RESUMO
Background/Aim: Inhalational methanol poisoning could cause severe damage to visual function. This study analyzed the prognosis of the correlation between the visual function and the relevant risk factors. Methods: In this retrospective study, 14 patients had confirmed inhalational methanol poisoning, resulting in visual impairment in both eyes. The following tests were performed: laboratory tests, best corrected visual acuity (BCVA), intraocular pressure, slit lamp, fundus photography, visual field (VF), pattern visual evoked potential (P-VEP), flash electroretinogram (F-ERG), optical coherence tomography (OCT), and orbital or cranial magnetic resonance imaging (MRI). Results: With active treatment, visual function improved to varying degrees in all 14 cases (28 eyes) in this study. The BCVA of 21 eyes declined to no light perception at the onset; 16 eyes showed different degrees of improvement after treatment, with the final BCVA (LogMar) mainly ranging from 2 to 3, and vision acuity stabilized after the 5th month. The VF pattern in the acute phase was mostly blind. Other VF patterns included the central visual island, large paracentral scotomas, hemipleural VF defects, and the temporal visual island. Retinal nerve fiber layer (RNFL) thickening was observed commonly in the acute phase (146.8 ± 33.2 µm), which subsided in the 1st month, showed dramatic thinning at the 3rd month, and then stabilized in the 5th month after onset. MRI showed that the main sites involved were optic nerve impairment, the optic disk, and retrobulbar segments. The basal ganglia region was the site most involved in the central nervous system (CNS). Conclusion: Inhalational methanol poisoning could lead to severe impairment of visual function, and the prognosis of visual acuity (VA) was highly relevant to the risk factors of duration of toxic exposure, delayed admission, and degree of acidosis.
RESUMO
OBJECTIVE: To study the clinical effects and safety of the auxiliary management with iris retractor for subluxated lens combined with cataract. METHODS: Thirty-one eyes lens subluxation with cataract come from 27 patients were reviewed, all of them were 30 - 78 years old and III - IV grade of nuclear. Among these patients, 14 were traumatic cataracts, 12 Marfan syndromes, two over-mature phase of cataracts, one caused suspensory ligament broken during phacoemulsification, and one unclear reason. 1 to 4 iris retractors were used during surgeries, according to the extension of zonular loss and nuclear hardness. Anterior vitrectomy would be taken if vitreous prolapsed. Visual acuities and reactions post-operative were observed, too. And correlation analysis would be used to study the relationship of those objections. RESULTS: There were no serious complications during the surgeries such as tearing of capsular, falling of nuclear, bleeding of intraocular, and so on. Only 9 of 31 eyes (29.0%) had vitreous prolapsed interoperation, which appeared a significant correlated with range of zonular loss (Spearman r = 0.453, P = 0.010). However, none of them happened during the phacoemulsification for lens nucleus and only 6 eyes took the anterior vitrectomy. The best corrected postoperative visual acuity of these patients attended to 0.2 - 1.2 at a half to 1 month, increased by 1 - 12 lines [average of (6.0 ± 2.7) lines] compared with preoperative. Twenty-three eyes visual acuity of them were no less than 0.5. Corneal edema postoperatively appeared a significant correlated with vitrectomy (Spearman r = 0.398, P = 0.026), while seemed no associated with the range of zonular loss, the number of iris retractors, energy and duration of ultrasound burst or type of intraocular lens (IOL) (P > 0.05). CONCLUSIONS: Phacoemulsification assists with iris retractor can simplify the process of cataract surgery of subluxated lens. Individualized surgical planning and flexible and decisive measures intra-operative achieved good results and well safety in these dangerous and complex lens diseases.
