[Histological changes related to scleral buckling for treatment of retinal detachment]

Treatment of retinal detachment frequently uses biocompatible materials to obtain scleral buckling. These materials are not devoid of consequences on surrounding tissues. In 3 eyes enucleated for failure of surgical treatment using scleral buckling materials, the changes prompted by episcleral implants could be observed. The sclera underwent both an inversion of its curvature and a reduction of its thickness under the material, as well as an encapsulation of the material was observed. While a silicone sponge was used in part to encircle one of these eyes, its capsular inner surface was regular and smooth. In contrast, hydrogel implants used in the three eyes showed a peripheral fragmentation prompting in two of them a typical foreign body giant cell granulomatous reaction. Changes in scleral curvature and scleral thinning were observed reflecting the consequences of the buckling procedure. The capsule formation occurred as it does for any nonabsorbable matérial implanted in tissues. Degradation and fragmentation of the hydrogel material suscitated a granuloma in response to fragments. These hydrogel specific changes should be recognized on microscopic examination of slides of either capsule or eyes previously in contact with this implanted material. They attested of the instability of hydrogel after implantation.

Leiomyoma of the ciliary body. Report of 2 cases

PURPOSE AND METHODS

The files of the Eye Pathology Institute contain only two cases of leiomyoma of the ciliary body. The diagnoses were re-evaluated, applying modern immunostainings.

RESULTS

The tumors were composed of interlacing fascicles of spindle-shaped cells with bright eosinophilic cytoplasm and cigar-shaped nuclei. Both tumors were well-vascularized, mostly by thin, branching capillaries. Larger vessels were also seen. In one case the tumor perforated the sclera. The tumor cells reacted with the reticulum stain and the Masson trichrome and were positive for antibodies against: smooth muscle actin (SMA), muscle specific actin (MSA), laminin and vimentin (one case).

CONCLUSION

Leiomyoma of the ciliary body is a rare smooth muscle cell tumor that may arise from either pericytes, ciliary - or intrascleral heterotopic muscle.

[Intraocular invasion of melanoma of the conjunctiva]

BACKGROUND

The treatment of a localised conjunctival melanoma usually requires local excision combined with cryotherapy, brachytherapy and/or local chemotherapy.

CASE REPORT

A 71 year old woman suffering from a conjunctival melanoma located at the limbus of her left eye was treated by local excision and cryotherapy. After this therapeutic procedure two recurrences occurred which had been again treated by excision and cryotherapy and finally brachytherapy. Nevertheless, a third recurrent tumor developed and was treated again with deep lamellar sclerectomy and keratectomy. During this procedure the anterior chamber was opened inadvertently in a tiny spot. Some months later an intraocular invasion of the melanoma was diagnosed clinically and the eye had to be enucleated 5 years after the first treatment. Histological examination revealed extended melanoma growth into iris, ciliary body, anterior choroid, and tumor cell seedings in the antertior chamber.

CONCLUSIONS

Removing a conjunctival melanoma especially such a tumor growing at the limbus, the surgeon has to pay attention not to open the anterior chamber during sclerectomy and keratectomy. The possibility that prior local surgical excision aided the intraocular extension is discussed.

Malignant melanoma of ciliary body: a case report

Ocular malignant melanomas are infrequently seen in Indian patents and most them involve the choroid. Ciliary body malignant melanoma is rather rare. This case report illustrates an occurrence in an Indian patient.

Orbital Wegener granulomatosis without systemic findings

PURPOSE

To describe a case of orbital Wegener granulomatosis without systemic disease.

METHOD

Case report.

RESULTS

A 69-year-old patient with bilateral inflammatory lacrimal gland masses underwent multiple biopsies that showed a nonspecific lymphoplasmacytic infiltrate consistent with orbital pseudotumor. After unsuccessful treatment with systemic corticosteroids and radiation, severe orbital disease rapidly progressed and the patient underwent unilateral enucleation. The enucleated specimen showed multifocal vasculitis, tissue necrosis, and granulomas consistent with Wegener granulomatosis (WG). Elevated antineutrophil cytoplasmic antibody titers supported the diagnosis of WG. The patient did not have any extraocular signs of WG and continues to be disease-free systemically.

CONCLUSION

The authors believe this is the first report of bilateral lacrimal gland masses presenting as a localized form of WG in the total absence of systemic disease.

Postoperative rotation of hydroxyapatite enucleation implants

OBJECTIVE

To determine the incidence of postoperative rotation of flattened hydroxyapatite enucleation implants.

METHODS

A retrospective review of patients receiving flattened hydroxyapatite enucleation implants was performed to determine the incidence and severity of postoperative implant misalignment.

RESULTS

Flattened hydroxyapatite implants had been placed in 16 patients. Five were noted to have postoperative implant rotation, which was detected between 11 and 60.3 months following enucleation. The malposition was mild, inconsistent, and clinically insignificant in 2 patients. The remaining 3 patients demonstrated marked implant misalignment, which likely would have been functionally significant had motility pegs been placed.

CONCLUSIONS

Postoperative rotation of flattened hydroxyapatite implants may occur late after enucleation. Such implant modification should not be performed in patients with preexisting strabismus, who have a higher incidence of this complication.

Endophthalmitis from Mycobacterium bovis-bacille Calmette-Guérin after intravesicular bacille Calmette-Guérin injections for bladder carcinoma

PURPOSE

To present clinical and histologic findings of intraocular infection with Mycobacterium bovis-bacille Calmette-Guérin after intravesicular bacille Calmette-Guérin injections for treatment of bladder carcinoma.

METHODS

A 77-year-old man was initially seen with visual acuity of 20/200, focal retinitis, vasculitis, and progressive vitreous opacity in the right eye and visual acuity of light perception, intraocular inflammation, and a dense cataract in the left eye 14 months after intravesicular injection of live bacille Calmette-Guérin organisms.

RESULTS

Vitreous cultures in the right eye demonstrated growth of bacille Calmette-Guérin organisms. Bilateral loss of light perception occurred despite systemic antimy-cobacterial therapy. Histopathologic examination demonstrated nongranulomatous inflammation and acid-fast bacilli in both eyes.

CONCLUSION

Delayed endogenous endophthalmitis may develop after intravesicular bacille Calmette-Guérin injection that may not respond to systemic agents. Intravitreal therapy may be indicated.

The influence of hyperbaric oxygen therapy and irradiation on hydroxyapatite ocular implant exposure and fibrovascular ingrowth in New Zealand white rabbits

PURPOSE

Lack of adequate fibrovascular ingrowth has been implicated as a cause of exposure of hydroxyapatite (HA) implants in anophthalmic sockets. We investigated the vasculopathic effects of external beam irradiation, and the fibrovascular-enhancement effects of hyperbaric oxygen (HBO), on HA implant exposure and fibrovascular ingrowth in a rabbit model.

METHODS

Eighteen rabbits underwent enucleation with implantation of a 12-mm HA sphere. Six rabbits received 20 Gy of external beam orbital irradiation prior to enucleation. Three irradiated and 6 nonirradiated rabbits received postoperative HBO. Three weeks postoperatively, all rabbits were evaluated clinically for evidence of implant exposure. Implants were then removed, and histopathologic analysis of fibrovascular ingrowth was performed.

RESULTS

The amount of vascularization as measured by the depth of ingrowth was greater for nonirradiated (89% ingrowth) than for irradiated (71% ingrowth) animals. HA implant exposure occurred in 1 of 12 (8%) of the nonirradiated, and 4 of 6 (67%) of the irradiated rabbit orbits. HBO did not protect irradiated rabbits from exposure, but did enhance fibrovascular ingrowth in nonirradiated rabbits (100% ingrowth vs. 77% ingrowth).

CONCLUSION

Impaired orbital vascularization from prior irradiation appears to retard fibrovascular ingrowth into HA implants, and is associated with an increased incidence of exposure. While HBO did not diminish the likelihood of exposure in irradiated sockets, HA fibrovascular ingrowth in normal orbits appeared to increase with HBO. This may have beneficial clinical application in cases of exposure in nonirradiated orbits.

Isolated brain metastasis of malignant choroidal melanoma 27 years after enucleation

Choroidal melanoma primarily metastasizes to the liver. Isolated extrahepatic metastases have rarely been reported and they generally resulted in death within 6 months. We describe a patient who developed an isolated brain metastasis 27 years after his left eye was enucleated for choroidal melanoma. The metastasis was successfully treated with surgery and radiotherapy. The patient is alive and disease free 3 years after treatment of the metastasis. Posterior location and other clinical and morphologic characteristics of primary choroidal melanoma could explain the unusually long latency of this solitary extrahepatic metastatic disease. Lifelong surveillance to detect early signs of metastasis is mandatory for any patient treated for choroidal melanoma.

A new variety of hydroxyapatite: the Chinese implant

PURPOSE

This study was designed to evaluate a new type of hydroxyapatite (HA) implant (produced in China) in a rabbit model.

METHODS

Three New Zealand white rabbits underwent enucleation of one eye followed by implantation of a 12-mm Chinese HA implant wrapped in Vicryl mesh (polyglactin 910). Magnetic resonance imaging was performed to assess host fibrovascularization of the implant 4, 8, and 12 weeks after implantation. One animal was sacrificed at each of these times for histopathologic examination. The Chinese implant was also examined chemically and by scanning electron microscopy. It was compared to the original BioEye and the third generation synthetic HA implant produced in France by FCI (FCI3).

RESULTS

This new variety of HA implant from China is heavier than the FCI3 implant but lighter than the original BioEye. The Chinese implant was easy to work with and not fragile. The pore size was more uniform than the FCI3 implant and similar to the BioEye implant clinically and by scanning electron microscopy. The pores in this implant are unidirectional. Analysis for impurities revealed a calcium oxide (CaO) content of 4.4%. Histopathologically, central vascularization occurred by 4 weeks and was similar in extent to the vascularization seen with the FCI3 implant and the BioEye.

CONCLUSIONS

The Chinese implant is less expensive then the BioEye and the FCI3 implants, and appears to be a viable alternative to the BioEye. Further refinements are in progress to eliminate the CaO contaminant.

[Functional complementation of intra- and extra-oral implants. Apropos of a case of extensive loss of substance of the face]

The respective indications for oral or extra-oral implants lead to no confusion: stabilization of dental prostheses for the first, stabilization of maxilo-facial epitheses for the others. We demonstrate that the complementarity of the two types of implants can prove to be very useful in maintaining the maxillary dental prosthesis and the epithesis in a case of severe loss of facial substance affecting particularly the pre-maxilla. This complementary characteristic made it possible to recover fairly rapidly phonation and deglutition, and to remedy somewhat the esthetic damage. In other words to create the essential conditions for a return to everyday life.

Coats' disease of the retina (unilateral retinal telangiectasis) caused by somatic mutation in the NDP gene: a role for norrin in retinal angiogenesis

Coats' disease is characterized by abnormal retinal vascular development (so-called 'retinal telangiectasis') which results in massive intraretinal and subretinal lipid accumulation (exudative retinal detachment). The classical form of Coats' disease is almost invariably isolated, unilateral and seen in males. A female with a unilateral variant of Coats' disease gave birth to a son affected by Norrie disease. Both carried a missense mutation within the NDP gene on chromosome Xp11.2. Subsequently analysis of the retinas of nine enucleated eyes from males with Coats' disease demonstrated in one a somatic mutation in the NDP gene which was not present within non-retinal tissue. We suggest that Coats' telangiectasis is secondary to somatic mutation in the NDP gene which results in a deficiency of norrin (the protein product of the NDP gene) within the developing retina. This supports recent observations that the protein is critical for normal retinal vasculogenesis.

Late presentation of a unilateral sporadic retinoblastoma in a 16-year-old girl

BACKGROUND

Retinoblastoma is the commonest intraocular tumour of childhood with the majority of cases being diagnosed before 5 years of age. Late presentation of retinoblastoma is rare.

CASE HISTORY

A healthy 16-year-old Caucasian girl presented with a 1-day history of blurred vision in the left eye. Examination revealed an inferonasal mass in the left retina with an overlying haemorrhage and vitreous seeding. Imaging studies revealed a 5-mm densely calcified opacity. Other investigations, including cerebral spinal fluid examination, bone marrow aspirate trephine, toxocara serology and serum protein studies, were normal. After considering the differential diagnoses such as toxocariasis and Coat's disease, a diagnosis of late-presenting retinoblastoma was made. The patient subsequently underwent enucleation with a primary orbital implant. The diagnosis was confirmed histopathologically.

CONCLUSION

Late presentation of retinoblastoma is uncommon but can be a cause of acute visual impairment in the non-paediatric age group. Retinoblastoma should be considered in the differential diagnosis of a fundal mass in any age group.

Effects of monocular enucleation on parvalbumin in rat visual system during postnatal development

PURPOSE

To evaluate the hypothesis that the expression of the calcium-binding protein parvalbumin (PV) in a subpopulation of gamma-aminobutyric acid (GABA)ergic neurons is an appropriate molecular marker for the effect on ocular dominance plasticity of monocular deprivation during the postnatal sensitive period.

METHODS

Long-Evans rats underwent monocular enucleation immediately before eye opening (postnatal day [P] 14). Immunohistochemical analysis using anti-PV antibody was performed on the superior colliculus (SC) and lateral geniculate nucleus (LGN) at P45. In the visual cortex (VC) developmental changes in immunoreactivity were also examined at the ages of P17, P20, P27, and P45. Northern blot analysis for PV mRNA was also performed at P45. Changes in PV expression in the visual system of these rats were evaluated by use of a computer-based quantitative technique.

RESULTS

PV-immunoreactive neurons were present in the SC and VC, whereas only a few were found in the LGN. The monocular enucleation at the onset of the sensitive period markedly reduced PV immunoreactivity in the neuropil of the SC, contralateral to the enucleated eye when examined one month later. No consistent and significant change in PV immunoreactivity was found in either the LGN or the VC. The number of PV-immunoreactive neurons in the VC rapidly decreased to the adult level during the middle of the sensitive period. The expression of PV mRNA in these central visual structures was not affected by early monocular enucleation.

CONCLUSIONS

Expression of PV is developmentally regulated, and marked changes in its protein expression in the SC can be induced by monocular enucleation. Contrary to the original hypothesis, monocular enucleation did not consistently affect the expression of PV in the rat VC. The expression of PV is probably regulated by multiple factors, not merely by binocular competition.

Ultrasonographic determination of the dimensions of ocular components in enucleated eyes of the one-humped camel (Camelus dromedarius)

The refractive status and visual capabilities of the one-humped camel are not currently known. Schematic eyes are important tools in studying the optical characteristics and refractive status of an eye. The variables required in developing a schematic eye for a particular animal species include the dimensions of the optical components. We have employed A-scan ultrasonography to measure the dimensions of optical components in freshly enucleated eyes of the one-humped camel. Measurements were made in eyes immersed in distilled water kept at 20 degrees C. The average values of the optical components were as follows: anterior chamber depth = 5.27 mm, lens thickness = 10.93 mm, vitreous chamber depth = 14.85 mm and axial length = 31.05 mm. The uncorrected average corneal thickness was 0.76 mm. These values would have to be confirmed in live animal subjects before they can be used to design a schematic eye for the one-humped camel.

Frequent loss of heterozygosity on chromosome 6p in uveal melanoma

Lack of expression of HLA class I antigens is frequently observed on primary uveal melanoma, and is correlated with improved patient survival. Several mechanisms may contribute to the observed loss of HLA class I expression, including changes at the DNA level. In this study, we used microsatellite analysis as a molecular genetic approach to examine loci on chromosome 6p for loss of heterozygosity (LOH). Three pairs of microsatellite markers were used to screen 20 formalin-fixed, paraffin-embedded uveal melanomas for LOH on the short arm of chromosome 6. In all cases, normal adjacent scleral tissue was used as a control. We identified LOH in eleven cases from microsatellite locus D6S105 to the telomere, in eight cases from microsatellite locus D6STNFa to the telomere (area includes D6S105), and in seven cases from microsatellite locus D6S291 to the end of chromosome 6p (includes D6STNFa and D6S105). In seven cases, retention of heterozygosity was found at all three loci using these primers. Our results suggest that loss of heterozygosity on chromosome 6p is a common feature in uveal melanoma. We did not find a correlation between the presence of LOH and locus-specific HLA-A and -B expression.

Volumetric determination of enucleation implant size

PURPOSE

To determine whether volumetric calculation of enucleation implant size improves the results of the enucleation procedure.

METHODS

The volume of the enucleated globe was measured in 33 eyes of 33 patients, allowing intraoperative calculation of implant size. The degree of postoperative anophthalmic volume deficit was evaluated by determining the relative enophthalmic position of the implant using Hertel exophthalmometry. These results were compared with those obtained from two groups of historical control patients who had previously undergone enucleation with the insertion of standard size 18-mm or 20-mm implants.

RESULTS

There was significant variability in the volume of "normal" size globes (range, 7.0 to 9.0 ml; mean, 7.9 ml; standard deviation [SD], 0.7), resulting in the placement of implants between 18 to 22 mm in diameter. Study patients undergoing volumetric determination of implant size demonstrated less implant enophthalmos (mean, 5.9 mm) than historical control patients who received 18-mm (mean, 8.5 mm; P =.0001) or 20-mm (mean, 6.8 mm, P = .0332) implants.

CONCLUSIONS

Volumetric determination and individualization of enucleation implant size appears to reduce postoperative anophthalmic volume deficit.

Indirect evidence for an association of 5-HT(1B) binding sites with retinal and geniculate axon terminals in the rat suprachiasmatic nucleus

The purpose of the present study was to investigate the possible cellular location of 5-HT(1B) receptors on retinal and geniculate afferents in the rat suprachiasmatic nucleus (SCN). Biocular enucleation significantly decreased 5-HT(1B) binding site labeling (35%), specifically in the ventral part of the SCN, while monocular enucleation produced a decrease of smaller magnitude (12%), limited to the ventral part of the contralateral SCN, these results being consistent with the known distribution of retinal afferents in the nucleus. By contrast, bilateral geniculate lesion did not induce any significant variation of 5-HT(1B) binding site labeling in the SCN. Previously, we reported that serotonin (5-HT) synthesis inhibition by parachlorophenylalanine increases 5-HT(1B) binding site labeling in the SCN. Using saturation studies, we have now demonstrated that this upregulation reflected an increase in the total number of 5-HT(1B) binding sites (+41% in the dorsal and +67% in the ventral part of the SCN). Furthermore, we evaluated the effects of bilateral geniculate lesion after 5-HT stores depletion in order to overcome problems of technical resolution limits. The magnitude of upregulation was significantly decreased (27%) after bilateral geniculate lesion, suggesting that part of the 5-HT(1B) receptor population was located on geniculate axon terminals within the SCN. The possible involvement of 5-HT(1B) receptors, according to their cellular locations evidenced in the present study, in photic and nonphotic entrainment of the circadian clock is discussed.

Kinetics of visual pigment regeneration in excised mouse eyes and in mice with a targeted disruption of the gene encoding interphotoreceptor retinoid-binding protein or arrestin

Photoisomerization of 11-cis-retinal to all-trans-retinal and reduction to all-trans-retinol occur in photoreceptor outer segments whereas enzymatic esterification of all-trans-retinol, isomerization to 11-cis-retinol, and oxidation to 11-cis-retinal occur in adjacent cells. The processes are linked into a visual cycle by intercellular diffusion of retinoids. Knowledge of the mechanistic aspects of the visual cycle is very limited. In this study, we utilize chemical analysis of visual cycle retinoids to assess physiological roles for components inferred from in vitro experiments and to understand why excised mouse eyes fail to regenerate their bleached visual pigment. Flash illumination of excised mouse eyes or eyecups, in which regeneration of rhodopsin does not occur, produced a block in the visual cycle after all-trans-retinal formation; constant illumination of eyecups produced a block in the cycle after all-trans-retinol formation; and constant illumination of whole excised eyes resulted in a block of the cycle after formation of all-trans-retinyl ester. These blocks emphasize the role of cellular metabolism in the visual cycle. Interphotoreceptor retinoid-binding protein (IRBP) has been postulated to play a role in intercellular retinoid transfer in the retina; however, the rates of recovery of 11-cis-retinal and of regeneration of rhodopsin in the dark in IRBP-/- mice were very similar to those found with wild-type (wt) mice. Thus, IRBP is necessary for photoreceptor survival but is not essential for a normal rate of visual pigment turnover. Arrestin forms a complex with activated rhodopsin, quenches its activity, and affects the release of all-trans-retinal in vitro. The rate of recovery of 11-cis-retinal in arrestin-/- mice was modestly delayed relative to wt, and the rate of rhodopsin recovery was approximately 80% of that observed with wt mice. Thus, the absence of arrestin appeared to have a minor effect on the kinetics of the visual cycle.

Rhegmatogenous retinal detachment after treatment of retinoblastoma

PURPOSE

To determine the rate of retinal detachment after treatment of retinoblastoma, to describe the clinical features and management, and to discuss possible pathogenic mechanisms.

METHODS

We retrospectively analyzed the charts of 80 patients (83 eyes) with retinoblastoma treated conservatively between 1963 and 1994, looking specifically for cases that developed a retinal detachment after treatment.

RESULTS

Five patients (5 eyes, stages IVa to Vb) developed a retinal detachment after treatment. Of these, four had undergone external radiotherapy and one had an episcleral cobalt plaque. Retinal detachment developed within three months after radiotherapy and relentlessly progressed in all four eyes over a period of five months to four years. In the eye that received the episcleral cobalt plaque, the detachment remained localized inferiorly. Even though no retinal break could be detected in four eyes, the clinical features were suggestive of a rhegmatogenous detachment: there was retinal thinning adjacent to the regressed tumors, and the evolution was much longer than that of an exudative retinal detachment. A scleral buckling procedure was performed in two eyes and the retina was successfully reattached. The retinal detachment was not operated on in the three other eyes: the hole was too posterior in one eye; retinal surgery was refused in the second eye; and the retinal detachment remained localized inferiorly in the third eye.

CONCLUSION

A retinal detachment developed in 6% of eyes after conservative treatment of retinoblastoma. The possibility of a rhegmatogenous origin should be considered even if no retinal break is detected. In the absence of tumor activity, a scleral buckling repair could be carefully considered if the retinal detachment threatens the macula, and if its evolution is not indicative of an exudative detachment.

Follow-up of functionally lost eyes after vitrectomy and silicone oil tamponade for tractional retinal detachment

BACKGROUND

Is there any association between, on the one hand, retention or removal of silicone oil or any specific ocular finding in patients with functionally lost eyes after vitrectomy and silicone oil tamponade for tractional retinal detachment and, on the other, a greater chance of preservation of the eye? This information is important in deciding whether to remove silicone oil, as well as in counseling patients about their individual chances of preserving their eye.

METHODS

Seventy-three consecutive patients with a functionally lost eye with a minimum follow-up of 3 years were retrospectively studied. The relation between the variables at study entry or the removal of silicone oil during the follow-up period and a subsequent intervention (enucleation, evisceration or conjunctival cover with a scleral shell) were tested for statistical significance with Cox proportional hazards analysis.

RESULTS

The absence or removal of silicone oil was not associated with a greater chance of finally preserving the eye. Nor could we identify other factors which predicted better chances of preservation.

CONCLUSION

The notion that functionally lost eyes after treatment with vitrectomy and silicone oil tamponade for complicated tractional retinal detachment have better chances of preservation of the eye without silicone oil is not supported by our study.

Retinoblastoma with low risk for extraocular relapse

OBJECTIVE

To define a subgroup of patients with retino-blastoma and low risk of extraocular relapse through histopathological and clinical variables.

PATIENTS AND METHODS

Inclusion criteria consisted of stage I (intraocular disease), stage IIb1 (without concomitant choroid and/or scleral invasion), and nonenucleated patients (according to the Grabowski-Abramson classification). A total of 112 consecutive patients admitted to Hospital JP Garrahan from 1987 to 1997 were evaluable. Treatment included enucleation or local therapy and no chemotherapy.

RESULTS

Forty-one patients had stage Ia (intraretinal), 8 stage Ib (prelaminar optic nerve invasion), 40 stage Ic (uveal invasion), and 12 stage IIb1 (postlaminar optic nerve invasion and cut end free of tumor). Eleven patients had neither eye enucleated. Median follow-up was 60 months. Only two events occurred: one patient had progressive disease in the contralateral globe and died of CNS metastasis and another had an orbital relapse that was successfully treated. Both had choroidal invasion. Five-year pEFS and pOS were 0.97 and 0.98, respectively. Neither length of the optic nerve stump, tumor size, anterior chamber invasion, degree of differentiation, nor degree of ocular coat invasion correlated with increased risk of metastasis.

CONCLUSIONS

A subset of patients with retinoblastoma with low risk of relapse can be determined using histopathological evaluation of the invasion of ocular coats. Adjuvant chemotherapy is not warranted for patients with intraretinal extension and prelaminar optic nerve invasion. It is also probable that those patients with isolated choroidal invasion and those with postlaminar optic nerve extension with surgical margins clear of tumor do not need chemotherapy.

Tarsal switch procedure for the surgical rehabilitation of the eyelid and socket deficiencies of the anophthalmic socket

PURPOSE

To describe a tarsal transfer procedure, which we have named the "tarsal switch," to correct the eyelid malpositions and camouflage the socket defects of acquired anophthalmos.

METHODS

The technique consists of an upper eyelid tarsectomy, with transfer of the autologous tarsoconjunctival graft to the posterior lamella of the lower eyelid.

RESULTS

The operation was performed in 21 anophthalmic patients. In 16 patients with eyelid malpositions, excellent results (within 1 mm of the fellow eye) were attained in 100% of the patients with ptosis, and in 88% of patients with lower eyelid retraction. In the remaining 5 patients, orbital volume loss with secondary implant migration, inferior prosthetic displacement and eyelid asymmetry predominated. In these patients the anophthalmic orbital defects and eyelid asymmetry were masked well. Patient satisfaction was high and complications were few during an average follow-up interval of 16 months.

CONCLUSION

The tarsal switch procedure is useful in managing the eyelid malpositions and masking the orbital deficiencies of the anophthalmic socket.

Adjuvant chemotherapy with vincristine, doxorubicin, and cyclophosphamide in the treatment of postenucleation high risk retinoblastoma

PURPOSE

To study risk factors and outcome of children with high risk retinoblastoma who receive postenucleation vincristine, doxorubicin, and cyclophosphamide.

PATIENTS AND METHODS

Charts of all patients who received adjuvant chemotherapy for retinoblastoma were reviewed. Thirty-six patients were identified who received chemotherapy for high risk histopathologic features. Histopathology slides of these 36 patients were retrieved and reviewed, and the disease was staged according to the modified St. Jude staging system. The disease was unilateral in 23 patients (64%). There were 9 patients with stage I disease, 18 with stage II, and 9 with stage III. Twenty-four patients (67%) completed 12 of the 12 scheduled chemotherapy cycles, and 11 patients (30%) received 4 to 11 cycles because of relapse, disease progression, or family reasons. A life-threatening complication developed in one patient after the first cycle, and this patient received no further chemotherapy.

RESULTS

Five (3 with unilateral and 2 with bilateral disease) of the 36 patients developed distant metastasis and subsequently died. All had massive tumors; three had choroidal and up to surgical margin optic nerve invasion, and two had tumor extending posterior to lamina cribrosa. Six other patients had local relapse or progressive disease. All of these six patients had bilateral disease and failed in the intact eye during (three patients) or after (three patients) chemotherapy. Only two of the six patients were alive with no disease 50 and 102 months from diagnosis. With a median follow-up of 5.6 years, the 5-year and 10-year actuarial overall survival rates were 86% and 74%, respectively. The 5-year survival rates for patients with modified St. Jude stage I, II, and III disease were 100%, 91% (95% confidence interval, 57% to 100%), and 58% (95% confidence interval, 22% to 94%), respectively (P = 0.008). The survival rate was significantly different among patients with optic nerve involvement anterior to lamina cribrosa, posterior to lamina cribrosa, and surgical margin involvement (100%, 55%, and 41%, respectively; P = 0.003). Multivariate analysis showed that only the degree of optic nerve involvement (and therefore, modified St. Jude stage) was predictive of poor outcome.

CONCLUSION

Patients with retinoblastoma involving the optic nerve beyond the lamina cribrosa have low survival rate despite local therapy and adjuvant chemotherapy with vincristine, doxorubicin, and cyclophosphamide. Progression of disease in the intact eye of three patients receiving chemotherapy is of concern. Alternative chemotherapeutic agents should be considered for patients with such high risk features.

The effects of early prenatal monocular enucleation on the routing of uncrossed retinofugal axons and the cellular environment at the chiasm of mouse embryos

Whereas it has been shown that early monocular enucleations produce a reduction in the uncrossed pathway from the surviving eye in rats and ferrets, similar evidence for binocular interactions in the development of the uncrossed component in mice is currently open to question. Using retrograde tracing, we have investigated the time course of changes in the uncrossed retinofugal pathway immediately after the early prenatal monocular enucleation in mouse embryos. Removal of one eye from C57 pigmented mice at embryonic day (E) 13 does not cause a reduction of the earliest uncrossed component from the central retina examined 1 day later at E14. However, a substantial reduction of the uncrossed pathway is seen at E15, the time when the major uncrossed projection first arises from the ventral temporal retina. This reduction is greater in E16 one-eyed embryos, indicating that most retinal axons from the ventral temporal retina rely on a binocular interaction for their turning at the chiasm. Further, early removal of one eye at E13 does not produce any obvious changes in the cytoarchitecture of RC-2-immunopositive radial glia at the chiasm, nor of the stage-specific antigen-1 (SSEA-1) -expressing neurons. This lack of changes in the cellular organization at the chiasm indicates that the reduction of the uncrossed pathway is probably produced by an elimination of binocular fibre interactions at the chiasm, rather than through a degenerative change of cellular elements at the chiasm as a consequence of the eye removal procedure.