G Chandra Sekhar

Variation in optic nerve and macular structure with age and race with spectral-domain optical coherence tomography.

PURPOSE To evaluate the effects of age and race on optic disc, retinal nerve fiber layer (RNFL), and macular measurements with spectral-domain optical coherence tomography (SD OCT). DESIGN Cross-sectional observational study. PARTICIPANTS Three hundred fifty adult subjects without ocular disease. METHODS Data from SD OCT imaging of the optic nerve head, peripapillary RNFL, and macula of 632 eyes from 350 subjects without ocular disease were imaged with SD OCT. Multivariate models were used to determine the effect of age and race on quantitative measurements of optic disc, RNFL, and macula. MAIN OUTCOME MEASURES Optic nerve, RNFL, and macular measurements with SD OCT across racial strata and age. RESULTS For optic nerve parameters, participants of European descent had significantly smaller optic disc area than other groups (P<0.0001), and Indian participants had significantly smaller rim area than other groups (P<0.0001). Indian and Hispanic participants had thicker global RNFL measurements than other groups (P<0.0001). Participants of African descent were associated with thinner inner retinal thickness in the macula (P<0.0001). Age was associated with several parameters, with rim area reducing by 0.005 mm(2)/year, RNFL thickness reducing by 0.18 μm/year, and inner retinal thickness reducing by 0.1 μm/year (P<0.0001 for all age associations). CONCLUSIONS Optic nerve, RNFL, and macular measurements with SD OCT all varied across racial groups and with age. These differences are important in defining the range of normal variation in differing populations and should be considered in the use of these instruments in the detection of optic nerve and macular disease across these population groups. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Problems Associated With Conjunctivodacryocystorhinostomy

Fifty-eight patients (69 eyes) underwent conjunctivodacryocystorhinostomy for lacrimal canalicular obstruction. The cause of lacrimal obstruction and the results and complications of the operation were analyzed. Trauma and idiopathic disease were the most common causes of lacrimal canalicular obstruction in 24 of 69 (34.8%) eyes each. Relief of epiphora was achieved in 68 of the 69 eyes (98.5%). The complications included tube displacement in 40 of the 69 eyes (57.9%), tube obstruction in 19 of the 69 eyes (27.5%), and infection of the lacrimal sac in four of the 69 eyes (5.8%). Despite frequent complications, most Jones tubes can be made to function satisfactorily. Conjunctivodacryocystorhinostomy remains the best surgical treatment at this time for permanent loss of canalicular function.

Sensitivity of Swedish interactive threshold algorithm compared with standard full threshold algorithm in Humphrey visual field testing.

OBJECTIVE To compare the sensitivity of Swedish interactive threshold algorithm (SITA) strategies with the standard full threshold algorithm in the Humphrey Field Analyzer. DESIGN Observational case series. PARTICIPANTS Forty-eight glaucoma patients who were experienced in automated perimetry. TESTING Central field testing was performed with the 30-2 program using standard full threshold (SFT), SITA standard (SS), and SITA fast (SF) strategies. All three tests were carried out on each of four different days in a span of 4 weeks. MAIN OUTCOME MEASURES Sensitivity, repeatability, time saved, and the extent of defect in the SITA strategies were compared with those of the SFT. RESULTS The sensitivity of SS and SF were 95.12% and 92.68%, respectively. The time saved in SS and SF was 53.12+/-9.51% and 70.69+/-8.81%, respectively. The repeatability as assessed by intraclass correlation showed excellent repeatability for the SFT and SS strategies and excellent to poor repeatability with the SF strategy. With increasing mean deviation, the defects (significant at P<0.5%) in the pattern deviation plots tended to be more in the SITA strategies as compared with SFT. CONCLUSIONS Swedish interactive threshold algorithm strategies have good sensitivity and are significantly faster as compared with the standard threshold algorithm. The repeatability of the SFT and SS strategies are excellent, whereas that of the SF strategy is variable.

Myocysticercosis: experience with imaging and therapy.

OBJECTIVE To compare computed tomography (CT) and B-scan ultrasonography (USG) in the diagnosis and to study the efficacy of a combination of oral albendazole and prednisolone in the management of myocysticercosis. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Twenty-six consecutive patients with myocysticercosis. INTERVENTION Diagnostic imaging was performed by CT scan and USG in 24 and 22 patients, respectively; serial USG was obtained in 7 patients receiving treatment. All patients received oral albendazole (15 mg/kg body weight per day) and prednisolone (1.5 mg/kg body weight per day) for 4 weeks. MAIN OUTCOME MEASURES Presence of scolex on CT scan compared to USG and clinical response to medical therapy were the main outcome measures. Recovery was defined as complete resolution of the scolex or of the main presenting clinical feature. RESULTS Presence of scolex on CT scan (11 of 24) and USG (11 of 22) was not different (P = 1.0; chi-square test). Recovery was seen in 24 (92%) of 26 patients receiving medical treatment. On serial USG of patients receiving treatment (n = 7), cysts with scolex were seen to progress to a cyst without scolex before final resolution. Time to recovery on treatment (0.5-35 months) correlated with the duration of symptoms at presentation (correlation coefficient r = 0.56, P = 0.003, linear regression analysis), but not with positive serum enzyme-linked immunosorbent assay for anticysticercal antibodies (P = 0.57, log-rank test) or the presence of scolex (P = 0.52, log-rank test). CONCLUSIONS Treatment with a combination of oral albendazole and prednisolone is effective in the management of myocysticercosis. Imaging methods CT and USG are equally effective in identifying the cyst and the scolex; serial USG is useful in studying the temporal sequence of therapeutic response. The longer recovery time correlating with the duration of symptoms may indicate the chronicity of the inflammatory changes requiring longer time for recovery.

Orbital Cysticercosis: Clinical Manifestations, Diagnosis, Management, and Outcome

PURPOSE To describe the clinical manifestations, diagnosis, management, and outcome of orbital cysticercosis in a tertiary eye care center in Southern India. DESIGN Retrospective observational case series. PARTICIPANTS A total of 171 patients with orbital cysticercosis. METHODS Retrospective case series involving consecutive patients with orbital cysticercosis from March 1990 to December 2001. MAIN OUTCOME MEASURES Clinical resolution and significant residual deficit. RESULTS The median age at presentation was 13 years (range 2-65 years), and 93 patients (54.4%) were male. The 3 main symptoms at presentation were periocular swelling (38%), proptosis (24%), and ptosis (14%) with a median duration of 2 (range 0-24) months. The 3 main signs at presentation included ocular motility restriction (64.3%), proptosis (44.4%), and diplopia (36.8%). The cyst locations in the decreasing order of frequency were anterior orbit (69%), subconjunctival space (24.6%), posterior orbit (5.8%), and the eyelid (0.6%). In all, 80.7% of patients had cysts in relation to an extraocular muscle. The superior rectus (33.3%) was the most commonly involved extraocular muscle. Contact B-scan ultrasonography was diagnostic of cysticercosis in 84.4% of patients. Orbital cysticercosis was managed medically in 158 of 166 patients. Although 149 patients received a combination of oral albendazole and prednisolone, 1 patient received oral albendazole alone, 7 patients received oral prednisolone alone, and 1 patient received oral praziquantel. Surgery was performed in 8 patients. Clinical resolution was seen in 128 of 138 patients (92.8%) at 1 month and 81 of 85 patients (95.3%) at 3 months. A significant residual deficit was present in 29 of 138 patients (21.0%) at the final follow-up and included proptosis in 7 patients, ptosis in 6 patients, ocular motility restriction in 3 patients, diplopia in 2 patients, strabismus in 2 patients, and a combination of the above in 9 patients. CONCLUSIONS Orbital cysticercosis is a common clinical condition in the developing world. It typically affects young individuals and has a wide spectrum of clinical manifestations. Both B-scan ultrasonography and computed tomography scan are useful in confirming the diagnosis. Despite resolution of cysticercosis with medical management, a significant proportion of patients may have residual functional deficits.

Etiology of ptosis after cataract surgery

Purpose: To determine whether using a lid speculum with a superior rectus bridle suture in cataract surgery results in levator rectus aponeurosis dehiscence caused by strong fascial attachments between the levator and superior rectus muscles. Setting: L.V Prasad Eye Institute, Hyderabad, India. Methods: This study comprised 220 patients having cataract extraction with posterior chamber intraocular lens implantation. The patients were randomly assigned to one of two groups. In the first group (n = 108), a lid speculum was used during surgery. In the second group (n = 112), no speculum was used. All patients had a superior rectus bridle suture. The occurrence of ptosis was analyzed by a masked observer who was not involved in the surgery. Results: The incidence of ptosis was significantly higher in the speculum (44.4%) than in the no‐speculum (23.3%) group (P = .0009). Conclusion: The results indicate that the opposing forces created by the lid speculum and bridle suture can cause levator aponeurosis dehiscence because of the strong fascial attachments between the superior rectus and levator muscles. The occurrence of ptosis in the no‐speculum group implies a multifactorial etiology, however.

Outside-in transscleral fixation for ciliary sulcus intraocular lens placement

Abstract We describe a new technique of transscleral intraocular lens fixation in the absence of adequate posterior capsular support. This technique of suture placement within the ciliary sulcus employs routinely used instruments, requires minimum manipulation, and has good visual outcome and negligible complications. We performed five intraocular lens implantations using the technique with good visual outcomes in each. No significant intraoperative or postoperative complications were noted.

Non specific orbital inflammatory diseases

The understanding of ‘pseudotumors’ has significantly changed with the advent of modern imaging techniques by which the tissues affected in the orbit can be identified, and nonspecific orbital inflammatory disease is classified according to the tissue involved. Twenty cases of nonspecific orbital inflammatory diseases were treated between July 1987 and September 1991. Eight patients had myositis, 6 had diffuse disease, 2 each had dacryoadenitis, periscleritis and perineuritis. Involvement of all four recti in one patient and isolated superior rectus and superior oblique each in 2 others are the unusual forms of myositis. Perineuritis presented as diffuse thickening of the optic nerve on CT scan with disc edema and normal vision in both patients with external ophthalmoplegia in one of them. All patients responded to oral steroids while the patient with myositis of all four recti required radiotherapy in addition. This series documents the spectrum of clinical presentation, diagnosis and management of nonspecific orbital inflammatory disease.

Primary angle closure glaucoma: a developing world perspective

Primary angle closure glaucoma (PACG) is estimated to affect a significant proportion of the population worldwide. Of those affected, the majority reside in developing countries. In the developing world, more than 80% of the people afflicted with glaucoma are unaware that they have the disease, and visual impairment from PACG is more severe than from primary open‐angle glaucoma. Considering the paucity of resources and competing opportunity costs, it is imperative that the developing world extrapolates current literature and exiting data sensibly, and develops cost‐effective strategies for the detection and management of angle closure glaucoma. The number needed to treat (NNT) was used to extrapolate the trials for an individual patient. To extrapolate to the overall population (where applicable) the authors used the population attributable risk percentage (PAR%). For individual patient care, treatment of a primary angle closure suspect (PACS) has an NNT of 6 over 5 years to prevent one patient progressing to primary angle closure (PAC). The NNT for PAC to prevent PACG over 5 years is 5. The ‘effective’ PAR% for PACS is 56.4% and the ‘effective’ PAR% for PAC is 65%. This suggests both PACS and PAC are important health burdens but because of the absence of a good screening test and the opportunity costs involved, population‐based screening will probably be unfeasible in developing countries.

Cystic lesions of the extraocular muscles.

Cystic lesions of the extraocular muscles (EOMs) are uncommon. Six patients with a cystic lesion in an extraocular muscle, as observed by computerized tomography (CT) scanning, were retrospectively identified from the practice of one of the authors (G.C.S.), and their clinical course was reviewed. All the patients were treated initially with oral corticosteroids. Those who did not respond to this therapy underwent surgical exploration. Four patients demonstrated complete resolution of clinical signs and symptoms with oral steroid therapy. Posttreatment CT scans performed in two of these patients showed resolution of the cystic lesion with residual muscle thickening in one. The two patients not responding to steroids underwent surgical excision and histopathology confirmed the diagnosis of cysticercosis. Cysticercosis is a previously reported cause of a cystic lesion in an EOM. To the best of our knowledge, cystic lesions of the EOMs resolving with steroids have not been previously reported. Response to oral steroids in four of our patients is suggestive of myositis with a cystic change in the muscle. We recommend a trial of oral steroid therapy in patients with a cystic EOM lesion before surgical exploration is performed.