Ranjeet Pandit

Mydriasis and glaucoma: exploding the myth. A systematic review

SUMMARY

Quality assurance in screening for sight-threatening diabetic retinopathy

Aims There is a need for continuous evaluation of screening services for diabetic retinopathy against agreed performance standards. We describe a quality assurance programme implemented in Newcastle in January 1999 and report on outcomes at 18 months.

Effectiveness of testing visual fields by confrontation

Many tests are used to examine visual fields by confrontation, but such methods have not been thoroughly compared with an accepted reference standard. The choice of test might affect the identification of subtle defects in the visual field. We prospectively compared seven confrontation field tests with full-threshold automated static perimetry among 138 outpatients in an eye clinic. Our primary outcome was detection of a defect in the visual field. With automated perimetry, most field defects were small or shallow. Most confrontation field tests were insensitive in the identification of field loss. The most sensitive method was examination of the central 20 degrees visual field with a small red target (73% [95% CI 63-82]). Assessment of the visual field should thus include such a test.

Clinical presentation, treatment, and outcomes in presumed intraocular tuberculosis: experience from Newcastle upon Tyne, UK

PurposeTo report the clinical manifestations and treatment outcomes of patients with presumed intraocular tuberculosis (TB) seen at the Newcastle Uveitis Service, Royal Victoria Infirmary, Newcastle upon Tyne, UK over a 10-year period.MethodsRetrospective review of case notes.ResultsA total of 21 patients were identified. Occlusive retinal vasculitis was the commonest ophthalmological presentation (12 patients). Eight patients (38%) were found to have underlying active systemic TB (four with mediastinal lymphadenopathy, three with pulmonary TB, one with cutaneous TB). Constitutional or respiratory symptoms, elevated inflammatory markers, and an abnormal chest radiograph were poor indicators of active TB. Two patients had inactive intrathoracic TB. Eleven patients had latent TB. Eighteen patients received anti-tuberculous treatment. Final visual acuity was better than or equal to initial visual acuity in 14 out of 16 patients who completed at least 6 months of standard anti-tuberculous treatment.ConclusionsMost patients with presumed intraocular TB have latent TB, but a significant minority has hitherto undetected active TB. Our series suggests that either proven or presumed intraocular TB occurs frequently in the absence of constitutional or respiratory symptoms, elevated inflammatory markers, or an abnormal chest radiograph. A minimum of 6 months standard anti-tuberculous treatment provides good visual outcomes in the majority of patients.

Acute optic neuropathy in patients with Behçet's disease. Report of two cases.

Although acute optic neuropathy has been rarely reported in patients with Behçet’s disease, a detailed description of its clinical course is lacking. We report in detail the course of acute optic neuropathy in two patients with Behçet’s disease. Our experience suggests that it can be bilateral, can affect both eyes simultaneously, and can be recurrent. The severity of the visual loss and its recovery can be very variable even in the same patient. Early recognition of this entity and treatment with high-dose systemic corticosteroids may limit the degree of permanent visual loss. However, the optimal treatment has not been established.

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.

Unilateral recurrent acute retinal necrosis syndrome caused by cytomegalovirus in an immune-competent adult

Purpose To report an immune-competent patient with unilateral recurrent acute retinal necrosis syndrome caused by cytomegalovirus, and to highlight the importance of diagnostic vitreous biopsy and specific antiviral therapy in this condition. Methods Case report. Results A 75-year-old man with good general health had two episodes of acute retinal necrosis syndrome affecting his left eye. Vitreous biopsy was performed in each episode, and polymerase chain reaction analysis on the vitreous specimen was positive for cytomegalovirus and negative for varicella zoster virus and herpes simplex virus 1 and 2. On each occasion, investigations indicated past cytomegalovirus infection but no evidence of a systemic reactivation. No indication of immunodeficiency was found over a 2-year follow-up period. His management, which included systemic and intravitreal antiviral therapy, is discussed. Conclusions To the authors’ knowledge, only two other cases of acute retinal necrosis syndrome caused by cytomegalovirus have been reported previously in immune-competent patients. This case illustrates the importance of vitreous biopsy for viral polymerase chain reaction studies in cases of acute retinal necrosis syndrome, in order to direct appropriate antiviral treatment. It also illustrates the role of an intravitreal antiviral drug that is effective against all three herpetic viruses.

Loss of vision? Clear as crystal!

In January, 2008, an 84-year-old woman presented with a 1-year history of painless progressive whitening of the pupil and reduced vision in her left eye. She also complained of tiredness, loss of appetite, and over 6 kg weight loss during the previous year. She had had uneventful left extracapsular cataract extraction with posterior chamber intraocular lens (PC-IOL) implantation 15 years previously and right phaco emulsifi cation with PC-IOL three years later. In 2005 she had an episode of uncomplicated left herpes zoster ophthalmicus that was treated with famciclovir. Other medical history included insulin-treated type 2 diabetes, hypertension, and left mastectomy followed by radiotherapy for breast carcinoma in 2004. On examination, her left visual acuity was reduced (6/18). The eye was not red or tender. Slitlamp examination showed a mild granulomatous anterior uveitis. The lens capsule was white and fi lled with numerous brilliant white crystals obscuring the visual axis (fi gure A). There was some retained lens matter in the capsular bag. The remainder of the left eye examination was normal. Other than the presence of a prosthetic lens, the right eye was normal on examination. On general examination she was apyrexial, weighed 59 kg, and her blood pressure was 140/80 mm Hg. A chronic localised intraocular infection was suspected. Biopsy of the lens capsule with removal of the crystalline material was done under local anaesthetic. At surgery the crystalline material was noted to have a hard and brittle quality similar to chalk. Postoperatively, she was treated with prednisolone and ofl oxacin eye drops, and oral ciprofl oxacin for 1 week. However, gram stain and extended cultures on the samples were negative, including after enrichment and prolonged anaerobic culture. Cytology showed an acellular specimen with crystals that polarised weakly to birefringent light. Histology showed calcifi cation of the lens capsule and retained lens substance. 1 week after surgery, cosmesis and vision improved greatly (6/6) and the uveitis resolved. The chalky quality of the crystals noted during surgery led us to check her serum calcium profi le. This showed hypercalcaemia (2·96 mmol/L, adjusted) with serum phosphate at the lower limit of normal (0·9 mmol/L), raised alkaline phosphatase (252 IU/L), low total vitamin D (23 nmol/L), and a high urine calcium:creatinine ratio (1·43). Parathyroid hormone level was high (160 ng/L), confi rming primary hyperparathyroidism along with mild coincident vitamin D defi ciency. Technetium-99m methoxyisobutyl isonitrile (MIBI) parathyroid scin tigraphy showed a hyperfunctional left lower parathyroid nodule (fi gure B). This was excised, and histology confi rmed a parathyroid adenoma. After 3 months, her anorexia and lethargy resolved, she gained 5 kg in weight, and her serum biochemistry returned to normal. The ophthalmological and medical improvements were sustained at fi nal review in April, 2009. Visible calcium deposition in the superfi cial cornea (band keratopathy) and conjunctiva is well described in hypercalcaemic states, including primary hyperparathyroidism, sarcoidosis, and vitamin D intoxication, and may be an early sign in these disorders. Similar calcifi cation can occur in renal failure with secondary hyperparathyroidism, when serum calcium is normal or low but the calcium–phosphate product is greater than 70. The reason for unilateral eye presentation in our patient is unclear. Symptoms of hypercalcaemia are often non-specifi c (anorexia, lethargy, weight loss, depression, nausea, constipation, abdominal pain) and patients may present with these to various specialties. This rare but easily visible eye fi nding should prompt investigations for hypercalcaemia and its cause. Removal of the intraocular crystals may restore cosmesis and vision, and excision of an underlying hyperfunctional parathyroid adenoma off ers the potential of cure.

Reply to Wakefield and Kumar

Sir, We would like to thank Wakefield and Kumar1 for their useful comments. It is true that the exact association between latent TB and uveitis is not known. In our series, all patients with presumed intraocular TB and active TB elsewhere received standard anti-tuberculous therapy (ATT). Patients with presumed intraocular TB and latent TB were generally offered ATT, but this was done after careful consideration of individual risk/benefit. Indeed, as we state in our article, two patients with latent TB and presumed intraocular TB received no ATT, because we estimated that the risks of treatment outweighed any potential benefit in them.2 ATT has well-recognized systemic and ocular adverse effects. On the other hand, it is known that ATT can eliminate latent TB and decrease a persons lifetime risk of developing active TB by 90%.3 Moreover, administering corticosteroid or immunosuppressive therapy for severe intraocular inflammation without the coverage of ATT may cause re-activation of systemic TB, resulting in severe disseminating TB or even panophthamlitis.4, 5 In a large series of patients with presumed intraocular TB and latent TB combination treatment with corticosteroids and ATT reduced the risk of developing recurrence of the uveitis by approximately two-thirds compared to treatment with corticosteroids alone.6 Based on the above and on the results of our study, we stated that a minimum of 6 months standard ATT is generally justified in patients with presumed intraocular TB and latent TB. However, we agree with Wakefield and Kumar1 that ATT should be considered with some caution in patients with latent TB who have high risk of complications. Decision to administer ATT should be made on an individual basis in these cases.