Clinical measurement and categorization of optic disc in glaucoma patients.

BACKGROUND: Assessment of optic disc size is an important component of optic nerve head examination. Agreement between different methods of disc size measurements is not very good. PURPOSE: To assess the agreement between the disc size assessed by Heidelberg retina tomograph (HRT) and stereobiomicroscopy with a 90 diopter (D) lens. To report the clinical (measured by biomicroscopy) disc diameters of small, average and large optic discs categorized by HRT disc areas. SETTING AND DESIGN: Observational study of subjects examined in the glaucoma clinic of a tertiary eye institute. MATERIALS AND METHODS: Seventy-five eyes of 75 glaucoma subjects were studied. Disc diameter was measured using stereobiomicroscopy and HRT. The agreement between the two sets of measurements was assessed by intraclass correlation coefficient (ICC). Discs were classified into small (<1.6 mm(2)), average (1.6-2.6 mm(2)) and large (>2.6 mm(2)) depending on cutoffs provided by the manufacturers of HRT. The means (95% CI) of the corresponding vertical disc diameter in these groups were assessed. STATISTICAL ANALYSIS: ICC, Bland and Altman plots. RESULTS: ICC for measurements of clinical and HRT horizontal disc diameter was 0.518 and for vertical disc diameter measurement was 0.487. The mean difference between the clinical and HRT measurements as analyzed by the Bland and Altman plot was 0.17 (95% CI, 0.13- 0.47) for horizontal and 0.22 (95% CI, 0.11- 0.54) for vertical disc diameter. Of the 75 eyes, 3 eyes had small discs, 54 average and 18 large discs. The mean clinical vertical disc diameter for small discs was 1.55 mm (95% CI, 1.2-1.7), for average discs was 1.91 mm (95% CI, 1.87-1.96) and for large discs was 2.15 mm (95% CI, 2.03-2.27). CONCLUSION: The agreement between clinical and HRT disc diameter measurements is moderate. Disc diameter measurement on stereobiomicroscopy can be used to categorize discs into small, average and large discs.

Planimetric optic disc parameters in normal eyes: a population-based study in South India.

PURPOSE: To study the optic disc parameters of normal eyes in a population-based south Indian study. METHODS: One hundred and fifty three subjects from a population-based sample of 1060 included in the Andhra Pradesh Eye Disease Survey (APEDS) were enrolled in the optic disc study. The male-female ratio, the refractive error and distribution of other ocular parameters in the disc study subjects and the APEDS were not significantly different. Magnification corrected morphometry of optic disc photographs obtained by Zeiss telocentric fundus camera was carried out in one randomly chosen eye of each of these 143 subjects. RESULTS: The mean optic disc parameters with the 95% confidence intervals for the distribution were: disc area 3.37 mm2 (2.04 - 4.7), vertical disc diameter 2.12 mm (1.67 - 2.57), vertical cup to disc ratio 0.37 (0.19 -0.55) and neuroretinal rim area 2.8 mm2 (1.76 - 3.84). The disc area, the vertical cup to disc ratio and the rim area showed a normal distribution. The cup to disc ratio correlated with the vertical disc diameter but the association was not strong. CONCLUSION: The disc area, the vertical cup to disc ratio and the neuroretinal rim area are normally distributed in the South Indian population. The normal optic disc parameters would form a basis for future comparisons in different forms of glaucoma.

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.

Optic disc size in ocular hypertension.

PURPOSE: To study the optic disc size in eyes with ocular hypertension (OHT) in comparison to primary open-angle glaucoma (POAG) and normals. METHODS: Optic disc photographs obtained with the Nidek 3dx NM camera were digitized (Nikon coolscan) and disc area calculated using Littmann correction in a randomly chosen eye of 28 OHT, 42 POAG and 30 normal subjects. OHT was defined as increased intraocular pressure with no disc or field changes suggestive of glaucoma with open angles. RESULTS: The optic disc area in OHT was 9.47 +/- 1.09 mm2; 12.27 +/- 2.87 mm2 in POAG; and 12.11 +/- 2.83 mm2 in normal individuals. CONCLUSION: Using magnification corrected morphometry and the criteria for OHT diagnosis, the optic disc area in OHT was significantly smaller (p < 0.0001) in POAG and normals.

Orbital cysticercosis.

BACKGROUND: Human cysticercosis is secondary to an infestation by cysticercus cellulosae, the larval form of Taenia solium. Cysticercosis is endemic to regions with poor sanitation. The purpose of this report is to present a large series of patients with orbital cysticercosis and to discuss the current treatment. METHODS: A retrospective chart analysis of all patients with orbital cysticercosis from an urban practice in southern India was performed. The clinical features, the results of investigations, the therapies instituted, and the outcomes realized were recorded. RESULTS: Twenty patients diagnosed with orbital cysticercosis were identified (11 female and 9 male). Their ages ranged from 5 to 25 years with a mean age of 12.5 years. Nine patients manifested subconjunctival cysts. Eight were excised and 5 of these were densely adherent to the adjacent extraocular muscle (EOM). The remaining 11 patients had a cyst in a single EOM. The EOM cysts had proptosis, restricted motility, recurrent inflammation, and blepharoptosis. Two of the EOM cysts were excised surgically and four extruded spontaneously. Six patients with EOM cysts were treated medically: they all received oral corticosteroids and, additionally, five were given oral albendazole and one was given oral praziquantel. CONCLUSIONS: Excisional biopsy is recommended for subconjunctival cysticercosis. Idiopathic cystic myositis can present like EOM cysticercosis, but is differentiated by resolution with corticosteroid treatment. Medical therapy in orbital cysticercosis with oral albendazole and corticosteroids can arrest recurrent inflammation and improve ocular motility.

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.

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.

Ocular toxicity of tamoxifen.

Tamoxifen is an antioestrogen drug used widely in the management of oestrogen-dependent metastatic breast carcinoma. A number of ocular complications have been described secondary to tamoxifen therapy. We report two patients, one of whom had superior ophthalmic vein thrombosis and the other who had painful proptosis and acute angle-closure glaucoma with choroidal detachment secondary to tamoxifen therapy, both of which have not been reported earlier. In both patients the signs and symptoms resolved rapidly after the discontinuation of tamoxifen therapy. Awareness of the ocular toxicity of tamoxifen is essential as prompt withdrawal can result in resolution of most of the complications.

Ocular manifestations of Hansen's disease.

A detailed ophthalmic evaluation including slitlamp biomicroscopy, measurement of corneal sensitivity using Cochet and Bonnet aesthesiometer, Schirmer's test and Goldmann applanation tonometry was carried out in 89 patients of Hansen's disease attending the leprosy clinic with or without ocular symptoms and willing to undergo eye evaluation. Thirty-one patients had lepromatous leprosy (8 with erythema nodosum leprosum), 56 patients had borderline disease (13 with reversal reactions) and 2 had tuberculoid disease. In addition to the well documented changes of lagophthalmos (6.7%), uveitis (7.3%) and cataracts (19%), we noted prominent corneal nerves in 133 eyes (74.7%), beaded corneal nerves in 19 eyes (10.7%), corneal scarring in 10 eyes (5.6%), corneal hypoaesthesia in 51 eyes (28%) and dry eye in 18 eyes (13%). Beaded corneal nerves and/or stomal infiltrates occurred mainly in the lepromatous group (75%). Ocular hypotony (IOP less than 12 mm Hg) was not seen more frequently in Hansen's as compared to age and sex matched controls with refractive errors or cataracts (33.7%, vs. 37.8%, p = 0.33). Our study highlights the primary corneal involvement with corneal neuropathy as the predominant feature of Hansen's disease.

Outside-in transscleral fixation for ciliary sulcus intraocular lens placement.

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.

Post-penetrating keratoplasty glaucoma.

To study the risk factors in the development of glaucoma following penetrating keratoplasty, we retrospectively analysed 190 eyes of 185 consecutive patients who had undergone surgery during 1990. The donor button was larger by 0.2 mm and 0.5 mm in phakia and aphakia/pseudophakia patients, respectively. Over a mean follow-up period of 14.5 months, 52 of the 190 eyes (27.4%) either developed glaucoma de novo or had worsening of preexisting glaucoma. Of these 52 eyes, 38 were managed medically and 14 required surgery. From our study, aphakia (37%), pseudophakia (24%), preexisting glaucoma (81.8%), and regrafting (43.18%) were found to be the significant risk factors in the development of glaucoma following penetrating keratoplasty.

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.

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.