Ronald L. Radius

Pseudophakia and Intraocular Pressure

We studied the change in intraocular pressure in 373 consecutive eyes undergoing cataract extraction with intraocular lens implantation between Jan. 1, 1981, and May 31, 1982. There was a mean increase in intraocular pressure of 0.1 mm Hg following this surgery. This increase, however, was not statistically significant (P greater than .5). There was a mean rise in pressure of 0.8 mm Hg in the eyes undergoing intracapsular surgery and a mean fall in pressure of 0.6 mm Hg in the eyes undergoing extracapsular surgery (P less than .05). The change in pressure was unrelated to age, surgeon, or lens type. The results of a separate analysis of 16 eyes with a preoperative diagnosis of glaucoma and eight eyes with ocular hypertension were similar.

Ab Interno Sclerostomy With a High-Powered Argon Endolaser

We used a high-energy argon blue-green laser (15-W maximum power output) to create full-thickness sclerostomies from the region of the anterior chamber angle to the subconjunctival space in pigmented rabbits using an ab interno approach. One to four laser pulses delivered through a 300-micron noncontact fiberoptic probe produced patent sclerostomies in all 20 eyes treated using 0.1-second pulse duration and 5 to 14 W of power. No intraoperative complications were encountered. Intraocular pressure, measured in 12 animals, decreased an average of 12 mm Hg in the treated eye relative to the fellow eye on the first postoperative day. The drop in intraocular pressure was associated with formation of a functioning filtration bleb. Intraocular pressure returned to preoperative levels in ten of 12 (83%) of the animals by the fourth postoperative day, and there was an associated flattening of the filtration bleb. Histologic and radioautographic analysis indicated that the effect of the laser was focal. Tissue damage and cellular proliferative response were limited to within approximately 200 micron of the wound margin.

Anatomy of the optic nerve head and glaucomatous optic neuropathy

The mechanism of axon damage in eyes with glaucomatous optic neuropathy remains undefined. Interestingly, it has been observed that, although the entire nerve cross-section may be involved by the nerve damage, in many instances, the superior and inferior axon bundles are preferentially affected by the pressure insult. Thus, recent studies by many investigators have stressed a re-examination of the optic nerve head anatomy, including the nerve head microcirculation, the glial and connective tissue elements within the nerve head, and the morphology of the axons themselves. Any correlation between regional differences in this anatomy and the preferential involvement by specific axon bundles within the nerve head by the pressure insult may suggest some further insight into the mechanisms underlying the pressure-induced axon loss in glaucomatous eyes.

Trabeculectomy for traumatic hyphema with increased intraocular pressure

We reviewed the medical records of 11 consecutive patients who underwent trabeculectomy with anterior chamber washout and peripheral iridectomy as the primary surgical treatment for traumatic hyphema that was unresponsive to medical management. The mean intraocular pressure before surgery was 48 mm Hg. In ten of the patients the intraocular pressure was lowered to 21 mm Hg or lower after surgery and remained below that level up to the most recent follow-up visit, which ranged from eight to 97 months. One patient required a topical beta-blocker and oral acetazolamide to lower pressure to this level after surgery. Eight patients had visual acuity of 20/60 or better at last follow-up. Corneal blood staining occurred in eight patients. Compared with other techniques for surgical management of traumatic hyphema, trabeculectomy provides a means to keep intraocular pressure lowered while the remaining blood is clearing from the anterior chamber. Trabeculectomy with anterior chamber washout and peripheral iridectomy appears to be a safe and reliable procedure in the management of traumatic hyphemas in which medical management fails to control intraocular pressure.

Histopathology in the Iris-Nevus (Cogan-Reese) Syndrome

A 23-year-old-woman had iris-nevus (Cogan-Reese) syndrome characterized by unilateral glaucoma with peripheral anterior synechiae, multiple iris nodules, and ectopic Descemets membrane. A surgical specimen excised from the involved eye was examined by light and electron microscopy. A cuticular membrane covered both the anterior and posterior surfaces of the iris in this specimen. On the anterior surface of the iris, many projections of apparently normal iris stroma pierced or were surrounded by this membrane. On the posterior surface of the iris, this membrane was associated with a monolayer of cuboidal cells.

Screening for glaucoma with stereo disc photography.

PurposeTo determine the value of taking simultaneous stereo photographs of the optic nerve head as a basis for identification of patients with glaucoma. MethodsTwo hundred fifty-eight patients received complete ophthalmological examinations and were ranked on a scale of 1–5 regarding the likelihood of their having glaucoma. Each eye was also photographed using the NIDEK camera, providing stereo pairs of the optic nerve head. The same patients were reclassified by two independent masked observers on the same scale of 1–5, based solely on examination of the photographs. ResultsExamination of stereo photographs alone provided maximum sensitivity of 75% and specificity of 95% in identification of glaucoma patients when photographic readings were compared with all available clinical information. ConclusionsStereo photographs of the optic nerve head can be used for glaucoma detection with an accuracy that is significantly greater than simple tonometry and with a sensitivity that is equivalent to screening with computerized perimetry.