OCT in choice of tactics for idiopathic macular hole treatment

Khristo Takhchidi, O. A. Ulasevich (Moscow)

Background: The frequency of idiopathic macular holes (IMH) in human population is 1 :3300 (Ezra E, 2001). Their distribution by stage according to classification of Gass is the following: stage 1 – 7%, stage 2 – 29 %, stage 3 – 49 %, stage 4 –23% (Johnson RN, Gass JDM, 1988). Prevailing meaning of vitreofoveal tractions by posterior
hyaloid membrane (PHM) in the development and prograssion of IMH has been
proved. Nowadays only surgical intervention gives a possibility to eliminate tractions and to achieve not only retinal status stabilisation, but also visual acuity improvement. Visual prognosis of IMH in stages 3 and 4 surgical trearment is determined by duration of hole existence, its size and involvement of adjacent retinal layers (Michael SI, Brad JB, Jay SD et all. 2002; Ullrich S, Haritoglou C, Gass C et all. 2002). Reasonability of surgical treatment of stage 2 and, especially, stage 1 is still debated. It may be explained by multiple factors: relatively hifh visual acuity in initial stages, possible intra- and postoperative complications, difficulty of result forecast.
According to literary data, transition of stage 1 into stage 2 makes from 27% to 89% (Akiba J et all. 1992, 1991, 1990), from stage 2 into stage 3 or 4 – about 74 % (Kim JW, Freeman WR, El-Haig W et all. 1995). At the same time there are publications concerning spontaneous closure of IMH in stages 3 and 4 – up to 10 % – and self-treatment or stabilisation of IMH in stage 1 – up to 30-50 % (Kokame GT, de Bustros S, 1995).
Optical coherence tomography (OCT) is one of modern non-contact and highly accurate methods of vitreoretinal space investigation with resolution of 10 microns that gives a possibility to estimate vitreoretinal interface with
high reliability.
Aim of our investigation is to develop the employment of preoperative and dynamic OCT for tactics choice in surgical treatment of IMH.
Patients and methods: Thirty-eight eyes with various IMH stages operated in our clinic have been analyzed.
Stages distribution was as follows: stage 1 (group 1) – 5 eyes (13 %), stage 2 (group 2) – 9 eyes (24%), stage 3 – 14 eyes (37%) and stage 4 – 10 eyes (26 %) – group 3.
Besides standard investigations, all the patients underwent OCT of both eyes. The purpose of OCT was to define the size of IMH, to specify IMH stage, to disclose posterior vitreous detachment and to perform differential diagnostics
in doubtful cases. In stages 1 and 2 more detailed scanning was performed including not less than 6 radial scans through the macular region and determining of PHM status, localization and direction of hyaloido-
foveolar fixation points, extent and configuration of the hole as well as revealing of “thin” or “weak” zones of the retina dangerous for retinal break. On the basis of OCT data zone of initial separation of PHM was determined (Takhchidi KP, Ulasevich OA, Kurbatov IV, 2002).
Patients with IMH stages 1 and 2 underwent dynamic follow-up. Surgery was planned in case of patient’s complains of worsened vision (even if objective visual acuity did not become worser) on mandatory condition of OCT
data confirming an increase of foveolar tractions.Specific tactics of surgical intervention was developed for every IMH stage. In stage 1 surgery was minimal. PHM separation in foveal region and, if necessary, partial posterior vitrectomy was performed. In stage 2 PHM separation and subtotal posterior vitrectomy with subsequent gas tamponade (25% C4F8 ) was used. In stages
3 and 4 PHM was separated, autologous platelets were applied to the hole as an adjuvant and gas tamponade (25% C4F8 ) was performed. In cases with pronounced radial folds of the internal limiting membrane (ILM)
around the hole, ILM was stained with 0.05 % trypane blue and circular maculorhexis was performed. Before adjuvant application and gas injection pneumatic compression of vitreous remnants for 10 minutes was performed
in all the patients. Prior to the end of surgery peripheral retina was examined and, in necessity, endolasercoagulation around the breaks was performed.
Results: The patients were followed for 9 months after surgery. Visual acuity (decrease, stabilization or increase) and changes of IMH profile at OCT were estimated. Criteria of IMH profile assessment were the following:
achievement of normal foveal profile, smoothing of IMH edges, no changes, increase of IMH size.
In group 1 (5 eyes) visual acuity increased in 4 eyes and remained unchanged in 1 eye. In group 2 (9 eyes) visual acuity increased in 5 eyes, stabilized in 1 eye and decreased in 3 eyes (in 2 due to cataract and in 1 eye with high myopia retinal detachment occurred). In group 3 (24 eyes) visual acuity improved in 14 cases, stabilized in 4 and decreased in 6 (5 eyes with cataract progression or development, 1 eye with recurrent IMH). No cases of IMH size increasing postoperatively were marked. In group 1 all the eyes showed normal foveolar profile at OCT. In group 2 (9 eyes) 7 eyes showed normal foveolar profile and one eye – smoothing of hole edges. In group 3 (24 eyes) 2 eyes did not show changes of IMH profile, 14 showed normal foveolar profile and
8 – smoothing of IMH edges.
Conclusion: Preoperative OCT gives a possibility not only of differential diagnostics and definition of correct diagnosis in doubtful cases as well as of visual forecast, but also – which is not less important – to obtain important
information about the presence of hyaloido – foveolar fixation, its extent and direction in initial IMH stages. Dynamic follow-up of cases with hyaloid0foveolar fixations gives a possibility of timely decision about surgical
treatment of initial IMH stages. The employed tactics of IMH surgical treatment based on OCT data is reasonable as it gives a possibility to obtain positive functional results, minimize intra – and postoperative complications and perform the operation with minimal traumaticity of the fovea.
The suggested approach to surgical treatment of initial IMH stages requires further detailed analysis.



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