Clinical significance of detection of multiple acute brain infarcts on diffusion weighted magnetic resonance imaging.

BACKGROUND: Detection of multiple acute brain infarcts (MABI) by diffusion weighted magnetic resonance imaging (DWI) may provide information about stroke mechanism in (1) acute lacunar stroke, where evidence of MABI suggests a cause other than small artery disease (SAD), such as embolism or vasculitis (type 1 MABI); or (2) acute non-lacunar stroke, where MABI in the territory of at least two of the aortic branches supplying the brain indicates the presence of aortic or cardiac embolism rather than artery to artery embolism (type 2 MABI). OBJECTIVE: To evaluate the prevalence of MABI and their impact on aetiological classification and prevention of stroke in patients with acute ischaemic stroke examined with DWI. METHODS: 182 consecutive patients defined by DWI were evaluated. Stroke aetiology was classified according to the TOAST criteria, though "lacunar stroke" included patients with possible aetiologies other than SAD. RESULTS: Type 1 MABI were detected in 21/72 patients (29%) with lacunar stroke, and type 2 MABI in 8/110 (7%) with non-lacunar stroke. A possible stroke mechanism different from SAD was found in nine type 1 MABI cases (43%): cardiac embolism (4); other determined aetiology (3); aortic embolism (2). Cardiac (2) or aortic (1) sources of embolism were detected in eight type 2 MABI cases. MABI patients with cardiac or aortic sources of embolism were treated with warfarin, the remainder with aspirin. CONCLUSIONS: Detection of type 1 MABI in patients with lacunar stroke improved diagnostic confidence and the choice of antithrombotic treatment. Further study is needed on stroke prevention in MABI cases caused by SAD alone.

Limbal relaxing incisions in congenital astigmatism: 6 month follow-up.

PURPOSE: To evaluate the effectiveness of limbal relaxing incisions (LRIs) for correcting naturally occurring astigmatism. SETTING: Ankara Hospital, Ankara, Turkey. METHODS: This prospective analysis of the results of the first LRIs in 22 eyes of 13 patients with congenital astigmatism was done using a modified Gills nomogram and was based on preoperative refractive astigmatism determined by manifest and cycloplegic refractions. There were no adjustments based on sex or age. RESULTS: An absolute decrease of 0.91 diopter (D) (44%) in mean astigmatism was achieved after 6 months in 22 eyes. The mean uncorrected visual acuity (logMAR) increased from 0.42 to 0.26 from preoperatively to 6 months postoperatively. No patient lost best corrected visual acuity. Most regression occurred in eyes with more than 3.50 D of astigmatism and between the first and third postoperative months. CONCLUSION: Limbal relaxing incisions are a practical, simple, and forgiving approach for the correction of lower degrees of astigmatism.

Cataract surgery in patients with Fuchs' heterochromic iridocyclitis.

PURPOSE: To evaluate the results of cataract extraction and posterior chamber intraocular lens (IOL) implantation in patients with Fuchs' heterochromic iridocyclitis (FHI). METHODS: We studied the records of 35 patients with FHI who underwent cataract extraction. Extracapsular cataract extraction (ECCE) was performed by phacoemulsification through a scleral flap in 9 patients and by manual delivery of the nucleus through a corneal section in 26 patients. RESULTS: After a mean follow-up time of 24 (3-60) months, the visual acuity in 21 eyes (60%) was 20/20, and all eyes had 20/40 or better vision. Six eyes with implanted regular PMMA IOL developed a marked anterior uveitis, which was resolved within 3 weeks with topical steroids. Only 1+ or 2+ cellular reaction was observed postoperatively in patients with heparin-coated lens implantation and patients who underwent phacoemulsification. Biomicroscopic evidence of giant cell activity was observed in two patients with heparin-coated IOL and in 11 with regular PMMA IOLs after ECCE (two after phacoemulsification). Four eyes developed intraocular pressure elevation that reverts to normal within 24 weeks with medical therapy. CONCLUSIONS: These results indicate that the surgical outcomes of FHI patients after cataract surgery appear to be better when the phacoemulsification technique is used or when heparin-coated lenses are implanted.

Corneal topography classification in myopic eyes based on axial, instantaneous, refractive, and profile difference maps.

PURPOSE: To refine and develop systems for classifying the topography of myopic corneas using axial, instantaneous, refractive, and profile difference maps. SETTING: Baylor College of Medicine, Cullen Eye Institute Houston, Texas, USA. METHODS: Using the EyeSys Corneal Analysis System, computerized videokeratographs of 153 corneas of 78 myopic patients were retrospectively analyzed. Patterns were defined with respect to the mid-dioptric green color. Relationships among pattern types, refractive power, corneal power, corneal uniformity index (CU index), and predicted corneal visual acuity (PC acuity) were calculated. RESULTS: Six types of patterns for axial, instantaneous, and refractive maps and 3 types of patterns for the profile difference map were defined. For a given cornea, there was a weak correlation among the patterns in the axial, instantaneous, and profile difference maps. The circular with central irregularity pattern in auto-scale refractive maps and the irregular pattern in profile difference maps and axial maps were correlated with lower CU index and PC acuity values. Clinical classification of instantaneous maps did not contribute substantially to the information provided by axial maps. CONCLUSION: Patterns of computerized videokeratographs varied according to the type of topographic map. The classification systems used provide a baseline for analyzing the response of the cornea to various interventions.

Preoperative screening of contact lens wearers before refractive surgery.

PURPOSE: To evaluate corneal stability, measured by computerized videokeratography (CVK) after discontinuation of contact lens wear in preoperative refractive surgery candidates. SETTING: Baylor College of Medicine, Cullen Eye Institute, Houston, Texas, USA. METHODS: Topographic differences were analyzed in 136 noncontact lens wearers (NCLW) and 76 contact lens wearers (CLW) (18 rigid gas-permeable contact lenses [RGPCL], 58 soft contact lenses [SCL]) using EyeSys CVK after discontinuation of SCL wear for 2 weeks and RGPCL wear for 5 weeks. RESULTS: There were no differences in CVK patterns between the NCLW and the CLW groups. There were no statistically significant differences between the 2 groups in topographic symmetry, asphericity, corneal uniformity index, predicted corneal acuity, and irregular astigmatism. The dioptric range for the axial and the profile difference maps in the CLW group was slightly lower than in the NCLW group. CONCLUSIONS: For patients whose manifest refraction and CVK maps were within 0.5 diopters of earlier values, discontinuation of SCL wear for 2 weeks and RGPCL wear for 5 weeks was adequate for the cornea to return to its baseline topographic state.

Corneal topographic changes induced by excision of perilimbal lesions.

BACKGROUND AND OBJECTIVES: To evaluate corneal topographic changes induced by excision of two pterygia and a perilimbal dermoid. MATERIAL AND METHODS: Using the EyeSys Corneal Analysis System, we retrospectively analyzed the changes in astigmatism, mean central corneal power, and other topographic parameters of three corneas before and after surgical removal of two pterygia and a perilimbal dermoid. RESULTS: Marked corneal steepening occurred along the preoperative flat meridian after the excision of the pterygia and dermoid cyst. For each patient, surgery increased the mean central corneal curvature and decreased total astigmatism. CONCLUSION: Surgical excision can ameliorate abnormal corneal topographic changes produced by limbal lesions.

Evaluation of relationships among refractive and topographic parameters.

PURPOSE: To examine the relationships among several refractive and topographic parameters. SETTING: Cullen Eye Institute Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA. METHODS: Using computerized videokeratography (EyeSys Corneal Analysis System), 287 corneas of 150 patients were retrospectively analyzed. The Holladay Diagnostic Summary (HDS) refractive maps were used to evaluate relationships among variables of the HDS and refractive error. RESULTS: Myopic spherical equivalent refraction (P = .0003) and more negative asphericity (Q-values) (P = .0119) were correlated with steeper corneas. The Q-values were less negative in eyes with moderate myopia (2.0 to 6.0 diopters [D]) than in those with hyperopia (1.0 D or greater). The Q-values below -0.3 were correlated with less favorable values for predicted corneal acuity and corneal uniformity index values. Mean corneal curvature measurements obtained by computerized videokeratography and standard keratometry showed a strong degree of correlation (P = .0001). CONCLUSION: As the degree of myopia and negative asphericity increased, the corneal radius of curvature decreased. Corneal Q-values less than -0.3 were associated with reduced optical performance of the cornea.

Comparative corneal topography and refractive variables in monozygotic and dizygotic twins.

PURPOSE: To investigate the role of heredity in determining corneal shape, axial length, and overall refractive error. METHODS: Twenty monozygotic and 19 dizygotic twin pairs, age 12 to 73 years, were enrolled in the study. Zygosity was determined by physical similarity and by responses to questions adapted from surveys. Two twin pairs were excluded because of undetermined zygosity and one pair because of keratoconus (both siblings). Refractive error was determined by an automated refractor. Manifest refraction was also recorded, as well as cycloplegic refraction in subjects under age 18 years. Corneal topography data and manual keratometer readings were also obtained. Axial lengths were determined by A-scan ultrasound. Data were analyzed by Student t tests only in the right eye. Left-eye data were comparable for all variables. RESULTS: Mean intrapair difference in refractive error (spherical equivalent) was less for monozygotic than for dizygotic twins (RE: 0.41 vs 1.53; P = .001). Mean intrapair difference in axial length was less for monozygotic twins (RE: 0.39 vs 0.76 mm; P = .031). Corneal topography data (power and meridian) in all zones (3, 5, and 7 mm) also showed smaller mean differences among monozygotic pairs than dizygotic, but the difference was statistically significant only for the 5-mm zone. In addition, most Holladay Diagnostic Summary variables that were studied did not show any statistically significant differences. CONCLUSIONS: Axial length and overall refractive error have a significant genetic basis. Corneal topography data appear to have other overriding determining factors for several of the variables studied.

Peripheral radial incisions to treat inferior contact lens edge lift after penetrating keratoplasty for keratoconus.

A patient with marked corneal astigmatism and inferior contact edge lift after penetrating keratoplasty for keratoconus had corneal relaxing incisions (CRIs) on the donor button and radial incisions on the host cornea. Results were evaluated by computerized videokeratography and by refitting the contact lens. Two pairs of CRIs decreased astigmatism from 11.00 to 4.25 diopters but did not alleviate the contact lens edge lift, which was caused by excessive steepness in the keratoconic host cornea. After 6 radial incisions were made to flatten the inferior host cornea, the peripheral cornea flattened and the patient was successfully refitted with a contact lens.

Limbal relaxing incisions with cataract surgery.

PURPOSE: To evaluate the effectiveness of limbal relaxing incisions (LRIs) for correcting corneal astigmatism during cataract surgery. SETTING: Cullen Eye Institute, Houston, Texas, USA. METHODS: In 12 eyes of 11 patients, cataract surgery was combined with LRIs. The LRIs were made according to a modified Gills nomogram and were based on preoperative corneal astigmatism determined with standard keratometry and computerized videokeratography (EyeSys Corneal Analysis System Version 3.2). RESULTS: The mean preoperative keratometric cylinder was 2.46 +/- 0.81 diopters (D). At 1 month postoperatively, mean arithmetic reduction in keratometric cylinder was 1.12 +/- 0.74 D, and the with-the-wound (WTW) change (calculated by Holladay, Cravy, Koch vector analysis formula) was -0.70 +/- 0.44. From 1 day to 1 month postoperatively, there was 0.55 D of WTW regression with minimal change in the mean cylindrical axis. There were no overcorrections. CONCLUSION: Limbal relaxing incisions are a practical, simple, and forgiving approach to the correction of astigmatism during cataract surgery.

Dehiscence of a radial keratotomy incision during clear corneal cataract surgery.

We report a case of dehiscence of a radial keratotomy (RK) incision caused by clear corneal cataract surgery. The patient had eight-incision RK in both eyes 9 months previously with enhancement surgery in the left eye 1 month later. Cataract surgery through a clear corneal incision was performed in the right eye and 1 month later, in the left. Surgery in the right eye was uneventful. However, during surgery in the left eye, dehiscence of one radial incision occurred. The wound dehiscence was closed with interrupted sutures, and the patient achieved 20/20, uncorrected visual acuity 1 week after surgery.

The effects of long-term topical glaucoma medication on conjunctival impression cytology.

Long-term use of topical drugs can induce changes in the conjunctiva and ocular surface. To determine the conjunctival changes resulting from topical glaucoma medication, patients with glaucoma were selected and classified into seven groups, according to the medication received: 24 eyes were treated with betaxolol, 20 eyes with levobunolol, 32 eyes with timolol maleate, 22 eyes with pilocarpine, 52 eyes with beta-blocker and pilocarpine, 34 eyes with beta-blocker and dipivefrin, and 32 eyes with maximum therapy. Patients who were under 18 were excluded, as were those with any history of ocular surgery and other interventions, long-term use of any topically administered medication except glaucoma drugs, and any history or slit-lamp examination evidence of ocular surface disorders. The changes in the conjunctiva of 216 eyes were evaluated by means of ocular surface impression cytology. The medication group showed statistically significant degrees of conjunctival metaplasia when compared to the control group (p < 0.01). The cytological grading was not correlated with age, sex, type of medication, duration of topical treatment or the number of drugs (p > 0.05). Duration of treatment exceeding three months was not correlated with cytological grading. Thus, as far as surgical treatment was concerned, it was concluded that intervention within the first three months after the diagnosis would be most beneficial in the management of glaucoma. The fact that the presence of the preservative benzalkonium chloride was the same in all preparations suggests that it may be the major factor in conjunctival metaplasia.

Efficacy of lodoxamide 0.1% versus N-acetyl aspartyl glutamic acid 6% ophthalmic solutions in patients with vernal keratoconjunctivitis.

In a double-masked, randomized and controlled clinical trial, the effectiveness and safety of lodoxamide 0.1% eye drops were compared with N-acetyl aspartyl glutamic acid 6% (NAAGA) drops in the treatment of 120 patients with vernal keratoconjunctivitis. There were 60 patients in each of the two study groups. The drugs were instilled 4 times daily for 60 days. Follow-up examinations were made on days 7, 30 and 60. Of the 120 patients, 98 (50 in lodoxamide and 48 in NAAGA groups) were still available for follow-up on day 7, 89 (45 in lodoxamide and 44 in NAAGA groups) on day 30 and 75 (38 in lodoxamide and 37 in NAAGA groups) on day 60. Lodoxamide was clinically more effective than NAAGA. Statistically significant trends toward improvement were noted in the lodoxamide group in resolving papillae on day 30, decreasing corneal staining on days 30 and 60, relieving photophobia on day 60, tearing on days 7, 30 and 60 and itching on days 30 and 60. Lodoxamide 0.1% was more effective in lowering the mean scores for corneal staining on days 30 and 60 (p < 0.05). The composite scores for clinical signs and symptoms calculated by averaging the mean scores for signs and symptoms showed clinically significant differences in favor of the lodoxamide group. More frequent follow-up visits might have resulted in better statistical correlations. Treatment-related adverse events were reported in both groups with similar frequency but none were permanent or serious.