title: Intraocular pressure changes in the contralateral eye after topical treatment: does an "ophthalmotonic consensual reaction" exist?
abstract: BACKGROUND
  The existence of "ophthalmotonic consensual reaction," a contralateral change in intraocular pressure in the fellow eye induced by treatment of the first eye only, was suggested in 1924. Since then, the validity of this mechanism has been controversial.
  
  
  OBJECTIVE
  To assess intraocular pressure changes in the contralateral fellow eyes of patients treated with IOP-lowering medication in one eye, and investigate the existence of an ophthalmotonic consensual reaction.
  
  
  METHODS
  The study population included 38 patients with newly diagnosed bilateral ocular hypertension or early open angle glaucoma. One eye of each patient was randomly treated with one of five compounds: prostaglandin analogues, beta-blockers, alpha-2 agonists, carbonic anhidrase inhibitors and a combination therapy: dorzolamide hydrochloride-timolol maleate (Cosopt, Merck Sharpe & Dohme). The eye with the higher baseline IOP was selected to be the treated eye. After 3 weeks a masked examiner measured the IOP in both the treated and untreated eye.
  
  
  RESULTS
  Mean IOP of the treated eyes at baseline was 26.1 +/- 4.2 mmHg and at follow-up 20.2 +/-2.9 mmHg, a reduction of IOP from baseline of -6 +/- 3.8 mmHg, a mean percent reduction of -22 +/- 10.1%. In the contralateral eyes, the mean IOP at baseline was 24.2 +/- 3 mmHg and 23.1 +/- 3.1 mmHg at follow-up; IOP reduction from baseline was -1.2 +/- 1.8 mmHg, or mean percent reduction -4.7 +/- 7.1%. A major contralateral IOP decrease was seen only in the beta-blockers and the combination (Cosopt) treatment groups (-6.1 +/- 8.3% and -12.3 +/- 8.3% mean percent reduction, respectively, P < 0.05). The contralateral eyes in the prostaglandin analogues, CAI or alpha2-agonist groups showed only a small change in IOP (-2.6 +/- 4.6%, -3.2 +/- 2.6%, +0.7 +/- 3.3%, mean percent reduction, respectively, P < 0.05).
  
  
  CONCLUSIONS
  The existence of an ophthalmotonic consensual reaction was not supported.
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. hadasng@gmail.com
authors.forename: Hadas
authors.initials: H
authors.lastname: Newman
authors.forename: Shimon
authors.initials: S
authors.lastname: Kurtz
authors.forename: Robert
authors.initials: R
authors.lastname: David
mesh_terms: D000287:Administration, Topical; D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology; D015331:Cohort Studies; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009798:Ocular Hypertension / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D009883:Ophthalmic Solutions; D011465:Prostaglandins, Synthetic / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D013999:Timolol / Q000494:pharmacology
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D002257:Carbonic Anhydrase Inhibitors; D004338:Drug Combinations; D009883:Ophthalmic Solutions; D011465:Prostaglandins, Synthetic; D013449:Sulfonamides; D013876:Thiophenes; C479140:dorzolamide-timolol combination; D013999:Timolol