, motility, refraction and fundoscopy (Group 1). Of the eight patients who were unable to attend, six patients (Group 2) had sufficient follow-up detail in their records to be included in the study.Results A total of 40 eyes in the 21 patients in Group 1 had been treated; 10 had received cryotherapy (eight bilateral) and 11 had bilateral laser. Mean follow-up was 5 years (range 2–12 years). A total of 23 treated eyes (in 16 patients) had an acuity of 6/12+ (57.5% of treated eyes). Four eyes of three patients had no light perception. Seven eyes in four patients had myopia of more than 3u2009D. Eight patients had a manifest squint: six esotropia, two exotropia. The retinal status of 36 eyes (90%) showed a favourable outcome. The four blind eyes had stage 5 disease. In Group 2, four eyes of two patients (33%) had 6/12+ acuity recorded; five eyes in three patients had stage 5 disease and no perception of light. In total, a favourable structural outcome was achieved in 81.4% and favourable functional outcome observed in 74.6%.Conclusion These results show that the favourable outcomes reported in the CRYO-ROP trial can be achieved in routine practice and maintained after long follow-up.

Does vitreoretinal surgery under local anaesthesia result in missed fellow eye pathology

PurposeThere has been a significant increase in the number of vitreoretinal procedures being performed under local anaesthesia over the past few years. This trend is expected to continue. This study was performed to investigate whether by undertaking retinal detachment surgery under local anaesthesia fellow eye examination was compromised.DesignThis was a prospective, consecutive, blind, observational study.Methods:SettingThis study was performed at a tertiary referral vitreoretinal unit in a teaching hospital.Study populationIn all, 108 consecutive patients undergoing retinal detachment surgery under general anaesthesia were included.Observation proceduresPatients were examined independently by different retinal surgeons pre- and intraoperatively.Main outcome measuresThe findings of the two examiners were compared and differences were analysed.ResultsThere were 108 patients in this study, 57 of these were males and 51 females. The mean age was 59.01 years (range 16–91). Of these 108 eyes, 48/108 (49.08%) the preoperative examination was regarded as unsatisfactory by the examiner. Over 34% of eyes had fellow eye pathology when examined preoperatively but there were nine (8.33%) eyes in which additional lesions were found intraoperatively.ConclusionGeneral anaesthesia should be considered for patients in whom preoperative fellow eye examination is unsatisfactory.