Venkatesh C. Prabhakaran

Orbital Compartment Syndrome: The Ophthalmic Surgical Emergency

Orbital compartment syndrome is an uncommon, ophthalmic surgical emergency characterized by an acute rise in orbital pressure. When intraorbital tension rises, damage to ocular and other intraorbital structures, including irreversible blindness, may occur if not promptly treated. The diagnosis of orbital compartment syndrome is completely clinical and early recognition and emergent orbital decompression (even prior to imaging) is essential in preventing permanent vision loss. Lateral canthotomy and inferior cantholysis remain the mainstays of management. More extensive incision of the orbital septum and orbital bony decompression may be necessary in unresponsive cases. This review discusses the various etiologies and mechanisms resulting in orbital compartment syndrome, clinical features, imaging findings, treatment, and prognosis.

Orbital Tuberculosis: A Review of the Literature

Purpose: To provide an up-to-date review of the clinical presentations, investigations, and management of orbital tuberculosis (OTB). Methods: Systematic review of the literature concerning OTB, limiting the results to English-language peer-reviewed journals. Results: Seventy-nine patients from 39 publications were identified as cases of OTB. The condition presents in one of five forms: classical periostitis; orbital soft tissue tuberculoma or cold abscess, with no bony involvement; OTB with bony involvement; spread from the paranasal sinuses; and tuberculous dacryoadenitis. The ocular adnexa, including the nasolacrimal system and overlying skin, may also be involved. Conclusions: Diagnosis can be difficult and may necessitate an orbital biopsy, in which acid-fast bacilli (AFB) and characteristic histopathology may be seen. Growth of Mycobacterium tuberculosis (mTB) from such a specimen remains the gold standard for diagnosis. Ancillary investigations include tuberculin skin tests and chest radiography, but more recently alternatives such as whole blood interferon-γ immunological tests and PCR-based tests of pathological specimens have proven useful. The management of OTB is complex, requiring a stringent public health strategy and high levels of patient adherence, combined with long courses of multiple anti-tuberculous medications. The interaction of the human immunodeficiency virus (HIV) with TB may further complicate management.

Histological parameters helpful in recognising steroid-treated temporal arteritis: an analysis of 35 cases.

Aim: To establish the histological and immunohistochemical parameters that are helpful in recognising temporal arteritis in patients who have been treated with steroids before biopsy, and to analyse the clinical features and correlate them with the histological findings. Methods: A retrospective review of charts of 35 patients treated with steroids before obtaining temporal artery biopsy specimens, spanning a 11-year period from 1995 to 2005. The study was conducted at the Ophthalmic Pathology Laboratory, Cullen Eye Institute, Houston, Texas, USA. The clinical features were evaluated and correlated with the histopathological findings. Each case was evaluated with respect to age, sex, race, clinical findings, erythrocyte sedimentation rate, corticosteroid dosage (oral versus intravenous) and the duration of treatment. The time interval between obtaining the biopsy specimen and the onset of steroid treatment was carefully recorded for each patient. In selected cases, histiocytic markers (CD-68 and HAM-56) were used to identify the presence of epithelioid histiocytes, which characterises a granulomatous inflammation. Other immunohistochemical studies (CD3, CD20, CD4, CD8, CD45RO, CD45RA and S-100 protein) were performed in selected cases to characterise the inflammatory cells. Results: The three most reliable histopathological parameters of corticosteroid-treated temporal arteritis are the following: (1) complete or incomplete mantle of lymphocytes and epithelioid histiocytes located between the outer muscular layer and the adventitia; (2) large circumferential defects in the elastic lamina (best seen with the Movat’s pentachrome); and (3) absent or few small multinucleated giant cells. In some cases the main artery appears normal, whereas the primary branches show evidence of a healing arteritis. The histological findings vary according to the duration of treatment before obtaining the biopsy specimen. Conclusion: Striking histological differences can be recognised objectively between patients with active (untreated) giant cell arteritis and patients who have been treated with corticosteroids. The earliest histopathological changes were detected by the end of the first week after steroid treatment (usually after day 4 to the end of the first week). The histological findings were more difficult to recognise at 2–3 months after steroid treatment. Ophthalmic and general pathologists should be able to recognise this entity on the basis of the histological findings including the special stains and results of immunohistochemical studies (CD-68 and HAM-56).

Non-traumatic enophthalmos: a review

Enophthalmos can be defined as a relative, posterior displacement of a normal‐sized globe in relation to the bony orbital margin. Non‐traumatic enophthalmos has a wide variety of clinical presentations and may be the first manifestation of a number of local or systemic conditions. It may present with cosmetic problems such as deep superior sulcus, pseudoptosis or eyelid retraction; or functional problems such as diplopia or exposure keratopathy. There are three main pathogenic mechanisms: structural alterations in the bony orbit; orbital fat atrophy; and retraction. Evaluation of enophthalmos patients includes orbital imaging and a thorough ophthalmic and systemic examination. In this review, we discuss the presenting features of non‐traumatic enophthalmos and include a brief description of the more important causes. An approach to the clinical evaluation of these patients is also discussed together with a brief overview of the principles of management.

Delayed complications of silicone implants used in orbital fracture repairs.

Purpose: To report a series of patients who developed late complications secondary to silicone implants used in orbital fracture repairs and review the literature. Design: Retrospective interventional case series. Methods: Analysis of records of patients who developed complications following repair of orbital wall fractures with silicone implants. Results: Over a 5-year period, 4 patients were seen with complications arising from a silicone orbital implant. There were 3 males and 1 female whose ages ranged from 41–73 years. The time interval between initial insertion of implant and development of complications was 1.5, 6, 10, and 20 years. The complications noted were worsening diplopia, recurrent orbital cellulitis, lower lid retraction with restricted upgaze, and orbital abscess. Computed tomographic scans demonstrated the implant in all cases. Histologic examination revealed nonspecific chronic inflammation and fibrosis in all cases and foci of squamous epithelium in one case. Treatment included surgical removal of the implant, resulting in complete resolution or significant improvement in symptoms and signs in all cases. Conclusion: The use of silicone implants is associated with a wide range of complications, which may occur many years following the original surgery. Surgical removal of the implant usually leads to resolution of symptoms. Given the potential of silicone implants to cause delayed complications, their use in orbital fracture repair is not recommended.

Transcanalicular approach to adult lacrimal duct obstruction: a review of instruments and methods.

Developments in fiberoptic technology and increasing interest in minimally invasive surgery have fueled advances in transcanalicular surgery. This article presents a review of instruments and methods for diagnostic and therapeutic approaches to adult lacrimal drainage obstruction. Available endocanalicular probes, microendoscopes, lasers, microdrills, trephines, and antegrade lacrimal balloon catheters are discussed and compared. Developments in microendoscopy, laser transcanalicular dacryocystorhinostomy, laser canaliculoplasty, transcanalicular drilling and trephination, and transcanalicular balloon dacryoplasty are also discussed in detail. Transcanalicular surgery provides a minimally invasive approach to adult lacrimal drainage obstruction that may also address the pathology causing the obstruction. Long-term success rates of transcanalicular dacryocystorhinostomy appear to be improving, but cost and a paucity of data on long-term results continue to limit the use of transcanalicular surgery.

Orbital arteriovenous malformations

OBJECTIVE To present the clinical features, management, and outcomes in a series of patients with orbital arteriovenous malformations (AVMs). METHODS Clinical records of patients with orbital AVMs confirmed using angiography were reviewed as a retrospective, noncomparative, interventional case series. RESULTS Eight patients (3 women and 5 men) with unilateral AVMs and a mean age of 39 years (median, 36.5 years; range, 26-70 years) were reviewed. Findings existed for an average of 11.2 years before diagnosis and included periocular mass (7 patients, 88%); periocular edema, pulsation/bruit, proptosis, episcleral congestion, and previous trauma (4 patients each, 50%); elevated intraocular pressure (3 patients, 38%); pain and reduced visual acuity (2 patients each, 25%); and restriction of extraocular movements, and diplopia (1 patient each, 12%). All of the patients except 1 underwent surgical resection, with 3 (38%) receiving preoperative embolization of feeder vessels; all of the patients had initial resolution of manifestations after treatment. CONCLUSIONS Angiography is essential for diagnosis and for planning the management of orbital AVMs. Treatment depends on patient-specific features and includes observation, embolization, and surgical excision or combined preoperative embolization/excision. Given their vascular nature, the main cause of poor management outcomes is perioperative hemorrhage. Outcomes after a multidisciplinary approach are good, with few recurrences reported at follow-up.

Peripheral branching of levator superioris muscle and Müller muscle origin.

PURPOSE To examine the structure of the distal levator superioris muscle and the origin of the Müller muscle. DESIGN Experimental dissectional study. METHODS Specimens from 10 postmortem upper eyelids and orbits of 7 white cadavers (6 right eyes and 4 left eyes; age range, 78 to 101 years of age at death; age average, 87.7 years) were used for microscopic observations. The upper eyelids and orbits with sagittal full-thickness sections of the central part were examined microscopically using Masson trichrome staining. RESULTS Sections from 9 of the specimens were suitable for analysis. The levator superioris muscle divided into a superior and an inferior branch by connective tissue in the peripheral region in all 9 samples. Although the thickness of each branch varied, that of the superior branch tended to be thicker than that of the inferior branch. In 8 specimens of 7 cadavers, the Müller muscle originated from the distal end of the inferior branch of the levator superioris muscle. In one specimen, the Müller muscle originated from the distal end as well as the posterior aspect of the levator superioris muscle. The levator aponeurosis originated from the superior branch. CONCLUSIONS The distal levator superioris muscle consisted of a branched structure, and the Müller muscle originated from the inferior branch of the levator superioris muscle.

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.

Lesions mimicking lacrimal gland pleomorphic adenoma.

Aim To report a series of patients with lacrimal gland lesions simulating the clinicoradiological features of lacrimal gland pleomorphic adenoma (LGPA). Methods Multicentre retrospective, interventional case series. Clinical records of all patients with lesions mimicking LGPA seen in five orbital units were reviewed. Results The study included 14 patients (seven men and seven women) with a mean age of 50.9 years. The diagnosis of LGPA was made in all cases by experienced orbital surgeons, based on clinicoradiological features, and lacrimal gland excision was performed. Postoperative histology revealed lymphoma (four patients), chronic dacryoadenitis (three patients), adenoid cystic carcinoma (two patients), Sjogrens syndrome (two patients), cavernous haemangioma (one patient), benign lymphoid hyperplasia (one patient) and granulomatous dacryoadenitis (one patient). Comparison with the total number of histologically confirmed LGPA cases seen during the study period revealed that 22.6% of cases of suspected LGPA were misdiagnosed based on clinicoradiological criteria. Conclusions Many different lesions may mimic the clinicoradiological features of LGPA. The accepted clinicoradiological criteria used for the diagnosis of LGPA have a high false-positive rate, even in experienced hands. Based on this study, the authors believe that fine-needle aspiration biopsy or intraoperative biopsy and frozen section diagnosis may help reduce unnecessary lacrimal gland excision.