The clinical and detailed angiographical findings taken during the follow-up of 182 patients with tumors of the iris and the ciliary body reported. On the basis of different angiographic staining patterns, these tumors were divided into three groups. Group I: Clinically, as a rule darkly pigmented, slightly or nonprominent tumors, which do not take up fluorescein at all, i.e. no staining of the tumor of its surroundings during the whole angiogram. 107 patients with such a tumor type did not show any clinical or angiographical changes during several years of follow-up. Those tumors which were excised (4) proved to be nevi. We therefore believe this fluorescein pattern indicates a benign lesion so that examination every 6 months suffice. Group II: These are usually less pigmented and only slightly prominent and have their own vascular network. On fluorescein angiography there is dye leakage within the tumor and into the surrounding iris stroma as well as into the aqueous humor. Of a total of 52 cases 9 were excised via iridectomy or iridocyclectomy. Of these 5 were shown to be benign nevi, 4 however were diagnosed as malignant melanomas. We therefore classify this fluorescein angiographical pattern as belonging to potentially malignant tumors, needing frequent controls, i.e. at 3-month intervals. Group III: Clinically these tumors are usually darkly pigmented, extremely prominent and mostly situated in the peripheral iris, originating here or spreading forward from the ciliary body. They are usually vascularized and show - if the melanin content is not too dense - early mottled staining in the vicinity of the tumor. They furthermore always have a marginal central borderline fluorescence as a typical sign, often accompanied by dye leakage from normal iris vessels, representing so-called 'tumor iritis'. 18 tumors of this type were excised via iridocyclectomy or enucleation and all were shown to be malignant melanomas of the iris or the ciliary body on histopathological examination. This fluorescence pattern group of tumors should always be regarded as definitely malignant, and therefore need prompt surgical excision.
(1) The incidence of retinoblastoma is 1/20,000. (2) About 94% of all retinoblastoma cases are sporadic, while 6% are familial. (3) The hereditary retinoblastomas, whether sporadic or familial, represent 40% of all cases. (4) A new dominant germinal mutation is responsible for 100% of the bilateral sporadic cases and for 10-15% of the unilateral sporadic cases. (5) Knudson's multistage mutation is the best explanation of retinoblastoma's behaviour. (6) A deletion of the long arm of a D-chromosome (13q14) may be the cause of some, if not of all retinoblastomas. (7) The main difficulty in genetic counseling is the lack of means for identifying which sporadic unilateral retinoblastomas are due to a new germinal mutation.
This book is divided into 8 sections, each containing several chapters. The first, entitled 'Basic Principles', contains a historical account of the use of ultrasound in medicine and the basic physical principles of ultrasonic diagnosis. Features of transducers are covered with great clarity, followed by a discussion of some pulse-echo techniques together with technical considerations in design of diagnostic equipment. A very worthwhile chapter is then devoted to the principles of grey scale echography, together with its applications; the best quality ophthalmic B-scans in the book are to be found in this chapter. Artefacts and standardisation techniques are described in the following 2 chapters. Next, transducer arrays and the relatively new application of computers to diagnostic ultrasound are discussed in a way the ophthalmologist can understand. Interesting chapters are then devoted to the principles of Doppler ultrasound together with scattering and attenuation of ultrasound by tissue. Finally, the biological effects and safety of ultrasound are considered. Thus, the first section of this book provides a comprehensive guide for the ophthalmologist working in ultrasonic diagnosis. Other sections are devoted to Doppler techniques and ultrasonic diagnosis in obstetrics and gynaecology, internal medicine, cardiology, neurology, and orthopaedics. The penultimate section of the book deals with diagnostic ultrasound in ophthalmology. This section begins with a lengthy article on so-called 'specialised' techniques, and many statements are controversial. It is hardly surprising, however, that the author feels grey-scale B-scanning is inadequate for observing echo amplitude when we see the very poor quality of the grey scale on B-scans presented in the third and fourth chapters of the section. These chapters are devoted to retinal and choroidal detachment and intraocular tumours, respectively. The authors of chapter 3 refer only to their own work in the list of references, while the author of the chapter on intraocular tumours states that macular melanomas are very rare (claiming to have seen only 3 cases in 14 years). In contrast, biometric studies are comprehensively covered in chapter 2, while the fifth chapter contains a practical and objective discussion of the role of diagnostic ultrasound in injuries due to foreign bodies. In the chapter on orbital disorders the author strongly advocates the use of A-scan rather than B-scan and make other controversial judgments. It is claimed, for example, that the A-scan technique should be used to measure the true diameter of the optic nerve and extraocular muscles. Anatomically, however, it is impossible to direct the sound beam so as to strike these structures perpendicularly and permit such measurements (even with deviated gaze). The author also claims that by his method an experienced examiner can expect to detect or eliminate an orbital lesion in 98% of cases, and in 99% of cases the diagnoses made are correct. Finally, the ophthalmology section closes with an interesting chapter on the use of Doppler techniques in diagnostic ophthalmology. Overall, the ophthalmic section of this book is disappointing. However, the ophthalmologist will benefit from reading the first section of the book. MARIE RESTORI
The purpose of the present study was to examine the mitotic activity of the normal pigment epithelium of the retina (RPE), the ciliary body and the iris of different animals during gestation and after birth by blocking the metaphase with colchicine and by marking the pigment epithelial nuclei with tritium-labeled thymidine. The colchicine examinations were made on 54 albino rabbits and 56 albino rats, the 3H-thymidine studies with 78 albino mice. In the rabbit the peak of mitotic activity (respectively the end) is found in the RPE at the beginning of the 2nd third of gestation (respectively at the 9th postnatal day), but in the pigment epithelium of the ciliary body and in the iris during the last third of gestation (respectively in the 2nd month of life and the 3rd postnatal week). In the rat the highest mitotic activity is reached in the RPE at the beginning of the 2nd half of gestation (respectively at the 13th postnatal day), in the ciliary body at the 3rd day of life (respectively the 24th postnatal day) and in the iris at the end of the gestational period (respectively the 17th postnatal day). In the mouse the highest rates of mitotic activity are found in the RPE from the 16th gestational day to the 8th day of life (respectively the 20th day of life), in the ciliary body from the 1st to the 4th day of life (respectively from the 12th to the 20th postnatal day) and in the iris on the 9th day of life (respectively the 12th to the 20th postnatal day). The present observations have also demonstrated that with maturation of all areas of the pigment epithelium, the mitotic activity stops. The cells of the pigment epithelium do not have an epithelial cell turnover but they are reversible postmitotic cells. Despite the enormous proliferative properties the pigment epithelium shows no regeneration by mitosis after severe damage.
