Investigating The Eyes After Trabeculectomy Under Gonioscope

ObjectIn this thesis paper we try to make a detailed portray to the anterior chamber angle in the surgery eyes suffering from PACG after successful trabeculectomy in order to better understand the state of the illness after trabeculectomy and as a control to the gonioscope examination of the failed cases.Methods1. This research is a clinical case analysis. Following the Edited Helsinki Declaration (1989, HONKON), every patient in this research had signed the informing contract.2. All the 14 patients (17 eyes) in this research have processed integrated examinations before and after the surgery conducted in our hospital including Gonioscope, split-lamp, tonometer, and other ophthalmic routine examinations. The patients in this research are primary angle-closure glaucoma patients who have received trabeculectomy (whose IOP is 21mmHg or higher before the surgery, anterior chamber angle is narrow in some degree, visual field has already been damaged or not yet, the optic nerve has already been typically cupped or not yet). If both the two eyes of a particular patient are eligible, the order of the examination to the two eyes is right first. All patients in this research is in the period of 3 months-5 years after trabeculectomy.The standard to exclude a patient are having received eye surgery other than trabeculectomy, having received trabeculectomy for two times or even more, atretopsia, using mydriatic drugs etc.3. The IOP is examined by non- contact tonometry at 3 Pm afternoon, theaverage of the IOP results for consecutive 3 times is used for statistical analysis. The modality of anterior chamber angle is obtained by gonioscope examination, the modality of the iris is obtained by split-lamp. Besides, the patients also received routine ophthalmic examinations, including the examination of visual activity, refraction status, ocular fundus cupping status etc.4. In clinical sense, in Scheie's anterior chamber angle grading system, patients with N Ⅰ chamber angle rarely happen angle-closure glaucoma, generally speaking, patients with N Ⅱ chamber angle, also rarely happen angle-closure glaucoma. Consequently, in this research we consider a quadrant is narrow when the anterior chamber angle is graded N Ⅲ or N Ⅳ level.5. The modality of the iris in iridectomy site is portrayed by the following four indexes: whether the iridectomy puncture is located at iris root and penetrates through all layers, whether the iris root residue is anterior synechia with the trabecular tissue, the adherence extent of the iris edge around the puncture, the adherence severity of the peripheral portion iris.6. In this research, all statistics analysis is conducted by t test or x 2 test according to the character of the data. All assessments are on the level of 5%.Results①There's no difference between the anterior chamber angle before and after the surgery of trabeculectomy.②There's difference between the condition of the whole anterior chamber angle and the condition of the anterior chamber angle in the site of trabeculectomy, the latter's iris root inserting position goes more forward in position.③17.6% surgery eyes' iris puncture after iridectomy is not located at iris root; 52.9% surgery eyes' iris residue is adherent to trabecular tissue in site iridectomy; 41.7% surgery eyes' iris anterior synechia bound in site iridectomy is more than 120%; 17.6% surgery eyes' peripheral portion iris anterior synechia degree is more than 1mm; 88.3% surgery eyes' anterior chamber angle in site iridectomy is 20° or narrower, concomitant with iris root inserting position leaning forward or not; 11.8% surgery eyes' anterior chamber angle pigmentation is grade Ⅲ or even more.DiscussionThere are four grading systems to the anterior chamber angle now, Scheie's grading system[9], Shaffer's grading system, Spaeth[10]'s grading system and Vanherick's grading system[11], grading the anterior chamber angle from different point. Meanwhile, the anterior chamber angle pigmentation grading system grades the pigmentation of anterior chamber angle to 5 levels. Compared with Scheie's grading system, Spaeth's grading system is more all-rounded to portray the anterior chamber angle than the Scheie's grading system from the following several aspects: iris root inserting position, width of anterior chamber angle, modality of iris, anterior chamber angle pigmentation. However, doctors of the patients in our research used only Scheie's grading system before their trabeculectomy, so we can't use Spaeth's grading system to assess the change of the anterior chamber angle modality in full length, and leave a defect to the research. Also, in clinical sense, in Scheie's anterior chamber angle grading system, patients with N I chamber angle rarely happen angle-closure glaucoma; and generally speaking, patients with N Ⅱ chamber angle, also rarely happen angle-closure glaucoma. Consequently, in this research we consider a quadrant is narrow only when the anterior chamber angle is graded N Ⅲ or NⅣ level, and use how many quadrants are narrow to reflect the condition of the anterior chamber angle narrowness.Through the 4 indexes portraying the modality of the iris in site iridectomy and the peripheral portion iris, we can assess the condition of the iris after iridectomy in more detail. The adherence severity of the peripheral portion iris can be calculated with the zoom multiple of the slit-lamp and gonioscope and its leaning degree.ConclusionThere's no difference between the anterior chamber angle before and after the surgery of trabeculectomy. There is difference between the modality of the whole anterior chamber angle and that in site iridectomy to patients after trabeculectomy. Moreover, we suppose that the factors promoting the failure of...