Congenital pits of the optic nerve head. II. Clinical studies in humans

Nonglaucomatous cupping of the optic disc

Optic disc cupping is a consequence of myriad disorders. The anatomy and vasculature of the disc provide great insight into why, how, and when ODC occurs in various conditions. Approaches to distinguish glaucomatous from nonglaucomatous causes of ODC should rely on patient history, visual fields assessment, and funduscopic findings, as described. Cupping can be seen with neurological processes, including benign tumors, that are treatable. The clinician must remain vigilant to detect uncommon but potentially threatening forms of nonglaucomatous optic disc cupping.

Optical coherence tomography of macular lesions associated with optic nerve head pits

PURPOSE

Although optic pits were described more than a century ago, the pathogenesis and pathologic nature of the associated macular lesions remain controversial. The authors used the technique of optical coherence tomography (OCT) to further define the anatomic relation that exists between optic pits, macular schisis-like spaces, and macular detachments.

METHODS

Four eyes of three consecutive patients with optic pit-related macular pathology were evaluated. Cross-sectional OCT images were correlated with findings from slit-lamp biomicroscopy and stereo fundus photography. All eyes previously had undergone unsuccessful photocoagulation to the temporal juxtapapillary retina. One eye had undergone vitrectomy and intraocular gas tamponade, resulting in partial resorption and displacement of the submacular fluid.

RESULTS

Retinal edema and cystic degeneration were present, overlying macular neurosensory detachments in all four eyes. The most prominent edema was present in the outer retina at the level of the outer plexiform layer. This mimicked a true retinoschisis cavity, although bridging retinal elements were identifiable. A lesser degree of edema was present in the inner retina, predominantly located between the disc and fovea. In one eye, a lamellar hole was shown to be a defect in the outer neurosensory retina. In another eye, a macular detachment developed under a pre-existing schisis-like cavity. The schisis-like cavity or edematous retina communicated with the optic disc in all eyes, whereas none of the eyes demonstrated a direct connection between the macular detachment and optic pit.

CONCLUSION

These findings support the concept of a bilaminar structure in which a macular detachment develops secondarily to a pre-existing schisis-like lesion consisting of severe outer retinal edema. Fluid may enter from the optic pit into the retinal stroma and not directly into the subretinal space, explaining the prolonged recovery and frequency of treatment failure after photocoagulation to the juxtapapillary retina.

Treatment of maculopathy associated with optic disk pit by sponge explant

PURPOSE

To evaluate the anatomic and functional outcome in nine patients with optic disk pit maculopathy after the use of the macular buckling procedure.

METHODS

In this prospective study, nine consecutive patients (five women and four men with a mean age of 28 years [range, 14 to 49 years] who had unilateral maculopathy associated with optic disk pit) were treated with macular buckling surgery. A scleral sponge of 7.5 x 5.5 mm was fixed at the posterior pole of the globe corresponding to the macula along the vertical axis of the 12-to-6 o'clock meridian. No additional treatment of any kind (laser, diathermy, or cryotherapy) was used. The correct positioning of the sponge during the operation was monitored by B-scan ultrasonography. Within the first week after surgery, indocyanine green angiography was performed to evaluate the choroidal circulation. During the same period, magnetic resonance imaging of the orbit was performed to determine the sponge position in relation to the optic nerve.

RESULTS

In all nine eyes, complete disappearance of subretinal and intraretinal fluid in the macula and in the surrounding area was noted. The absorption of the macular fluid started immediately after the operation and was completed after five to six months. No further change of the appearance of the fundus was noted during the follow-up period, which ranged from 18 to 66 months (mean follow-up, 42 months). Six eyes gained four or five lines of visual acuity, and two eyes improved by three lines.

CONCLUSIONS

The macular scleral buckling procedure in optic disk pit maculopathy can yield favorable anatomic and functional results.

Post-traumatic macular break associated to congenital optic disc pit and pre-existing sensory macular detachment

BACKGROUND

Optic disc pits represent a rare congenital abnormality frequently associated with macular detachment. Several theories on the pathogenesis of the detachment have been proposed, but the issue still remains unclear. Treatment remains speculative as well; advocated treatments include eye-patching, bed rest, steroids, laser photocoagulation, pars plana vitrectomy with fluid-air exchange and optic nerve sheath decompression.

METHODS

The Authors report on the case of an optic pit with associated macular detachment which developed an inner layer macular hole and, after an apparently insignificant skull trauma, a large macular break. The patient underwent a standard three-port pars plana vitrectomy, fluid gas-exchange, posterior scleral buckling and laser treatment.

RESULTS

Twelve months after surgery the retina was flat, posterior buckling was evident and laser treatment pigmented. Visual acuity was 20/600.

CONCLUSIONS

The presence of strands of condensed vitreous strands crossing the posterior lacuna and exerting traction over the macula and optic disc, support the theory of a possible tractional role of anomalous vitreous adhesion in the pathogenesis of the detachment and macular break. Anomalous vitreous adhesion over the posterior retina could be related to the malformative genesis of the syndrome, and the anomalous persistence of the Cloquet's canal or primary vitreous could be responsible for the traction.

Vitrectomy for macular detachment associated with optic nerve pits

OBJECTIVE

To describe the pathogenic mechanism for a central retinal detachment in eyes with a pit of the optic disc.

DESIGN

Three patients with macular detachment associated with optic nerve head pits were prospectively controlled following pars plana vitrectomy.

METHODS

Three cases of macular detachment associated with congenital optic nerve pit were treated with pars plana vitrectomy and air-fluid exchange and sulphur hexafloride (SF6) gas injection. During vitrectomy posterior hyaloid removal caused visible traction on the elevated retina, when the hyaloid detached. Removing the posterior hyaloid resulted in reattachment of the macular and an increase in the visual acuity without laser treatment.

CONCLUSION

We recommend the removal of the posterior hyaloid face during pars plana vitrectomy in patients with central macular detachment associated with a pit of the optic disc.

Congenital optic disk anomalies

Over the past decade, a wealth of information has accumulated pertaining to the diagnosis and management of patients with congenital optic disk anomalies. As new examples of each entity have been detailed, the diagnostic criteria for each anomaly have become more clearly defined. The advent of sophisticated noninvasive neuroimaging techniques has further refined our ability to accurately detect and categorize the associated CNS anomalies that complicate many of these conditions. In light of recent findings, this review will critically examine many of the well-entrenched concepts pertaining to the diagnosis, evaluation, and treatment of patients with congenital optic disk anomalies. In so doing, it will attempt to dispel some longstanding misconceptions that pervade the literature and obscure our understanding of the pathogenesis, neuroradiological associations, and systemic implications of each anomaly.

Classification of microphthalmos and coloboma

A new classification of microphthalmos and coloboma is proposed to bring order to the complexity of clinical and aetiological heterogeneity of these conditions. A phenotypic classification is presented which may help the clinician to give a systematic description of the anomalies. The phenotype does not predict the aetiology but a systematic description of ocular and systemic anomalies improves syndrome identification. There are two major classes, total and partial microphthalmos, and a subclassification which follows the embryology of the anomalies. The aetiological classification consists of three classes: (1) genetic (monogenic and chromosomal), (2) prenatally acquired (teratological agents and intrauterine deformations), and (3) associations. Genetic disorders give rise to malformations; prenatally acquired anomalies are disruptions or deformations. The aetiological classification can be applied to other congenital birth defects and improves counselling of families. Recurrence risks vary considerably between the classes.

Vitreous findings in cases of optic nerve pits and serous macular detachment

We examined biomicroscopically the relationship between the optic nerve and the vitreous in 17 eyes of 16 consecutive patients with pits of the optic nerve that demonstrated an associated serous detachment of the macula. The posterior vitreous was attached in 15 eyes (88%); the posterior vitreous was partially detached with a vitreous strand terminating at the optic pit in two eyes (12%). Of the 15 eyes without posterior vitreous detachment, 11 (73%) had an anomalous Cloquet's canal that was markedly condensed and terminated at the margin of the pit. During ocular movement, we observed a back-and-forth movement of the anomalous Cloquet's canal and a pulsating translucent membrane that covered the pit. Our findings suggest that the intravitreal traction on the optic pit by the anomalous Cloquet's canal may have a role in the development of macular detachment.

A case of presumed congenital herpes zoster ophthalmicus

Images

Resolution of an external layer macular hole associated with an optic nerve pit after laser photocoagulation

Images

Serous macular detachment associated with optic nerve pits

Between September 1972 and March 1989, we examined 25 eyes of 24 patients exhibiting optic nerve-head pits associated with serous macular detachment. We followed 21 patients for a period of 1-15 years (mean, 62 months). Various treatment modalities were applied, depending on the time of initial examination. Five eyes underwent no treatment and three eyes underwent two distinct treatment modalities. Photocoagulation treatment was performed in ten eyes. Argon laser photocoagulation was combined with intravitreal injection of pure SF6 in eight eyes and of C3F8 in three. Intravitreal injection of pure C3F8 without photocoagulation was carried out in two eyes. The results of biomicroscopy of the vitreous gel and of fluorescein angiography and the responses to the various treatment modalities support the hypothesis that the mechanism underlying serous macular detachment complicating optic nerve-head pits is traction retinal detachment combined with a rhegmatogenous component in the roof of the optic pit.

Long-term visual outcome in patients with optic nerve pit and serous retinal detachment of the macula

Serous detachment of the macula is a well-known complication in patients with an optic nerve pit. Despite the many descriptions of this condition and possible treatment options, the long-term natural history is not well known. The authors identified 15 eyes of 15 consecutive patients seen over 21 years who were diagnosed with a serous detachment of the macula arising from an optic nerve pit. Average length of follow-up was 9 years. Twelve eyes lost three or more lines of vision, two eyes remained unchanged, and only one eye improved. All of the 12 eyes losing three or more lines of vision experienced this decrease within the first 6 months of follow-up. Although only two patients had a visual acuity of 20/200 or less initially, 12 of 15 patients had a visual acuity of 20/200 or less at the time of their last examination. The appearance of the macula at last examination included cystic changes of the neurosensory retina, full-thickness hole formation, retinal pigment epithelial mottling, and lamellar hole formation in the outer retinal layer. The long-term visual prognosis in patients with optic nerve pit and untreated serous retinal detachment of the macula is poor, and visual loss occurs within 6 months of the serous detachment.

Congenital pit of the optic nerve

Congenital pit of the optic nerve is a rare condition which can lead to serous retinal detachment. A case history of a patient with a small pit of the optic nerve is presented and management by the optometrist is discussed.

Evolving techniques in the treatment of macular detachment caused by optic nerve pits

Fourteen patients with macular detachments caused by optic nerve pits were treated for progressive visual loss, cystoid macular changes, or atrophy of the macular retinal pigment epithelium. Photocoagulation of the temporal disc border alone was unsuccessful in two cases but promptly reattached the macula of two patients immobilized after laser surgery. Vitrectomy and gas tamponade improved vision and flattened the macula of three patients over various periods. The detachment recurred in one patient. Prompt and sustained macular reattachment with improved vision was noted after photocoagulation, vitrectomy, and gas tamponade in eight patients, although four required second operations. The prompt reattachment and visual recovery noted in these eight patients surpasses the reported 25% rate of spontaneous resolution.

Optic nerve coloboma associated with renal disease

Optic nerve colobomas can occur as sporadic abnormalities, may be inherited as an autosomal dominant defect, occur as part of syndromes, and are rarely associated with cardiac malformations and midline encephaloceles. Karcher [1979] described a father and son with the "morning glory" optic disc anomaly and renal disease as a new association. We report on two brothers with optic nerve colobomas associated with renal disease. The ophthalmologic findings and renal histopathology are presented. This second familial occurrence suggests that the association of optic nerve coloboma and renal disease is a newly recognized syndrome.

Treatment of sensory retinal detachment associated with optic nerve pit or coloboma

Six eyes with optic nerve pit and associated sensory retinal detachment of the macula were treated using a management plan that utilized a combination of techniques including laser photocoagulation, pars plana vitrectomy, and intraocular air/fluid exchange. In each treated eye the retina was eventually flattened. This paper discusses this plan of management and series of treatment modalities.

Treatment of retinal detachment with congenital optic pit by krypton laser photocoagulation

Five patients with a congenital pit of the optic nerve and serous detachment of the macular retina were treated with krypton laser photocoagulation to the juxtapapillary region in an attempt to induce resolution of the retinal detachment. The subretinal fluid resolved after laser therapy in four of the patients. In the fifth, the retinal detachment was successfully treated with pars plana vitrectomy. One patient developed a macular hole and decreased visual acuity, despite resolution of the subretinal fluid.

Optic pit syndrome

In a study of 15 eyes with optic pits fluorescein angiography revealed that only pits associated with serous detachment of the macular retina showed fluorescence in the late venous phase, while the pits uncomplicated by detachment remained hypofluorescent throughout the test. This finding strongly supports the hypothesis that the subretinal fluid producing the macular detachment originates from leakage of vessels located in the floor of the pit. In addition a high incidence of anomalies was found to be associated with optic pits. Therefore the author suggests to call the association between optic pit and large optic disc, parapapillary chorioretinal changes, cilioretinal vessels, situs inversus and eventual other vessel abnormalities, the 'optic pit syndrome'.

Aniridia, atypical iris defects, optic pit and the morning glory disc anomaly in a family

A two-month-old girl with aniridia was found to have an optic pit in one eye and the morning glory disc anomaly in the other eye. The patient's mother had corectopia and atypical iris defects. The findings are described and the embryology of the various abnormalities briefly reviewed. This is the first report of such an association of findings in a family with aniridia. Failure of normal neuroectodermal development may play a role in the development of optic pits and the morning glory disc anomaly.

Congenital anomalies of the optic disc

Although anomalies affecting the optic nerve head are usually clinically innocuous, they can sometimes cause significant symptoms and lead to visual loss. It is important to be able to recognize even the relatively benign lesions in order to differentiate them from other more threatening lesions or disease processes which they may clinically resemble. An awareness of the clinical appearance of disc anomalies is especially important in the differential diagnosis of optic nerve glaucomatous changes. Some anomalies cause various types of visual field loss which, if the actual disc lesion is not recognized, may lead to unnecessary neurologic evaluation or even to intracranial surgery. The optic nerve changes in acquired myopia and in the congenital tilted disc syndrome should be clearly defined and differentiated: high (pathologic) myopia may be highly progressive with many dangerous secondary sequelae, while the latter anomaly is stationary. Finally, there is a group of conditions, collectively termed "elevated anomalies of the disc," which must be considered in the differential diagnosis of papilledema and potentially dangerous intraocular tumors, particularly retinoblastoma. This review provides a clinicopathologic correlation comparing the characteristics of the normal optic disc to those of the most important congenital anomalies of the disc.

Optic nerve hypoplasia and colobomatous defects

The case of a 21-year-old woman with an optic nerve head coloboma and optic pit in one eye, a hypoplastic optic nerve head in the second eye, and a small retinochoroidal coloboma in each eye is presented. The probable etiology is some unknown insult involving several ocular embryonic structures and occurring during the 11-mm to 20-mm stage of development. The occurrence of these multiple anomalies in the same patient lends further support to the theory that optic disc colobomas and optic nerve hypoplasia represent a spectrum of developmental anomalies of the optic nerve.

Ocular coloboma

Ocular coloboma is common malformation which includes a spectrum of anomalies that ranges from iris coloboma to clinical anophthalmos. Coloboma is etiologically heterogeneous. As an isolated defect, it is usually inherited as an autosomal dominant disorder, although autosomal recessive inheritance also occurs. Patients with multiple malformations and coloboma may have a recognized malformation syndrome of unknown etiology, a single gene disorder, or chromosomal abnormality. Prognosis and recurrence risk can be determined only after complete evaluation of the patient and other family members.

Low tension glaucoma: a critical review and new material

Low tension glaucoma (LTG) is a condition consisting of typical gluacomatous disc and field changes, an open angle and pressures within the statisticaly normal range. The controversy surrounding low tension glaucoma pertains not only to the definition and characteristics of the entity itself, but to the fundamental questions it raises regarding the causal relationship between intraocular pressure and disc and field changes. This review of LTG is based on material from three major sources: Sjögren's review from 1857 to 1946; the author's review of the world literature from 1947 through 1979; and an analysis of 32 of the author's cases. 767 cases from clinic and private practice and 241 cases from defined populations are considered. Definitions, incidence, characteristics, differential diagnosis and management of LTG are discussed, as are its relationship to primary open angle glaucoma and its possible association with various other entities. Pathogenesis and possible mechanisms are also explored.