Proliferation of human ocular fibroblasts. An assessment of in vitro colorimetric assays.

Growing interest surrounds the pharmacologic modulation of ocular wound healing and fibroblastic proliferation. Therefore many investigators have developed assays to screen potential antiproliferative drugs on cultured fibroblasts. Such assays are extremely labor intensive, especially when many compounds are tested. Using proliferating human ocular fibroblasts, the authors explored the feasibility of three in vitro colorimetric assays as rapid, simple alternatives to more tedious proliferation assays, such as Coulter counting. These were: (1) the mitochondrial metabolism of a tetrazolium dye, (2) the cytoplasmic activity of hexosaminidase, and (3) the lysosomal uptake of neutral red, a weak basic dye. Serial dilutions of fibroblasts were assayed with each colorimetric technique; Coulter counting was used as a standard. All three colorimetric methods showed strong linear relationships between optical density and Coulter-cell counts. The MTT and neutral-red techniques were relatively insensitive, unable to quantify reliably fewer than 20,000 or 50,000 cells, respectively. On the other hand, the hexosaminidase assay was far more sensitive, reliably detecting a few hundred cells. Despite their differences and limitations, these three colorimetric techniques are useful as inexpensive screens whenever multiple drugs are tested for antifibroblastic effects.

Suprachoroidal hemorrhage after glaucoma filtering surgery.

We reviewed a series of 305 consecutive glaucoma filtering procedures performed by one surgeon. Five eyes (1.6%) had a postoperative suprachoroidal hemorrhage. All five eyes were aphakic, and four had undergone a partial or complete vitrectomy before the glaucoma surgery. The incidence of this complication was 13% (five of 37) among the aphakic eyes and 33% (four of 12) in the aphakic, vitrectomized eyes in this series. Despite drainage of the hemorrhage and reformation of the anterior chamber, three patients had a poor visual outcome.

Congenital rubella syndrome: ophthalmic manifestations and associated systemic disorders.

Congenital rubella syndrome has a wide variety of severe ophthalmic and systemic complications. A worldwide rubella epidemic from 1963 to 1965 affected thousands of infants. This is a 20 year follow up study of patients with congenital rubella syndrome analysing the prevalence of ophthalmic disorders, associated systemic problems, and correlations among these defects. The authors statistically analysed 125 cases of congenital rubella seen in the Mayo clinic ophthalmology department over a 32 year interval. Most patients were young adults. Ocular disease was the most commonly noted disorder (78%), followed by sensorineural hearing deficits (66%), psychomotor retardation (62%), cardiac abnormalities (58%), and mental retardation (42%). Multiorgan disease was typical (88%). Ocular disease and hearing loss were frequently associated (53% had both) but not significantly correlated. A similar association existed between ocular and cardiac disease. Cataracts and microphthalmia were significantly correlated with poor visual acuity (each p < 0.0001). Glaucoma was significantly correlated with cataracts (p = 0.0002) and microphthalmia (p = 0.0024) but not poor visual acuity. Four patients with microphthalmia developed late onset glaucoma. No significant association was found between gestational age at time of maternal infection and the incidence of individual ocular conditions. However, several cardiac disorders were significantly associated with gestational age. Although new cases of congenital rubella are rare, surviving victims continue to challenge the ophthalmic and medical communities with a wide range of ocular and systemic disorders.

Antiproliferative drugs and human ocular fibroblasts: colorimetric vs. cell counting assays.

Utilizing a rapid colorimetric assay that relates cell number to cytoplasmic hexosaminidase activity, we conducted drug-induced cytotoxicity experiments on human ocular fibroblasts cultured from Tenon's capsule specimens. The effects of two different agents--dimethyl sulfoxide (DMSO) or mitomycin C--on the proliferation of human ocular fibroblasts were studied. Simultaneously the sensitivity of this technique was compared to electronic cell counting with a Coulter counter, a conventional means of quantifying proliferation. Known numbers of cells were exposed to varied concentrations of either DMSO or mitomycin C for 11 days. Cell attachment was quantified after 24 hours, and proliferation was quantified periodically thereafter over the remaining 10 days. Colorimetric data contained a similar or smaller amount of random error than corresponding Coulter values. Both assays identified statistically significant antiproliferative effects and inhibitory effects on cell attachment at higher drug doses; however, Coulter counting alone detected many additional significant effects among lower-dose DMSO and mitomycin treatment groups. Although the hexosaminidase assay displayed lower sensitivity than Coulter counting, it may still be useful to rapidly screen new compounds for strong antifibroblastic effects.