This study was a single-site retrospective case series. It was performed after approval from the local research ethics committee (University of Campinas Ethics Committee) and was conducted in accordance with the tenets of the Declaration of Helsinki and current legislation on clinical research. Written informed consent was obtained from all subjects after the explanation of the procedures and study requirements. The inclusion criteria were the indication of phacoemulsification and at least 40 years of age. Our residency program requires that more difficult surgeries, such as those involving small pupils, dense cataracts, zonulopathy, Fuchs’ dystrophy and traumatic cataracts, be performed by a fourth-year resident, who is, by definition, a cataract fellow, as well as under an attending surgeon’s supervision. Therefore, surgeries included this study involved all the cases of cataracts without other factors that could increase the degree of difficulty, and the surgeries were equally distributed among the three groups. The exclusion criteria were, signs of ocular or periocular infection, advanced glaucoma and severe ocular surface disease, and cataract surgery associated with other concomitant procedures, such as glaucoma filtering surgery, vitreoretinal surgery, or corneal surgery. There were no exclusions of surgeries with unfavorable outcomes.
Data were collected from patients undergoing cataract surgery at UNICAMP Clinical Hospital. Medical records, preoperative routine clinical exams, intraoperative descriptions and data from the first, seventh, thirtieth, and forty-fifth postoperative days were collected on each patient. Data was obtained from medical records that were completed on the day of surgery and during each scheduled follow-up appointment by the resident and the attending surgeon. Comprehensive protocols for cataract surgery data collection have been created and used in our department in order to thoroughly and objectively record information on all variables involved in the surgical procedure, as well as in the pre- and postoperative periods. To avoid the risk of recall bias inherent to retrospective studies, only data from these medical records have been included herein.
CDVA, IOP, ECD, and CCT were obtained for all included patients prior to surgery and at the last follow-up appointment.
In accordance with the protocols used in the Department of Ophthalmology of the University of Campinas (UNICAMP), all cataract surgeries are performed by ophthalmology residents and a senior attending surgeon with substantial experience in cataract surgery, regardless the level of the resident’s training. The attending surgeon provides residents with verbal instructions during the surgical procedure, and if the resident is unable to perform a specific surgical step or in cases of complications, the supervisor takes over the surgery, demonstrating how to solve that step. Variations and preferences between surgeons performing cataract surgery, such as the choice of incision position or the phacoemulsification technique used, are accepted in our department. However, surgical protocols, instrumentation, and techniques are standardized, as are all intraoperative drugs, solutions, ophthalmic devices, blades, and IOLs. Preoperative antibiotics were not prescribed. Briefly, the local phacoemulsification protocol consists of skin antisepsis with 10% povidone-iodine, placement of a sterile surgical drape to isolate the lid margin and eyelashes, application of four drops of 5% povidone-iodine into the conjunctival sac and subsequent irrigation using a balanced salt solution. In cases of povidone-iodine allergy, an aqueous solution consisting of 0.05% chlorhexidine was used. All surgeries were performed with peribulbar anesthesia. Phacoemulsification using the Infiniti® or the Laureate® phacoemulsifier (Alcon Laboratories Inc, Fort Worth, Texas, USA) was performed, and an AcrySof® intraocular foldable lens (Alcon Laboratories Inc, Fort Worth, Texas, USA) was implanted. A clear corneal incision was used. The phacoemulsification technique was either the stop and chop or the phaco chop. Intracameral moxifloxacin (Vigamox®) was injected as the final step of the surgery (150 µg in 0.03 ml).(20) In the immediate postoperative period, patients received 0.5% moxifloxacin and 0.1% dexamethasone eye drops prior to bandaging. Similarly, the topical postoperative regimen consisted of 0.5% moxifloxacin combined with 0.1% dexamethasone every 3 hours for 7 days only during waking hours. On the seventh postoperative day, this regimen was changed to only 0.1% dexamethasone, which was tapered over the course of 3 weeks. In cases of intraoperative or postoperative complications, patients received appropriate follow-up care in the Department of Ophthalmology at UNICAMP and underwent all necessary treatment.
A series of parameters were compared in order to better characterize the learning curve among ophthalmology residents at UNICAMP. These parameters included rates of complications and reinterventions, as well as previous and final CDVA, IOP, ECD, and CCT. The most common intraoperative complications include posterior capsule rupture (PCR), vitreous loss, aphakia, dropped nucleus, incision burn, Descemet’s membrane detachment, iris herniation, Argentinian flag sign, zonular dehiscence.
In the Department of Ophthalmology of UNICAMP, the training protocol for cataract surgery is as follows: in the first year, residents learn from theory, surgery simulation, and assisting attending surgeons. In the first semester (the first 6 months) of the second year of program, residents learn extracapsular cataract extraction (ECCE) and learn the first steps of phacoemulsification. In the second semester of the second year onward, they practice phacoemulsification under the supervision of a senior surgeon until the end of the third year of the residency program. The residents’ phacoemulsification practice is thus spread out over three consecutive semesters, and the surgeries included herein were therefore divided into those performed during residents’ first semester of training in phacoemulsification (the S1 Group, which represents the last 6 months of the second year of residency), those performed during the second semester of training (the S2 Group, which represents the first 6 months of the third year of residency), and those performed during the third semester (the S3 Group, which represents the last 6 months of the third year of residency). The surgeries were included based on a convenience sample of patients who completed 45 weeks of follow-up care after undergoing phacoemulsification surgery performed by a group of ten residents over the course of eighteen months (July 2016 to January 2018).
Initial and final CDVA, IOP, ECD, CCT, and intraoperative events were recorded and compared.
Descriptive statistical analyses were employed in the presentation of the results using central tendency and variance measurements. The groups’ continuous variables were compared using the t-test or ANOVA (parametric variables) or the Mann-Whitney or Kruskal-Wallis tests (non-parametric variables). Statistical analyses of the categorical variables were performed using Fisher’s exact test or the chi-squared test. Analyses were performed using STATA 14.0 (StataCorp LP, College Station, TX, USA). Statistical significance was established when p≤0.05.