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PURPOSE: To evaluate agreement in measurements of astigmatic axis power and location between keratometry and computer assisted videokeratography (corneal topography) on normal corneas with less than 1.50 D of idiopathic astigmatism. METHODS: Keratometric readings with the 10 SL/O Zeiss ophthalmometer and corneal topographic maps with the TMS-1 were obtained by two independent examiners on 32 normal corneas. Measurement agreement between the two instruments was evaluated in regard to steep and flat meridian power and location, and in astigmatism magnitude (D). RESULTS: The limits of agreement (d-2 SD to d+2 SD) between the two instruments were found to be broad for clinical purposes in measuring the steep meridian power (-0.16 to -1.20 D), flat meridian power (0.43 to -1.25 D), and astigmatism (0.60 to -1.12 D). A constant bias of the TMS-1 towards the 10 SL/O Zeiss ophthalmometer was found, in measuring steeper both principal meridians and higher amount of astigmatism. Mean location difference was 19 degrees (+/-190) for the steep meridian and 17 degrees (+/-20 degrees) for the flat meridian. CONCLUSIONS: Despite the differences seen in measurements between the 10 SL/O ophthalmometer and the TMS-1, these differences may be clinically small enough for the methods to be used interchangeably in measuring only the magnitude of astigmatism on normal corneas. However, the disagreement in astigmatism axes is too great to be ignored.

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OBJECTIVE: To investigate the original definition and use of the term nyctalopia in ancient medical literature in view of the controversy between the English and some continental European literatures. DESIGN: Historical manuscript. METHODS: We review the use of the term in ancient Greek, Roman, and early Byzantine medical literature (5th century BC-7th century AD) and include a quick reference to the theories on its etymology. RESULTS: Physicians of antiquity defined as nyctalopia the symptom of defective dark adaptation, most commonly in the clinical setting of vitamin A deficiency. An alternative definition, the improvement of vision at night, is not recorded before the 2nd century AD and seems to result from a broader interpretation of the word, lacking medical acceptance at that time. CONCLUSIONS: We propose to the ophthalmic community the use of the term nyctalopia exclusively for the description of defective dark adaptation.

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PURPOSE: To introduce a less invasive therapeutic method in selected patients with primary nasolacrimal duct obstruction. METHODS: Noncomparative interventional case series. Seven patients with primary acquired nasolacrimal duct obstruction who were poor candidates for dacryocystorhinostomy because of underlying medical conditions and two symptomatic patients with previous incomplete dacryocystectomy were included. Ethanolamine oleate 5% was slowly injected through the puncta into the patent portion of the lacrimal drainage apparatus. RESULTS: After a mean follow-up period of 26 months, the lacrimal pathway was permanently obliterated in 6 cases (66.7%). In two cases, the procedure was repeated successfully and in one case, the patient refused to repeat the procedure after the initial failure. CONCLUSIONS: In selected patients, ethanolamine oleate dacryocystosclerotherapy appears to offer a simple, low-cost, less invasive alternative to dacryocystectomy.

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PURPOSE: To investigate the hemostatic effects of SF6 gas in preventing postoperative vitreous hemorrhage in diabetic vitrectomy. METHODS: A prospective, randomized study of 33 diabetic eyes with vitreous hemorrhage, treated by vitrectomy. In 17 of our cases SF6 20% was injected into the eye at the end of the operation, while in 16 cases BSS remained in the vitreous cavity. RESULTS: The incidence of vitreous hemorrhage recurrence was 17.6% for the SF6 group and 12.5% for the BSS group (statistically not significant). Progression of lens opacities was observed in 23.5% of the SF6 group, and in 18.8% of the BSS group (statistically not significant, with a higher incidence in the SF6 group). CONCLUSIONS: SF6 gas did not show hemostatic effects in the cases studied. Furthermore, it may have contributed to cataract progression. Therefore we suggest that the use of SF6 is not recommended as a treatment modality in preventing new vitreous hemorrhage after diabetic vitrectomy.

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PURPOSE: To add clinical features to the description of the Vogt-Koyanagi-Harada syndrome. METHOD: Case report. RESULTS: The case presented with a typical medical history of Vogt-Koyanagi-Harada syndrome, including headaches, low-grade fever, nuchal rigidity, and from the eyes bilateral visual loss, a reaction from the anterior chambers, bilateral uveities with localized exudative retinal detachment from the left. In addition there were tonic pupils, anesthesia of the corneas, and an accommodative deficit. CONCLUSION: Corneal anesthesia, tonic pupils and accommodative impairment can be features of the Vogt-Koyanagi-Harada syndrome.

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PURPOSE: To describe a case of retinal perivasculitis in an immunocompetent patient with systemic herpes simplex infection. METHODS: Polymerase chain reaction amplifications were performed for aqueous and blood samples using primers specific for the following members of the herpesvirus family: cytomegalovirus, Epstein-Barr virus, herpes simplex virus (types 1 and 2), and varicella-zoster virus. The patient was placed on intravenous acyclovir and systemic corticosteroids. RESULTS: A positive polymerase chain reaction signal was found only for herpes simplex virus type 1. Vision in the left eye improved from light perception to 20/25, and signs of retinal perivasculitis resolved. CONCLUSION: The use of molecular diagnostic modalities in clinical practice may aid in determining infectious etiologies in patients with atypical clinical manifestations.

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The present study deals with the retinal vascular involvement in 64 patients with toxoplasmic retinochoroiditis during the acute phase of the disease and its evolution. Vascular involvement was noted in all 64 eyes during the acute phase of the disease. In 59 (92%) out of 64 cases the vascular involvement was located in the same retinal quadrant as the active toxoplasmic lesion. In the remaining 5 eyes (8%) the vascular participation was found in all four retinal quadrants. In 3 (5%) out of 64 cases, the vascular infiltration was extremely severe and resulted in retinal vascular obstruction. In all three cases the vessel traversed the active toxoplasmic lesion. In 35 (55%) out of 64 patients the initial vascular picture changed in the course of the acute phase of the disease. In these patients, the lesions had extended to the adjacent vessels or to other parts of the involved vessel. In the further course of the evolution of the active toxoplasmic lesion, the vascular involvement did not persist indiscriminately. It was noted that in 14 (22%) out of 64 cases the vascular lesions gradually regressed and eventually disappeared together with the active toxoplasmic lesion and the formation of the retinochoroidal scar. In the remaining 50 (78%) out of 64 cases the vascular involvement either disappeared after the establishment of the retinochoroidal scar in 3-12 months (29 cases) or remained permanently (21 cases).

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Six cases of recurrent vitreous hemorrhage are described. The hemorrhage was due to a retinal vessel rupture or injury caused by vitreous traction. The traction was exerted by the detached vitreous and the vessel drawn into its cavity without the simultaneous occurrence of a tear in the retinal area corresponding to the point of traction. The avulsed vessel was usually a small vein in the upper temporal fundus quadrant. The vessel either projected as a hooklet into the vitreous cavity or its peripheral end was found to be floating freely within the cavity after having moved away from the retina. Treatment consisted in laser coagulation alone or in conjunction with an indentation created by fixing a silicon episcleral explant. Recurrent vitreous hemorrhages caused by a retinal vessel drawn into the vitreous cavity after posterior vitreous detachment without a retinal tear have hitherto not been accorded the attention they deserve.

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We examined the tear drainage system of twenty-fiv normal volunteers by scintillography with Technetium Tc 99m (Pertechnetate). We photographed the changes occurring in the lacrimal sac and nasolacrimal duct during closure and opening of the eyelids. Our findings support Jones' views of normal tear drainage. The tracer was concentrated in the lacrimal sac while the lids were closed for 3 minutes and descended into the nasolacrimal duct as soon as they opened.

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This investigation is based on 262 cases of retinal detachment treated with episcleral silastic sponge implants and cryopexy. Anatomical restoration of the retina after one operation or more was successful in 89 percent. Drainage of subretinal fluid was carried out in 52 percent of the cases. Supplementary light-coagulation 3 or 4 weeks after the operation was applied in 43 cases (17 percent) in order to seal off retinal holes on the buckle due to inadequate chorioretinal adhesion following cryopexy. Insufficient adhesion was directly related to the retinal elevation in the area of the tear. Chorioretinal haemorrhages in the group without release of subretinal fluid were caused by the following factors: Repeated cryo-application in the same place, application of the probe on the open part of the tear instead of around the tear, sponge-fixation in the immediate area to vortex veins, pressure exerted by the sponge on choroidal and retinal vessels, particularly in persons of advanced age. Local haze of the vitreous corresponding to the location of the cryp-application was directly related to the number of applications and the position of the tear. Vitreous haze was more frequent where the hole was situated towards the ciliary body. Pigment migration was observed in 9 percent of the cases. It should be noted that this complication was also encountered preoperatively in a group amounting to 4 percent of the total number of cases after padding of the eyes and absorption of subretinal fluid. Such cases should be distinguished from those of postoperative occurrence of pigment migration. Detachment of the choroid happened more often in the group in which subretinal fluid was released. In this group expulsive haemorrhage also occurred, which, apart from the choroidal detachment, resulted, immediately upon drainage of subretinal fluid, in high intracular pressure. Macular puckering was noticed in 5 cases (2,7 percent). In 4 out of the 5 cases with this complication, the tear was located towards the posterior pole and sponge fixation was radial.

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The follow-up of 262 cases of retinal detachment operated on after the Custodis-Lincoff method in combination with cryopexy permitted the following observations: (1) The implant protruded in a number of cases under an intact conjunctiva and Tenon's capsule without discomfort to the patient. This protrusion depended mainly on the size and the manner of fixation of the implant, the distance of the point of fixation from the limbus and the condition of the conjunctiva. (2) Changes were observed in the conjunctiva in the fixation area, such as subconjunctival haemorrhage, cystoid degeneration of the conjunctiva and rupture with extrusion of the sponge. Subconjunctival haemorrhages were observed in 3.4% of the cases and were either absorbed or led to an inflammation. Cystoid degenerations occurred in 2.2% of our cases. These were limited to the edge of the sponge proximate to the limbus and involved only cases of radial fixation. Rupture of the conjuctiva and extrusion were noticed in 3.4% of the cases. (3) An inflammation due to the sponge was observed in 4.1% of the cases. Its time of onset varied between 3 days and 22 months. According to the time of onset the patients were divided into three groups. The gravity of the inflammation was proportionate to the earliness of the time of onset. Predisposing factors for the above complications were mentioned and discussed.

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