Lens epithelial apoptosis and cell proliferation in human age-related cortical cataract.

PURPOSE: To probe the presence of apoptosis in the epithelium of human lenses with age-related cortical cataract as well as to assess cell proliferation, a predicted consequence of apoptotic cell death, in this specific cell population. METHODS: DNA fragmentation was assessed using terminal digoxigenin-labeled dUTP nick end labeling (TUNEL) in capsulotomy specimens obtained from patients who underwent either extracapsular cataract extraction for the removal of adult-onset cortical cataract (n=27) or clear lens extraction for the correction of high myopia (n=25). Cell proliferation was assayed in 23 epithelia of cataractous lenses, and 20 epithelia of non-cataractous lenses with the proliferation marker MIB1, a monoclonal antibody against the nuclear antigen Ki-67 that is detected throughout the cell cycle but is absent in the resting (G0) cell. RESULTS: TUNEL staining was observed in 25 (92.6%) specimens of cataractous lenses, whereas cells undergoing apoptosis were identified in 2 (8%) of the epithelia from non-cataractous lenses. Only two MIB1-positive samples were detected, one of which was a capsule obtained during intracapsular cataract extraction. CONCLUSIONS: The epithelium of human lenses with cortical cataract undergoes low rate apoptotic death. This limited epithelial apoptosis is unlikely to result in any significant cell density decrease since epithelial gaps are likely to be replaced by cell proliferation at the germinative zone of the anterior lens capsule. Nevertheless, the accumulation of small-scale epithelial losses during lifetime may induce alterations in lens fiber formation and homeostasis and result in loss of lens transparency.

Diffuse retinal pigment epitheliopathy: treatment with laser photocoagulation.

PURPOSE: To evaluate the effectiveness of laser treatment in eyes with diffuse retinal pigment epitheliopathy (DRPE). METHODS: The authors retrospectively reviewed the medical records of 56 consecutive patients (78 eyes) with DRPE. All eyes were treated with digital fluorescein angiography guided argon green laser photocoagulation, direct on the focal retinal pigment epithelium (RPE) leaks and in a grid pattern to the RPE decompensation areas. A processed digital red-free fundus image including all the important traces on it was used as a guide to the laser treatment. The follow-up period ranged from 6 months to 7 years. RESULTS: At the end of the follow-up time, 70 (89.7%) eyes showed anatomic improvement with complete or partial resolution of the macular exudative lesions. Visual acuity of less than 20/40 was noted in 60 eyes (76.9%) preoperatively compared with 46 eyes (59.0%) finally (p=0.0252). The visual acuity was improved in 19 eyes (24.4%), stabilized in 51 (65.4%), and reduced in only 8 eyes (10.2%). CONCLUSIONS: In this series of patients with DRPE, the results of laser treatment were uniformly satisfactory producing a gradual resolution of the macular exudative lesions and an improvement or stabilization of the visual acuity.

Elastic cord-induced ocular injuries.

PURPOSE: To evaluate the incidence and severity of ocular injuries caused by elastic cords. PATIENTS AND METHOD: A retrospective review of patients' records from the Emergency Department was conducted to identify cases of elastic cord-induced ocular injuries. Over a 67-month period starting in October 1996, 28 patients (24 males and 4 females, mean age 38.6 years) with elastic cord-associated ocular trauma were identified. Patient demographics, mechanism of injury, presenting and final visual acuity, ocular injuries, medical and surgical intervention and length of follow-up were noted. RESULTS: The most common anterior and posterior segment injuries were hyphaema/microhyphaema (71.4%) and commotio retinae (60.7%), respectively. The most severe injuries sustained were corneal or scleral lacerations (7.1%), formation of retinal tears (10.7%) or retinal detachment (3.6%), lens subluxation (7.1%) and traumatic cataract (7.1%). Eight patients (28.6%) were admitted for surgical or medical treatment. Mean visual acuity was 20/40 on presentation and 20/25 at the end of the follow-up period. CONCLUSIONS: Elastic cords may cause a wide range of ocular traumas of varying severity. Appropriate design modifications that would prevent the spontaneous release of their hooks are likely to make their use significantly safer.

Nyctalopia in antiquity: a review of the ancient Greek, Latin, and Byzantine literature.

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.

Dacryocystosclerotherapy.

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.

The a- and b-wave latencies as a prognostic indicator of neovascularisation in central retinal vein occlusion.

To evaluate the prognostic value of ERG in cases of central retinal vein occlusion (CRVO) regarding the development of neovascularisation (NV), we studied 20 patients with unilateral CRVO. Half of them were allocated in the perfused group and the other 10 finally developed NV and were allocated in the non-perfused group. Flash ERG was recorded from all patients. Our findings suggest that b-wave latency is the most reliable parameter in predicting NV, followed by the a-wave latency. The b/a wave amplitude of ERG ratio does not seem to be suitable for clinical use.

Neurovisual impairment: a frequent complication of alpha-interferon treatment in chronic viral hepatitis.

Following our earlier observation of clinically evident optic tract neuropathy in patients receiving low-dose interferon (IFN) therapy, we prospectively evaluated 53 consecutive patients treated for chronic hepatitis B or C with a median dose of 3 MU of IFN-a2b thrice weekly. Measurements included routine ophthalmologic evaluation and recordings of visual evoked responses (VER), electroretinograms (ERG), visual acuity, and visual fields, before, at the end of IFN treatment, and at follow-up visits. Baseline P100 latencies of VERs (base-VER) were abnormally prolonged in 24 patients (32 of 106 eyes, 30.2%); age was the only significant covariate associated with increased risk for an abnormal base-VER by multiple logistic regression (relative risk [RR] 5.3 per each 5-year increase in age). In 45 patients (74 eyes) with normal baseline P100 latencies, the end-of-treatment VERs (end-VER) were significantly prolonged compared with baseline, becoming abnormal in 11 (15 of 74 eyes, 20.3%) (138.8+/-8.7 vs. 117.7+/-5.2 ms, P < .001). This subgroup had older age (59.1+/-11.0 vs. 47.5+/-15.3, P=.007) and reduced visual sensitivity compared with their own pretreatment measurements (24.5+/-1.6 vs. 23.0+/-1.2db, P=.019). Changes of end-VERs by age had a sigmoid distribution with a steep increase of values beyond the 5th decade (R2=.326, P < .001). In a logistic regression model, significant predictors of abnormal end-VERs were, patients' age (RR 5.6 per each 5-year increase), presence of hepatitis B virus (HBV) infection (RR 15.1 compared with hepatitis C virus [HCV] infection) and serum cholesterol levels above 240 mg% (RR 7.1 compared with values < 240 mg%). Subconjunctival hemorrhages were seen in 2 cases and funduscopic examination revealed cotton wool spots in one other. ERG recordings and the P100 amplitude remained unchanged. After stopping IFN, the treatment-associated neurovisual abnormalities reversed to normal in 7 patients (10 of 15 eyes) and persisted in 5 (5 of 15 eyes, 33.3%) for up to 37 (median 7.3) months observation, all patients remaining clinically asymptomatic. In conclusion, subclinical neurovisual impairment is a frequent, largely unrecognized complication of low-dose IFN therapy, and patients with chronic hepatitis B and older age appear to be most susceptible. This apparently innocuous complication is long lasting, possibly irreversible in some patients, with yet undetermined consequences on visual function.

Corneal anesthesia in a case with Vogt-Koyanagi-Harada syndrome.

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.

The effect of low-dose interferon treatment on visual evoked potentials.

Patients suffering from chronic viral hepatitis, treated with interferon alpha-2b in a dose of 3 million units trice weekly subcutaneously, were studied. The influence of interferon on the optic nerve was evaluated by measuring the P100 implicit time of the visual evoked potentials. The results before the treatment were compared with those after 6 and 12 months of therapy, as well as with those of normal subjects. There were statistically significant differences between the groups. Furthermore, in 10 of 56 eyes (17.8%) after 6 months of treatment, and 8 of 22 eyes (36.3%) after 12 months of treatment, the P100 was abnormally delayed. The long term neurovisual effects of low-dose interferon are currently under investigation.

Psychophysical tests in X-linked retinitis pigmentosa carrier status.

Psychophysical tests were performed in 22 normal women and 17 X-linked carriers of retinitis pigmentosa. The tests consisted of luminance contrast sensitivity, grating at the fovea and broken annulus at the periphery, color contrast sensitivity, letters for the fovea and broken annulus for the periphery, along the three known confusion axes of protan, deutan and tritan observers. Statistical analysis of the data shows that there were significant differences between the carriers and age-similar normal subjects with all the tests. The most significant differences (P < 0.001) were found with the color contrast sensitivity at the periphery along the protanopic and deutanopic axes and the luminance contrast sensitivity at the periphery. The influence of the age is discussed.

Optic tract neuropathy complicating low-dose interferon treatment.

Optic neuritis occurred in three of our patients receiving treatment with alpha interferon-2b (Intron-A; 3MU thrice weekly) for chronic hepatitis. The complication appeared within, 1, 9 1/2 and 10 months of treatment, respectively. In all cases, blurred vision was the initial complaint and subsequent electrophysiologic investigation confirmed the presence of optic tract neuropathy. The patients had no other neurologic signs. Computerized tomography and magnetic resonance image of the brain were not remarkable. Psychiatric symptoms, in the form of an interferon-associated depressive reaction, were present in two of them; in one case, it was severe enough to require immediate discontinuation of treatment. In two patients the visual symptoms resolved and the parameters of neurophysiologic testing returned to normal within 1 month after stopping interferon. In one case, however, residual optic tract impairment associated with a unilateral central scotoma and a substantial decrease of visual acuity was present 2 years later, despite a course of methylprednizolone. In this patient the interferon treatment was continued for 3 months despite the visual symptoms, and he later received two additional interferon courses because of relapses of hepatitis. We conclude that clinically evident optic tract neuropathy may complicate interferon administration. Candidates for interferon treatment may need routine examination of optic fields and visual evoked potentials, before and during administration of the drug to avoid possibly permanent visual sequelae.

C-wave study in cone dysfunction syndrome.

An electroretinogram (ERG) and C-wave were recorded from 15 patients suffering from cone dysfunction syndrome. Our results show that the photopic ERG was diminished with extinction of the oscillatory potentials. On the other hand, the mean value of the C-wave amplitude was diminished and the implicit time prolonged. This may serve as a further diagnostic sign of the disease.

C wave of electroretinogram and visual evoked response in optic neuritis due to demyelinating diseases.

In 21 consecutive cases with unilateral optic neuritis due to demyelinating disease, ERG, C wave of ERG and VER were recorded and studied in both eyes. Also 8 cases suffering from optic atrophy due to trauma or glaucoma were included. The analysis of data shows that the C-wave is significantly diminished in both eyes, namely the affected and the sound, in the cases of optic neuritis. Also in comparison to VER, C wave has a comparative probability in diagnosing optic neuritis due to demyelinating disease. The C wave of ERG is normal in the cases of optic atrophy. The mechanism of C wave involvement during the course of demyelinating disease may be related with an abnormality of the ionic homeostasis of the subretinal space.

ERG and electron microscopic findings after intravitreal use of aminoglycosides.

The electroretinographic (ERG) changes and the retinal lesions shown by electron microscopy were studied in rabbits after intravitreal use of amikacin and tobramycin. We studied 40 eyes of 20 rabbits in which different doses ranging from 250 micrograms to 1000 micrograms of aminoglycosides were injected into the vitreous cavity. Tobramycin, and to some extent amikacin, were toxic to the retina even in doses of 500 micrograms as shown by ERG changes. The pathologic retinal lesions shown by electron microscopy were characterized by membranous inclusions in the retinal pigment epithelium, tumefaction of the photoreceptors, and partial disorganization of the inner layers. In doses of 250 micrograms or less, these two antibiotics seem to be nontoxic after a follow-up of three months.

C wave study in optic neuritis due to demyelinating disease.

The C wave was recorded from 20 eyes suffering from neuritis due to demyelinating disease and in 5 eyes showing optic atrophy due to trauma or to increased intracranial pressure. Our results show that in cases with optic neuritis the C wave amplitude was clearly lower than normal. It is interesting that in the other 'healthy', at least clinically, eye the C wave was subnormal too. On the contrary, in the eyes with optic atrophy the C wave was normal. These findings are against the possibility of an efferent neuronal pathway involvement, which influences the level of the retinal pigment epithelium, and support the view of its involvement during the course of the demyelinating disease that causes the optic neuritis.