| Established 1995 | ||
Aims
To evaluate the effect of the chronic use of apraclonidine 0.5% on the intraocular pressure (IOP) of patients with glaucoma; also, to study the side effect profile of this drug when used chronically.
Methods
All patients who had uncontrolled IOP, who were either already on glaucoma medications, or who were intolerant of other glaucoma medications were enrolled. A total of 185 patients were started on apraclonidine 0.5% two to three times a day in one eye.
Results
Follow up extended to 35 weeks. The mean difference in IOP between treated and control eyes was 2.1 (SD 5.0) mm Hg. A similar IOP lowering effect was obtained comparing IOP difference from baseline in the treated eye only.
Conclusion
By the end of the follow up period, 46% of patients were still on the medication. The drug was stopped in 23% of patients because of side effects and in 31% of patients because of failure to lower IOP significantly.
Authors' Abstract, BJO
Philadelphia, PA
| [ ORJ-Subject ] | [ ORJ-Date ] | [ IO Home ] | [ Glaucoma ] |
Prostaglandins are a class of molecules that have been around for some years. In the past decade, synthetic analogues have been tested for biological effect. PG F2alpha is an interesting compound with a myriad of effects. Perhaps its most studied property is its effect on uterine muscle during childbirth, promoting intense contractions. An analogue has been tested in the eye and found to decrease intraocular pressure.
Pilot studies showed it lowered intraocular pressure in humans. These were short duration studies involving small sample sizes. This paper looks at a larger sample size followed over a six month period comparing the pressure lowering effect of once daily 0.005% Latanoprost to Timolol 0.5% given twice daily.
268 patients were enrolled. Criteria for inclusion were stringent. Some of these criteria were the presence of ocular hypertension (OHT), primary open angle glaucoma (POAG), exfoliation syndrome (PXE) or pigment dispersion syndrome (PDS) in at least one eye. Exclusion criteria of note: currently pregnant or breast feeding; concurrent use of a non-glaucoma eye mediciation; narrow angles or synechiae on gonioscopy; less than 6 months status post glaucoma surgery (,aser or otherwise); recent ocular inflammation; known allergy or contraindication for either drug; history of non-compliance; and medically unstable. All patients enrolled were judged by the examiners to be stable enough to participate in the study for the full duration. Selection was limited further to patients with an IOP greater than 21 on a maximum of one glaucoma mediciation. No person with rapid visual loss or severely elevated pressure was selected.
Effect on intraocular pressure: 6 months Latanoprost - 6.7+/- 3.4 mmHg (27%) Timolol 4.9+/- 2.9 mmHg (20%)
No significant difference in ocular symptoms/complaints were noted between the two medications.
This is the third paper to clearly show 0.005% Latanoprost given once daily is more effective than Timolol 0.5% given twice daily over a six month period. It may become the first line therapy for the treatment of glaucoma.
Raymond G. Magauran, M.D.
Buffalo, New York
| [ ORJ-Subject ] | [ ORJ-Date ] | [ IO Home ] | [ Glaucoma ] |
Laser iridotomy OD eliminated the concave iris configuration in the untreated state. Exercise testing was repeated several weeks later. Prior to exercise, IOP was 18 mmHg OD and 19 mmHg OS, and there was no detectable pigment in the anterior chamber in either eye. Thirty minutes after playing basketball for two hours, anterior chamber pigment was 2+ OD and 4+ OS and IOP was 21 mmHg OD and 36 mmHg OS.
Two weeks later he underwent exercise testing after pretreatment with one drop of 0.5% pilocarpine OU. Prior to exercise, IOP was 17 mmHg OD and 19 mmHg OS, and there was no detectable anterior chamber pigment in either eye. Thirty minutes after exercise, there was still no detectable anterior chamber pigment in either eye and IOP was 15 mmHg OD and 17 mmHg OS. Gonioscopy revealed a flat iris contour OD, while that OS was slightly convex.
Ultrasound biomicroscopy (UBM) was performed OU before and after treatment with pilocarpine. The iris configuration OD was planar both before and after pilocarpine. The peripheral iris OS was concave prior to pilocarpine and became convex after treatment.
Some patients with PDS have a burst of pigment liberation into the anterior chamber accompanied by a sudden rise in IOP after pharmacologic pupillary dilation or after exercise. 2, 4, 5, 9, 11 Pretreatment with pilocarpine before exercise can prevent this phenomenon, presumably by elimination of iridozonular contact. 4
Miotics not only lower IOP, but produce relative pupillary block, eliminating iridozonular contact. UBM of eyes with PDA has shown that pilocarpine not only eliminates the peripheral iris concavity and iridozonular contact, but causes a slightly convex contour. 10 Ideally, treatment would not only lower IOP but would eliminate iridozonular contact. Patients treated for prolonged periods with miotics develop reversal of the pigment signs of PDS and normalization of intraocular pressure. 12 Younger patients often cannot tolerate miotic drops, which produce accommodative spasm and blurred vision, but, in our experience, do well with pilocarpine Ocuserts, which deliver a sustained, low concentration of pilocarpine. 13, 14
More recently, laser iridotomy has been noted to eliminate the iris concavity. 1, 7, 8 Flattening of the iris concavity after iridotomy has been confirmed by UBM. 3, 10 There appear to be exceptions, however. 6 It has been hypothesisized that a reverse pupillary block prevents free passage of aqueous between the posterior and anterior chambers, resulting in a higher pressure in the anterior chamber than in the posterior chamber. 1, 7 Iridotomy equalizes the pressure differential between the two compartments.
In our patient, laser iridotomy eliminated the iris concavity and produced a planar configuration, while pilocarpine produced a convex one. After exercise, there was moderate pigment liberation into the anterior chamber and a slight rise in IOP in the eye which had had the iridotomy, while pilocarpine in the fellow eye again completely prevented this phenomenon. Topical pilocarpine administered to the eye which had had the iridotomy successfully prevented pigment liberation during exercise.
The fact that pigment liberation can still occur after iridotomy raises the possibility that pigment dispersion may be a result not only of the posterior concavity of the iris, but also of iris flaccidity. Miotic-induced relative pupillary block appears more effective than iridotomy alone at eliminating pigment liberation during vigrous exercise. Further investigation comparing the long-term effectiveness of miotic treatment and iridotomy at preventing progression of pigment dispersion appears warranted.
Robert Ritch, M.D.
NY, NY
| [ ORJ-Subject ] | [ ORJ-Date ] | [ IO Home ] | [ Glaucoma ] |
The study is retrospective. The title refers to the authors experience with neovascular glaucoma yet this diagnosis represents only 33% of the cases. The ideal study would be a prospective study using one sized Baerveldt implant (350mm according to the study), only one preÐoperative diagnosis, one implantation technique including tube inclusion during the early (question hypertensive) phase. I would also exclude patients who have undergone or require penetrating keratoplasty. 8 of the 28 eyes requiring penetrating keratoplasty prior to or during the surgical procedure ultimately rejected or failed. Given the restrictions for creating such a study, the results obtained may be the best data we can obtain.
Initial studies reported success rates with shunting devices from 58 to 83%. The overall success rate in this retrospective study was 72%. Success was defined as a pressure less than or equal to 21 mm of mercury. In order to be considered successful, no further surgical intervention including laser could be undertaken. In addition, loss of light perception vision qualified a patient as a failure. Use of glaucoma medications postÐoperatively was not an element of the author's qualification for success. 43% of the eyes required medication postÐoperatively. For intractable glaucomas having such devastating diseases as neovascular glaucoma or glaucoma refractory to standard guarded trabeculectomy procedures, the Baerveldt implant offers a reasonable alternative. It is easier to implant compared to a double plated molteno. However, as with all shunting devices the complication rate is fairly high. Diligent care and prompt intervention will minimize the long term consequences and one may begin to approach the excellent success rates the authors have achieved.
Raymond Magauran, M.D.
Buffalo, New York
| [ ORJ-Subject ] | [ ORJ-Date ] | [ IO Home ] | [ Glaucoma ] |
Raymond G. Magauran, M.D.
Buffalo, New York
| [ ORJ-Subject ] | [ ORJ-Date ] | [ IO Home ] | [ Glaucoma ] |