Orbital fibrous histiocytoma: case report and literature review.

BACKGROUND: Fibrous histiocytomas are a diverse group of soft tissue tumors classified histiologically as benign, locally aggressive, and malignant. These tumors are found throughout the body, but seem to have an affinity for the periorbital area. They account for one percent of all ocular masses and are the most common primary mesenchymal tumor of the orbit. Associated ocular signs and symptoms include decreased visual acuity, proptosis, diplopia, pain, restricted extraocular muscle movement, swelling of the eyelids, and conjunctiva, as well as disk edema. CASE REPORT: A case of a benign orbital fibrous histiocytoma is presented. The patient reported intermittent pain and occasional diplopia; severe edema of the right upper eyelid; and proptosis and inferior vertical displacement of the right globe were observed. Computed tomography revealed a well-defined mass that was subsequently surgically removed and histopathological results from the Armed-Forces Pathology Institute confirmed the diagnosis. CONCLUSIONS: Orbital fibrous histiocytomas are rare periocular tumors that can manifest multiple ocular signs and symptoms. Careful histologic examination is necessary for diagnosis, since these tumors have a wide range of morphology. Differential diagnoses include orbital masses with similar radiologic or histologic findings.     

Balanced orbital decompression combined with fat removal in Graves ophthalmopathy: do we really need to remove the third wall?

PURPOSE: To compare the reduction of proptosis and the incidence of new-onset diplopia after 3-wall (medial, lateral, and inferior) orbital decompression versus balanced medial and lateral wall decompression combined with orbital fat excision in patients with Graves ophthalmopathy. METHODS: Three-wall orbital decompression including medial, inferior, and lateral walls was performed in 13 eyes of 7 patients (group 1), and balanced medial and lateral wall decompression combined with fat removal was performed in 18 eyes of 11 patients (group 2). A transnasal endoscopic approach was used for medial wall removal. A lateral canthotomy incision combined with a short upper eyelid incision was used for extended lateral wall removal, and this was combined with an inferior conjunctival fornix incision when floor decompression was performed. RESULTS: The mean reduction of proptosis was 6.9+/-1.6 mm and 6.5+/-1.3 mm in the first and second groups, respectively; the difference was not statistically significant (P=0.37). After 3-wall decompression, 57.1% of the patients had permanent new-onset diplopia (group 1), whereas none of the patients had permanent postoperative diplopia after balanced medial and lateral wall decompression combined with fat removal (group 2). The difference in permanent new-onset postoperative diplopia between two groups was statistically significant (P<0.001). CONCLUSIONS: Balanced medial and lateral wall decompression combined with orbital fat removal provides an effective reduction in proptosis and reduces the incidence of postoperative permanent diplopia when compared with 3-wall decompression. This technique may eliminate the need for orbital floor excision.     

Oral montelukast and cetirizine for thyroid eye disease

PURPOSE: To study the efficacy of oral montelukast, a cysteinyl leukotriene receptor antagonist, in combination with cetirizine, a histamine-1 receptor antagonist, in the treatment of thyroid eye disease. METHODS: Patients considering surgical correction of eyelid retraction for inflammatory symptoms of thyroid eye disease were offered a preoperative medical regimen of oral montelukast/cetirizine. Exclusion criteria included prior use of oral montelukast (i.e., for seasonal allergy or asthma), compressive optic neuropathy, severe ophthalmopathy requiring systemic corticosteroids, and orbital and/or muscle surgery. A 6-week course of oral cetirizine (10 mg every morning) and oral montelukast (10 mg every evening) was administered and patients subjectively rated their ocular surface dryness, tearing, itching, injection, eyelid swelling, eyelid retraction, double vision, proptosis, and visual clarity, at baseline, after 3 weeks and 6 weeks of medical therapy, and after 3 weeks off of the medications. RESULTS: Six of the 12 patients recruited for the study reported a subjective improvement in tearing, dryness, and itching. Less effect on diplopia and proptosis was noted after 6 weeks of medical therapy. Two of the patients who did not report response chose to proceed with eyelid retraction surgery and both had evidence of mast cell infiltration in their Müller muscle specimens. CONCLUSION: The response observed in this open-label trial suggests that oral montelukast and cetirizine may be an effective medical regimen for patients with thyroid eye disease who experience mild to moderate orbital congestion and inflammation.     

Customized Orbital Decompression Surgery Combined with Eyelid Surgery or Strabismus Surgery in Mild to Moderate Thyroid-associated Ophthalmopathy

Purpose

To evaluate the efficacy and safety of customized orbital decompression surgery combined with eyelid surgery or strabismus surgery for mild to moderate thyroid-associated ophthalmopathy (TAO).

Methods

Twenty-seven consecutive subjects who were treated surgically for proptosis with disfigurement or diplopia after medical therapy from September 2009 to July 2012 were included in the analysis. Customized orbital decompression surgery with correction of eyelid retraction and extraocular movement disorders was simultaneously performed. The patients had a minimum preoperative period of 3 months of stable range of ocular motility and eyelid position. All patients had inactive TAO and were euthyroid at the time of operation. Preoperative and postoperative examinations, including vision, margin reflex distance, Hertel exophthalmometry, ocular motility, visual fields, Goldmann perimetry, and subject assessment of the procedure, were performed in all patients. Data were analyzed using paired t-test (PASW Statistics ver. 18.0).

Results

Forty-nine decompressions were performed on 27 subjects (16 females, 11 males; mean age, 36.6 ± 11.6 years). Twenty-two patients underwent bilateral operations; five required only unilateral orbital decompression. An average proptosis of 15.6 ± 2.2 mm (p = 0.00) was achieved, with a mean preoperative Hertel measurement of 17.6 ± 2.2 mm. Ocular motility was corrected through recession of the extraocular muscle in three cases, and no new-onset diplopia or aggravated diplopia was noted. The binocular single vision field increased in all patients. Eyelid retraction correction surgery was simultaneously performed in the same surgical session in 10 of 49 cases, and strabismus and eyelid retraction surgery were performed in the same surgical session in two cases. Margin reflex distance decreased from a preoperative average of 4.3 ± 0.8 to 3.8 ± 0.5 mm postoperatively.

Conclusions

The customized orbital decompression procedure decreased proptosis and improved diplopia, in a range comparable to those achieved through more stepwise techniques, and had favorable cosmetic results when combined with eyelid surgery or strabismus surgery for mild to moderate TAO.     

Ectopic chordoma with orbital invasion

PURPOSE: To report a rare ectopic chordoma within the orbital wall. METHODS: Case report. RESULTS: A 63-year-old woman developed swelling of the eyelid, tearing, blurred vision, and progressive proptosis RE of 1 month's duration. Neuroimaging studies revealed an osteolytic mass with epicenter at the sphenozygomatic suture that eroded intracranially, invaded into the orbit, and compressed orbital soft tissues. Surgical debulking was done followed by radiation treatment. The pathologic findings of physaliphorous epithelial cells with multiple vacuoles containing mucin, prominent nuclei, and positive immunohistochemical staining for S-100, Vimentin, epithelial membrane antigen, and pancytokeratin were diagnostic for chordoma. CONCLUSION: Orbital wall ectopic localization of a chordoma distant from the clivus is a rare occurrence.     

Transconjunctival orbital decompression in Graves' ophthalmopathy: lateral wall approach ab interno

AIMS: A modified surgical technique is described to perform a one, two, or three wall orbital decompression in patients with Graves' ophthalmopathy. METHODS: The lateral wall was approached ab interno through a "swinging eyelid" approach (lateral canthotomy and lower fornix incision) and an extended periosteum incision along the inferior and lateral orbital margin. In addition, the orbital floor and medial wall were removed when indicated. To minimise the incidence of iatrogenic diplopia, the lateral and medial walls were used as the first surfaces of decompression, leaving the "medial orbital strut" intact. During 1998, this technique was used in a consecutive series of 19 patients (35 orbits) with compressive optic neuropathy (six patients), severe exposure keratopathy (one patient), or disfiguring/congestive Graves' ophthalmopathy (12 patients). RESULTS: The preoperative Hertel value (35 eyes) was on average 25 mm (range 19-31 mm). The mean proptosis reduction at 2 months after surgery was 5.5 mm (range 3-7 mm). Of the total group of 19 patients, iatrogenic diplopia occurred in two (12.5%) of 16 patients who had no preoperative diplopia or only when tired. The three other patients with continuous preoperative diplopia showed no improvement of double vision after orbital decompression, even when the ocular motility (ductions) had improved. In the total group, there was no significant change of ductions in any direction at 2 months after surgery. All six patients with recent onset compressive optic neuropathy showed improvement of visual acuity after surgery. No visual deterioration related to surgery was observed in this study. A high satisfaction score (mean 8.2 on a scale of 1 to 10) was noted following the operation. CONCLUSION: This versatile procedure is safe and efficacious, patient and cost friendly. Advantages are the low incidence of induced diplopia and periorbital hypaesthesia, the hidden and small incision, the minimal surgical trauma to the temporalis muscle, and fast patient recovery. The main disadvantage is the limited exposure of the posterior medial and lateral wall.     

Orbital and Adnexal Rosai-Dorfman Disease

Purpose: To report the clinico-radiological findings, clinical course, and treatment outcomes in five patients with orbital and adnexal Rosai-Dorfman(R-D) disease. Methods: Analysis of case records of patients with Rosai-Dorfman disease seen at four orbital units between January 2000 and December 2006. Results: Five patients (3 Caucasian males, 1 Hispanic female, and 1 African female), mean age 41.1 years, (range 18 months to 75 years) with orbital or adnexal Rosai-Dorfman disease were seen during the study period. Four of the patients had orbital involvement and one had eyelid involvement. Presenting features were proptosis (4 patients), diplopia (1 patient), epiphora (1 patient), and eyelid thickening (1 patient). Three of the patients with orbital involvement also had adjacent paranasal sinus involvement, and the nasolacrimal duct was involved in one patient. The patient with eyelid involvement had evidence of cutaneous R-D disease elsewhere in the body. The follow-up period (since initial diagnosis of R-D disease) ranged from 1 month to 15 years, and 2 of the patients had a history of recurrent growth despite treatment. Surgical debulking was employed in 2 patients with good results. Conclusions: Orbital and adnexal Rosai-Dorfman disease is a condition with protean manifestations that may show indolent but unremitting growth despite treatment. The disease may remain extranodal and localized for many years. Adjacent paranasal sinus involvement is commonly seen in conjunction with orbital disease, simulating midline destructive lesions. Surgical debulking gives good results in patients with functional or significant cosmetic problems.     

Primary orbital ganglioneuroma in a 2-year-old healthy boy

A 2-year-old healthy child presented with progressive unilateral proptosis.Complete work up including: general examination, detailed ophthalmic evaluation and radiological imaging were done. He underwent orbital exploration via anterior orbitotomy incision and debulking of the tumor was done.The histopathological examination confirmed the diagnosis of orbital ganglioneuroma.Ganglioneuroma is an unusual benign tumor of neuroplastic origin with extremely rare orbital involvement with only one prior reported case in a youth. The tumor is slow growing and non-metastasizing. Biopsy is necessary to differentiate it from the malignant neuroblastoma and excision is usually curative.     

Isolated medial rectus muscle rupture after a traffic accident.

A 30-year-old male suffered an orbital trauma due to a traffic accident. At the Emergency Unit, the patient presented with avulsion of the upper left eyelid in the medial canthus, wounds in the lower eyelid and the inferior canaliculus, conjunctival laceration, proptosis and palpebral hematomas. The patient reported persistent diplopia. During the examination, exotropia and total absence of adduction were observed. Computerized tomography (CT) revealed a discontinuity at the left medial rectus. No orbital fractures were identifiable. The medial rectus was still attached to its anatomic insertion at the globe. The discontinuity was suggestive of laceration or rupture of this muscle at approximately 10-12 mm from its insertion. Surgical exploration revealed total rupture of the medial rectus at approximately 12 mm from its insertion. The posterior edge of the damaged muscle was found and sutured to its anterior edge with 6-0 polyglactin. The following day, the eyes were completely straight and the patient did not mention any signs of diplopia. Botulinum toxin injection into the ipsilateral lateral rectus was not necessary. After six months of follow-up, the patient still reported no diplopia. When muscular laceration is suspected after an orbital trauma, early CT is recommended. The only procedures that assure a significant recovery of the normal function of the eye are early muscle repair and avoidance, if possible, of transposition surgery.     

Balanced orbital decompression in Graves' orbitopathy: Upper eyelid crease incision for extended lateral wall decompression

INTRODUCTION . This study reports on the results and complications detected in patients with Graves' orbitopathy who underwent balanced medial and lateral wall orbital decompression through concealed incisions. MATERIALS AND METHODS . The medial and lateral orbital walls of nine consecutive patients (14 eyes) were removed. A transnasal endoscopic spheno-ethmoidectomy was performed for the medial wall decompression. A lateral wall decompression was performed via an upper eyelid crease incision which was extended laterally in a relaxed skin tension line. The lateral aspect of the orbit was sculpted with a high-speed surgical drill from the inferior orbital fissure inferiorly and frontal bone of the lacrimal fossa superiorly to the orbital apex posteriorly, including the thick bone of the greater wing of the sphenoid. RESULTS . The decompression was performed for cosmetic purposes in seven patients (10 orbits) and for exposure keratopathy and restrictive myopathy in the remaining two patients (4 orbits). The average follow-up period was 13.6 months. The mean reduction of proptosis was 4.8 mm. The preoperative diplopia in two cases demonstrating restrictive myopathy worsened during the postoperative period. New onset diplopia was not detected in seven cases operated on for cosmetic purposes. All patients were satisfied with their eye status, visual rehabilitation and cosmetic appearance. CONCLUSIONS . The transnasal endoscopic approach for medial wall and extended lateral wall decompression with hidden eyelid crease incision provides a favorable cosmetic and physiologic outcome with proper retroplacement of the globe.     

Sclerosing lipogranuloma of the orbit after periocular steroid injection

PURPOSE: To report the clinical and histopathologic findings of a large sclerosing lipogranuloma of the orbit arising after a sub-Tenon's corticosteroid injection. DESIGN: Interventional case report and review of the literature. METHODS: A complete ocular and systemic evaluation was performed on a 81-year-old patient, who developed a large orbital mass subsequent to a periocular corticosteroid injection producing proptosis, ptosis, and ocular motility impairment. The lesion was biopsied and submitted for histopathologic analysis. MAIN OUTCOME MEASURES: Orbital, computed tomography, and histopathologic findings. RESULTS: Histopathologic examination revealed lipogranulomatous inflammation. Specifically, this type of reaction was consistent with a diagnosis of sclerosing lipogranuloma. CONCLUSIONS: It is extremely rare to find a large granulomatous orbital lesion arising subsequent to a periocular corticosteroid injection. Only one case has been reported in the English-language literature to date. It is important to include this type of lesion in the differential diagnosis of an orbital mass seen after the injection of periocular corticosteroids.     

Balanced orbital decompression in Graves' orbitopathy: Upper eyelid crease incision for extended lateral wall decompression

INTRODUCTION. This study reports on the results and complications detected in patients with Graves' orbitopathy who underwent balanced medial and lateral wall orbital decompression through concealed incisions. MATERIALS AND METHODS. The medial and lateral orbital walls of nine consecutive patients (14 eyes) were removed. A transnasal endoscopic spheno-ethmoidectomy was performed for the medial wall decompression. A lateral wall decompression was performed via an upper eyelid crease incision which was extended laterally in a relaxed skin tension line. The lateral aspect of the orbit was sculpted with a high-speed surgical drill from the inferior orbital fissure inferiorly and frontal bone of the lacrimal fossa superiorly to the orbital apex posteriorly, including the thick bone of the greater wing of the sphenoid. RESULTS. The decompression was performed for cosmetic purposes in seven patients (10 orbits) and for exposure keratopathy and restrictive myopathy in the remaining two patients (4 orbits). The average follow-up period was 13.6 months. The mean reduction of proptosis was 4.8 mm. The preoperative diplopia in two cases demonstrating restrictive myopathy worsened during the postoperative period. New onset diplopia was not detected in seven cases operated on for cosmetic purposes. All patients were satisfied with their eye status, visual rehabilitation and cosmetic appearance. CONCLUSIONS. The transnasal endoscopic approach for medial wall and extended lateral wall decompression with hidden eyelid crease incision provides a favorable cosmetic and physiologic outcome with proper retroplacement of the globe.     

Deep lateral wall orbital decompression following strabismus surgery in patients with Type II ophthalmic Graves’ disease

Purpose: Surgical management of ophthalmic Graves’ disease traditionally involves, in order, orbital decompression, followed by strabismus surgery and eyelid surgery. Nunery et al. previously described two distinct sub-types of patients with ophthalmic Graves’ disease; Type I patients exhibit no restrictive myopathy (no diplopia) as opposed to Type II patients who do exhibit restrictive myopathy (diplopia) and are far more likely to develop new-onset worsening diplopia following medial wall and floor decompression. Strabismus surgery involving extra-ocular muscle recession has, in turn, been shown to potentially worsen proptosis. Our experience with Type II patients who have already undergone medial wall and floor decompression and strabismus surgery found, when additional decompression is necessary, deep lateral wall decompression (DLWD) appears to have a low rate of post-operative primary-gaze diplopia.

Methods: A case series of four Type II ophthalmic Graves’ disease patients, all of whom had already undergone decompression and strabismus surgery, and went on to develop worsening proptosis or optic nerve compression necessitating further decompression thereafter. In all cases, patients were treated with DLWD. Institutional Review Board approval was granted by the University of Kansas.

Results: None of the four patients treated with this approach developed recurrent primary-gaze diplopia or required strabismus surgery following DLWD.

Conclusions: While we still prefer to perform medial wall and floor decompression as the initial treatment for ophthalmic Graves’ disease, for proptosis following consecutive strabismus surgery, DLWD appears to be effective with a low rate of recurrent primary-gaze diplopia.     

Efficacy and side effects of 'swinging eyelid' orbital decompression in Graves' orbitopathy: a proposal for standardized evaluation of diplopia

OBJECTIVES: To evaluate the efficacy and side effects of 'swinging eyelid' orbital decompression in patients with Graves' orbitopathy (GO). To calculate the incidence of postoperative new-onset diplopia (NOD) using a newly proposed scoring system for diplopia. METHODS: We reviewed the clinical data on proptosis, visual acuity, and diplopia in 104 consecutive patients (198 orbits) with GO, who underwent orbital decompression. A combined lateral canthal and inferior fornix incision ('swinging eyelid' approach) was used for removal of the medial wall, the orbital floor and, if indicated, the lateral wall. Indications for surgery were disfiguring/congestive GO (DGO) in 79 patients (149 orbits) and compressive optic neuropathy (CON) in 25 patients (49 orbits). Diplopia was scored according to four grades. In both groups, the incidence of new-onset (continuous) diplopia (NOD), deterioration of diplopia (DOD), and improvement of diplopia (IOD) were calculated, using strictly defined criteria. Our data on NOD were compared to those from other series, after recalculation according to our criteria. RESULTS: The mean proptosis reduction was 4.6 mm (range 0-9.5 mm) after three-wall decompression (95 patients, 180 orbits) vs 3.1 mm (range 0-7 mm) after two-wall decompression (nine patients, 18 orbits). The visual acuity improved in 98% of the patients with CON. In patients with DGO, NOD occurred in 14%. In patients with CON, NOD was not observed, but DOD occurred in 41%. Our data compare favourably to the reported incidence of NOD after either transantral or transnasal decompression. CONCLUSIONS: "Swinging eyelid' orbital decompression is efficacious for proptosis reduction as well as for optic nerve decompression. A scoring system for standardized evaluation of diplopia is proposed.     

Acute periscleritis – a variant of idiopathic orbital inflammation

We examined seven patients who had eyelid swelling, proptosis, conjunctival injection, mild orbital pain and visual loss. Although several patients had mild limitation of eye movement, none experienced diplopia. Simultaneous bilateral involvement occurred in two patients. All patients were treated with oral corticosteroids and promptly improved, although recurrences in several required repeat courses of therapy. We identified inflammatory thickening of the posterior ocular wall and Tenon's capsule in some patients by means of B-scan ultrasonography and computerized tomography. We call this variety of anterior orbital inflammation without significant extraocular muscle involvement acute periscleritis, which is distinguished from other forms of idiopathic orbital inflammation and scleritis.     

Cavernous hemangioma with rapidly developing proptosis

Purpose: To report an unusual case of cavernous hemangioma with rapidly developing proptosis. Methods: Case report. The clinical features, imaging findings and orbital surgery were presented. Results: A 54-year-old man presented with rapidly developing proptosis and a mass in the lower eyelid of his left eye for 8 h. The left eye had 5 mm of proptosis. Color Doppler ultrasonography and computed tomography disclosed a well-defined soft tissue mass in the left anterior orbit, which extended along the floor of the orbit and sized 1.7 × 2.2 cm without bone destruction. An anterior orbitotomy was performed. At surgery a red-purple, well-defined and cone-shaped mass and a hematoma, which was found on the lateral part of the mass, were removed. The histopathological evaluation of the mass revealed cavernous hemangioma. Conclusions: Patient with a rapidly developing proptosis might have the possibility of orbital cavernous hemangioma. The paper was sponsored by the Natural Science Foundation of Guangdong Province, China (036651).     

Strabismus following endoscopic orbital decompression for thyroid eye disease

Endoscopic orbital decompression may be used to treat disfiguring proptosis or sight threatening optic nerve compression in patients with thyroid eye disease. Strabismus is common in thyroid eye disease and frequently follows decompression surgery. We retrospectively reviewed patients undergoing endoscopic decompression for thyroid eye disease, by a single surgeon, from 1994 to 2000. Twenty-three patients (21 female, 2 male) were identified with a mean age of 47.5 years. At presentation, 21 patients had proptosis, 8 optic nerve compression (2 without proptosis) and 11 strabismus (9 complained of diplopia) with a mean BSV score of 24.5 before decompression. Forty orbits were decompressed with a mean decrease in proptosis of 3.3mm. Following decompression, the mean BSV score was 25, and 17 patients had manifest strabismus in primary gaze (3 at near only) of whom 10 had pre-existing strabismus. Five patients had new diplopia (22%). Eleven patients ultimately required strabismus surgery of whom 8 had manifest strabismus before decompression. Following strabismus surgery, the mean BSV score was 37. The final BSV score for those not requiring strabismus surgery was 29. Mean follow-up was 28 months. Endoscopic orbital decompression can effectively treat disfiguring proptosis. Diplopia is a common complication, but pre-existing diplopia may improve.     

Pneumatocele of the orbit

PURPOSE: To describe an uncommon sinus condition that can cause proptosis. METHODS: Intermittent unilateral proptosis and diplopia developed in a 29-year-old man. Computed tomography showed an enlarged frontal sinus with erosion of the floor of the sinus and air in the orbit. RESULTS: Endoscopic ethmoidectomy and frontal sinusotomy corrected an outlet check valve of the nasal frontal duct and eliminated the proptosis. CONCLUSION: Pneumatocele of the orbit is an uncommon cause of proptosis and diplopia and can be corrected with endoscopic sinus surgery.     

Strabismus following endoscopic orbital decompression for thyroid eye disease

Endoscopic orbital decompression may be used to treat disfiguring proptosis or sight threatening optic nerve compression in patients with thyroid eye disease. Strabismus is common in thyroid eye disease and frequently follows decompression surgery. We retrospectively reviewed patients undergoing endoscopic decompression for thyroid eye disease, by a single surgeon, from 1994 to 2000. Twenty-three patients (21 female, 2 male) were identified with a mean age of 47.5 years. At presentation, 21 patients had proptosis, 8 optic nerve compression (2 without proptosis) and 11 strabismus (9 complained of diplopia) with a mean BSV score of 24.5 before decompression. Forty orbits were decompressed with a mean decrease in proptosis of 3.3 mm. Following decompression, the mean BSV score was 25, and 17 patients had manifest strabismus in primary gaze (3 at near only) of whom 10 had pre-existing strabismus. Five patients had new diplopia (22%). Eleven patients ultimately required strabismus surgery of whom 8 had manifest strabismus before decompression. Following strabismus surgery, the mean BSV score was 37. The final BSV score for those not requiring strabismus surgery was 29. Mean follow-up was 28 months. Endoscopic orbital decompression can effectively treat disfiguring proptosis. Diplopia is a common complication, but pre-existing diplopia may improve.     

Graded orbital decompression based on severity of proptosis

OBJECTIVE: To study the results of orbital decompression based on the severity of preoperative proptosis. DESIGN: A retrospective noncomparative interventional case series. PARTICIPANTS: Thirty-nine orbits in 23 patients with thyroid-related orbitopathy at a university-based referral center. INTERVENTION: Graded orbital decompression was performed in all patients based on the severity of preoperative exophthalmometry. MAIN OUTCOME MEASURES: Exophthalmometry, visual acuity, margin-to-reflex distance, prism cover testing, and intraocular pressure. RESULTS: Mean proptosis reduction in all orbits was 6.4 +/- 2.7 mm (P < 0.01). In group 1 (preoperative exophthalmometry <22 mm), proptosis decreased with a mean of 4.8 +/- 1.3 mm (P < 0.01); mean proptosis reduction was 6.0 +/- 2.3 mm (P < 0.01) and 8.9 +/- 3.4 mm (P < 0.01) in group 2 (exophthalmometry between 22-25 mm) and group 3 (exophthalmometry >25 mm), respectively. In four of five eyes with compressive optic neuropathy there was an improvement of best-corrected visual acuity of 2 lines or more. Margin-to-reflex distance of the upper and lower lids and intraocular pressure were reduced in all groups. New-onset diplopia developed in two patients (8.7%); 13 of 15 patients (86.7%) who had diplopia preoperatively had persistent diplopia postoperatively. Two patients (13.3%) had relief of diplopia postoperatively. CONCLUSIONS: Graded orbital decompression based on the severity of preoperative exophthalmometry is useful to determine the type and amount of orbital surgery to be performed.