|Degree:||doctor of medicine|
|Speciality: ||14.00.08 - Ophthalmology|
doctor habilitat, professor, State University of Medicine and Pharmacy "Nicolae Testemitanu"
The thesis was presented on the 6 September, 2006
Approved by NCAA on the 26 October, 2006
– 0.47 Mb / in romanian
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secondary cataract, pseudofak, medico-social rehabilitation, Nd:YAG-laser, visual impairment
Secondary cataract (SC) is one of the late complications following extracapsular cataract extraction that diminishes the functional efficiency of the operation and causes professional and social disadaptation of the patients. Based on literature references, it appears in terms from 3-4 weeks to 5 years after the surgery, and has an incidence of 3,6-87% cases. Clinical and morphological manifestations are various. Despite of the multitude of prophylactic measures, two main methods of management are known:
- 1) laser treatment;
- 2) surgery.
This study based on 160 SC patients aimed multilateral examination of the patients and visual impairment estimation, elaboration of therapeutic strategy, optimization of the treatment procedure, visual efficiency prognosis, prevention of intra- and post treatment complications, evaluation of the results, early rehabilitation of the patients. All the patients have been investigated using traditional methods and special techniques (ultrasound examination, autorefractokeratometry, etc.). All the patients demonstrated reduced visual acuity in the pretreatment stage (0,19±0,01). Visual impairment was more severe and appeared earlier in the group of patients with inflammatory type
of SC (capsulofybrosis, pupilary membrane). The study demonstrated, that the most common type of SC in afakia patients was posterior capsule opacification with Elschnig “pearls” (58,5% cases), in pseudofakia patients - capsulofybrosis (70,1% cases). During the study the mecanism of optic aberrations caused by SC was revealed: posterior capsule irregularities and folds disperse the light
rays inside the eye making the image on the retina unclear. Taking into account the origin of this phenomenon it was described as “capsular astigmatism”.
According to the method of treatment for SC all the patients were distributed into 2 main groups:
- • I group enrolled 110 patients (68,75% cases) treated by Nd:YAG-laser
- • II group – 50 patients (31,25% cases) treated surgically included the following cases: uncompliant patients, afakia associated to highest myopia (>20D), thickness of posterior capsule more than 1 mm (capsulofybrosis grade IV), lack of technical equipment (laser).
The treatment procedure was in dependence of clinical-morphological type of SC:
- - in cases of capsulofybrosis (92 patients - 57,5% cases) posterior capsulotomy was made using the following types of capsule openning: cross, circular, concentric and multifoveolar. The last type was proposed to afakia patients to keep the posterior capsule as natural barier between intraocular structures.
- - In presence of Elschnig “pearls”(48 patients - 30% cases) peeling of the posterior capsule or capsulotomy were made.
- - To optimize the treatment procedure in SC patients it was decided to differenciate as a separate clinical-morphological type “pupilary membrane” which presents an inflammatory exudate in pupilary area adhesive to the iris independent of IOL presence.
In cases of pupilary membrane (20 patients - 12,5% cases) the problem was solved by discision, excision or desintegration of it.
Following the treatment of SC visual acuity increased in all the persons. Multilateral examination of the patients in pre- and post treatment period, statistic analysis of obtained data gave the possibility to predict early visual efficiency and risk of postoperative complications. In presence of associated ocular pathology (glaucoma, central retinal degeneration, vitreous opacity and 107 posterior vitreous detachment, neuro-sensorial system disorders and others) the functional result of SC treatment is clouded in 79,24% cases in dependence of type and severity of concomitant diseases.
Nd:YAG-laser treatment of SC is efficient, modern, mini-invasive, possible to perform in outpatient department, contributes to early medical and social rehabilitation of the most of the patients. To minimize the adverse effects of laser energy all the patients followed post treatment medication witch included antioxidant agent “Aevit” in capsules (1 capsule 3 times per day 1 months). In the early post treatment stage visual acuity increased up to 0,4-1,0 in the most of laser-treated patients (87 cases – 79,1%). In the surgical group visual acuity reached 0,1-0,7 values in 92% cases (46 patients) in the same terms.