Comparison of intraocular pressure lowering by topical and systemic carbonic anhydrase inhibitors in the rabbit

We compared the effect on intraocular pressure (IOP) of maximal doses of a topical carbonic anhydrase inhibitor (CAI) at acidic and alkaline pH where it is maximally effective with full systemic CA inhibition in ocular normotensive New Zealand Albino rabbits. Tonometric IOP levels were measured hourly during 3 hour control period. Topical MK-417 (pKa 5.8, 8.3), a close congener of MK-507 (Dorzolamide) was given as a 1.4% solution at pH 4.5 (n=6) and pH 9.2 (n=6). MK-417 was instilled to the left eye with the right eye used as an untreated control. One hour later methazolamide was given intravenously at 10 mg/kg, a dose known to give full inhibition of the enzyme. Control IOP (mm Hg) was 19.12+/-0.50. One hour following MK-417, the left eye IOP was 13.40 +/-0.70 (pH 4.5) and 13.25+/-0.70 (pH 9.2). The right eye pressure was unchanged. Methazolamide injection at this time gave no further drop in the left eye IOP at either pH. IOP in the right eye fell to 14.00+/-0.70 so that 2 hours after methazolamide injection, the 2 eyes had the same pressure. In conclusion, topical CAI in sufficient dose and correct pH yields IOP lowering equivalent to a maximally effective dose of systemic CAI in rabbits.

Modified aqueous drainage implants in the treatment of complicated glaucomas in eyes with pre-existing episcleral bands

OBJECTIVE

Control of intraocular pressure (IOP) after retinal surgery with scleral band placement may be problematic. In this study, outcome after silastic drainage implant placement is reviewed.

DESIGN/PARTICIPANTS

A retrospective chart review of 11 eyes in 11 patients with severe glaucoma after multiple surgeries, including scleral buckle procedures.

INTERVENTION

Patients received silastic drainage implant surgery, either a long Krupin Denver valved implant (7) or a trimmed Baerveldt seton (4).

MAIN OUTCOME MEASURES

Vision, IOP, and need for further glaucoma medication or glaucoma surgery were measured.

RESULTS

One- and 2-year life-table success rates (either complete or qualified success) were 82% and 73%, respectively, defining success as final IOP of 21 mmHg or less without need for further glaucoma surgery and no loss of visual acuity. Half of the successful eyes required antiglaucoma medication.

CONCLUSIONS

Silastic drainage implants may be a viable option in the treatment of complicated glaucoma after retinal surgery.

Propionibacterium endophthalmitis following Molteno tube repositioning

PURPOSE

We describe an aphakic patient who developed recurrent Propionibacterium acnes endophthalmitis after Molteno tube revision.

PATIENT AND METHOD

The patient presented with a red painful right eye, decreased vision, and a hypopyon. A moderate anterior chamber reaction and mild vitritis were present. Two weeks earlier, the patient had undergone Molteno tube repositioning. A diagnosis of P. acnes endophthalmitis was made after positive culture of anterior chamber needle aspirate.

RESULTS

Initially the patient was treated with repeated intraocular vancomycin injections, to which the eye "responded poorly." Temporary clearance of the infection was achieved after placement of the tube in the subconjunctival space. The patient required explantation of the implant to achieve complete resolution of the infection.

CONCLUSION

Tube reinsertion into the anterior chamber resulted in recurrence of the infection. The evaluation of alternative therapies of aqueous tube shunt-related endophthalmitis would require a large case-controlled series of patients.

Ophthalmic manifestations of Rochalimaea species

Rochalimaea henselae and R. quintana belong to the order Rickettsiales and are thought to be responsible for trench fever, bacillary angiomatosis, and cat scratch disease. We recently examined four patients with intraocular inflammation of unknown origin. Each patient had either unilateral or bilateral moderate loss of visual acuity ranging from 20/25 to counting fingers. Bilateral intraocular inflammation manifested by anterior and posterior segment cells, retinal lesions, macular exudate, and optic nerve head swelling was present to varying degrees. The R. henselae to R. quintana antibody titers were greater than or equal to 1:256 in each case. Marked improvement in vision occurred after treatment with either oral ciprofloxacin hydrochloride and prednisone or doxycycline hyclate. Rochalimaea species should be considered in the differential diagnosis of intraocular inflammation and inflammatory optic neuropathy. Appropriate treatment may result in marked improvement in visual acuity.

Temporary blindness in the TUR syndrome

The TUR syndrome is a clinical disorder consisting of circulatory, gastrointestinal, and neurologic signs that are infrequently seen in some patients undergoing endoscopic surgery of the prostate gland with the use of nonconductive irrigating fluids. Several theories of its pathogenesis have been proposed. The condition may occasionally be associated with bilateral profound loss of vision. We report a patient with the TUR syndrome who suffered bilateral temporary blindness and speculate on the etiology of the visual loss and localization of the dysfunction along the visual pathway.

The prevalence of neurologic dysfunction in children with strabismus who have superior oblique overaction

BACKGROUND

Children with certain neurologic diseases (hydrocephalus, meningomyelocele, or cerebral palsy) have been reported to manifest a high frequency of A-pattern strabismus and superior oblique overaction. However, it is not generally recognized whether children with strabismus who have superior oblique overaction are more likely to have concurrent neurologic diseases than those without superior oblique overaction. In this study, the authors examine this issue.

METHODS

The authors retrospectively reviewed the medical records of all patients (n = 168) with overdepression of the downturned eye in adduction, who were examined between October 1989 and March 1992. A randomly selected population of children with strabismus who did not have overdepression of the eye on infraduction and adduction served as controls (n = 98). Patients with simulating or confounding conditions such as pseudo-superior oblique overaction, inferior rectus skew deviation (alternating skew on lateral gaze), and restrictive or paralytic strabismus, and who were older than 20 years of age, were excluded.

RESULTS

One hundred twelve patients with true superior oblique overaction were analyzed. Of these 112 patients, 45 (40.2%) had concurrent neurologic abnormalities, compared with less than one fifth (17.3%) of control subjects (17 of 98) (P < or = 0.001).

CONCLUSIONS

Children with strabismus who have superior oblique overaction were found to have higher prevalence of concurrent neurologic diseases than control subjects. Superior oblique overaction may represent a clinical marker for an associated neurologic dysfunction, possibly representing a form of skew deviation in some cases.

Chronic idiopathic inflammation of the retropharyngeal space presenting with sequential abducens palsies

We describe a patient who presented with sequential, bilateral abducens palsies associated with a mass of the nasopharynx. Biopsy of the mass showed chronic non-specific inflammation and fibrosis. The diagnosis of idiopathic inflammatory pseudotumor was arrived at by exclusion of other known causes of inflammation of the retropharyngeal space. Magnetic resonance imaging suggested that injury to the sixth cranial nerves probably occurred as they traversed the dura and subarachnoid space overlying the clivus.

Ciliary sulcus fixation of a dislocated posterior chamber intraocular lens using liquid perfluorophenanthrene

A posterior chamber intraocular lens was transsclerally sutured to the ciliary sulcus with the aid of liquid perfluorophenanthrene (Vitreon). This vitreous substitute facilitates the procedure and reduces the possibility of damage to the retina.

Reduction of postoperative adhesions secondary to strabismus surgery in rabbits

The efficacy of tissue coating with sodium hyaluronate solution or oxidized regenerated cellulose (Interceed) sleeves in reducing the occurrence and severity of postoperative adhesions following strabismus surgery was tested in rabbits in vivo and compared with the efficacy in this regard of treatment with balanced salt solution. The use of Interceed sleeves significantly increased formation of postoperative adhesions, but coating with sodium hyaluronate solution prior to and during surgery significantly reduced such formation.

Synergistic divergence: saccadic velocity analysis and surgical results

The clinical findings are described in four patients with synergistic divergence (SD), an ocular motility disorder which is considered to be a variant of Duane retraction syndrome (DRS). Saccadic velocity studies in three patients demonstrated preserved abducting saccades in the affected eye with equally reduced amplitudes on both attempted abduction and adduction. The preserved saccades on attempted abduction of the affected eye, coupled with electromyographic evidence that shows maintenance of normal reciprocal innervation with respect to gaze on attempted abduction as dictated by Sherrington's law, strongly suggest that the abducens nerve is not necessarily absent or severely hypoplastic in this condition. One patient showed typical DRS in the contralateral eye and had a son with bilateral DRS, attesting to a possible genetic and etiologic relationship between SD and DRS. Three patients underwent strabismus surgery. Review of our surgical results and an analysis of the literature indicate that a crippling procedure to the ipsilateral lateral rectus muscle, such as extirpation, may be necessary to eliminate simultaneous abduction. Overcorrection did not occur following lateral rectus extirpation.