緑内障眼における網膜神経線維層厚の経時的変化

Longitudinal changes in retinal nerve fiber thickness in glaucoma eyes

（D−7PM−11）　正常人14例24眼，正常眼圧緑内障（NTG）15例24眼，原発開放隅角緑内障（POAG）25例39眼に対して，初回，6か月後，12か月後にNerve Fiber Analyzer GDx^TMを用いて網膜神経線維層厚（RNFLT）を測定し，各パラメーターに関して検討を加えた。さらに，初回，12か月後にハンフリー自動視野計で視野を測定し，MD値を解析した。全群で6か月後に全てのパラメーターに有意差はなく，12か月後に有意差が認められたのは，NTG群でSup．Max, POAG群ではInf．Max,Inf．Ratio，Max．Mであった。MD値は正常人，POAG群ともに12か月後に有意差を示さず，NTG群では有意な低下を示した。早期緑内障群（MD≧−5.0dB）ではNTG群，POAG群間で初回のMD値に有意差はなく，早期POAG群のみで12か月後にInf．Ratio, Max, Mが有意差を示した。以上より，POAGでは視野障害の進行に先行して下象限のRNFLTが減少する可能性が示唆された。

We examined the retinal nerve fiber layer thickness (RNFLT) in 87 eyes. The series comprised primary open-angle glaucoma (POAG) 39 eyes, normal-tension glaucoma (NTG) 24 eyes and 24 normal eyes. RNFLT was measured by a Nerve Fiber Analyzer GDX^TM at 6-month interval up to 12 months. The visual field was evaluated for MD value using a Humphrey automated perimeter initially and at 12 months. There was no change in RNFLT at 6 months. Significant changes were present at 12 months regarding Inf Max, Inf Ratio and Max M in POAG eyes and Sup Max in NTG eyes. The MD value showed a significant decrease at 12 months in NTG eyes only. There was no significant difference in initial MD value between early POAG and NTG eyes with MD value of -5.0 dB or greater. The findings show that RNFLT in the inferior sector may be decreased in POAG eyes before manifest field defect shows progression.