Relation of response to treatment with dorzolamide in X-linked retinoschisis to the mechanism of functional loss in retinoschisin.
OBJECTIVE
To determine if a positive response of macular cysts to treatment with dorzolamide eye drops in patients with juvenile X-linked retinoschisis (XLRS) can occur with mutations that result in different types of retinoschisin protein dysfunction.


METHODS
Retrospective case series.


METHODS
Thirteen eyes of seven patients seen at the University of Illinois at Chicago with a known diagnosis of XLRS were included. Each patient had received or currently was receiving treatment with topical dorzolamide. One patient from each family was screened for a genetic mutation. Using the method of cell transfection and protein preparation, the mutation in each patient was analyzed further and was categorized into one of three groups: 1) total absence of retinoschisin protein secretion, 2) decreased expression of the secreted protein, or 3) secretion of a nonfunctional protein. The response to dorzolamide was observed using optical coherence tomography.


RESULTS
Significant improvement in the foveal zone thickness was observed with the use of dorzolamide in three of four patients with absence of protein secretion, in two patients with a lack of protein expression, and in one patient with a nonfunctional protein secretion.


CONCLUSIONS
This study showed that the response of macular cysts to dorzolamide in patients with XLRS may be observed independent of the mechanism responsible for retinoschisin protein dysfunction. Hence, treatment with dorzolamide may be effective in patients with different mechanisms of dysfunction in retinoschisin.
Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
Saloni
S
Walia
Gerald A
GA
Fishman
Robert S
RS
Molday
Frank M
FM
Dyka
Nalin M
NM
Kumar
Mary A
MA
Ehlinger
Edwin M
EM
Stone
D000328:Adult; D015153:Blotting, Western; D002257:Carbonic Anhydrase Inhibitors / Q000627:therapeutic use*; D003560:Cysts / Q000188:drug therapy; D004252:DNA Mutational Analysis; D005136:Eye Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008297:Male; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D009883:Ophthalmic Solutions / Q000627:therapeutic use; D016133:Polymerase Chain Reaction; D041441:Retinoschisis / Q000188:drug therapy* / Q000235:genetics*; D012189:Retrospective Studies; D013449:Sulfonamides / Q000627:therapeutic use*; D013876:Thiophenes / Q000627:therapeutic use*; D041623:Tomography, Optical Coherence; D055815:Young Adult
D002257:Carbonic Anhydrase Inhibitors; D005136:Eye Proteins; D009883:Ophthalmic Solutions; C108726:RS1 protein, human; D013449:Sulfonamides; D013876:Thiophenes; C062765:dorzolamide