Causes of enucleation in Nigeria

Enucleation

The three most common indications for enucleation are intraocular malignancy, trauma, and a blind, painful eye. Recommending enucleation is one of the most difficult therapeutic decisions in ophthalmology. In some cases of malignancy, cryotherapy, laser photocoagulation, diathermy, chemotherapy, and radiation therapy may be viable alternatives to surgery. When surgery is chosen, evisceration or exenteration may be alternatives to enucleation. Once the decision is made to perform enucleation or evisceration, the surgeon must choose from several types of implants and wrapping materials. These devices can be synthetic, autologous, or eye-banked tissues. With certain implants, the surgeon must decide when and if to drill for subsequent peg placement. In this review, the authors discuss choices, techniques, complications, and patient consent and follow-up before, during, and after enucleation. Controversies and results of the Controlled Ocular Melanoma Study are summarized.

Analysis of 24,444 surgical specimens accessioned over 55 years in an ophthalmic pathology laboratory

PURPOSE

To summarize the pathologic diagnoses of a large number of surgically-obtained specimens over an extended time period in a single ophthalmic pathology laboratory.

METHODS

We analyzed the records of 24,444 surgically obtained specimens accessioned in the L.F. Montgomery Ophthalmic Pathology Laboratory, Emory University, Atlanta, GA between May 1941 and December 1995. Age, sex, topography, clinical procedure, and histologic diagnosis were entered into a database using the modified SNOMED coding system. The diagnosis of the surgically enucleated eyes were analyzed with respect to years of enucleation.

RESULTS

The most common topographic area associated with a histologic diagnosis was the cornea (39.3%), followed by lens (16.0%), vitreous (12.0%), uvea (9.8%), eyelids (8.0%), conjunctiva (7.7%), retina (7.7%), and orbit (2.1%). The relative proportion of vitreous specimens has continuously increased and became the most common surgical specimen in 1995. The most common underlying disease of surgically enucleated eyes is trauma (40.9%), followed by ocular neoplasia (24.2%), 'surgical' diseases of the cornea, lens and retina including glaucoma (17.3%), vascular diseases (6.7%), and inflammatory conditions (6.7%). The relative frequency of trauma and ocular inflammation as a cause of enucleation decreased significantly (p < 0.05) over the time of the study period while the relative proportion of ocular neoplastic processes increased (p < 0.0001).

CONCLUSIONS

The availability of new surgical techniques has caused a change in the relative frequencies of different ocular specimens submitted for histologic examination.

Ocular injuries in Africa

Injuries to the eye can cause severe damage because of the delicate structure of ocular tissues. Such injuries may often cause impaired vision or sometimes total loss of vision, in addition to other incapacities. Traumatic blindness therefore assumes an unusual socio-economic dimension. In Africa, injuries have their own peculiarities regarding aetiology, severity and management. More than 80% of injuries occur in rural areas where the necessary services are generally unavailable. This paper surveys the types, occurrence and impact of ocular injuries and suggests how they should be treated.

Mutational mosaicism and genetic counseling in retinoblastoma

Mutations may arise throughout an organism's life cycle. Typically, sporadic meiotic mutations give rise to individuals with all their germinal and somatic cells bearing the mutant gene. These mutations may be amorphs (with full penetrance and expressivity) or hypomorphs (with reduced penetrance and expressivity). Mutational mosaicism, however, involves the origin of mutations occurring during mitosis, whether in the parent at some stage prior to reproductive maturity or in the offspring at some time following fertilization. The phenotypic expression and transmission of these new mutations are dependent on the proportion of cells bearing the mutant gene as well as the location of these cells in somatic and/or germinal tissues. Mutational mosaicism was used as a developmental model to analyze 1,500 sporadic and 179 familial cases of retinoblastoma from the world literature. This model provided an interpretation for the origin, onset, and transmissibility of the sporadic unilateral retinoblastoma cases, which represent over 60% of all retinoblastoma patients. The model also permits a reclassification of all transmissible types of retinoblastoma; based on this classification, more accurate risk figures for genetic counseling can be offered. In addition, mutational mosaicism can be extended as a model to other autosomal dominant and X-linked mutations.

The essentials of data sources in eye epidemiology

The extensive literature on eye epidemiology was selectively reviewed to provide a concise and comprehensive summary on the current status of available data sources. The topics being covered were epidemiologic data evaluation, data handling, card registration, computer analysis, geographic factors, socio-economic conditions, personal attributes, genetic backgrounds, twin analysis and laboratory procedures for host defense factors including humoral and cellular immunity. Also, the scope of this article encompassed such major practical issues as glaucoma, cataract and other blinding diseases as well as traffic and occupational hazards. Epidemiologic information thus obtainable through data searching may prove tobe instrumental in the identification of any potential preventive measures in ophthalmology and public health.