Summary of medical doctoral thesis study on the efficacy of surgical treatment for recurrent retinal detachment

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH HANOI MEDICAL UNIVERSITY BUI HUU QUANG STUDY ON THE EFFICACY OF SURGICAL TREATMENT FOR RECURRENT RETINAL DETACHMENT Speciality: Ophthalmology Code: 62720157 SUMMARY OF MEDICAL DOCTORAL THESIS HANOI – 2020 THE THESIS WAS PRESENTED AT HANOI MEDICAL UNIVERSITY Supervisors: Associate Professor Cung Hồng Sơn, PhD Reviewer 1: Reviewer 2: Reviewer 3: The thesis will be defended in front of the University Thesis Evaluation Council At Hanoi Medical University At the time of day month year 2020 The thesis can be found at: Vietnam National Library Library of Hanoi Medical University BACKGROUND Primary retinal detachment is a serious disease that is difficult to treat, its prevalence is about case / 10000 people a year The disease can cause blindness if not treated properly or in case of treatment failure Since the 1970s, the introduction of vitrectomy technique has made a fundamental change in the treatment of retinal detachment (RD) However, RD is still a severe disease that is difficult to treat, and the failure rate varies according to the clinical forms of retinal detachment There may be almost no failure in the case of simple retinal detachment without vitreo-retinal proliferation (PVR) but can reach 50% in more severe forms According to Girard et al (1994), the relapse rate was about 4.75% in a study of 1136 retinal redetachment eyes in 1073 patients Recurrent retinal detachment (RRD) can occur very early after retinal detachment or later after months or years The characteristics of RRD are much more clinically complex as well as more difficult to manage In Vietnam, there have been a number of reports on RRD that many authors mentioned clinical, etiology, treatment methods However, there has not been a comprehensive clinical study of the causes of RRD and the treatment of RRD Therefore, we conduct research topics "Study on the efficacy of surgical treatment for recurrent retinal detachment" aim to: Describe the clinical features of recurrent retinal detachment Find out the causes of recurrent retinal detachment Evaluate the result of surgical treatment and related factors of recurrent retinal detachment MEANING AND NEW CONTRIBUTION - This is the first study of recurrent retinal detachment in Vietnam with a sufficiently large number of patients and a relatively long followup period - The study has summarized the clinical characteristics of recurrent retinal detachment quite comprehensively and the treatments corresponding to each morphology, thereby pointing out the relationships between clinical characteristics and surgical results - The study has initially assessed the results of surgical methods to treat recurrent retinal detachment The study has drawn a number of suitable surgical indications for each particularly recurrent retinal detachment The surgical methods applied to achieve a high rate of retinal reatachment after surgery and improved vision for patients THESIS STRUCTURE The thesis consists of 131 pages Introduction pages, an overview of literature 44 pages, subject and methodology 16 pages, research results 32 pages, discussion 33 pages, conclusion pages, future works page In the thesis, there are 31 tables, 11 charts, figures, and illustrations with photo pages The thesis uses 105 references including 15 Vietnamese, 14 French, the rest are English, including 23 documents in the past 10 years Chapter AN OVERVIEW OF LITERATURE 1.1 Recurrent retinal detachment 1.1.1 The concept of Recurrent retinal detachment Recurrent retinal detachment is phenominent of a RD successfully operated then because of any reason the retina was redetached The concerpt of recurrent retinal detachment is still controversy Some cases were misunderstood between recurrent retinal detachment and the failure of operation.Distintion of this different is not really clear They suposed that after a good operation, retina was reatached but some risk factors make retina redetached again, it could be considered as a recurrent retinal detachment 1.2 Clinical characteristics of recurrent retinal detachment Time varies with each study of the different authors: According to Foster (2002), days According to Benson (1988) before weeks, after weeks According to Hilton (1989) after months 1.2.1 Symptoms of recurrent retinal detachment - Mechanical symptoms - Physical symptoms 1.3 Causes of recurrent retinal detachment 1.3.1 The cause belongs to the tear 1.3.1.1 Missing tears 1.3.1.2 Reopen the old tear According to Sicault (1968): 8.4% due to reopening old tear According to Smiddy in the study of 26 cases, the author found that: 30.8% misplaced retinal tear site, 19.2% misplaced but not protruding enough to support the retina to reattache 1.3.1.3 Due to the new tear When impacted on the eyeball and the retina DK causes the shrinkage into the retina DK as the reason of the retinal tearing 1.3.1.4 Risk factors of surgery with Recurrent retinal detchment * Influence of chorioretinal adhesion: Cryotherapy and photocoagulation overdose * Time of new tear formation - Peroperative: shrinkage due to surgical operations - Postoperative early: due to strong pulling of the air balloon, the patient's posture is not good - Postoperative late: due to the traction of vitreoretinal proliferation * New types of tear * Complications during, after surgery, handle complications 1.3.1.5 Relevant factors of the patient's compliance to postoprerative posture Follow correct postoperative posture helps to heal the tear, It is found that the inflammatory reaction will reach a maximum from day to 810 days after surgery 1.3.2 Cause by vitreous condition - Shrinking vitreous body - Transformation of vitreous body: liquerfaction of vitreous body, - Due to the postoperative inflammatory reaction - Due to the vitrectomy 1.3.2.1 Cause by vitreoretinal proliferation According to the retina association since 1983, vitreoretinal proliferation is a mask of vitreous traction, preretinal membrane mask of preretinal proliferation Vitreoretinal proliferation causes a retinal detachment complication and is the cause of 75% of surgical failure * The hypothesis that pathogenesis of vitreoretinal proliferation is a process similar to the process of scarring elsewhere in the body includes: - Inflammatory phase characterized by platelet activity - Synthesis stage: F.G.F (Fibroblast Growth Factors) - Stage of shrinkage: due to the shrinkage, it leads to the risk of reopening treated tear and creating new ones 1.3.2.2 Risk factors causing PVR in Rhegmatogenous retinal detachment * Favorable factors for vitreoretinal proliferation - The degree of pigment epithelial revealed in RD: tear - Inflammatory reaction before and after surgery - Posterior vitreous detachment is not completely - Time to delay RD surgery - Hemorrhage in the vitreous, anterior chamber and under the retina - Surgical operations such as coagulation or laser can cause PVR * Clinical factors out of risk factors of vitreoretinal proliferation in operation According to Bonnet: -Increased DKVM before surgery in stage C - The circular expansion of the tear has a flap width of 90 degrees or more - The flanging and fixing of a flap with a flap has a risk of about 26.5% - Black choroid before surgery, but this is still being debated 1.4 Treatment of recurrent retinal detachment 1.4.1 Rule of treatment - The first is surgery to re-attache the retina - The second is the treatment of vitreoretinal proliferation 1.4.2 The treatment of relapses 1.4.2.1 Examining and detecting the cause recurrent retinal detachment 1.4.2.2 Internally medical treatment Summary of research by Ghasemi Falavarjanin et al 2014 on medical treatment of anti-inflammatory drugs, corticosteroids, restriction of inflammatory reactions, Bevacizumab usually takes 6-12 weeks 1.4.2.3 Surgical treatment Some techniques used in RD surgery: the previous surgery may make the changes of anatomical landmarks, scarring between the membranes * Examination : * Preparation for surgery * Surgical operations: * Causes sticky inflammatory reaction: - Cryotherapy from outside the sclera around the tear - Photocoagulation: also according to general principles, can use intraocular laser, or external * External indentation * Scleral buckling * Drainage under the retina * Vitrectomy: Vitrectomy is indicated in case of vitreous opacity, vitreoretinal traction, peelling and cutting preretinal membrane *Internal indentation: 1.5 Results of RD treament - Summary of research by Raffaele Mancino et al (2015) on the results of retinal detachment treament - Summary of research by Ghasemi et al (2014) on the results of retinal detachment treatment Chapter SUBJECTS AND METHODOLOGY 2.1 Research objects Patients who have rhegmatogenous retinal detachment treated being recurrent came to visit and treated at Department of Trauma and Vitreoretinal department- Vietnam National Ophthalmology Hospital from January 2013 to September 2015 2.1.1 Selection criteria - Patients who have rhegmatogenous retinal detachment treated, retina is attached after discharge then got a redetachment Having complete medical records of previous surgery Agreed to participate in the study 2.1.2 Exclusion criteria: - Patients have other retinal pathologies such as diabetis retinopathy or other cause as trauma, uveitis or other operative complication like endophthalmitis - Children are younger than years old, Old people are too old and weak combine with sever systemical deseases 2.2 Study method 2.2.1 Study design Clinical intervention study, prospective and longitudinal studies have no control groups 2.2.2 Study sample - Sample size: The sample size is calculated using the formula: N  Sample size n ≈ 62 eyes Z (21 / ) qp  p. 2 Sample selection: take a sufficient number of patients from the starting time of the study until the sample size is reached, according to patient selection criteria 2.2.3 Research facilities 2.2.3.1 Instrument for examining and evaluating results 2.2.3.2 Surgical facilities 2.2.4 Method of implementation 2.2.4.1 Evaluation before surgery * Identify the cause of recurrent retinal detachment Clinical morphology of recurrent retinal detachment: * Identify the cause of retinal recurrence Clinical morphology of BVMTP often has: + Open the old tear or not: observe whether the tear is located in the old scar area due to laser or freezing + New tear or not: usually outside the old surgical area, outside the belt + Vitreoretinal proliferation, appear sooner or later Physical function symptoms Symptoms attached * Subclinical 2.2.4.2 Indications for surgery Our indications are based on a patient’s retinal detachment, specifically as follows: - Surgical method: External scleral indentation Vitrectomy + Gaz or Silcon and combine Scleral buckle Vitrectomy + Gaz or Silicon without scleral buckle.depend on each case 2.2.4.3 Conducting surgery 2.2.4.4 Postoperative care and follow up after treatment 2.2.4.5 Management of surgical complications 2.2.5 Research variables 2.2.5.1 Research variables of clinical characteristics of retinal detachment 2.2.5.2 Research variables of the cause of recurrent retinal detachment 2.2.5.3 Research variables for the results of surgical treatment for RD 2.2.6 Criteria for evaluating research results 2.2.6.1 Clinical characteristics - Visual acuity: we classify into the following groups + From LP to smaller than CF meter + From CF 1m to 20/40 and above - Vision is converted from Snellen table to logMAR table, respectively, to calculate the average value - Intraocular pressure: Intraocular pressure is measured with a Maclacov tonometer and divided into the following groups: + Low: below 15 mmHg + Normal: from 15 to 24 mmHg + High: above 24 mmHg - Mechanical symptoms: blurred vision, flying flies, flashing lights or losing sight Number of previous RD surgeries, recurrence time, surgical methods - Physical symptoms + Anterior section: The anterior chamber is clear or with hemorhage, exudase, vitreous gel + Posterior section: Retinal detachment area, macular detachment, clinical type of tears, vitrolretinal proliferation Areas of retinal detachment: Evaluation of retinal detachment areas by quadrant: 1,2,3,4 quadrants or posterior pole retinal detachment Macular situation: attached or detached Number of retinal tears Morphology of retinal tear: according to the following forms: o Tear-shaped horseshoe with a flap o Retinal hole on degenerative background o Giant tear o Retinal break o The macula hole The location of the tear in the quadrant: the tear is located in what kind of quadrant (upper tempral, lower tempral, upper nasal, lower nasal) Tear size: o Minor tear: under hour arc o Average tear: 1-3 hours arc o Large tear: over hours arc Evaluation of vitrolretinal proliferation : according to the classification of the World Retina Society in 1983 Combined lesions: Vitreous hemorhage or choroidal detachment 2.3.3.2 Causes of recurrent retinal detachment - Reopen the old tear – new retinant tear – vitreous retrolretinant proliferation – silicon oil under retina – macular hole 2.2.6.3 Surgical results - Evaluating retinal attachment results + Attached retina: As clinically and echography retina is is completely attached from centre to periphery after month postop + Not attached retina: As clinically and echography retina is detached in every level - Evaluating visual acuity results: Corrected visual acuity was documented at the discharge time and follow up times as same as document before operation – Evaluating IOP results: IOP was measured by Maclakov tonometer and evaluation as before operation - Complications: - As peroperation - As soon postoperation - As postoperation later on months - Completement surgery: scleral buckle, inject heavy oil such as PFCL (Decalin) 2.2.7 Data analysis Data were processed by SPSS 18.0 statistical software Compare the average using the T-student verification algorithm The qualitative variables are compared proportionally with the test algorithm χ2 The difference is considered to be statistically significant when p