Faculty Bibliography

The incidence of primary open angle glaucoma in patients with central retinal vein occlusion is reported to be between 5.7 and 66%, while that of primary angle closure glaucoma is from 0 to 9%. (Corrected for the relative incidence of these two types of glaucoma in the general population, these rates are comparable). There appears to be a causal relationship between elevated intraocular pressure and central retinal vein occlusion, which does not correlate with the height to which the pressure is elevated. Other etiologic factors may be important, particularly arteriosclerosis. The association between elevated pressure and branch vein occlusion is less clear. Central vein occlusions occur in 3.5 to 5% of patients with primary open angle glaucoma. Similarly, central vein occlusions occur in approximately 3% of patients with ocular hypertension. It is recommended that ocular hypertensive patients over the age of 65 be treated to lower their pressure below 25 mm Hg

Trabeculectomy is classically and almost universally performed with a limbal-based conjunctival flap. This method has definite theoretic and practical disadvantages compared with a fornix-based conjunctival flap, including (1) poorer visualization and exposure of the area for surgical treatment; (2) a greater chance of button-holing the conjunctival flap; (3) a more anteriorly placed conjunctival bleb; and (4) a higher risk of a thin flap overhanging the cornea. The practical advantages of a fornix-based flap, the surgical results, and the surgical techniques are discussed. Because of its advantages, this method is preferred to the use of a limbus-based conjunctival flap

The use of a fornix-based conjuctival flap in trabeculectomy and in the combined trabeculectomy and cataract operation is described. Of 105 eyes subjected to trabeculectomy, the intraocular pressure was maintained at less than 21 mm Hg in 97 (92%). Of these 97 eyes, 58 (60%) required medication following the surgery. There were ten eyes in which combined trabeculectomy and cataract surgery was performed. All ten eyes had normal intraocular pressures postoperation; five (50%) with medication. This method has many advantages when compared with the limbal-based flap and gives excellent surgical results with few complications. The advantages are enumerated and the results are reported on 115 eyes operated on over the past ten years

A 32-year-old man with pigmentary dispersion syndrome had blurred vision and halos after strenuous exercise, associated with a release of pigment into the anterior chamber and increased intraocular pressure (IOP). Additionally, he had typical symptoms after emotional stress or exposure to dim illumination, and had a high IOP without angle closure during a darkroom provocative test. The exercise-induced symptoms and the increase of IOP were prevented by the use of pilocarpine 0.5% drops immediately before exercise

The management of eyes with both cataract and glaucoma is reviewed. An argument is made for the use of combined cataract and glaucoma surgery as the initial procedure in eyes that have glaucoma, regardless of preoperative control, with cataract which requires removal. The combined operation is also recommended in eyes that require glaucoma surgery and have significant cataract (i.e. visual acuity of 6/12 or reading 6 pt print). A comparison of the results of a modified combined procedure with those of an initial cataract or glaucoma procedure followed by a second procedure at a later date and with those of previous combined procedures demonstrates the advantages of the former. The combined trabeculectomy and cataract extraction is modified by the use of a fornix-based conjunctival flap and by tightly suturing the lamellar trabeculectomy scleral flap to its base. The advantage of this technique is that a 3 1/2-year follow-up demonstrates a lower risk of postoperative complications compared with combined trabeculectomy with a loosely-sutured or unsutured scleral flap which has the same risk of postoperative complications, including shallow or flat anterior chamber, as do combined classical filtering procedures (thermal sclerostomy, trephination, sclerectomy, iridencleisis). We have reviewed 46 eyes operated by this technique and followed them for an average of 3 1/2 years. In 44 eyes the postoperative intraocular pressure is well controlled and the visual fields remain stable

The appearance of the anterior chamber angle shows considerable variation in eyes with glaucoma caused by congenital or developmental causes. These differences, in over 100 eyes studied, correlate well with the effectiveness of trabeculotomy in controlling the intraocular pressure. In angles harboring what is probably embryonic mesoderm (although they may vary in their gonioscopic appearance), prognosis for control of IOP by trabeculotomy is excellent, while in those that show evidence of a fibrotic process at the limbus, the prognosis for trabeculotomy is hopeless. The latter, once recognized, should be treated by trabeculectomy, this condition being the only good indication for trabeculectomy in these eyes

Forty-four eyes in 25 black patients are compared with 92 eyes of 47 white patients in a population with ocular hypertension followed up for 1 to 12 years in a glaucoma clinic. The black patients present at a younger age than the whites and their mean initial intraocular pressure is significantly higher. The fact that more black ocular hypertensives developed glaucoma--8 eyes (18.1%) in the black population as compared with 5 eyes (5.4%) in the white population--is attributed to these two differences

Pilocarpine 4% solutions at pH 4.1 and 5.8 were compared in a double-blind clinical trial on 24 eyes of patients with primary open-angle glaucoma. Each drug was used over a period of 1 week. No significant difference in the lowering of intraocular pressure was found, and the near-neutral solution of pilocarpine was found to be equally stable when compared to the acid solution over a 6-month period

Uveitis is divided into five clinical groups based on its severity and natural history. By using this classification appropriate and graded forms of therapy can be applied to individual patients with uveitis. In Group 1 patients (anterior uveitis syndrome) topical cortisone drops or ointment will control the disease. Group 2 (posterior uveitis) patients require local steroids (topical, subconjunctival or retrobulbar) and systemic steroids. Appropriate specific therapies are indicated if a causal organism can be identified. Patients in Groups 3 (cyclitis), Group 4 (uveitis in children) and Group 5 (severe intractable uveitis) are exposed to a high risk of cystic macula degeneration and must be treated with local and systemic cortisone and cytotoxic drugs if the steroid fails to control the inflammation or if cortisone has to be used excessively high dosage. The recommended regime of treatment is summarised in the diagram in figure 7