Hugo Verbraeken

Therapeutic pars plana vitrectomy for chronic uveitis: a retrospective study of the long-term results

Abstract• Background: Pars plana vitrectomy has both diagnostic and therapeutic potential in chronic uveitis. In this paper the therapeutic value of vitrectomy is investigated. • Methods: This is a retrospective study on 25 eyes that underwent pars plana vitrectomy with therapeutic intent. Surgery was considered in patients with severe vitreous clouding or macular pucker and in those who responded poorly or not at all to conventional treatment for uveitis. The mean period of follow up was 4.5 years, varying from 2 to 12 years.• Results: Improved vision was observed in 56% of the eyes (14/25). Twenty-four percent of the eyes (6/ 25) had stable vision. Macular edema disappeared in 40% (10/25) of cases and persisted in 60% (15/25). Two of the nine eyes with persistent macular oedema progressed to a macular hole. Four of the six eyes with macular pucker suffered recurrence, one ended in phythisis, while the pucker was cured in only one patient. Twelve percent of the eyes (3/25) subsequently experienced a recrudescence of uveitis, making systemic treatment necessary. One patient presented, after vitrectomy, a traction retinal detachment with proliferating vitreoretinopathy. No complications or recurrences were seen in 44% of the eyes (11/25).• Conclusion: Vitrectomy has a definite place in the treatment of chronic uveitis, both on the functional level, with improvement or stabilisation of visual acuity and on the therapeutic level, with possible reduction or cessation of systemic treatment.

Diagnostic vitrectomy and chronic uveitis

Abstract• Background: From the introduction of vitrectomy, infectious endophthalmitis was one of the indications for this surgical technique. Vitrectomy was later found to be a valuable method in both diagnostic and therapeutic evaluation of chronic uveitis. • Methods: Twenty-eight eyes of 25 patients were operated on with purely diagnostic intent. These were patients not responding, or no longer responding, to their cortisone treatment and for whom no etiology had been found previously. • Results: Vitrectomy itself yielded the diagnosis in nine eyes of eight patients. Three had unexpected infectious pathology (one bacterial, one mycotic, one viral), while five had tumoral pathology: four with non-Hodgkin lymphoma and one with a metastasis of a malignant melanoma of the skin. In four other patients, typical fundus lesions were seen during the surgery, providing a clue to the etiology: three cases of retinal necrosis and one case of a pseudotumoral mass suggestive ofToxocara canis. Serologic tests confirmed three cases of herpes simplex infection and one ofToxocara canis. Apart from the fact that a diagnosis could be made in half of the patients, the diagnostic vitrectomy also had a favorable effect upon vision in half the cases. • Conclusion: In cases of chronic uveitis where no etiology has been found, vitrectomy is able to provide a diagnosis in about one-third of eyes directly. During surgery a typical appearance of the fundus may reveal a supplementary diagnosis, resulting in an overall diagnosis in about half of the cases. Moreover, half of the patients will have improved vision after surgery.

Ocular non-Hodgkin’s lymphoma: a clinical study of nine cases

BACKGROUND Primary oculocerebral large cell malignant non-Hodgkin’s lymphoma, formerly called ocular reticulum cell sarcoma, runs a uniformly fatal course. Once the central nervous system (CNS) is involved, survival without treatment is very limited. Although treatment does not substantially improve the long term survival, it provides short term improvement in these patients. METHODS The charts of all patients with ocular involvement of non-Hodgkin’s lymphoma followed during the period 1984–93 were reviewed. The diagnosis of non-Hodgkin’s lymphoma was made by different diagnostic approaches: CNS biopsy, anterior chamber tap, vitrectomy, haematology, and necropsy. RESULTS Eight patients had oculocerebral large cell and one had small cell non-Hodgkin’s lymphoma. Five patients with pure ocular localisation had initially received steroid treatment for intermediate uveitis. First diagnosis was made on CNS biopsy in three, anterior chamber tap in one, vitreous aspirate in three, haematology in one, and necropsy in one case. CONCLUSION Ocular non-Hodgkin’s lymphoma is a difficult diagnosis. Vitrectomy allows cytological diagnosis in most but not all cases. When no treatment is given, patients survive for only a few weeks once the CNS is involved. Although the disease is eventually fatal, treatment by means of radiotherapy, steroid administration, and vitrectomy can allow these patients to lead a normal professional and social life during the years between recurrences.

Diagnostic problems in chronic vitreous inflammation

We reviewed 188 patients with chronic vitreous inflammation initiallydiagnosed as intermediate uveitis, who were seen at the Ghent Eye Clinic during the period 1978 to 1988. We were able to establish a more specific diagnosis in 55 patients. The different approaches that contributed to the diagnosis were analyzed, (comprehensive history-taking and clinical examination, laboratory tests and special investigations, vitrectomy, and following the evolution of the disease). No etiology was found in 133 patients (70.7%), subsequently diagnosed as idiopathic intermediate uveitis. The major characteristics of the disease were analyzed.

Penetration of gentamicin and ofloxacin in human vitreous after systemic administration

Abstract• Background: Data on the penetration of antibiotics into the aqueous humor in man and animals, as well as on the intravitreal penetration in animals, are numerous. Data on their intravitreal penetration in humans, however, are sparce. The intravitreal penetration of gentamicin was studied in different ocular pathologies to see whether these alter the vitreal pharmacodynamics. The intravitreal penetration of ofloxacin, a fluoroquinolone, was determined to see whether levels sufficient to treat infectious endophthalmitis could be reached. • Methods: The intravitreal penetration of gentamicin and ofloxacin was studied in patients undergoing pars plana vitrectomy for various ocular pathologies. Those with recent hemorrhages and those already receiving general antibiotic treatment were excluded. • Results: Gentamicin was found to penetrate the vitreous very poorly. No difference could be found between the various pathologies: trauma, diabetes, proliferative vitreoretinopathy, longstanding vitreous hemorrhage and macular pucker gave the same poor penetration. The ofloxacin levels were higher but did not reach the MIC90 levels of most organisms involved in bacterial endophthalmitis. • Conclusion: The hemato-ocular barrier is more difficult to cross than originally thought. Different ocular pathologies do not alter the ocular barrier substantially. Ofloxacin alone does not seem to be sufficient for the treatment of established bacterial endophthalmitis.

Retinal phototrauma during intra-ocular lens-implantation

The use of the operating microscope has become almost a necessity in the surgery of the anterior segment of the eye. However the coaxial light of the operating microscope is potentially hazardous for the retina, especially during intra-ocular lens implantation. The risk of producing a photic retinopathy increases if the duration of the surgical procedure is prolonged once the pseudophakos is in the eye and if high levels of illumination are used. We encountered our first case in a patient, whose intervention was filmed and where thus an increased illumination was needed. This complication is however also found in cases where no extra illumination was needed. As the clinical signs are usually very mild, the retinal lesions related to over-exposure to light are easily overlooked.

High field resolution magnetic resonance imaging of malignant choroidal melanoma

High resolution surface receiver coil nuclear magnetic resonance imaging (MRI) of the eye and paraorbital areas was performed in a patient with a malignant choroidal melanoma before and after local radiotherapy using rhutenium application. The resulting improvement in signal-to-noise ratio allows for a reduction in the imaging voxel size to 0.31 × 0.31 × 3 mm3 which provided useful morphological information with respect to delineation of tumoral mass.In the same MRI session using a standard head coil imaging method, T1 and T2 relaxation time values were calculated in regions of interest of 3 × 3 mm by means of transversal scan images of orbital and cranial tissues performed in scan times of 7 to 9 minutes.The procedure presented here combines in one single session high resolution imaging performance, previously unobservable in MRI and in other noninvasive imaging techniques, with fast and reliable measurement of T1 and T2 relaxation times within small regions of interest.MRI, a non ionizing technique, offers within reasonable acquisition times not only a good multiplanar description of the site, size and volume of normal and pathologic orbital structures, but, in addition, the prospect of soft tissue differentiation and of accurately documenting the response to and side effects of the therapy of ocular tumors.

Ultrasonography in the diagnosis and follow-up of Ruthenium-treated malignant melanomas

There are many unanswered questions regarding the correct treatment of malignant melanoma of the choroid. Is radiation therapy a more effective form than enucleation or local surgical excision? Which form of radiation therapy is most effective? Should adjuvant chemotherapy be used?